Applied Ruminant Nutrition (NTR 550)

Week 1 Aug 18-24

Set 2: Classification Role of Ruminants

• classification 

  • how living things make a living staying alive

    • autotrophs: don’t eat other living things to survive

    • heterotrophs: eat other living things to survive

• phylogeny of ruminants

  • kingdom: animalia

  • phyla: Chordata (skeleton type)

  • class: Mammalia (milk producing)

  • order: Arteriodactyla (hooves)

  • suborder: Ruminantia (number of chambers in the stomach)

  • family: Bovidae, Giraffidae, Cervidae

    • subfamily: caprinae - sheep and goats

    • subfamily: bovinae: cattle, antelope, bison, and buffalo

    • subfamily: antilopinae: antelopes and gazelles

  • genus species: bos taurus, bos indicus, ovis aries, capra hircus, bison bison, odocoileus virginianus

• what makes a ruminant a ruminant?

  • key characteristics:

    • 4 chambered stomach

    • 2 toed-foot

      • may have dew claws

    • 0 upper incisors

      • some species do have “reduced” upper incisors

    • chew cud

    • herbivores

    • mammals

    • over 150 species

  • pseudo-ruminants

    • 3-chambered stomach

      • camels, llamas, alpacas

• classification of ruminants

  • grazing preferences and adaptions are unique

  • 3 distinct feeding types:

    • concentrate selectors (deer)

    • intermediates (goats)

    • grass/roughage eaters (sheep)

• role of ruminants

  • why were ruminants domesticated?

    • they have been domesticated for over 10,500 years

      • multi-purpose and benefits to humans

        • food souce: milk, meat, blood, fat

        • clothing and tools: hides, hair/wool, hooves, horns, and bones

        • fuel: dung as heat source

        • labor: pull heavy carts and plow (cattle, oxen, yak)

    • all of theses functions are still vital to society today

  • what do they contribute to society today

    • food source:

      • high quality protein (AA balance)

        • lamb has the highest out of all the ruminants

      • high bioavailable Ca, P, Zn, Fe

      • animals only source of B12

      • good source of healthy fats (medium chain saturates vs. CLA)

    • clothing:

      • wool and leather are now considered high end textiles

        • there is rich history and prestige to these products

    • heat:

      • biodigestion of manure (not common in developed countries)

      • labor:

        • thousands if not millions still used as labor resources

    • cultural role:

      • religious symbol in India

      • symbol of wealth in Africa

      • Icon of history in America

        • American cowboy

        • nostalgic connection to the land

    • entertainment:

      • rodeos

      • farming as a hobby

      • zoos and wildlife parks

    • utilization of natural resources

      • convert sun’s energy into products capable of supporting life

      • low value land (grasslands) into high value products

        • aid in carbon sequestration

      • natural nutrient recycling

        • fertilizer

      • species conservation

Set 3: Rumen Anatomy Physiology

• structure of digestive system

  • concentrate feeders have the smallest rumen size to body weight ration

  • forage/roughage feeders have the largest rumen to body weight

    

• ruminant digestive anatomy and physiology

  • mouth

    • collect feed into mouth

    • grazing animals 25,000-40,000 prehensile bites per day

    • do not chew food during initial eating

    • rule of thirds

• mouth structure of ruminants

  • have split lips

  • larger incisors that match on both sides

    

  • cows have a uni-lip

    • shorter and wider incisors and a longer tongue

• the grazing bovine

  • grazing time and rumination time are opposite

  • tend to graze in the morning and afternoon

  • rumination overnight generates heat

    • important in the winter months

    

• ruminant digestive anatomy and physiology

  • saliva

    • up to 50 quarts

    • contains enzymes

      • salivary lipase (fats)

      • salivary amylase (starch)

    • important for buffering rumen

      • sodium, potassium, phosphate, bicarbonate, urea, chlorine, magnesium, calcium

  • rumination

    • chewing the cud

    • esophagus is a 2-way route

    • very important process for microbial attachment and fermentation

  • stomach

    • 4 chambered

    • 75% of body cavity

    • left side of the body

    • average 48hr passage rate

  • rumen

    • ~75% of total stomach volume

    • 40-gallon capacity in mature cow 4 regions divided by muscular pillars to open the rumen wall and muscular contractions for mixing (important for fermentations)

      • dorsal, ventral, caudodorsal, caudoventral

    • anaerobic (limited O)

    • pH range 6.5-6.8

      • pH extremes: 3.5 - 8

    • home to microorganisms

      • bacteria, protozoa, fungi

      • fermentation of starch and fiber

      • NPN and RDP utilization

        • mostly urea

      • vitamin K and B’s synthesized

    • site of fermentation

      • volatile FA: acetate, propionate, and butyrate

      • gas: methane, carbon dioxide, hydrogen sulfide

    • 50-65% starch and soluble sugar consumed is digested

    • papillae lining

  • reticulum

    • ~9% of total stomach volume (3rd in size)

    • 5 gallon capacity

    • honeycomb

    • sorts particle size

      • small to omasum

      • larger return to rumen

    • hardware disease

      • traps large/dense metal objects

  • omasum

    • ~ 12% if total stomach volume

    • many plies, butcher’s bible

    • lots of surface area traps large particles

    • water and some VFA absorption

  • abomasum

    • ~ 4% of total stomach volume

    • true stomach

    • hydrochloric acid, pepsin, pancreatic lipase

      • protein, starch, fat digestion

    • pH: 3.5 - 4.0

    • mucous lining

    • true stomach

    • microbial protein

  • small intestine

    • 150 ft long tube in mature cow

    • 20-gallon capacity

    • 3 sections: duodenum, jejunum, ileum

    • pH raises from 2.5 to 8

    • pancreatic, liver, gall bladder secretions

    • villi

    • nutrient absorption

      • peptides, AA, carbs, fats, some vitamins and minerals

  • cecum

    • minor functionality and development

    • microbial fermentation

      • microbial protein and VFA

  • large intestine

    • 3 ft long in mature cow

    • 2 gallon capacity

    • water absorption

      • minerals and some VFA from cecum

• rumen development

  • from birth to 2-3 months young ruminants have non-ruminant like digestive system function (abomasum is the largest compartment at birth)

    • reticular groove (esophageal groove)

      • muscular folds in the reticulum

      • shunts milk directly to omasum (bypass rumen and reticulum)

    • rumen needs microbial inoculation

      • occurs through contact with mature ruminants in environment

      • cannot utilize NPN

    • rumen development

      • papillae growth (lengthen)

    

  • milk and grain (concentrate) showed the most papillae development

    • development occurs at three weeks

    • propionic and butyric acid contribute to the development of rumen papillae on a grain diet

    • acetic acid is made more on a forage diet

    • butyric acid is actually used for papillary growth (energy)

    

Set 4: Domestic Ruminant Management

• beef cattle management

  • divided into production segments

    • cow-calf

      • cow nutrition

      • calf nutrition

      • replacement heifer nutrition

    • stocker

      • growing cattle

    • finishing

      • feedlot cattle

      • pasture finished cattle

• beef cow nutrition

  • there are 4 distinct phases during the yearly cycle of a beef cow

    • calving to breeding (80-85 days)

      • peak nutritional demands

    • breeding to weaning (120-125 days)

      • moderate nutritional demands

    • weaning to late gestation (110 days)

      • lowest nutritional demands

    • late gestation to calving (50-60 days)

      • moderate nutritional demands

    • stay in production until 8-10 years

    

  • primarily forage based

    • pasture

    • harvested forages - hay, silage, haylage

  • supplemental protein and energy

    • concentrates - corn, soybeans

    • by-product - distillers, hulls, meals

  • other supplements

    • vitamins and minerals

• beef calf nutrition

  • milk nutrition (directly from dam)

    • 60-70% of nutrients before weaning from milk

  • other calf nutritional sources

    • pasture

    • supplemented forage

    • creep feed

  • calf weaned ~7 months of age

• heifer development and stockers

  • high forage diets

    • supplement with protein, energy, and minerals

      • by products (lower starch supplements)

        • lots of protein

    • goal of 1.5 - 2.0 lbs./day ADG (average daily gain)

    • heifer goals

      • 65% mature weight at puberty around 9-12 months of age

      • 75% mature weight at 1st breeding by 14.5 months of age

      • 85% mature weight at 1st calving at 23-24 months of age

• feedlot nutrition (< 1/3 of their lifetime)

  • approximately 3 phases of diets

    • receiving (70% roughage; 30 days)

    • growing (50% roughage; varies)

    • finishing (20% roughage; 90 days)

  • diet composition (TMR) (everything they need will mixed in one ration)

    • forage

      • silage, hay, by-product roughages

    • concentrates

      • corn (whole, cracked, steam flaked, dry rolled, high moisture)

      • protein sources (soybean meal distillers grain, urea (NPN))

    • fats

      • tallow, vegetable oils, AV blends

    • additives

      • ionophores, MGA (heifers only), buffer, vitamins, minerals

• dairy cattle management

  • stages of production

    • calves typically hand fed

  • replacement heifers

  • dry cows

    • ~ 2 months when cow is not lactating

  • lactating cows

    • ~10 months after calf is born

• dairy cattle nutrition

  • pre-weaned claves

    • milk based diet for 6-8 weeks (separated from dam)

      • colostrum

      • “non-saleable milk”

      • milk replacer

      • concentrate starter feeds

  • growing replacement heifers

    • forage based diet supplemented with concentrates

    • goals

      • breed at 12-15 months 60% of mature body weight

      • calve at 22-24 months at 85% of mature body weight

• mature dairy cattle

  • lactating cows

    • ~ 50:50 forage: concentrate TMR

      • need effective fiber

      • high energy rations

      • buffers

      • lactation lasts ~10 months

  • dry cow

    • preparation for next lactation

    • critical time in dairy nutrition

    • higher roughage diets

• sheep and goat management

  • divided into production segments

    • maternal production

      • ewe/doe nutrition

        • meat/wool vs. milk

      • lamb/kid nutrition

    • growing/finishing

      • feedlot lambs/kids

      • pasture finish lambs/kids

• ewe/doe nutrition

  • phases of production cycle

    • flushing (2 weeks)

      • pre-breeding supplementation

    • breeding (< 6 weeks)

    • gestation (5 months)

    • lactation (2 months or 10 months)

      • highest nutritional demands

    • maintenance (5 months)

      • lowest nutritional demands

    • pasture based

      • supplemental protein, energy, vitamins and minerals

• meat production

  • feedlot

    • growing phase (3-5 months)

    • finishing phase (2 months)

    • roughage and concentrates

      • vitamins and minerals

    • pasture finished

      • 7-9 months

    • high quality forage

      • minerals and vitamins

• exotic ruminants under human management

  • not exactly the same as domestic ruminants

  • feed resources vary greatly from global region of origin

    • selection by animal in wild is difficult to mimic

    • feed resource nutrient profiles

  • necessity of animals to be visible to audience

    • people love to watch animal eat

  • lifespan much longer than in wild

• overview

  • to apply nutritional management, one must first understand the basics of nutrition and the general management of the species

Set 5: General Nutrition

• classifying nutrition

  • 6 classes of nutrients

    • protein, lipids, carbs, vitamins, minerals, and water

      • note energy is not a nutrient (quality of nutrients)

  • categorizing nutrients

    • essential vs. non-essential

    • macro vs. micro

    • water-soluble vs. fat-soluble

    • available vs. bypass (proteins)

• proximate analysis

  

• summary of nutrient digestion

  • nutrients are broken down during digestion

    • metabolized by the animal or microorganisms

  • often utilized enzymes to break down structure into basic units

    

  • nutrients need to be digestible

  • diets must have the right proportion of nutrients to meet requirements

  • lipids are mostly broken down by animal enzymes

  • proteins can be digested by microbial and animal enzymes

• nutrient requirements and the life cycle

  • animal nutrition involves eating feed to get nutrients

    • growth, reproduction, and production

  • a balanced ration:

    • contains the nutrients at the required concentrations for that particular animal

