Feeds and Feeding Exam 1 Review

Samuelson, Lecture 1-6

nutrition

process of providing or obtaining the food necessary for support of life processes

digestion

process of converting complex nutrients into simple forms that can be more easily absorbed

absorption

process by which digested nutrients cross the membranes of the GIT and pass to the blood supply or lymphatic system

transporting components of digested feeds across cellular membranes (gut wall)

metabolism

all changes that take place after absorption from digestive into cell

provision of nourishment and energy for bodily processes

The gastrointestinal tract anatomy of livestock is classified into non-ruminants and ruminants. Discuss these 2 classes

ruminant rely on microbes in stomach to break down forages that non-ruminants cant do (as efficiently)

Label the diagrammatic representation of the gastrointestinal tract of the pig

total GIT, stomach, small intestine, and large

intestine

Discuss the anatomy and functions of the pig’s gastrointestinal tract (total GIT, stomach, small intestine, and large intestine)

non-ruminant:

stomach - initiate chemical/enzymatic digestion, secrete HCl/digestive enzymes(pepsin, rennin, lipase), mechanical preparation of feed, inborn protection, storage

small intestine -absorption, mechanical preparation via muscle contractions mixing bile/enzymes

large intestine - water absorption, some fermentation by anaerobic microbes

Discuss functions of the lips

entrance to mouth

Discuss functions of the teeth, and beak

differ based on species (cut, rip, smash, grind, etc.)

Discuss functions of the salivary glands

Secrete serous, mucous, or mixed saliva into the mouth which are responsible for \n -Lubrication and buffering \n -Chemical digestion of feeds

Discuss functions of the esophagus

swallowing, rumination

Discuss functions of the non-ruminant stomach

Initiate chemical/enzymatic digestion

Mechanical preparation of feed

Inborn protection

Storage

Discuss functions of the ruminant stomach

Forestomach (non-glandular) = Microbial digestion of feedstuffs

Abomasum (glandular) = similar to non-ruminant stomach

Discuss the inborn protection mechanism of the stomach

Stomach secretes mucus, which protects the stomach lining from strong acids and digestive enzymes

Discuss the functions of the small intestine

Final stages of enzymatic digestion and serves as the main site of nutrient absorption

Discuss why the small intestine is the major site of absorption

Effective at absorbing nutrients because it has a large surface area, due to many folds as well as villi and microvilli

Discuss functions of the large intestine

water absorption and some bacterial fermentation (hind-gut fermenters)

Label the diagrammatic representation of the gastrointestinal tract of the horse

total GIT, stomach, small intestine, and large

intestine

Discuss the anatomy and functions of the horse’s gastrointestinal tract (total GIT, stomach, small intestine, and large intestine)

non-ruminant, hindgut fermentors:

stomach - initiate chemical/enzymatic digestion, secrete HCl/digestive enzymes(pepsin, rennin, lipase), mechanical preparation of feed, inborn protection, storage

small intestine -absorption, mechanical preparation via muscle contractions mixing bile/enzymes

large intestine - water absorption, significate digestion, active microbe population to break down carbs/fiber to VFAs

Label the diagrammatic representation of the gastrointestinal tract of the chicken

total GIT, crop, proventriculus, gizzard, small

intestine, ceca, and large intestine

Discuss the anatomy and functions of the chicken’s gastrointestinal tract (total GIT, crop, proventriculus, gizzard, small intestine, ceca, and large intestine)

non-ruminant:

crop - storage of excess feed, regulate intake/flow to proventriculus

proventriculus - “true stomach,” chemical digestion (glandular chamber secretes HCl/digestive enzymes)

gizzard - “mechanical stomach,” “teeth,” muscular contractions with stones grinds feed, mixes with acid from proventriculus

small intestine - site for absorption and chemical digestion

ceca - have 2, fermentation of fibrous feed

large intestine - water absorption, some fermentation by anaerobic microbes

Label the diagrammatic representation of the gastrointestinal tract of the cow

total GIT, stomach and its compartments, small

intestine, and large intestine

Discuss the anatomy and functions of the cow’s gastrointestinal tract (total GIT, stomach and its compartments, small intestine, and large intestine)

ruminant:

stomach:

omasum - slow down food passage, push food to abomasum, absorb 30-60% water

abomasum - “true stomach,” glandular, like non-ruminants in function and anatomy

rumen - holding vat for fermentation, mechanical preparation of feed, absorption of fermentation products, papillae increase area, symbiosis with microbes

reticulum - receives and traps foreign objects, gateway to rumen, gather ingested food for regurgitation, reticular groove allows milk to bypass rumen

small intestine - final stage of enzymatic diegstion, main site of absorption

large intestine - water absorption, some bacterial fermentation, excretion of waste

Compare the anatomy and function of the gastrointestinal tract of the horse to that of the pig, the chicken, and the cow.

