Animal Nutrition Exam 4

what is the #1 most commonly fed energy feedstuff provided to livestock?

corn

name 5 energy concentrate feeds

corn, sorghum, oats, barley, rye, wheat

what is the #1 most commonly fed protein feed?

soybean meal

name 1 feed that is high in pectins and therefore is a better feed stuff for ruminants and hind gut fermenters than it is for omnivores like pigs and poultry

beet and citrus pulp

name 4 oilseed byproducts that are fed to provide protein to animal diets

soybean meal, canola meal, linseed oil, sunflower meal, cottonseed meal

why are beet pulp and citrus pulp better feeds for ruminants than non-ruminants?

high in fiber and low in starch, it produces rumen gas and makes the animal look bigger

based on amino acid profile alone, why do many diets include both soybean meal and corn or corn by-products?

the amino acid content in soybean meal complements the amino acid profile in corn

name 1 feed that can contain the toxic compound gossypol (two are possible)?

cottonseed meal

what is the name of the feed that is a by-product of the sugar beet industry, and can serve as a pellet binder.

beet pulp

are animal proteins or plant proteins better at providing the correct amino acids required for growth and production of animals?

animal proteins

what is the nutritional-relevant portion of the plant cell wall called?

Neutral Detergent Fiber (NDF)

which different molecules make up the fiber portion of the plant? how do they differ in digest ability?

cellulose, hemicellulose and lignin. hemicellulose is highly digestible, cellulose is moderately digestible, and lignin is indegestible

what are the 4 different polyphenolic compounds that make up lignin? how do they compare in inhibition of fiber digestibility?

p-coumaric alcohol, Coniferin 5 - hydroxy Coniferin, mustard alcohol. it impairs fiber digestibility. G lignin less inhibitory than S lignin, H lignin less inhibitory than ferulic acid, non-core lignin is less inhibitory than core ligning

how does forage species, forage growing conditions, planting density, forage genetics, and forage maturity influence the concentration of lignin within a plant?

forage species: legumes generally have more lignin than grasses do, growing conditions: warm-season forages synthesize more lignin than cool-season forages, planting density: mixed results, but greater planting density generally reducing cell wall thickness (lignin deposition), genetics: BMR mutation reduces lignin concentration of forages, forage maturity: more mature forages have greater cell wall lignin concentration, more mature forages synthesize more S lignin than G lignin

how do particle size, ruminal pH, dietary fat concentration and dietary protein concentration influence fiber digestibility?

particle size: fiber particles are too small to pass through the rumen before optimal digestion, ruminal pH: bacteria that ferment fiber do so most effectively at high ruminal pH (forage: concentrate ratio), saturated fats: generally no impact on fiber digestion, unsaturated fats: highly toxic to fibrolytic bacteria. Protein: most fibrolytic bacteria require free ammonia as a N source to replicate and produce the enzymes required to ferment fiber

what are the legumes and how do they fix atmospheric nitrogen?

they form symbiotic relationships with soil microbes at their roots

name 5 common species of grass used in pastures or for hay for livestock

Kentucky bluegrass, smooth bromegrass, orchardgrass, timothy, reed canary grass, tall fescue

what is a cover crop? name 5 reasons why are they used?

planting specific crops to cover the soil. Used for erosion control, water infiltration, soil health, soil organic matter , nitrogen uptake and production, mineral movement, microbial biodiversity

name 7 plants that are commonly used as cover crops

clovers (white clover, crimson clover, red clover, berseem clover, alsike clover), brassicas (kale, mustard, turnips, radishes, forage rape), millets (pearl millet, foxtail millet), peas (forage pea, grain pea, cowpea)

what are anthelementics used to control, and provide 3 examples

used to reduce parasitic intestinal nematodes (dewormers). Tape worms, round worms, hookworms

list the common antibiotic growth promotants used in feed?

chlorotetracycline (CTC), oxytetracycline (OTC), Tylosin, virginiamycin, bambermycin, carbadox

what is the veterinary feed directive and why was it implemented?