• hierarchy of nutrient use

  • maintenance

  • development

  • growth

    • brain and CNS

    • bone

    • muscle

    • fat

  • lactation

  • reproduction

  • fattening

• nutrient hierarchy

  • maintenance of the animal

    • breathing heartbeat

    • walking

    • chewing

    • cell structures

  • development

    • cell regeneration

    • learning

  • production purposes

    • growth, lactation, reproduction, fattening

      • meat, milk, pregnancy

• nutrients throughout life cycle

  • start with conception

  • work through stages of pre/post-natal growth and development

  • maintenance requirements of animal post growth

  • reproduction

  • lactation

  • fattening

  • note: not all animals will go through each stage of the hierarchy of nutrient use altering requirements

• prenatal nutrient requirements

  • in utero growth during gestation

    • all nutrient are provided by dam

  • most development occurs in the 1st trimester

  • most growth occurs in the 3rd trimester

  • nutrient supply can alter metabolism and health of animal for entire lifetime

    • fetal programming: effect of nutrition of the dam to the fetus

    

• mammalian neonatal nutrient requirements

  • colostrum

    • 1st milk provided by dam

    • rich in nutrients: fat, protein, vitamins

    • supply of antibodies

      • provides passive immunity

        • immunity of newborn until its immune system matures and can make antibodies

    • timing of consumption is critical

      • antibodies and initial nutrients are large

      • gaps in intestinal lining begin to close within 12 hours after birth

      • critical for long term health of newborn

  • milk

    • transition to milk from colostrum at ~ day 2

    • excellent source of all (most) nutrients for that species

      • milk or milk replacer is species specific

      • veal calves are raised on milk alone

        • pale color of meat

      • main milk protein = casein

      • primary milk sugar = lactose

      • d

• juvenile nutrient requirements

  • growth of the young animal:

    • muscle growth requires protein for the building blocks

    • bone slowly and steadily increases as animal grows

    • market animals typically are harvested before excessive fat deposition occurs

      • hierarchy of at deposition

      

• nutrients and life cycle

  • tissue growth of the animal affects the nutrient requirements of the animal

    • young (juvenile) animals

      • high protein

      • high energy

    • mature animals (maintenance)

      • low protein

      • high energy

    • fattening animals

      • low protein

      • high energy

• reproduction effects on nutrient requirements

  • age of animal during reproduction will impact nutrient requirements

    • reproduction increases protein and energy requirements in all animals

  • young, pregnant females

    • very high nutrient requirements

      • she is still undergoing growth, development, and maintenance

      • adding in reproduction and preparation for lactation

      • insufficiencies = reduced genetic potential, dystocia, decreased productivity

    • affects fetal development

      • fetal programming

  • number of offspring

    • fewer fetuses = bigger fetuses

    • more fetuses = more nutrient requirements

    • less space for rumen capacity

      

      • lactation peaks

        • goats: 55 days

        • sheep: 3 days

        • cows: 60-80 days (also the time for rebreeding)

• life cycle and nutrient requirements

  • amount an animal can eat will affect nutrient density of diet required

    • animals need amount of nutrients, not percentages

    • total amount increases during growth while percentage declines until maturity

    • example of growing calf:

      • 500 lbs. eats 4% of BW = 20 lbs.

        • 18% CP = 3.6 lbs. CP

      • 750 lbs. eats 3% of BW = 22.5 lbs.

        • 17% CP = 3.8 lbs. CP

      • 1000 lbs. eats 2.5% BW = 25 lbs.

        • 16% CP = 4.0 lbs. CP

• estimate of % DMI based on stage of production cycle

  

• feed efficiency

  • meat animals

    • pounds of feed required per pound of body weight gain

  • dairy animals

    • pounds of feed per pound of milk

      • dairy cow

    

Week 2 Aug 25-31

Set 6: Feedstuffs

• feed classification

  • source or part of the plant and what they contribute to a balances diet

    • forage/roughage

    • concentrate

      • energy

      • protein

    • supplements

      • vitamins

      • minerals

      • feed additives

• feeds into diets and rations

  • there are 100’s of feedstuffs available to incorporate into ruminant diets

  • ingredients

    • availability, cost, handling, palatability

  • requirements

    • nutritional demands

  • putting it all together in rations

• roughages

  • high fiber plant products and by-products

    • vary in protein and energy

      • plant species, harvet/storage

    • critical in all ruminant diets

      • may be a stand-alone diet for ruminants

  • main roughage categories used in ruminant diets:

    • forages:

      • pastures

      • hays

      • silage/haylage

    • straws

    • by-products

  • types

    • alfalfa: hay, cubes, pellets

    • beet pulp

    • bermudagrass: pasture, hay

    • citrus pulp, dried

    • corn silage

    • cottonseed hulls

    • fescue: pasture, hay, haylage

    • haylage

    • oat or rye: hay, haylage

    • orchardgrass: pasture, hay

    • peanut hulls

    • red clover

    • textile byproduct (cotton)

    • timothy: pasture, hay

    • wheat straw

    • white clover

• pasture as forage resource

  • pastures are grazing systems in which the animal directly consumes the forage resource

    • wide variety of options for pasture management with impact nutritional value

      • plant species (fescue, bermudagrass, orchardgrass, clover)

      • grazing management practices

• hay as forage resource

  • hay is a conserved forage: plant material was cut when plant was alive, dried and compressed for storage

    • wide variety of options for hay management which impact nutritional value

      • plant species (fescue, bermudagrass, orchardgrass, clover, alfalfa)

      • harvest conditions

      • storage conditions

      • feeding management

• silages/haylage as forage resource

  • silage are preserved forage: plant material harvested, compressed to create anaerobic environment, and them fermented for storage

    • 2 main types of fermented forages

      • corn silage

      • haylage

• straw as roughages

  • straw is conserved roughages of dead plant material after the primary grain crop has been harvested

    • typically much lower nutritional vailue than pasture, hay, or silages

      • supply bulk for rumination, rumen fill

    • main types of straw

      • wheat corn (corn stover)

      • soybean

      • peanut

• by-products as roughages

  • cottonseed hull

    • outside coating of the cottonseed

      • contains fiber (shell and lint)

      • highly palatable to ruminants

      • can be incorporated up to 30% of diet dry matter

  • peanut hulls

    • shell removed from peanuts

      • low every value

      • less than 10% of diet

• concentrates

  • nutrition dense feedstuffs that typically contribute energy and/or protein to ruminant diets for higher production scenarios

    • these cannot be fed to ruminants alone, total diet must also contain roughages

  • broken into 2 categories

    • energy concentrates

    • protein concentrates

• high energy concentrates (energy less than CP less that 20%)

  • 4 main feedstuffs in this category

    • grains (starch)

    • potatoes/tubers (starch)

    • sugars/candies

    • fats/oils

  • contain fat/oil or readily available carbohydrate (sugar/starch)

• concentrates: energy

  • barely

  • citrus pulp dried

  • cookie meal

  • corn: whole, cracked, steam rolled, ground

  • cottonseed: whole

  • molasses

  • oats

  • peanut processing waste

  • rye

  • sorghum (milo): whole, dry rolled

  • soy hulls (soybean hulls)

  • sweet potato

  • wheat midds (middlings): loose, pelleted

  • wheat: whole or rolled

  • lipids

• energy concentrates - grains

  • seeds from plants (separated from plant)

    • contain protective outer covering

    • starch is inside the grain

      • in nature, provides energy for the new plant’s growth

• energy concentrates - grains-corn (maize)

  • main grain used on all animal feed

    • 75% of all grain utilized

  • very digestible

  • very palatable

  • does not cause nutritional problems when fed properly

  • may contain a mycotoxin (poison from mold)

• energy concentrated - grain-sorghum (milo)

  • drought tolerant

  • heat resistant

  • more pest resistant than corn

  • lower yielding than corn

  • good for animal fee if processed

    • flaking or grinding

    • not digestible whole

• energy concentrated - grains-oats

  • has fibrous coating on outside of seed

    • higher fiber than other grains

    • less energy per pound of feed because fiber is less digestible than starch

    • more expensive

• energy concentrates - grain-barley

  • similar to oats

    • starch not quite as digestible

  • needs to process barley to increase starch digestibility

  • palatable

    • ruminants

  • very few problems with it as a feedstuff

    • cost and availability

• energy concentrates - grain-wheat

  • higher energy compared to oats/barley because no fibrous seed coat

  • mostly used for human consumption

    • very expensive to add to livestock diets

  • can be fed to animals in limited amounts

    • starch forms a pasty mass in GI tract if feed too much

  • lodged wheat plants can be fed to ruminants

    • if not moldy

    • sprouted grain is okay

• energy concentrates - byproducts-whole cottonseed

  • whole cottonseed

    • protein, energy, and fiber

    • mature ruminants only

      • contains gossypol

    • incorporate at up to 15% if diet dry matter

      • <0.5% of BW for mature cows

      • <.33% BW for growing calves

• energy concentrates - byproducts-soybean hulls

  • great source of energy

    • highly digestible fiber, low in starch

      • will not cause bloat

      • will not form a rumen mat

    • moderate protein

• concentrates - energy-potatoes

  • NC is #1 sweet potato state in US

  • limited use in cattle diets

    • comes in a slurry with potato chunks

    • low pH

• concentrates - energy-sugars

  • molasses

    • quick energy source

    • good source of minerals

      • Ca, Na, K, Mg, S, Cu, Zn, Fe, Mn

    • reduces dustiness of feed

    • increases feed palatability

    • feed in a restricted format

• concentrates - energy-fats/oils

  • excellent source of calories

  • improves palatability of feed

    • reduce dustiness

  • limited amount can be fed to ruminants

    • 5% of diet or less

    • can cause problems with fermentation and the microbes

  • forms of lipids

    • rumen protected formants

    • vegetable oil (restaurant grease)

    • animal fat (rendering by-product)

• concentrates - protein

  • protein concentrates must contain at least 20% CP, and are lower in fiber

    • blood meal

    • cottonseed meal

      • fed to adult ruminants only

      • contains gossypol

        • toxic to non-ruminants (death)

          • toxicity can occur in calves, lambs, or kids because of pre-ruminant

        • not deactivated with heat

      • no hulls so lower fiber content

    • distillers’ grains

      • increased in popularity with expansion of ethanol market

        • products can vary by

          • distilling process (ethanol for fuel vs. drinking alcohol)

          • other processing - fat removal

          • water content (wet and dry forms available)

        • can be great source of protein and energy

        • caution of incorporation rate due to high sulfur

    • fish meal (fine/coarse)

    • poultry litter (broiler/turkey)

      • fed to ruminants on a regular basis

        • still legal to feed (only temporarily banned)

      • concern spilled poultry fees is found in poultry litter

        • poultry feed may contain meat/bone meal of ruminant origin

    • soybean meal

      • does not have trypsin inhibitor

    • soybean screenings

    • urea (regular/prilled)

      • urea is a non-protein nitrogen (NPN) protein supplement for ruminants

        • does not contain AA

        • for the microbes

          • can make high amounts of microbial protein

      • provides nitrogen to microorganisms to synthesize protein

    • soybeans

      • can be consumed by all species

        • no toxin or problems

      • standard protein supplement

      • whole soybean

        • toasted or with the oil removed

• supplements

  • minerals

    • copper sulfate

      • primarily added to diet as a source of copper

    • defluorinated rock phosphate

    • dicalcium phosphate

      • added to diets to supply calcium and phosphorus

        • typically, 18% P and 21% Ca

    • limestone

    • magnesium oxide

    • monocalcium phosphate

    • salt (sodium chloride)

    • sodium bicarbonate

    • trace-mineral salt

      • high iron

      • high copper (no good for sheep)

  • vitamins

    • vitamin premix

  • additives

    • aureomycin crumbles

    • rumensin

• combinations are endless

Set 7: Forage Plant Classification

• forage plants

  • there are lots of different plant varieties available for utilization in supplying nutrition to ruminants

    • complex system

      • livestock managers vs. forage producers

      • use of reliable information

      • consideration of timelines

      • use of adapted species and varieties

      • matching crop needs

      • maximizing grazing season

      • soil testing and fertility

      • climatic conditions

      • forage conservation resources (hay, silage, stockpiling)

      • animal nutritional needs

• classification

  • plants can be classified by:

    • season

      • cool vs warm

    • lifespan

      • annual vs perennial

    • ability to fix nitrogen

      • yes (legume) vs. no (grass, forb…)