horse is a hindgut fermenter, pig is a monogastric

chicken is a non-ruminnat, cow is a ruminant

Label the diagrammatic representation by identifying the 4 compartments of the stomach of a ruminant

reticulum, rumen, omasum, abomasum

rumination

passage of food bolus, formed in stomach to mouth

Discuss the function of the reticulum

receives swallowed particles and traps foreign objects, gateway to rumen, gathers ingested feeds for regurgitation

Discuss the function of the rumen

holding vat for microbial fermentation, mechanical preparation of feed, absorption of fermentation products, storage of feed and delayed passage

Discuss the function of the omasum

slow down food passage, push food to abomasum, absorb water (30-60% that enters)

Discuss the function of the abomasum.

chemical/enzymatic digestion, secrete HCl and digestive enzymes, inborn protection, storage, mechanical preparation of feeds

Label the diagrammatic representation by identify the 4 different layer of contents in the rumen

gas, solid (fiber mat), slurry, liquid

Discuss the 3 groups of microorganisms that are found in the ruminant stomach

bacteria (>20billion/mL), protozoa (>20 million/mL), and fungi

Discuss why ruminants are more effective with regard to utilizing fiber as sources of energy than non-ruminants

Rumen has symbiosis between ruminants and microbes, microbes provide special digestive enzymes that animals cannot synthesize, but are designed to digest fiber.

Discuss the symbiotic relationship between the ruminant animal (host) and anaerobic microorganisms in its gastrointestinal tract

microbes provide nutrients for the animal as:

Protein (microbes that wash to abomasum)

Energy (microbial fermentation end-products like VFA as energy)

Vitamins ( vitamins synthesized by microbes)

nutrient

any element or compound in a diet of living organisms that support normal functioning of life processes like:

growth, maintenance, reproduction, lactation, and health

Name the 6 classes of nutrients

water, carbohydrates, proteins, lipids, vitamins, minerals

Provide 4 general classifications for feedstuffs

high roughage feeds, roughages (TDN<70%, NDF > 30%, CP 20%)

high energy feeds, concentrates (TDN>70%, NDF<30%, CP 20%)

high protein feeds (TDN>70%, NDF<30%, CP>20%)

minerals/other

Discuss how feedstuffs are classified internationally and name the 8 classification categories

based on nutrient composition and physical characteristics: \n Dry Roughages \n Pasture and range grasses \n Ensiled roughages \n High-energy concentrates \n Protein sources \n Minerals \n Vitamins \n Additives

Why are feedstuffs assigned an International Feed Number (IFN)?

allows people to discuss same feed because the name may vary (ie. corn v maize)

Describe the proximate analysis system

Most common method used to determine nutrient content of feeds: \n Dry Matter \n Ash \n Crude Protein \n Crude Fiber \n Ether Extract \n Nitrogen Free Extract

Discuss how the proximate analysis system can be used to classify feeds

can be used to classify feeds bas on energy concentrates (ie TDN = all organic nutrients summed x digestion coeff)

Identify the feedstuff based on their proximate analysis: Feed 1 = <70% TDN, >18% CF,<20% CP

high roughage feeds

Identify the feedstuff based on their proximate analysis: Feed 2 = >70% TDN, <18% CF, <20% CP

high energy feeds

Identify the feedstuff based on their proximate analysis: Feed 3 = >70% TDN, <18% CF, >20% CP

high protein feeds

Describe the detergent fiber system.

NDF (hemicellulose, cellulose, lignin) measured by washing in Neutral Detergent

ADF (cellulose, lignin) measured by washing in Acid Detergent

ADL (lignin) measured by washing in strong Acid

How does the detergent fiber system differ from fiber analysis for the proximate analysis system?

NDF is more used today as its more accurate

Discuss 3 sources of water

drinking water - commonly available at all times

free water - moisture associated with feeds

metabolizable water - chemically bound and released during metabolism (nutrient oxidation)

Discuss the functions of water

Solvent

Substrate for chemical reactions

Transportation of nutrients and waste

Regulation of temperature

Lubrication, shaping, cushioning

Discuss the digestion and absorption of water

water doesn’t need to be digested

absorbed by small/large intestines (non-ruminants) or rumen, omasum, small/large intestine (ruminants)

Compare water consumption of ruminants to non-ruminants. Give reasons for possible differences

type of digestive tract affects consumption

ruminants require larger amounts of water to form suspension of ingesta

Compare water consumption of dairy cattle to beef cattle. Give reasons for possible differences

dairy require far more water

water loss is greater in lactating animals, milk production lowers when water supply’s low

Compare water consumption of cattle to horses. Give reasons for possible differences

cattle require more water due to them being ruminants (GIT is different)

Discuss factors that affect drinking water consumption

environmental factors (temperature and humidity)

species type (GIT type, water loss amount, urinary tract type)

stage of production (ie lactating animals)

dietary factors (DM consumption, diet type)

toxic elements (salinity, nitrates, sulfates, iron, algae, ag. chemicals)

Discuss how the type of urinary system of mammals versus birds may affect water consumption

mammals require more water

mammals excrete urea in urine (95% water) and birds excrete uric acid (semi-solid) as they don’t actually urinate