no more growth promotion or preventative use of antibiotics, they must come to farm, diagnose, and fill out a form that is sent to the feed distributor. This is because of the high antibiotic-resistant microbes and mortality rate, its linked to animal antibiotics.

mycotoxin binders would be most likely added to feed when what is present?

fungi infect, or other toxins entering the animal’s bloodstream (mycotoxin)

Why are coccidiostats fed? What organisms and disease do they control? Name 3 examples

improve growth rate by reducing clinical and subclinical coccidiosis. Coccidiosis is a gastrointestinal disease that causes diarrhea and decrease growth and feed efficiency. commonly used as growth promotant in poultry species. amprolium, lasalocid, clopidaol, monensin.

How do ionophores modify rumen fermentation?

they use the same compounds as coccidiostats

Define probiotic. Give 3 examples of each.

live microorganisms fed to promote healthy digestive and immune function (direct-fed microbials). yeast, bifidobacterium, lactobacillus.

What is the difference between a buffer and an alkalizer. Why would both be used? Give an example of each.

a buffer is maintaining a stable rumen pH and reduce pH fluctuations (sodium bicarbonate and sodium sesquicarbonate), and an alkalizer is increasing rumen pH (magnesium oxide (MagOx) and magnesium hydroxide).

Name two examples of enzymes that may be added to livestock diets, and why in general enzymes are used?

phytase to release plant phosphorus, and enzymes to degrade some complex carbohydrates (fiber). they are used to degrade compounds that are not digestible by the species. (pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEP-CK)

How do beta-adrenergic agonists alter nutrient partitioning?

partitions energy towards muscle and away from fat, leads to improved growth and feed efficiency. it mimics action catecholamines epinephrine and norepinephrine

Which hormone does MGA mimic to prevent reproductive cycling?

progesterone agonist

what is estrus suppressants?

prevent cycling, usually progesterones, like MGA and altrenogest

Antioxidants are most commonly added to feeds that are high in which specific nutrient?

protect from unsaturated fat degradation: vitamin A, D, and vitamin E

Provide 2 examples of common antioxidants added to diets.

tocopherols, BHA, BHT, ethoxyquin

What can be added to feeds to inhibit mold growth?

mold inhibitors (acidifiers like propionic acid is an example)

Provide 1 example of a common pellet binder.

clays, wood products, dried whey

Name 8 reasons why we may choose to process feeds at a feed mill

more efficient with ease and handling, reduce waste, alter feed density to reduce transportation costs, increase digestibility by exposing digestible components and increasing surface area, slow the rate of fermentation in ruminants, increase palatability, improve feed safety by reducing bacterial load or detoxifying harmful compounds, isolate specific plant parts or remove anti-nutritional factors

Name the 7 items that are required to be included on feed labels according to the Association of American Feed Control Officials?

feed ingredients, guaranteed nutrient analysis, active drug ingredients, instructions for use, mixing or feeding directions, timing or age-specific feeding instructions, precautions or warnings.

Which regulatory body determines labeling of livestock feed? What about pet food

both are regulated by AAFCO

Why is steam added to feeds during steam flaking and steam rolling?

to soften the hull of the grain and breaks down the granular structure of the corn grain

Why does gelatinization of starch particles within a grain improve digestibility of that grain?

it breaks down intramolecular bonds of starch molecules in the presence of water and heat, making it more dissolvable in water and easier to digest

What is the difference between steam flaking and steam rolling?

steam flaking exposes grain to steam for 15-30 minutes, leading to stach gelatinization and improved feed value. steam rolling exposes grain to steam for 1-8 minutes, with less starch alteration and no improvement in feed value compared to dry rolling

Related to grain processing, what does a Ro-Tap shaker measure?

it measures the particle size of grains

Regarding oilseed processing, what is the difference between in the process of solvent extraction and expeller extraction? How does this affect nutrient composition?

solvent extraction uses organic solvents like hexane to remove oil which results in lower fat content and higher crude protein in the meal. expeller extraction uses mechanical pressing to squeeze oil, producing meal with higher fat and lower crude protein

Which reaction occurs when a feedstuff is overheated and what is the biochemical change that occurs during this reaction? What is the symptom in terms of nutrient digestibility?