    • palatability as a forage for livestock consumption

      • yes vs. no

    • anti-nutritional properties

      • toxins

      • thorns

      • bitter

• season: photosynthesis pathways

  • C-3 = cool season

    • 1-3C compounds are formed which combine into glucose

      • fructose and sucrose

    • reserve energy stored as starch (more than warm season)

    • reactively high digestibility

    • higher total protein

      • rumen degradable protein

  • C-4 = warm season

    • 4C organic acids formed (malate or aspartate)

    • relatively lower digestibility

    • lower total protein

      • more rumen by-pass protein

• growth pattern of cool season plants

  • fescue

  • orchardgrass

  • bluegrass

  • ryegrass (A and P)

  • small grains (A)
    prairie grass

  • clovers (A and P)

  • alfalfa

    

• growth pattern of warm season plants

  • Bermuda grass

  • Sudan

  • crab grass

  • millet

  • switchgrass

  • gamagrass

  • bluestem

  • dallisgrass

  • johnsongrass

  • soybean

  • corn

    
  

• annual vs. perennial

  • annual

    • corn

    • crabgrass*

    • pearl millet

    • sorghum-sudan hybrids

    • oats

    • barley

    • wheat

    • cowpea

    • soybean

    • arrowleaf clover

    • hairy vetch

    • crimson clover

  • perennial

    • bermudagrass

    • johnsongrass

    • dallisgrass

    • orchardgrass

    • tall fescue

    • timothy

    • kudzu

    • sericea lespedeza

    • alfalfa (last only 2-3years)

    • red clover (last only 2-3 years)

    • white clover

• annual forages

  • annuals are great flexible option forages for ruminants

    • require replanting

    • short term flexibility

    • grasses and legumes, warn and cold season

    • work well in variety of settings

      • pasture, hay, haylages

      • cover crops

      • pasture transitions

• perennial forages

  • perennials make up the backbone of forages for ruminants

    • grow back every year without replanting

    • long term sustainability

    • grasses and legumes, warm and cool season

    • work well in a variety of settings

      • pasture, hay, haylages

      • land that is not easily navigable with equipment

• what are legumes

  • legumes have a rhizobia bacterium in the root system

    • found nodules on roots

    • rhizobia bacteria convent atmospheric nitrogen into a form the plant can use

    • fixing the nitrogen

    • higher in CP

• nitrogen

  • what do plants do with nitrogen

    • make plant protein

    • legumes are desirable in pastures to provide nitrogen to grasses and animals

• nutritional value of forages

  • legumes typical advantages over grasses at ideal harvest maturity:

    • higher leaf: stem ratio

    • more protein

    • more calcium

  • legumes disadvantages from grasses

    • can cause bloat

    • leaf shatter risk in hay knocking the leaves off)

    • alfalfa and clover

• putting season and type together

  • cool season grasses

    • fescue

      • very common cool-season grass

      • comes in several varieties

        • Kentucky 31 endophyte infected

          • persistence, heat/drought/grazing/insect tolerant

          • causes toxicity in grazing animals

        • endophyte free

          • poor persistence

        • novel endophytes

          • almost as persistent as K-31

          • no toxicity concerns

        • works well as pasture or hay

          

      • orchardgrass

        • popular cool-season grass

          • limited adaptability across NC

          • mostly in the northern part of the US

        • good grass for grazing and hay

        • palatable

          

      • timothy

      • bluegrass

  • cool season legumes

    • clover

      • white

        • popular legume to add to pastures

          • utilization in mixed pastures with grasses so reduced bloat risk

        • grazing tolerant

        • good source of protein

        • lower yield due to small size of plant

          

      • red

        • upright growing legume

        • bi-annual

        • good source of protein

        • limited grazing utilization

          • bloat

          • persistence

          

      • crimson

    • alfalfa

      • queen of legumes

      • excellent source of protein

      • great for hay and cubes

      • expensive

      • limited grazing utilization

        • bloat

        • persistence

        

    • vetch

      • hairy, crown

    • birdsfoot trefoil

      

  • warm season grasses

    • bermudagrass

      • grows abundantly in summer

      • can be grazed or made into hay

        

    • bahia grass

    • dallisgrass

    • crabgrass

  • warm season legumes

    • lespedeza

    • kudzu

    • not as popular for legumes

    • also, can be considered invasive

• forbs and brassicas

  • tuberous (deep, large taproot) provide nutritional and soil health benefits (turnups_

  • increasing in popularity for cover-crop systems

• putting the species together

  

• case study

  • goat farm has 35 acres and 75 Boer does

    • kid in early March

    • current pasture system is broken

    • into 3 sections

    • forage base is tall fescue

      • traces of red and white clover

    • currently feeding hay/grain ~6 months a year

      • does December to April and July to august

      • kids July to October

    • goal of marketing grass - finish kids at 80 lbs. by 7 months of age

      • what could the farm be doing wrong now that they are not achieving their goals? What more information do you need to know? Suggestions?

Set 8: Forage Plant Concerns

• forage concerns

  • it takes more than knowledge of nutrition to properly feed animals

• toxic plants

  • decreased production or death

• nitrate poisoning

  • nitrate poisoning

    • excess nitrate (over .5% nitrate ion) is toxic to ruminants

    • excess fertilization can lead to high nitrates in some forages

      • NCDA tests forages for nitrate at no charge

    • some ruminants can be adapted to higher levels of nitrogen

      • if the animal has never been exposed to that forage/area/high nitrogen it can be fatal

• prussic acid poisoning

  • prussic acid forms in some plants when they are stressed by drought or frost

    • this hydrocyanide acid is highly toxic to ruminants

    • prussic acid can be a problem with:

      • sorghum/suban grasses

      • wilted leaves from cherry trees

• ergot alkaloids and fescue

  • tall fescue is widely distributed across the mid and eastern US

  • over 35 million acres of pasture and hay land

  • there are different types of fescues

  • also, with rye grass

• Kentucky 31 fescue

  • “Kentucky 31” fescue is the most prevalent type in NC and elsewhere

    • it withstands drought, flooding, overgrazing, trampling

    • this resistance to harsh conditions comes for the symbiotic relationship with an “endophyte”

      

• endophyte infected fescue

  • cattle

    • growing cattle

      • rough hair

      • heat stress, panting

      • low growth rate

      • increased respiratory rates

      • vasocontraction

    • brood cows

      • decreased pregnancy rate

      • decreased milk production

• endophyte free fescue

  • fescue varieties selected without endophytes

    • no health problems for cattle

    • not suitable solution to problem

      • expense of “destroying” pasture and replanting

      • not drought, insect, or grazing tolerant

      • lacks persistence

• novel endophyte fescues

  • now we have endophyte friendly fescue

    • example of novel endophyte fescue:

      • Max Q

    • has modified endophyte

      • hardy, but nontoxic to ruminants

      • it does a good job of keeping E-infected fescue out

      • still have expense of re-establishing pastures

        • takes 20-30 years

        • have to use cover crops

        • decreased land utilization

• animal growth based on fescue type

  

Set 9: Feed additives

• feed additives

  • what is an additive?

    • included in diet for reason other than nutrition

    • non-nutritive

  • if additive is classified as a “drug” it is regulated by the food and drug administration

    • withdrawal time

    • inclusion limitations

    • takes years to get approval

• types of feed additives

  • antibiotics

  • anthelmentics

  • probiotic

  • ionophores

  • coccidostat

  • bloat guard

  • others…

  • safety concerns

  • approval

• antibiotics

  • antibiotics kill or slow bacteria

    • do not impact viral diseases

  • concerns with use of antibiotics

    • withdrawal time

    • microorganism resistance

    • highly controversial issue

    • most regulated

    • misuse and overuse

  • not used in most natural or any organic programs

  • types

    • bacitracin methylene disalicylate

    • chlorotetracycline

    • monensin

    • tyloxin

    • carbodox

  • feed- grade antibiotics for disease outbreak

    • veterinary prescribed (VFD - veterinary feed directive)

    • short-term cure

    • narrow spectrum

  • disease prevention

    • rare cases (not widespread use)

    • broad spectrum

      • weaning/feedlot entry

• ionophores

  • ionophores are rumen fermentation enhancers through altering rumen bacterial populations

    • improve rumen fermentation efficiency

      • less methane and carbon dioxide

      • more propionate and less acetate

      • less lactic acids

        • lower risk of acidosis

      • other benefits

        • less coccidiosis, flies, bloat

    • common added to stocker and feedlot cattle

  • examples

    • monensin (rumensin)

    • lasalocid (bovatec)

    • laidlomycin (cattlyst)

• coccidiostats

  • coccidiosis can be a fatal disease

    • cattle

    • sheep

    • goats

    • decoquinate (Deccox) is often used as coccidiostat

• anthelmintics

  • what are anthelmintics

    • control internal parasites

  • considerations for feeding

    • parasite spectrum

    • withdrawal time

    • seasonality

    • cost

  • deworming is hard

    • pre- and post- deworming

    • parasite burden and shedding

• fly control

  • larvacides

    • deposited in manure and kills fly larvae upon hatching from eggs

      • Altosid

      • Rabon

      • ClariFly

• probiotics

  • mixture of living bacteria/yeast to establish a desirable microflora in GI

    • good microbes

  • how do they work?

    • microbial competition

    • improve fermentation

    • healthy gut

  • common bacteria

    • lactobacillus

    • streptococcus

    • bifidobacterium

    • saccharomyces

• bloat control

  • bloat = build up of gas in rumen

    • can be fatal

  • poloxalene (bloat guard) prevents legume (frothy) bloat in ruminants

    • can be fed as molasses blocks, lick tanks or granular forms

    

• buffers

  • high starch diets

    • decrease rumen pH

    • buffers help increase pH

      • keep it closer to neutral

    • improve fermentation

    • prevent acidosis

  • examples

    • sodium bicarbonate (bi-carb) (baking soda)

    • potassium bicarbonate

    • calcium carbonate

• acidifer

  • ammonium chloride

    • used to acidify urine of small ruminants

      • prevention and treatment of urinary calculi

• beta agonists

  • promote lean growth

    • Ractopamine

      • “Optaflezz” for finishing cattle

    • Zilpaterol

      • “Zilmaz” for finishing cattle

      • temporarily off the market in 2013

    • beta agonists result in leaner and less fat

    • not approved for use in breeding animals

• hormones

  • hormones are not routinely added to animal feed

    • only one hormone is approved as a feed additive:

      • MGA (melengesterol acetate)

      • mimics progesterone to alter estrous cycle in cattle

      • beef cattle only

        • stops their reproduction cycle

          • saves energy that can be used for growing

• feed additives

  • remember:

    • feed additives are non-nutritive

      • therefor mineral supplements and vitamins are not in this category

Week 3 Sept 1-7

Set 10: Digestion Calculations (Estimating Digestibility)

• determining digestibility

  • waste most of what is consumed

    • 25 lbs. of dry matter intake per day

    • 40% digestible

    • 60% indigestible (15 lbs. of dry matter excretion) (30 lbs. on a wet matter biases which is more than it ate. this why some ruminant operations are targets more waste than initial output)

  • methodology for apparent digestibility

    • total fecal collection

      • measure everything going in and everything coming out

      • bag attached to animal or crate behind animal

    • marker methods

      • utilize an indigestible marker and put known concentration in and the collect representative fecal sample coming out and adjust calculations based on marker concentration

        • chromic oxide

        • ytterbium

• determining apparent digestibility

  • (intake - fecal output x 100) / intake = % apparent digestibility

  • 1. dry matter intake

    • how much was actually consumed

      • 1-2 weeks for feed adaptability transition

  • 2. fecal output

    • 1. total fecal collection

      • 5-7 days

    • 2. digestive markers

  • 3. length of collection

    • 1. need adjustment period

• determining apparent digestibility of whole diet

  • intake - fecal output x 100 = % apparent digestibility intake

  • example: lamb

    • 1000 g/d as is consumed

    • diet is 87% dry matter

    • 55% NDF

    • 11% CP

    • 500 g/d as is feces

    • feces is 60% dry matter

    • 60% NDF

    • 10% CP

• determining apparent DM digestibility

  

• determining apparent CP digestibility

  

• determining apparent NDF digestibility

  

• estimating digestibility of diet components

  

  • in situ = with the animal use mesh bags and then put it into the rumen and then take out 24-48 hours later

  • in vitro = can be used to show more measurements

    • uses rumen fluid

• estimating digestibility

  • showing byproducts

  • adjusting for markers

  • alternatives

    • are the approving feed efficiency of the rumen

      

Set 11: Digestion

• digestion

  • the process of events that occur in the GI tract that breaks down complex feeds into water soluble molecules available for absorption

    

• how?