Discuss water quality and how it may affect water consumption

lower quality lowers consumption

Discuss potential toxic elements in drinking water

high salinity, nitrates, sulfates, iron, algae, agricultural chemicals

Discuss deficiencies of water

depresses performance (more quickly than any other deficiency)

decreases intake

weight loss (due to dehydration)

Discuss the chemical composition of carbohydrates

Organic compounds that contain carbon, hydrogen, and oxygen \n 1C:2H:1O

Identify a glucose molecule

it is this lol

Discuss the classification of carbohydrates

Monosaccharides (simple sugars - not decomposable into simpler sugars by hydrolysis)

Oligosaccharides (2 to 10 saccharide units)

Polysaccharides (>10 saccharide units)

examples of monosaccharides

Aldopentose (5C), Aldohexose (6C), Ketohexoses (6C)

examples of oligosaccharides (disaccharides)

Maltose (a1,4 glucose-glucose)

Lactose (beta1,4 glucose-galactose)

Sucrose (alpha1,4 glucose-fructose)

examples of polysaccharides

Starch (Amylose and Amylopectin)

Glycogen

Cellulose

Hemicellulose

Pectins

Describe the difference between amylose and cellulose

amylose - unbranched starch with alpha 1,4 linkages

cellulose - unbranched fiber with beta 1,4 linkages

Describe the difference between amylopectin and glycogen

amylopectin is a starch?

Describe the differences between pentoses and hexoses

pentose - 5 Carbons

hexose - 6 Carbons

Describe the difference between an alfa-linkage and a beta-linkage between sugars and how these linkages affect the digestibility of carbohydrates

alpha - “U” shaped, both Oxygen on bottom and face downward, easier to break

beta- “zig-zag” shape, Oxygens on opposite sides, harder to break apart

Discuss the difference between structural carbohydrates and non-structural carbohydrates

Non-structural - alpha linkages \n Structural - beta linkages

Discuss the digestion of carbohydrates in mammals

saliva, pancreas, and duodenum secrete enzymes that cleave alpha linkages resulting in monosaccharides (ie glucose)

\n Discuss the digestion of carbohydrates in anaerobic microorganisms

found in rumen and large intestine and secrete enzymes that cleave alpha and beta linkages resulting in VFAs

Discuss carbohydrate requirements

Little evidence of requirement for any specific CHO by mammals

Ultimate source of energy for most animal tissues is glucose

Discuss deficiencies of carbohydrates. Describe ketosis.

disorder in CHO and lipid metabolism, common in lactating and pregnant animals

caused by a blood glucose drain causing the mobilization of fat faster than what it can be used for energy, result in production of ketones.

Symptoms: weight loss, decreased milk production, and abortion in pregnant animals

Prevention: energy supplementation during last trimester of pregnancy and lactation

Describe the composition of a protein

Chemically consist of long chains of amino acids

Physical and chemical nature of proteins are determined by amino acid sequence, length of amino acid chain, and type of linkages

Describe an amino acid

carbon center, hydrogen, carboxyl group, amino group, side chain / R group

Describe how amino acids are classified

essential and non-essential

Give 2 examples of an essential amino acid and 2 examples of an nonessential amino acid

essential - lysine and valine

non-essential - alanine and aspartate

Discuss the functions of proteins

basic structural units of body

metabolism (enzymes, hormones, immune, energy source)

Describe how proteins are digested.

proteins too big to be absorbed so they need to be broken into amino acids, which occurs via digestive secretions in the stomach (HCl and Pepsin) and small intestine (trypsin)

Discuss protein digestion in the rumen of ruminants by using the diagram of a ruminant stomach

microbes degrade RDP to ammonia and rest of protein (RUP) cannot be degraded by microbes

rumen can also synthesize protein from many sources of Nitrogen (RDP and NPN)

Discuss the protein requirements of non-ruminants

cannot synthesize some amino acids, essential amino acids are required in the diet

Discuss the protein requirements of ruminants

cannot synthesize essential amino acids, but ruminant microbes can synthesize both essential and non-essential amino acids, but they may be limited in what they can produce

Describe the role that rumen microbes play in protein metabolism by ruminants

ruminant microbes can synthesize both essential and non-essential amino acids, but they may be limited in what they can produce (ie. methionine)

What are the most limiting amino acids for pigs, cattle, sheep? Explain why?

pigs - lysine (requirements of outweigh the amount in diet)

ruminants (cattle, sheep) - methionine (lack of results in lower protein products, even if rest of AA are in high concentrates)

Discuss protein deficiencies and symptoms

caused by 1 or more limiting As or inadequate protein consumption

symptoms - poor growth and reproduction, reduced milk/egg production

prevention/treatment - increase dietary protein supply, supplement diet with limiting AAs

Discuss protein toxicities and symptoms

excess degradable protein particularly NPN can cause Ammonia toxicity

symptoms - excessive salivation, rapid breathing, incoordination, bloat, tetany, death (neurological disturbances)

treatment - oral administration of vinegar