Reaction: The Maillard reaction.
Biochemical change: Degradation of protein quality through the binding of sugars and amino acids.
Symptom: Reduced intestinal digestibility of proteins.

Name 7 advantages and 5 disadvantages of pelleting feed?

Advantages:
Reduces dustiness and feed loss.
Improves palatability.
Prevents sorting.
Enables use of fibrous feeds.
Reduces storage space.
Partial starch gelatinization.
Compatible with automated feeding systems.
Disadvantages:
High cost.
Challenges in maintaining pellet quality.
Risk of spoilage if improperly processed.
Requires finer grinding.
Difficult to pellet high-fat feeds.

Name 3 major types of wet feed processing

Steam rolling.
Steam flaking.
High moisture storage (ensiling).

Which feed processing method applies heat and pressure to a grain using a tapered screw to add air to the grain and eventually create a ribbon-like product that breaks into flakes?

extruding

Name 6 reasons why land would be used for grazing as opposed to crop production?

Economical
Utilize land not suitable for crop production
Rugged terrain - not accessible to farm machinery
Poor Land fertility
Limited water distribution
Environmental reason - wildlife considerations, diverse vegetation, water runoff concentrations

How does the nutrient composition of pastures change across the growing season?

Increase rate of growth but decrease digestibility

What is the difference between intensive and extensive grazing?

Intensive Grazing
- graze all plants
- best in high rainfall with plants that grow tall
- individual animal performance reduced

Extensive Grazing
- raised on food from natural grassland, shrublands, woodlands, wetlands, or deserts

Define deferment, rest, and rotation, in the context of grazing

Delay of grazing in pasture until seed maturity of key forage specie is reached,Nonuse of pasture for one year, Movement of livestock from one pasture to another on a scheduled basis

Name 6 common nutritional diseases associated with grazing and give 1 symptom of each

Bloat -> distended left flanks
Grass tetany -> high potassium and low magnesium
Cyanogenic glycosides -> rapid respiration
Estrogenic flavonoids -> reproductive problems
Coumarin -> prevents proper blood clotting
Nitrates -> limits oxygen transport

Why is rotational grazing done?

Advantages
• Plant is maintained in vegetative state
• ↑ stand persistence
• ↓ selective grazing
• ↓ trampling
• ↑ carrying capacity
• ↑ gain per acre

Name 4 different grazing strategies that can be used to maintain pasture quality

Short Duration
Strip grazing
Mob grazing
Patch-burn Grazing

what is silvopasture?

The combining of trees and pasture space into a single system

define utilization in the context of forage consumption

The proportion of current year's forage production that disappears by grazing animals. Includes disappearance from consumption, destroyed, weathering, and respiration

define harvest efficiency in the context of forage consumption

The proportion of current year's forage production that is consumed by grazing animals. Depends on forage quality and less mature forage is usually higher in digestibility and lower in fiber.

Which specific feed ingredient is the primary driver of the price of all energy ingredients? What about for protein ingredients?

co-products

List 7 major factors that influence commodity price

U.S. corn Yield (weather conditions), corn yield in major export markets, biofuel demand, livestock feed demand, human feed demand, global trade factors , speculative trading, transportation costs, rising input costs due to inflation

List the 3 different channels of feed distribution

vertical integration (produced directly by farmer), Direct sales (direct to farm, coop to farm sales), dealer/distributor network (local cooperative, feed stores)

list 7 factors that influence the nutrient requirements of animals

age, life stage, breed, body weight, body composition, sex, productivity/activity level, health status

define minimum requirements

baseline standards, qualifications, or conditions that must be met

define recommended daily allowance (RDA)

average daily intake level of a nutrient sufficient to meet the requirements of nearly all healthy individuals

define estimated average requirements (EAR)

average daily nutrient intake level that is estimated to meet the requirements of 50% of healthy individuals in a specific age and gender group

define tolerable upper intake level

“maximum tolerable levels”, highest daily nutrient intake that is likely to not pose an adverse health risk to most individuals in the population

what are the differences between empirical and mechanistic nutritional models? what purpose would each be used for?