  • strategies vary species

    • overall goal is to survive long enough to reproduce

      • concentrate selectors (moose, mule deer, white tailed deer)

      • intermediate types (mountain goat, pronghorn, goat, elk, bison)

      • grass/roughages eaters (sheep, cattle, mouflon, aurox)

        • quality attributed to more cell contents and less cell wall

        • cattle have a larger omasum for stems that sheep which are more selective eaters

  • prehension

    • mouth

    • seeking out food

  • microbial fermentation

    • rumen and reticulum

  • acid and enzymatic hydrolysis

    • abomasum and small intestine

    • water capture

  • microbial fermentation

    • cecum and colon

• factors affecting digestibility of feed

  • what determines how much of a feed will be digested

    • feed intake

    • papillae development

    • negative associative effects

    • feed processing

    • rumination

    • positive associative effects

    • fiber and lignin content

    • microbial population

    • passage rate

    • 10-15% of energy is actually retained in the growing animal

  • stomach development of “pre-ruminant” to “ruminant”

    

  • esophageal groove

    • calcium salts in milk stimulate muscles to close

    • shunts milk to abomasum

    • avoid microbial breakdown of milk proteins

  • abomasum

    • rennin production to coagulate milk

      • slows down passage rate to increase digestibility

      • milk replacers have to have thickeners in them because they don’t really react to rennin

    • holds large volume of milk

  • small intestine

    • first 24 hours low trypsin activity and loose cell junctions

    • low amylase production at birth

    • never any sucrase production

      • no digestion of sugar but can be used for rumen fermentation

      • if digested in the hindgut scours will occur

      • no sweeteners added to milk replacers

    • lactase and lipase are adequate

    • large fat globule absorption and about 100 g of IgG absorption

  • rumen development

    • needs to be inoculated by mother

  • papillae

    • line rumen interior to increase surface area

    • very small when on milk diet

    • grows rapidly with feeding of solids

      • butyrate is desired VFA substrate

  • rumen capacity

    • rumen capacity increases at greater rate than rate of body weight growth

      • increasing intake of digestible forage per unit of energy needed for body weight gain

  • nutrient deficiencies

    • inhibition of microbes

    • decrease microbes

      • water

      • nitrogen

      • these are vital nutrients for the microbes

  • feed intake

    • increasing feed intake = increased rate of passage = decreased digestibility

    • important consideration for fine chopped forages and grains because they fit through the omasal orifice

    • need a dense fiber mat

  • passage rate

    • passage rate ←→ feed intake ←→ digestion

    • different layers will have different passage rates

      • liquids will flow faster

  • complex relationship on intake and disappearance

    • digestion, absorption, passage (urination and defecation)

  • liquid and solid fractions have differing passage rates

    

    • passage rate is about 48 hours for solids in the rumen

  • comminution (reduction of feed size to swallow)

    • chewing during eating only reduces size enough to soften and swallow

    • more size reduction by rumination after interior parts of plants have been removed and cell wall weakened through microbial degradation

      • sorting of layers of digested feed in rumen

      • trapping of CO2 inside plant stems (will float and form rumen mat)

  • feed processing

    • grinding of grains

      • increases digestibility

        • ex. 92% corn diet

        • cracking the feed increases the starch availability

        • be aware of acidosis and high blood sugar

          

        • example hay diet

        • smaller particles will be washed out of the rumen decreasing digestibility

        • retention rate is crucial for fermentation

          

  • associative effects on digestion

    • characteristics of one feed affect the digestion of another

    • can be positive or negative

      • rumen adaptation time

    • starch vs. fiber fermenter bacteria

• negative associative effects

  • forage + grain

    

  • grain depressed forage digestibility

  • this happens because the grain decreases the rumen pH making forage harder to digest

• positive associative effects

  • forage + forage

    

  • improve forage digestibility with providing forage with adequate energy

• factors affecting digestibility of feed

  • site of fermentation (rumen vs. cecum and colon)

    • VFA provide energy to animal regardless of fermentation site of origin

      • can be in the rumen or colon

      • sheep have more post rumen fermentation the cattle

      • microbial protein and AA that are produced after the abomasum will probably not be absorbed and flushed out

    • microbial protein

      • microbial protein flowing to duodenum can be digested and AA absorbed

      • microbial protein produced in large intestine or cecum provide no AA to animal

  • papillae development

    • vary throughout life of ruminant

      • start small, enlarge, degenerate

      • “scratch” theory on papillae

        • minor effect on development

      • when forage in the diet is low the papillae degenerate

    • important in calves and when switching from forage to grain diets

    • specialized bacteria colonize rumen epithelium

      • ureolytic

        • urea = 2 ammonia = bacterial protein

        • 5% CP from urea to 9% usably CP

  • volatile fatty acids

    • production per mol of glucose

      • 2 acetate (CH3COO-) + 2 CO2

      • 2 propionate (CH3CH2COO-)

      • 1 butyrate (CH3CH2COO-) + CO2

    • ratio of protonated form (RCOOH) to dissociated/anionic form (RCOO-) dependent on pH and pKa

    • 5-10 lbs. of sodium bicarbonate (NaHCO3) per 40-80 gal saliva/day

      

• volatile fatty acids

  • VFA absorption and rumen pH

    

• factors affecting digestibility of feed

  • motility of stomach

    • mixing of new feed with colonized feed particles

      • move and mix bacteria and fungi

      • the moving of feed also stimulates papillae growth

    • coordination of swallowing, eructation, regurgitation

      • rumination

      • scratch factor

  • health of the animal

    • reduced motility is used as clinical signs of health problems

      • hardware disease

      • intestinal compaction

      • displaced abomasum

        • flip or twist in the gut

      • acidosis (grain overload)

    • time spent ruminating is clinical observation as well

• health of animal

  • rumen parakeratosis (rumen papillae become hard and keratinized after acidosis and crack)

    • result of continual exposure of rumen to pH below 6.0

      • pits in rumen epithelial barrier an allow “leakage” of bacteria into blood

      • abscessing of liver typically not seen until inspection of carcass

        • could reduce function and efficiency

        • 10-20% of slaughter animals have abscesses on their livers

        • happens a lot in dairy cattle

      • antibiotics and/or ionophores can help efficiency

        • reminsion and bovatech

  • bloat

    • legume bloat

      • proteins in certain legumes stabilize foam in rumen

    • grain bloat

      • starch producing bacteria produce a slime that stabilizes bloat

• digestion and absorption from small intestine

  • digestion and absorption in the small intestine is similar to that of non-ruminants

    • similar enzymes

    • considerable increase in surface area of epithelium in small intestine resulting from villi and microvilli

  • low pancreatic lipase and related enzymes

    • not that much fat digestion aka low lipase

  • adequate proteolytic enzymatic activity for very good protein digestion

    • digest microbial protein

    • digest free AA

    • absorption of AA by small intestine is via active transport

  • AA balance

    • ruminants have limiting AA(s) just like non-ruminants

    • beef and dairy NRC (national remodels

    • AA imbalance is a metabolic disturbance caused by feeding an excess of an AA

      • diets imbalanced and depress feed intake

      • problems increase when rumen protected AA’s

      • methionine (1st limiting AA in ruminants but too much is also bad)

• adequate amylase for intestinal digestion

  • ruminal microbes possess amylase activity

    • for starch to glucose

  • pancreatic amylase activity

  • hindgut starch digestion

Set 12: Feed Intake Calculation (Feed Intake Impact and Estimation)

• mechanisms of feed intake regulation

  • what determines how much a ruminant will eat

    • feed factors

    • physical

    • body weight

    • body temperature

    • pregnancy

    • lactation

    • endocrine

    • fat

    • palatability

    • environmental temperature

    • chemostatic/metabiotic

• impact of feed intake

  • 1. directly influences production

    • eat more, gain more, more milk (profitability)

    • example

      • 600 lb. steers

      • corn silage based diet (65% moisture)

      • requires 7lbs. of DM for maintenance

        • A. eats 13 lbs. of feed DM/d and grains 1.6 lbs./d

          • feed conversion = 13/1.6 = 8.1

        • B. eats 17.6 lbs. of feed DM/d and gains 2.7 lbs./d

          • feed conversion = 17.6/2.7 = 6.5

  • 2. total mixed rations (TMR)

    • most common type of diets in industry (beef feedlot/dairy)

      • concentration basis

    • examples

      • weaning and transportation stress of beef calves

        • will have to increase CP intake to 17-19% CP

      • early lactation Holstein dairy cow

        • 17-18 CP at first and later in lactation 15% CP

      • hot summer

        • rumination increase heat production, so a nutrient dense diet decreases feed intake

  • 3. changes associated with metabolic disorder

    • ketosis

      • late gestions or high milk production

    • acidosis

      

  • 4. key factor in forage utilization and value

    • 60-70% of value of forages is dependent on how much will be consumed

• tools for calculating feed intake

  • on average: 2-4% BW on dry matter basis

  • NRC (National Research Council) feed intake equations

    • beef cattle (pregnant mature females)

      

    • NEm = net energy maitanence

    • assume 4% shrink

    • NRC has additional adjustments for: mud, temperature, milk production

  • example beef cow DMI calculation

    

  • NRC feed intake equations

    

  • assume 4% shrink

  • NRC has additional adjustments for: breed, body fat, implants, temperature, mud

  • example beef finishing DMI calculation

    

• tools for calculation feed intake

  • dairy cattle

    

  • use beef equations for replacement heifers

  • example dairy cow DMI calculation

    

• summary of dry matter intake

  • decrease relative energy requirements

  • drive gain

  • #1 factor for milk production

  • cost of intake

  • calculating NRC DMI expectations

Set 13: Feed Intake Regulation

• importance of feed intake

  • approximately 2/3 input cost of a livestock operation is spent on feed

  • therefore, it is critical to combine

    • what an animal eats and how much an animal eats

    • with what the animal produces

• mechanisms of feed intake regulation

  • what determines how much a ruminant will eat?

  • fat, environmental temperature, chemostatic/metabolic, pregnancy, physiology, body temp, body weight

    

• 1. palatability

  • acceptance of a feed to the animal

    • taste

    • smell

    • moisture

    • memory

    • texture

    • avoidance compounds

      • animal by-products

      • fats/oils

      • endophytes

      • tannins

      • molds/mildew

• 2. physical

  • gut fill

    • stretch receptors send neural feedback to regulate feed intake

      • limits to expansion ability = stretch receptors

      • rate of fermentation

        • ADF and NDF digestibility

        • quality of the forage

      • passage rate

      • physiological state of the animal

        • pregnancy, lactation

      • feed moisture

        

• 2. fiber intake regulation theory

  

• 3. chemostatic or metabolic

  • animals eat to satisfy their energy needs

    • ruminants rely on volatile fatty acids regulation

      • mechanisms of regulation are complex pathways

      • acetate = rumen wall

      • propionate = liver

    • blood glucose much lower impact on ruminants

      • much lower concentration than non-ruminants

      • lower fluctuations associated with meals

    • will also rely on their innate hunger/fill the animal will eat more if their body tells them to because it is fulfilling a nutrient requirement

  • digestible energy intake regulation theory

    • Dr. H. Russell Conrad (The Ohio State University)

      

  • why can hormonal implants work in ruminants but not non-ruminants?

    • estrogenic impact on glucose

    • increase blood glucose decrease feed intake

  • why can ionophores work?

    • alter rumen microbial population to increase propionate and decrease acetate production

    • monensin can decrease feed intake because feed can be digested better

    

  • nutritional wisdom

    • toxic factors

      • endophyte (alkaloid)

      • selenium

      • cyanide (prussic acid)

    • nutrient deficiencies

      • nitrogen

      • minerals

      • can stimulate feed intake

      • feeding grain tend to decrease forage intake

• 4. endocrine

  • hormones regulate feed intake

    • increase feed intake

      • neural peptide Y (NPY)

        • works with the hypothalamus

        • inhibited by insulin production

        • opposite impact of leptin

      • melanin concentrating hormone (MCH)

        • increases feed intake

      • ghrelin

        • hunger hormone

        • also causes stomach growling

        

  • hormones

    • regulated feed intake

      • decrease feed intake

        • leptin

          • produced in fat cells (more produced in beef cows)

          • inhibits NPY

        • insulin

          • inhibits NPY

          • stimulated with high glucose levels

          • insulin growth factor 1 in the liver

        • GLP-1

          • the presence of fat in the small intestine causes the release of GLP-1

          • increases insulin production

        • CCK

          • cholecystokinase

          • decrease gut motility

          • inhibits NPY

        • GIP

      

• 5. environmental temperature

  • thermal neutral zone

    • cattle = 50-70 F

    • heat stress = decreased feed intake

    • cold stress = increased feed intake

      

• 6. body temperature

  • conditions that raise body temperature

    • illness, fescue toxicosis

    • decrease feed intake

      

• 7. pregnancy

  • last 2 months of gestation

    • increased fetal size

    • decreased rumen space

    • gut fill regulation takes precedent

    • decrease feed intake

• 8. lactation

  • increased feed intake

  • increased energy requirements

  • increased gut capacity

  • increased gut motility

  • less stress on the rumen wall from pregnancy

  • the release of oxytocin and prolactin increase gut motility

• 9. body weight

  • increasing body weight results in increased feed intake

    • not in a linear relationship

    • metabolic body weight

      • BW^.75

• 10. fat

  • body fat

    • adipose tissue is not just a storage vessel for extra energy

      • endocrine organ

      • start decrease DMI at BCS 6

        • BCS 1-9 in cows

  • dietary fat

    • intake will affect total DMI

    • >5% dietary fat will decrease DMI

• 11. feed factors

  • moisture

  • mold

  • forage quality

  • physical form

  • fat

  • N or S deficiency

  • NH3 (NPN) (urea)

  • sulfur toxicity

    • distilling of corn

  • 0.35% will start decreasing food intake

    

Week 4 Sept 8-14

Set 14: Effective Fiber

• ruminants need fiber - acid neutralization

  

  • saliva is about 10-20% sodium bicarbonate

  • Carboxyl groups/VFA have to be protonated to be absorbed across the rumen wall

• effectiveness of fiber

  • concept is NDF% x % effectiveness = %eNDF

    • forage NDF> non-forage NDF for eNDF

    • effectiveness is based on the ability to stimulate rumination and chewing

    • eNDF not in the NRC because of the incomplete data

  • many ration balancing programs have terms:

    • eNDF: the effectiveness to maintain milkfat %

    • peNDF: the physical effectiveness to maintain chewing relative to a forage standard

• example of effectiveness calculation

  

  • anything under 12 is not considered effective and might decrease chewing and rumination time

• milk fat and rumen pH

  

  • the lower the rumen pH the lower the amount of milk fat

    • good indicator of eNDF and that effects more than just chewing

• effectiveness of feedstuffs

  

  • remember by-products are very variable so one batch might not as effective as the next

• usable measures of effectiveness

  • effectiveness values or forage NDF are guidelines, with considerable variation among farms

    • chewing hard to measure on farms

      • milking parlor

        • milk fat

      • at least 40% of the cows should be chewing cud anything else you have to look at management

        • are the cows sorting the feed

        • are the feed particles too small

        • heat stress

        • cow comfort

        • stall size

  • some nutritionists spend a lot of time studying feces

  • chewing is hard to measure ruminants spend 6-9 hours chewing

  • so looking about milk fats a good reference of how the rumen is doing

• manure screening and scoring

  

  • long loose feces might mean not enough long forages to stimulate fermentation rumen

• functional specific gravity

  

  • they type of feed and size determines where it will be n the rumen

  • the rumen mat is formed by fibrous particles that lock together and typically have greater digestibility and produce more gas as it is being fermented

    • spend longer time in the rumen

  • small particles sink and cannot trap gases like larger particles

  • things that inhibit CO2 production can inhibit digestibility and speed up passage rates requiring the animal to eat more feed

• Penn state separator

  • horizontal shaking separates by length

  • check diet before feeding

  • can help estimate the NDF

  • can help see if animals are separating feed

    • good for pre and post screening

• NDF for dairy cattle

  • maximal

    • dietary NDF

      • 35-40% of total diet

    • forage NDF

      • >25% FNDF can decrease DMI

  • minimal

    • forage NDF

      • <20% FNDF can decrease digestive efficiency

      • <15% FNDF can decrease DMI

• minimum forage NDF to neutralize NFC

  

  • NFC = non forage carbohydrates

  • might have to give buffers to decrease the risk of acidosis

• adjustment to forage NDF

  

• conclusions

  • getting better at defining role of fiber and fiber requirements

  • balance or adjust for rumen-degradable starch

  • prevent excessive particle size reduction in mixer

  • prevent sorting

  • as variability increases or feeding management decreases the need more effective fiber

Set 15: Microbes (rumen microbiology)

• rumen microbiology

  • ruminant animal

    • lack of enzymes to digest fiber

    • cellulose (beta 1-4 linked complex carbohydrate)

    • hemicellulose and pectin are alpha 1-4 linkages

      • like uronic acids

    

  • symbiosis with microorganisms

    • fermentation

      • hydrolysis of carbs makes VFA (short chain carbs), methane, and carbon dioxide

• rumen conditions (constantly changing)

  • general ruminal conditions

    • temp: 39-41 C

    • pH: 5-7

    • gases: CO2, CH4, N, H, O2

    • the type of diet depends on the saliva contents

      • buffers

      • urea can go in and out of the rumen wall and into saliva

    • volatile FA: acetate>propionate>butyrate

    • differential removal of solids

    • complex an intermittent

    • substrates available

    • passage rates

    • sodium bicarb = changes rates of passage by changing what and the amount digesta is in each layer of the rumen

      

• microbial diversity

  • always changing and adapting

    • complex nature of feed

    • highly specialized or widely adapted

    • ability to accomplish maximal growth

    • altering nutrients/substrates alters fermentation

    • biochemical interactions affect cell growth and conditions for each reaction vary

• rumen microbiology

  • 3 main classes of microorganisms

    • bacteria

      • ~ 10^10/ml or /g

      • ~ 50% of microbial biomass

      • different species

    • protozoa

      • ~ 10^6/ml

      • ~40% of the microbial biomass

      • fauna of rumen

      • holotrichs (ciliates) vs. entodiniomorphs (flagellates)

    • fungi

      • 10³/ml

      • 5-10% of microbial biomass

• bacterial species

  

  • 2 main classifications

    • what are their substrates

    • what are they producing

  • lytic = lyses molecular bonds for energy

    • examples = cellulolytic, xylanolytic, amylolytic …

    • microbes produce reduced environment produces reduce carbons such as methane

    • host produces oxidized carbons such as CO2

• bacteria

  

  • 1st step is attachment most bacteria are not good at moving so they rely on being bumped into feed particles

  • primary colonizers

    • degrade cell wall to expose rest of plant cell

    • 1. cellulolytics

      • prefer pH>6

      • degrade crystalline and cellulose structure

    • 2. hemicellulolytics

      • digest mostly hemicellulose

      • some can digest some cellulose

        • generals but cannot compete with cellulolytics for cellulose

    • 3.pectinolytics

      • rapid digestion w/o lowering pH

        • not much lactic acid production

      • digest pectin

    • polysaccharides and sugars for microbial energy

    • colonize on inside of cell wall due to wax of cell wall

    • competitive for substrate

      • exponential growth rates

    • fiber breakdown is slow because of branching structure (increases with maturity)

  • secondary colonizers (grow rapidly)

    • not capable of breaking down cellulose cell walls

    • produce AA, ammonia, and growth factors that the primary colonizers use

    • 1. amylolytics

      • dependent on starch in diet - rapid reproduction

      • can be proteolytic and break down protein matrix around starch

    • 2. sugar fermenters

      • also amylolytic

        • ex. Streptococcus bovis

      • produce lactic acid which is high energy wastage

      • tolerant low pH - rapid reproduction

    • 3. lactic acid users

      • hold back 1 and 2 users unless diet change too fast

      • slow growth, not acid tolerant

      • convert lactic acid to propionate and butyrate

    • degrade cytoplasmic contents of cells

      • starches, sugars, proteins

      • not capable of digest cell walls and most cellulose

    • synergistic ecology

    • can grow without restriction

      • acidosis risk

    • interact with primary colonizers

      • use substrates from primary colonizers

• protozoa

  

  • trich means air

  • huge

  • classification based on morphology and not products

  • also keep fungi in check

  • free swimmers

    • populate anywhere in the lquid phase

  • can decrease oxygen in the rumen which helps the bacteria

  • contribute to fiber degradation

  • contribute to starch digestion

  • chemotatic toward free sugars

    • ingulfs the whole sugar molecule which slows down starch digestion

  • proteolytic of protozoa

  • will die if pH goes below 6

  • 40-50% of the biomass

  • only about 20% when reaching the small intestine

  • the products it makes are proteins (when other microbes feed on kind of a wasteful system, the animal could be using that protein, but it turns into microbial protein in the small intestine)

  • protozoic protein has no use to the host

    

• fungi

  • not well understood

    • discovered in the 1980’s and 1990’s

    • 5-10% of biomass

    • attach to cell wall

    • zoospores attach and burrow into cell wells

    • less important than bacteria and protozoa

      

• microbial compartmentalization

  • 3 zones

    • liquid phase = soluble CHO

    • solid phase = insoluble CHO

      • those who digest fiber and starch

    • rumen wall = “epimural” ureolytic, facultative organisms

      • aid in ureolosis and oxygen transfer

        
    

Set 16: Rumen Fermentation

• rumen degradation and carbon flow

  

• fermentation

  • free sugars and carbon skeletons are oxidized in metabolic pathways

    • yield 2-4 ATP per glucose

  • energy retention

    • VFA

  • some microbes have ant ETC to make ATP

  • the animal oxidizes the result of fermentation

    • about 80% of the energy is retained

  • hydrogen must be balanced

    • methane in the H “sink” - energy lost from the system

  • to increase quality of ruminant feed we are often looking how to improve energetics

• energetics of fermentation

  

  • this processed is affected by ammonia, bacterial lyses, relative amounts of protein and carbs being fermented, and sulfur

• fermentation balance

  • specific pathways of VFA production

    • high forage vs. concentration diets

  • efficiency of fermentation

    • yields of VFA energy

    • total VFA yields and profile

    • ATP yield

    • methane yield

• carbohydrate fermentation (digestion) in ruminants

  

• specific uses of VFA’s

  • absorption by the papillae

  • propionic acid (propionate)

    • forms glucose, milk sugar (lactose), AA

    • anti-ketogenic

    • promotes intramuscular fat (marbling)

    • low heat increment

  • acetic acid (acetate)

    • oxidized for energy

    • FA synthesis

    • promotes milk fat and back fat

    • ketogenic

    • heat production

    • can be converted into glucose

  • butyric acid (butyrate)

    • energy source for papillae

    • ketogenic

    • low heat increment

    • lower amount of the VFA

    • cannot be converted into glucose

• altering actetate:propionate

  • increase passage rate

    • increase feed intake

    • grinding or pelleting forages

    • increase starch digestibility

    • unsaturated fats

    • ionophores

      • no known antobiotiv resistance

    • valuable for feedlots (intramuscular fat)

      • higher pelleted lower NDF will shift the ratio away from acetate

        • decreases chewing and rumination time and increases passage rates

    • cause a drop in pH

  • increase acetate: decrease propionate

    • increased feeding frequency

      feeding TMR

    • higher milk fat

• microbial protein

  • AA profile

    • similar to the profile of meat and milk

  • duodenal protein

    • about 60% of the protein in the duodenum is microbial protein

  • yield

    • OM intake - (OM flow to duodenum -microbial OM flow) = true OM digested

      • good for estimating digestibility

    

• predicting microbial protein

  • modeling

    • Ohio Dairy model

      • microbial N flow, g/d = (22.9 x DMI) - (.365 x DMI²) - (1.74 x NDF)