empirical models: determined by observed relationship input values without considering underlying biological systems, mechanistic models: explicitly determined by biological understanding of the system

what is the difference between a steady state model and a dynamic model?

steady state: assumes constant flux between pools in a system. No element of time included in the system and tends to be linear responses. Dynamic models allows for changes in rates of, includes a factor of time, typically non-linear.

list 3 examples of how mathematical models are used in animal nutrition?

prediction of feed intake based on diet composition, prediction of diet and nutrient digestibility based on feed characteristics and intake, and models used in feed purchasing to reduce ration costs

What does LCA stand for in the context of environmental model

life cycle assessment

Which environments to the lithosphere, hydrosphere, biosphere, and atmosphere each refer to?

land, water, living organisms, air

Define circularity, efficiency, and harmony in the context of livestock sustainability

maximizing recycling and avoiding resource depletion, meeting human needs at the lowest environmental cost, contributing to a functioning agroecosystem

What is the equation used to calculate environmental footprint?

amount of pollutant/amount of animal product

Name 4 feed production processes that cause greenhouse gas emissions

production of synthetic fertilizers and agrochemicals, use of fuel and electricity to prepare, cultivate, and harvest, decomposition of crops residues and volatilization of compounds from soil, and land use change

Name 2 major approaches to reduce methane emissions due to enteric fermentation

feed manipulation, and increasing animal production through genetics and management

What is the relationship between feed digestibility and methane emissions from manure?

CH4 emission from feed digestion is afected by the quality and quantity of the feed consumed and physical conditions in the digestive tract

What percent of the world’s population could be sustained without synthetic N?

~50%

What is eutrophication?

used to describe the growth of algal blooms within water supplies due to nitrogen runoff. This leads to the rapid growth of algae and phytoplankton.

What is PM 2.5 and why is it important to livestock operations?

small particulate matter that’s less than 2.5 microns. They react with other things in the air, so it challenges air quality and human health

What are nitrogen and phosphorus use efficiency and why do we care about those metrics?

livestock consume, use and excrete N & P, so it affects nutrient cycle. (retention/consume) x 100

What are the causes that lead to excessive N and P excretion? How can they be reduced?

overfeeding nutrients, mismatching forms of nutrients with animal needs, poor nutrient bioavailability. Reduced by feeding exactly the amount required, matching forms of nutrients with animal needs, good nutrient bioavailability

what is nitrogen composed of?

amino acids

what is phosphorus is composed of?

phosphate

what grazing term describes the proportion of the year’s forage production that is actually consumed by the animals

harvest efficiency

who are the major exports for the U.S. Animal Feed?

Canada, Mexico, China, Japan, South Korea

which type of feed additive is an anti-microbial modifier specifically fed to improve nutrient utilization in the rumen?

ionophore

what decreases cell wall lignin concentration?

Brown midrib (BMR) mutation

Which channel of feed distribution is defined by the use of farm stores of local cooperative selling to end-users?

dealer/distributor networks

Define prebiotic. Give 3 examples of each.

Non-digestible fiber that serves as substrates to promote specific “healthy microbes” in the gut that will improve digestible and immune function. Inulin, mannooligosaccharids (MOS), Galactooligosaccharides (GOS)

what is nonthermal grain processing?

grinding/milling: reduce particle size, increase digestibility

what is thermal grain processing?

steam processing, extruding: heat & pressure, pressed with tapered screw - ribbon like structure, partially gelatinized starch, pelleting: feed is compacted & forced through die, pressure + heat/steam solidifies outside of pellet, flaking: steam exposure for 15-20 mins, starch is gelatinized

what are antibiotics?

growth promotants (no longer fed off-label as of 2017), like tylosin, chlortetracycline, virginiamycin, coccidiostats (anti-protozoa)

mycotoxin binders

stop mold growth, like clay, betnoites, zeolite