    • NRC empirical model

      • TDN intake x .130 = microbial flow to duodenum

    • Cornell model

      • use multiple equations

• rumen microbiology

  • always changing and adapting

    • bacteria, protozoa, fungi

    • complex nature of feed

    • highly specialized or widely adapted

    • ability to accomplish maximal growth

    • altering nutrients alters fermentation

Week 5: Sept 15-21

Set 17: Metabolism and Metabolic weights

• metabolism

  • metabolism is the process in which the body uses nutrients once they have been absorbed

    • affects estimate of digestion

    • digestibility and gut function

      • N levels

        • microbial growth

        • diet

        • N recycling (urea)

• nitrogen investigation

  • initial studies done in pigs

    • 16% CP required = fed 10, 12, 14% CP to measure response

      • why not ruminants

        • limiting the N in ruminants impacts the microbes decreasing energy intake

    • biological value

    • utilization of N in rapidly growing or lactating animals

      • these animals are studied because typically during maintenance most of the nitrogen is lost

    • measure response to N

    • determine true absorption

      • N digested

      • endogenous

        • urinary N loss

• the energy scheme

  • gross energy (GE): intake energy - potential energy available

    • feces

  • digestible energy (DE): GE - fecal energy

    • urine and gases

  • metabolizable energy (ME): DE - (urinary energy + rumen gas losses)

    • heat

  • net energy (NE): ME - heat loss (energy available to animal)

    • net energy maintenance (NEm)

    • net energy growth (NEg)

    • net energy lactation (NEl)

      

• metabolizable of feedstuff

  • factors involved in determine metabolizablity of a feedstuff for energy

    • 1. digestibility

      • feed processing and intake

    • 2. species

      • methane loss

      • concentrate vs. grazers

    • 3. feed additives

      • ionophores for methane and N

    • 4. protein content

• basal metabolism

  • in order to understand how production factors affect nutrient requirements, need to know basal metabolism

    • net energy required for maintenance

    • derivation of metabolic weights

      • ration balancing

      • feed intake prediction

• percentage of ration energy used for maintenance

  

• metabolic weight

  • motive

    • devise a consistent way to measure/calculate the heat loss/heat production/oxygen consumption

    • Lavosier’s experiment

      • 1700’s

      • guinea pig melting ice (homeotherms)

      • heat production due to oxidative metabolism

• surface law

  • surface law

    • Richet (1889) and Rubner (1883)

      • heat loss constant when expressed on per unit of surface area

      • rabbits and dogs

      • Rubner claimed 1000 kcal/d/m² of surface

    • Voit’s table (Kleiber, 1961)

      • summary of heat loss data

• Voit’s Table

  

• surface law

  

  • problem

    • difficult to get accurate, consistent estimates of surface area

    • human example combined height and weight

      • S(cm²) = 1.84 W(kg)^.475 x L(cm)^.725

      • why not just use a function of body function

        • W0, W1, W0.5, W0.66, W0.73

• exponential weights

  

  • surface area is proportional to body weight

• basal heat production relative to weight (W, Kg) and surface are in various species

  

• Brody, 1945

  

• basal metabolic rate

  • basal/minimal/standard/fasting

    • 70 kcal/ BW^0.75

    • standards

      • adult

      • resting

      • post absorptive metabolic state

      • thermodynamics

      • functional BMR

      • other factors

  • thermodynamics

    • internal work

      • pressure/volume (lungs, heart)

      • synthesis/breakdown of complex molecules

        • anabolic and catabolic pathways

        • gradients

      • maintain electrochemical gradients

  • basal metabolic rate

    • functional explanation of BMR

      • service functions

        • heartbeat

        • respiration

        • conscious neural activity

        • renal activity (clearing toxins from the body)

        • cellular maintenance functions

          • ion transport (Na+, K+, -ATPase)

        • protein, lipid, nucleic acid turnover

• basal metabolic weight

  • other factors affecting BMR

    • time of day, time of year

    • age/health

    • sex

    • nutritional status

    • body composition

      • body fatness

        • adipose tissue

      • active body mass

        • visceral organs as a proportion of total body mass

        • organs such as the liver require unproportionate energy requirements

          • a thin cow with a large gut organ ratio will require more energy than a fat muscular animal at the same age

    • environmental conditions

• defining maintenance energy

  • what about energy required for maintenance

    • define maintenance: energy (metabolizable) to maintain 0 energy balance

• bovine air flow dynamics

  

  
  

Set 18: Fat Metabolism

• biohydrogenation

• chemical assessment of fat

  • ether extract

    • crude fat

      

    • waxes and other indigestible or unusable energy sources

    • phospholipids of soybeans and the galactolipids of forages only have 2 fatty acid side chains

    • fatty acids

      • triglycerides

      • phospholipids

      • galactolipids

      

• chemical assessment of fat

  • iodine value (i.v.)

    • measure of saturation of the fat (double bonds = darker reaction)

    • iodine attaches to the double bond

    • more double bonds more color

    

• fatty acid composition of some feeds

  

  • biohydrogenation

    • bonds made by plants are cis

      • double bonds typically occur at 3,6, and 9 carbons from the omega side

    • animals desaturate FA from 9th C toward COOH

      • animal enzymes place double bonds with 3 carbons in between them

    • rumen bacteria can change the cis bonds to trans and also move the double bond over by one carbon (makes the double bonds conjugated)

    • biohydrogenation with bacteria

      • incomplete biohydrogenation alters ruminant tissues

        
  

  • megasphaera can cause milk depression

    • also is pH tolerant will be there in acidosis

    • ionophores might be able to prevent this

  • 2 major processes of biohydrogenation

    • 1. conversion of 18:2 or 18:3 cis to trans intermediates

    • 2. complete hydrogenation to 18:0

      • these bacteria are sensitive to low pH

    • trans intermediates have profound impact on metabolism

• incomplete biohydrogenation products in ruminant products

  • diet and management impact biohydrogenation in the rumen

    • roughages promote higher pH which supports Butyrivibrio fibrosolvens

      • more c9, t11 18:2 conjugated linoleic acid

        • shown to reduce heart disease in humans

      • 6 oz serving: grain finished: 0.14g grass finished: .36g

        • CLA needed to alter human health: 2.4-6 g/day

        • 17 servings grain finished, or 7 servings of grass finished beef

• inhibition of fibrolytic and methanogenic bacteria by FA

  • unsaturated FA with free carboxylic acid

    • interfere with the rumen bacteria

    • gram-negative are more susceptible because of their cell wall structure

  • can with stand low concentrations of unsaturated FA

  • slugs of unsaturated fat are more toxic

  • decrease of the H2 and CH4 producers = decreased A:P ratio

• inhibition of protozoa by unsaturated FA

  • 25-50% reduction in protozoa

  • inert fats depress protozoa too

    • megalac and tallow

  • fat substitution for grains

    • increase energy without increasing grain which decreases risk of acidosis

    • but also decreases feed intake and efficiency of the microbes also decreases microbial protein in the duodenum

      

• FA soaps

  • soaps (megalac) are inert

    • R1COO- Ca++ -OOCR2

    • bypass

    • high digestibility

    • less soluble and less toxic

    • in lower pH the soaps break apart

• digestibility of fat

  • small intestine

    • low pancreatic lipase activity

    • low solubility of very saturated triglycerides probably decreases interaction with lipase

    • phospholipase and bile

      • normal levels are able to handle the inclusion of fats unless the soaps/fats are highly saturated and cannot be solutalized

  • above ~5% supplemental fat in diet the digestibility becomes more variable/decreases

    

• ketosis

  • symptoms

    • low blood sugar

      • drops below 40 mc/ml

    • happens when too much fat is being metabolized too quickly

    • ketones in breath, milk, urine

      • beta-hydroxybutyric acid (BHBA)

        • decreases urine pH

      • acetoacetic acid

      • acetone

        • made fromacetoacetic acid

      • urine analysis

    

• Kreb’s cycle

  

• ketosis

  • treatment

    • IV with glucose

    • oral propylene glycol

    • calcium propionate

    • long term is to increase propionate

      • 60-70% of glucose is from propionate

  • prevention of occurrences

    • promote feed intake with appropriate forage:concentrate diets

    • maintain proper BCS

    • avoid sporadic feeding

  • happens with multiple fetuses

    • and with high milk production in dairy cows

• fat metabolism

  

Week 6: Sept 22-28

Topic 19: Vitamins

• vitamins

  • fat soluble vitamins

    • vitamin A, D, E, K

      • supplement ADE

      • K microbial synthesis

      • tissue synthesis vitamin D

  • water soluble vitamins

    • B complex, vitamin C

      • microbial synthesis B complex

      • tissue synthesis vitamin C

• vitamin A

  • sources: carotenoids in feedstuffs

  • toxicity: 50-500x’s over requirement

  • the more yellow the more vA that can be produced

  • function:

    • night vision

    • epithelial cells

    • adipose tissues

  • feeding more than NRC recommendation in feedlot cattle can inhibit fat cell development particularly in intramuscular cells (marbling)

  • needed for skin function and epithelial function

  • may need supplementation of feed has been stored for a while, bleached, low quality

  • dairy cattle recommendation

    • 110 IU/Kg BW (3,160 IU/Kg DM)

  • beef cattle recommendation

    • 2,200 IU/Kg /DM

  • beef heifers and pregnant cows

    • 2,800 IU/kg/DM

  • beef bulls and lactating cows

    • 3,900 IU/kg DM

  • sheep

    • 17 IU/kg BW (570 IU/kg DM)

    

• vitamin D

  • sources

    • sunshine

    • cholecalciferol and ergocalciferol (plant vitamin D)

  • toxicity

    • ca deposits in soft tissue

    • brittle bones

    • only happens with extreme supplementation

  • function

    • Ca and O and Mg absorption

    • rickets or osteomalasia

  • animals with 1-2 hours of sun end up being fine

    • like the estimated daily value

  • beef cattle requirement

    • 275 IU/kg DM

  • dairy cattle requirement

    • 460 IU/kg DM (30 IU/kg BW)

  • sheep requirement

    • 5.5-6.6 IU/kg BW

• vitamin E

  • sources

    • plants

    • alpha-tocopherol

  • not stable and will break down

    • some synthetic versions are more stable

  • will breakdown if the fat goes bad

  • functions:

    • cell membrane integrity

    • antioxidant

    • interaction with Se

      • white muscle disease or ademia

  • beef cattle

    • 50-100 IU/day

  • dairy cattle

    • 1417 IU/day

    • higher because vD travels into the milk

  • sheep

    • 15 IU/kg DM (35 IU/day)

      • 25-30 mg/kg in feed

• b-vitamins for ruminants

  • not typically supplemented due to synthesis by rumen microbes

    • only supplemented the animals was really sick

  • in high producing dairy cattle, some may be added to provided additional benefit

    • niacin: shown to increase microbial protein synthesis and increase peak milk production

    • biotin: when added to high concentration diets helps improve hoof health and milk production

    • choline: when feed in a rumen protected format can help reduce fatty livers

• vitamin K

  • rumen bacteria synthesize adequate concentrations

    • exceptions:

      • surgery or traumatic injury causing bleeding

      • consumption of moldy forage (moldy sweet clover)

        • contain dicumarol (a blood thinner)

          • vK helps with blood clotting

Topic 20: Minerals

• minerals

  • sources of minerals for ruminants

    • forages and other feedstuffs

    • mineral supplements

    • others: water, soil

  • used for growth, reproduction, bone immunity

• why are supplements needed

  • prevention of mineral deficiencies

    • primary

      • lack of a mineral in the diet

      • low bioavailability of mineral in the diet

        • form that the animal can’t absorb

    • secondary

      • antagonist interactions of minerals in the diet

    

• mineral deficiency

  • types of deficiencies

    • severe

      • clinical signs directly attributable to mineral

      • broken bones, lesions, hair falling out, hair color change, lameness, contusions, discoloration

    • marginal (no clinical signs)

      • low reproductive rates

      • reduction in weight gain

      • slight reductions in milk production

      • increased incidence of disease

• goals of mineral supplementation

  • to provided adequate but not toxic amounts of each mineral

• types of mineral supplements

  • 1. white salt

    • provides sodium and chloride

    • almost always supplement when the animals are not consuming TMR

  • 2. trace mineral salt

    • most to don’t have selenium or macro minerals

  • 3. complete mineral supplement

    • trace minerals, salt, P, Ca, Mg

  • 4. protein-molasses blocks

    • 5-250 lbs.

    • feed during winter and energy

    • expensive

  • 5. liquid supplements

    • molasses, corn steep, distillers

    • minerals are added so there is a benefit (protein, energy and minerals)

• meeting mineral requirements

  • mineral supplementation vary dependent on management system

  • TMR

    • dairy cattle

    • feedlot cattle

    • added to the feed

  • Multipart ration

    • grazing cattle

    • sheep, goats…

    • free choice option

• How to:

  • 1. determine the amount of mineral required per day

    • NRC tables

    • have to know how much dry matter they are consuming

    • how much they are eating of the supplements

  • 2. determine the amount of a mineral provided from a diet

    

• converting units

  • parts per million = ppm = g of mineral/1,000,000 g of feed

    • 1 ppm = 1mg/kg

  • percent = parts per hundred = g of miner/100g of feed

    • % x 10,000 = mg/kg or ppm

  • example:

    • if feed is 0.3% Ca how many ppm of Ca does it have

      • .3% x 10,000 = 3,000 ppm

• differences among mineral supplements

  • amount of minerals provided

  • sources of minerals used

    • inorganic (elemental or natural form), chelated (typically more bioavailable but also more expensive)

  • level of intake

• factors affecting intake of a free-choice mineral

  • level of salt

    • low salt the animals are going to eat more to meet the salt requirement

    • high salt levels the animals are going to eat less of the free choice minerals

  • level of non-mineral ingredients

    • molasses, grain byproducts, flavoring agents

      • used to encourage animal to eat more

• Ca and P

  • ratio of Ca:P is critical!

    • regulated by hormones

  • recommended by ratio for all:

    • Ca:P → 2:1

      • can handle up to a 6:1 ratio

      • always try and avoid a 1:1 ratio

    • less of a concern for ruminants

    • Low Ca or excess P can cause urinary calculi

      • water belly

      

• minerals most likely to be deficient in grazing situations in NC

  • copper

  • magnesium

  • selenium

  • zinc

• zinc

  • deficiency signs of zinc

    • reduced growth rate and feed intake

    • impaired reproduction

      • excessive salivation

      • scaly lesions on legs, neck, head, and around nostrils

      • loss of hair

• selenium

  • deficiency symptoms of selenium

    • .1-.3 ppm requirement

    • young animals

      • muscular dystrophy

      • unthriftiness and diarrhea

    • mature animals

      • increased incidence of retained placentas

      • increased rate or duration of mastitis

• copper

  • deficiency signs of copper

    • anemia

      • copper deficiency results in iron deficiency and the inability to use iron for hemoglobin synthesis

    • cardiovascular disorders

      • can cause heart attack due to collagen and elastin not cross linking in the heart

    • fragile bones that fracture easily

    • neonatal ataxia - lamb and goats

      • brain disorder - not treatable and fatal

      • the dams must be supplemented to prevent this

    • lack of pigmentation in hair

      • black hair turns red

      • red hair turns lighter or grey

      • white hair turns reddish brown

    • impaired reproduction

    • diarrhea

      

  • factors affecting bioavailability of cooper

    • sulfur

    • molybdenum

    • iron

      • high iron causes antagonist reactions with copper

    • zinc

    • fescue toxicity

    • source of copper supplementation

      • avoid cooper oxide

        • limited bioavailability

      

  • 1. copper-sulfur

    • possible formation of CuS in rumen

      • insoluble and cannot be absorbed

    • copper-sulfur-molybdenum

      • formation of thiomolybdates that bind copper

      • concern if Mo> 1 ppm

      • S- + MoO4

      • MoO2S2

      • MoOS3

      • MoS4

      • can be absorbed and then steal copper from enzymes and other molecules and cells

  • sheep

    • exception, have very low copper requirements

      • store copper in liver

      • toxicity risk is much higher than other species

      • 5 ppm required in total diet

      • toxicity at 25 ppm

      • cattle and goats

        • 25-100 ppm in total diet

• magnesium

  • deficiency signs of magnesium

    • anorexia

    • increased excitability

    • convulsions

    • aka grass tetany

    • they cannot stand up

  • treatment

    • IV or subcutaneous injection of magnesium into the blood stream

  • older cows are more at risk because of higher milk production and low mobilization of Mg

  • prevention

    • supplementation in the spring when it is more likely to occur

  • rumen in primary site of absorption

  • factors affecting absorption

    • potassium

      • spring forages tend to be high in potassium lowering the ability to absorb Mg

    • rumen ammonia

      • from CP

    • sodium

      • sodium is required to absorption

• commercial supplements

  • consider major mineral needs?

    

  • trace minerals, ppm

  • are there copper antagonists

    

• red salt

  • cattle will eat 1 oz salt/day

  • Se

  • Ca

  • P

  • Mg

  • Zn

  • Cu

  • Mn

  • Fe

• cost considerations

  • prices of mineral supplements have increased over past several years

• mineral pricing: 20-50$ per 50lb. bag

  • most commercial minerals are 2-4 oz intake/day

    • how long will it take 100 cows to consume one bag ……… 50 lbs. x 16 oz = 800

      • 100 cows per 2 oz = 200 oz so 4 days

      • 4 oz per cow = 2 days

    • what is the cost per head / day

    • 4oz for $20 = .10 4oz for 50 = .25

      

• reducing mineral supplementation costs

  • reduce or eliminate phosphorus in supplement

    • forages generally contain adequate P

  • see what is available in your area

  • stay up to date on news and science

    

• in general, some mineral program is better than none

Week 7: Sept 29- Oct 5

Topic 21: Feed and Forage Quality

• what is feed and forage quality

  • animal performance when feedstuff evaluated is fed alone and free choice

    • or in combination with other dietary ingredients

  • determined by nutritive value and voluntary intake

• forage: definition

  • bulk, high fiber (>35% NDF, <70% TDN) feeds typically representing the vegetative portion of plants consumed by animals

• importance of forages in the US

  • single most important feed base for all ruminants

  • 528 million acres (>1/4 of land area) used for grazing land in US

  • 2021: US total crop value: $201 billion

    • hay value was $19.2 billion

      • ~50/50 alfalfa vs. all other hays

    • grain crop values:

      • corn $86.2 billion

    • soybean $57.5 billion

    • sorghum $11.9 billion

    • wheat $8.6 billion

• nutritive value

  • aspects of forage composition affecting nutrition independent of intake

  • determined by nutritional composition and digestibility

• nutritional composition

  

• aspects of fiber

  • cellulose and hemicellulose % are = in grasses but in legumes hemicellulose is < cellulose

    • easier to digest

  • cellulose and hemicellulose availability will depend on their rumen digestion rate

  • lignin is completely unavailable and on top also sequesters some fiber too

    • lignin % is higher in legumes compared to grasses

    • pectin and beta-glycans are cell wall components but not considered part of NDF

      • digested at rate about 40% per hour

    • warning— request sequential NDF-ADF when analyzing ADF of legumes and fruit pulps

    • 2.4% x the amount of lignin will tell you the non-digestible fiber

• forage non-fiber carbohydrates (NFC)

  • sugars:     

    • sucrose most abundant but some monosaccharides also present

    • digested/fermented at almost a 100% digestion rate per hour

  • starches and fructans:

    • reserve polysaccharides

    • rumen digestibility 10-40% per hour

    • fructans are only found in cold season grasses

• crude protein (CP)

  • crude protein

    • non-protein nitrogen (type A)

    • soluble true protein (type B1)

      • rubisco (found in leaves)

    • insoluble true protein (type B2)

      • not associated with the NDF

  • unavailable CP

    • neutral detergent insoluble nitrogen (type B3)

      • in the cell wall protein called extensin

    • acid detergent insoluble nitrogen (type C)

      • bound to tannins and lignin

      • could be the result of the maillard reaction (gives aldol condensation)

        • aka hedwig reaction

• ether extract (EE)

  • forage EE

    • fatty acids

      • 1-3% of forage DM

      • ~50% of EE

      • polyunsaturated

      • linoleic and linolenic acid

        • will be saturated biohydrogenation

    • waxes and terpenes

      • ~50% of EE

  • grains and oilseed EE

    • highly variable depending on plant and processing

    • DDG

• digestibility

  • in vitro analysis for 24 or 48 hours

  • in most cases, digestibility will decrease as plant matures

  • ranking of species

    • legumes

      • 67-81% NDF

    • cool-season grasses

      • 49-81% NDF

    • warm-season grasses

      • 45-66% NDF

• impact of fiber concentration on intake

  

• voluntary intake

  • unfortunately, routinely measuring intake is challenging

  • however, forage in vitro NDFD is a good predictor of intake and milk production

• “Kind words help the dairy cow produce good milk. they go in one ear and out the udder”

Topic 22: Feed and Forage Analysis Reports

• feeds and forages for ruminants

  • not all ruminants are created equal

    • beef cattle, dairy cattle, sheep, goats

  • physiological differences of goats from cattle/sheep

    • faster passage rates

    • lower ability to digest cell-wall fiber

    • eat more on a % BW basis

  • physiological differences form cattle/goats

    • store copper in their liver

• why invest in feed and forage analysis

  • feed is major expense in livestock production

  • determine if the feedstuff will meet the animal requirements

  • diagnose problems

  • forage and by-products are highly variable

  • all feed and forage analysis reports are estimates

    • there is some margin of error due to sampling, sample preparation, and analysis methodology

  • how big of an investment are we talking???

• forage testing

  • start with collecting a goof sample

    • need approximately 1 gallon of representative forage

    • pasture

      • cut at least 20 samples 6’’ x 6’’ (2’’ residual) from random points in field

        • avoid biased areas of field

          

  • silage 12 core or face samples if sample at feed out

    • keep 1-2 gallon of each load, mix, subsample if collect at ensiling

  • hay

    • determine “lot” of hay

    • sample 20% of bales or at least 6 bales (3 cores each)

      

  • concentrates

    • 10-15 core samples from bulk storage

    • 10% of bagged feed (5-6 bags)

      

• NC farm feed testing service form

  

• Test report samples (2x)

  

• interpreting the results - dry matter

  • % dry matter (DM) (% moisture)

    • influences the stability of feedstuff

  • reports list test values on both AF and DM basis

  • animals use nutrients on a DM basis

  • ration formulation is conducted on DM basis

  • DM ranges of common feedstuffs

    • pasture: 15-25%

    • hay: 85-92%

    • haylage: 35-65%

    • silage: 30-40%

    • dry concentrates: 85-95%

    • wet concentrates (DG, BG): 20-30%

      

• interpreting the results -protein

  • % crude protein

    • 6.25% of the N of the feedstuff

    • mixture of all N sources

      • true AA, nitrate, NPN (urea/ammonia)

  • unavailable CP

    • some protein is bound thus making it unavailable for digestion

    • >10% of total protein indicates heat damage

  • % adjusted CP (insoluble CP)

    • use this value if >10% CP is unavailable

  • CP of some feeds

    • hays and grass: 5-20%

    • fibrous co-products: 12-29%

• interpreting the results - fiber

  • % neutral detergent fiber (NDF)

    • total fiber component

      • hemicellulose, cellulose, lignin

    • can be used to estimate voluntary feed intake

      • >NDF<DMI

  • % acid detergent fiber (ADF)

    • primary fiber components not digested

      • cellulose, lignin, ask, fiber-bound protein

    • used to calculate energy potential of forage

      • >ADF<energy

  • NDF of forages

    • 50-80%

  • ADF of forages ~40%

    

• interpreting the results - minerals

  • % ash

    • total mineral

    • normal range 3-12%

      • >15% possible contamination

  • % calcium (Ca) and % phosphorous (P)

    • ratio is critical

      • 1.5:1 to 4:1

      • watch P levels to determine if Ca needs to be supplemented

  • dry cow requirements

    • .25% Ca and .15% P

  • lactating cow requirements

    • .31% Ca and .21% P

  • % sulfur (S)

    • forages are rarely deficient

    • excess S in forage and water can limit copper availability

      • poultry litter, municipal biosolids, distiller’s grain

  • % magnesium (Mg), sodium (Na), and potassium (K)

    • Mg typically adequate

    • Na requires supplementation

    • K typically adequate, seasonally high

    • use hug quality free-choice mineral

  • sulfur requirements

    • .15%

    • UL .40%

  • lactation requirements

    • .12% Mg, .08% Na, .6% K

  • PPM copper (Cu), iron (Fe), manganese (Mn), zinc (Zn)

    • Cu is almost always deficient for cattle and goats

    • Fe is typically adequate

      • >1000 ppm is a concern

    • Mn is typically adequate

  • Zn is often marginal or deficient

  • selenium (Se)

    • not analyzed due to cost of analysis

    • deficient in NC- need supplementation

  • cattle micro-mineral requirements

    • Cu 10-15 ppm

      • more if S, Fe, Mo are high

    • Fe 50 ppm

    • Mg 40 ppm

    • Zn 30 ppm

  • % nitrate ion

    • high accumulation possible in some forages, especially during plant stress

      • sudan x sorghum hybrids

    • adapt animals slowly to nitrate forages

      • abortion and/or death can result

    • nitrate considerations

      • <.25% is considered safe

      • >.5% concern for un-adapted animals

      • >1% considered very dangerous

• interpreting the results - energy

  • % total digestible nutrients (TDN)

    • calculated estimate of energy content

      • ADF, NDF, CP, ash used in calculation

    • used in beef cattle ration balancing

  • net energy

    • more precise system

      • gain and lactation requirements

      • more common in dairy and beef feedlots

  • TDN requirements:

    • dry beef cow: 52%

    • lactating beef cow: 60%

    • dry ewes: 55%

    • growing lambs: 65%

  • TDN of forages

    • low quality hays: 40-50%

    • high quality hays: 50-60%

    • legume hays: 60-70%

• interpreting the results - other options

  • pH

    • measured in ensiled forages

      • indicator of fermentation success

  • mycotoxins

    • aflatoxin

      • can be valuable in silage

  • pH ranges after ensiling

    • corn silage: 3.5-4.5

    • haylage: 3.8-5.3

  • aflatoxin levels

    • <20 ppb for cattle

• quick look at the results

  

  
  

Topic 23: Interpreting Results

• Sample picture

  

• how do I calculate if my forage will meet my cow’s needs?

  • step 1: determine predicted DMI of free-choice hay

    • use the hay analysis provided to you:

      • medium quality

      • medium TDN (56.14%) medium CP (10.5%)

    • the average BW of lactating cow her is 1150 lbs.

      

    • calculate DMI

      • DMI = 1150 lbs. x 0.025 = 28.8 lbs

  • step 2: determine if forage will meet the CP requirement of the cow herd

    

    • calculate CP intake

      • 28.8 DMI x 0.105 = 2.9

        • 27.8 * 0.105 = 2.9

        • 28.4 * 0.105 = 3.0

        • 27.4 * 0.105 = 2.9

        • 26.5 * 0.105 = 2.8

      • CP would be adequate

  • step 3: determine if forage will meet the TDN requirements of the cow herd

    • determine TDN intake:

      • 28.8 lbs DMI * 0.5614 = 16.2 lbs/d TDN

        • 27.8 * 0.5614 = 15.6

        • 28.4 * 0.5614 = 15.9

        • 27.4 * 0.5614 = 15.4

        • 26.5 * 0.5614 = 14.9

      • TDN is limiting for cows 2-3 months after calving even at maximum DMI

• comparing the results

  • were CP and TDN requirements met at maximum DMI?

  • yes, CP and TDN exceed requirements

    • feed resource is an option for the animals under the given conditions

  • yes CP and/or TDN greatly exceed requirements

    • if fed as libitum animals may gain weight (increase BCS)

    • limit feed the forage to prevent weight gain

    • consider a lower quality forage for the animals

  • no CP and/or TDN were below requirements

    • animals could lose BCS

      • fetal programming effect/conception rates

    • need supplemental protein/energy

      • co-products

    • provide higher quality forage when current forage is inadequate

    • mix higher and lower quality forage to optimize diet

• how much forage will I need

  • estimate hay requirements

  • step 1: convert DMI to as-fed intake

    • 28.8 lbs. DMI/0.9534 = 30.2 lbs./ as fed

  • step 2: estimate total hay fed

    • 20 cow herd for 90 days

    • 20 cows *90 days * 30.2 lbs./d / 2000 lbs./ton = 27.2 tons

  • step 3: estimate has losses from storage and feeding

    • assume 20% loss (5-50% can be lost depending on methods)

    • 27.2 tons/0.80 = 34 tons

  • step 4: calculate cost

    • estimate cost at $165/ton

    • 34 × 165 = $5,610

      

• Another sample picture

  

• How much forage will I need?

  • estimate pasture requirements

  • step 1: convert DMI to as-fed intake

    • 28.8 lbs DMI /0.1894 = 152 lbs/d As Fed

  • step 2: estimate total pasture DM consumed

    • 20 cow herd for 90 days

    • 20 × 90 × 28.8 = 51,840 lbs.

  • step 3: estimate grazing efficiency

    • assume 70% efficiency (40-80% can be consumed depending on grazing strategies)

    • 51,840/0.70 = 74,057 lbs.

  • step 4: calculate acreage available

    • if 3,000 lbs. DM/acre available

    • 74,057/3000 = 24.7 acres

  • step 5: calculate cost

    • estimate cost at $85/acre

    • 24.7 acres * $85/acre = $2,100

• summary

  • you know what you have … you know what you need

    
    

Topic 24: Comparing Feed Resources

• farm scenario

  • there are 4 forage resources available to feed the cow herd

    • capacity for hay and/or pasture feeding

  • there are 2 groups of cattle to focus on feeding

    • can be grouped or fed separately

  • the cattle need feed for 30 days

• forage analysis results

  

• cattle requirements

  

• where do we go from here

  • multiple approaches to consider

    • start with determining feed resources available

      • actual DM available

      • cost per lb. DM, Cp, TDN

    • start with determining needs of herd

      • each group of animals

      • total herd

• fescue hay 1

  

  • 50 bales * 800 lbs. AF / 2000 lbs./ton = 20-ton AF

  • 20 ton * $150 = $3000 for whole lot

  • 20 ton * 75 % uses = 15-ton AF available to feed

  • 15 ton * 86% DM = 12.9-ton available DM

    • 12.9 ton *64.9% TDN = 8.4-ton TDN

    • 12.9 ton * 13.3% CP = 1.7-ton CP

      • $3000 / (12.9 ton * 2000 lbs./ton) = $0.12 /lb. DM

        • $3000 / (8.4-ton TDN* 2000 lbs./ton) = $0.18 /lb. TDN

    • $3000 / (1.7-ton CP* 2000 lbs./ton) = $0.88 /lb. CP

• fescue hay 2

  

  • 60 bales * 700 lbs. AF / 2000 lbs./ton = 21-ton AF

  • 21 ton * $120 = $2520 for whole lot

  • 21 ton * 80 % uses = 16.8-ton AF available to feed

  • 16.8 ton * 77% DM = 12.9-ton available DM

    • 12.9 ton *57.9% TDN = 7.4-ton TDN

    • 12.9 ton * 9.3% CP = 1.2-ton CP

      • $2520 / (12.9 ton * 2000 lbs./ton) = $0.10 /lb. DM

        • $2520 / (7.4-ton TDN* 2000 lbs./ton) = $0.17 /lb. TDN

      • $2520 / (1.2-ton CP* 2000 lbs./ton) = $1.05 /lb. CP

• oat hay

  

  • 50 bales * 750 lbs. AF / 2000 lbs./ton = 18.75-ton AF

  • 18.75 ton * $175 = $3281 for whole lot

  • 18.75 ton * 85 % use = 16-ton AF available to feed

  • 16 ton * 90% DM = 14.4-ton available DM

    • 14.4 ton *63.9% TDN = 9.2-ton TDN

    • 14.4 ton * 12.6% CP = 1.8-ton CP

      • $3281 / (14.4 ton * 2000 lbs./ton) = $0.11 /lb. DM

        • $3281 / (9.2-ton TDN* 2000 lbs./ton) = $0.18 /lb. TDN

      • $3281 / (1.8-ton CP* 2000 lbs./ton) = $0.91 /lb. CP

• stockpiled fescue

  

• where do we go from here?

  • multiple approached to consider

    • start with determining feed resources available

      • actual DM available

      • cost per lb. DM, CP, TDN

    • starting with determining needs of herd

      • each group of animals

      • total herd

• 2 year old cows

  

• mature cows

  

• where do we go from here

  • begin comparing what is available vs. what the herd needs

    • in quick look how does supply meet demand

      • combined herds need 12.3 ton of DM

      • all forage resources have ample DM for one or both groups

    • how will forage quality impact intake

      • need to make adjustments

      • all 3 hays will reduce intake of heifers from NRC expectation of 2.9%

        • 2.7% FH1, 2.5% FH2, 2.7% OH

    • how do forages compare to each other

      • any major concerns

        • high moisture content of FH2 may limit storage (molding potential)

    • cost comparisons

      • FH1 most expensive on DM basis

      • FH2 most expensive on CP basis

      • FH1 & OH equal, expensive on TDN basis

      • SF cheapest on DM, CP, and TDN basis

• management decision

  • management decides that trying to avoid excess nutrient intake is important

  • want to optimize both groups

  • decision:

    • strip graze 2-year-old heifers on the stockpiled fescue

    • drylot the mature cows and limit feed oat hay

      • 1 bale per day for the herd would be ~2.3% BW DMI and still slightly exceed requirements

        • 2.2% BW DMI would be ideal but harder to manage than feeding 1 bale/day

• other factors to consider

  • know what you have ... know what you need

    • underutilized resources

    • feed allocation based on requirements

    • supplement strategies

    • improve feedstuff quality

    • farm productivity

    • fencing and water capacity

    • breeding or management groups

    • equipment and labor

    • feed storage resources

    • 
      

Week 8: Oct 6-12

Topic 25: Small ruminant nutrition - overview

Topic 26: Small ruminant nutrition - nutrients

Topic 27: Small ruminant nutrition - health

Topic 28: Small ruminant nutrition - feeding calculations

• dry matter vs. as-fed

  • lamb weights 75 lbs.

  • how much of its body weight should it consume?

    • average 4-6% (average 5%)

  • what is the dry matter percent of haylage

    • 50-70% ?????????

• how much protein is an animal eating?

  • example: a 80-pound lamb is eating 5 pounds of 88% dry matter diet (dry corn and supplement) that is formulated to contain 12.5% crude protein (CP)

    • 1. convert intake to dry matter basis (DMB) to get rid of water intake (water doesn’t contain CP)

      • Lbs. of feed x %DM = Lbs. of DM

      • 5 pounds x .88 = 4.4 pounds of dry matter intake

• how much protein is an anima eating

  • example: a 80-pound lamb is eating is eating 5 pounds of an 88% dry matter diet (dry corn and supplement that is formulated to contain 12.5% crud protein)

  • 2. check to make sure this is reasonable. remember that lambs eat to up 6% of their body weight on a dry matter basis

  • lbs. of DM/lbs. BW x 100 = % BW DMI

  • 4.4/80 × 100 = 5.5%

• how much protein is animal eating

  • 3. calculate the pounds consumed

    • 4.4 of DMI x .125 = .55 lbs. CP

  • lamb of this size gain 0.8 lbs. per day requires 0.52 lbs. of CP

• Pearson square

  

• nutrient supply case study

  • take the previous ration (78% corn and 22% SBM). this ration approximately 18% CP. if you wanted to feed 1 lb./hd/d of this ration, how much TDN and CP are you supplying to your sheep/goats

    

• nutrient supply case study

  

• how much does this ration cost

  • same ration (78% corn and 22% SBM) at approximately 18% CP. current corn prices are $7.20/bu. soybean meal is currently $16.10/bu. what does the ration cost on per ton basis? What about per lb?

    • 2000 lb/ton

      • 2000 lb x .78 = 1560 lb. corn

      • 2000 lb. x .22 = 440 lb SBM

      • ]\

      • 
        

Week 9: Oct 13-19

Topic 29: Beef overview and Cow nutrition

Topic 30: Beef - growing cattle nutrition

Topic 31: Beef Feedlot nutrition

Week 10: Oct 20-26

Topic 32: Feeding lactating dairy cattle

Topic 33: Dry and Transition Cows

Topic 34: Calves and Heifers