AVS 455 1

Why is animal nutrition important?

An increase in the efficiency of nutrients increases profitability in the current globalized livestock markets.

70% of cost

is due to feed used for raising animals

nutrient

chemical element in the diet that is required for normal reproduction, growth, lactation, or maintenance of life

food

an edible material that provides nutrients

feed

animal food

feedstuff

any material made into or used as feed

diet

mixture of feedstuffs used to supply nutrients to an animal

ration

daily allocation of feed

digestion

Breakdown of food substances into simpler forms, preparation of food for absorption

Absorption

passage of small molecules from the GIT lumen through the mucosal cells lining the lumen and into the blood or lymph systems

Components of the GI tract

mouth, glands, esophagus, stomach, small intestine, large intestine, rectum, anus

tubular structure

used for ingestion, digestion, and absorption, elimination of metabolic wastes

organs involved in digestion

liver and pancreas

non-ruminants

Single-chambered stomach animals.

ruminants

Animals with four chambered stomachs

carnivores

meat eaters, limited fiber digestion

omnivores

eat both plants and animals

herbivores

plant eaters

pre-gastric fermenters

-ruminants (cow, goat, sheep, camel, deer, antelope)
-non-ruminants (kangaroo, hippo, colobus monkey, hamster, vole)
-grazers/foragers

hindgut fermenters

Fermentation occurs in the large intestines and cecum

colonic fermenters

rely little on cecum, microbe activity occurs in lower intestine

sacculated colon

horse, donkey, pig, elephant

un-sacculated colon

dog, cat, panda

large herbivores

grassland animals that graze such as bison/buffalo, zebra, horse, etc.

small herbivores

cecal fermenters often do coprophagy

taste buds

sensory organs that guide nutritive choices and motivate feed intake

mouth structure

teeth, canines, premolars, molars

carpet looking (papillae)

rumen

rumen absorbes what

volatile fatty acids (VFA)

many folds (book)

omasum

honeycomb

reticulum

Reticulum (honeycomb)

filter/forces roughage back to the mouth for rumination and further breaks down the feed
- Hardware disease

omasum function

water absorption

rumen function

fermentation

looks similar to human stomach

abomasum

abomasum function

acidic and enzymatic digestion of feed (pepsin)

permanent dental formula

2[I2/2, C1/1, P2/2, M3/3]\=32

ruminant teeth

no upper incisors, depend on upper dental pad and lower incisors

mouth

take in feed or water

salivary glands

produce saliva

salivary amylase

breaks down starch and carbohydrates

salivary lipase

breaks down fats (lipids)

saliva number in cows

150 liters per day

saliva number in sheep

10 liters per day

cementum

material covering the tooth root

gingiva

gum tissue

pulp chamber

tooth nerves and blood vessels

dentin

calcified connective tissue, makes up the majority of the tooth

enamel

outer layer of the tooth, 90% mineralized, thinner than humans

periodontal disease

inflammation and degeneration of gums, teeth, and surrounding bone

gingivitis

inflammation of the gums

periodontis

plaque build up and bone loss

four stages of periodontal disease

stage 1: gingivitis
stage 2: periodontal pocket formation
stage 3: attachment loss with bone destruction and increased dental mobility
stage 4: furcation and tooth loss

acid production

generation of acid through cellular metabolism

Zinc Compounds

inhibit calculus

enzymes in toothpaste

reduce plaque

fluoride

toxic to animals

essential oils

reduces gingival bleeding and halitosis

dry texture

promotes mechanical plaque abrasion

tissue integrity

adequate protein, calcium, phosphorus

vitamin C

antioxidant

espohagus

tube connecting mouth to the stomach

stomach

sac-like organ that chemically mixes and prepares food received from the esophagus

cardiac sphincter

connects esophagus to stomach

pyloric sphincter

connects stomach to duodenum

squamous

part of the gastric mucosa

cardiac

some bicarbonate secretion

fundic

source of HCl and pepsin

pyloric

source of gastrin

fundus of the stomach

dorsal portion, involved with reception and storage of contents

corpus (body)

mixing vat for the mixture of saliva and gastric juice with food

antrum

gastric pump that regulates the propulsion of food past the pyloric sphincter into the duodenum

storage of the stomach

feed stored temporarily in the form of chyme

chyme

partially digested food that leaves the stomach (pH 2) and enters the small intestine

mixing and crushing in the stomach

regular contractions of muscular walls causes mixing of chyme and crushing of any feed particles \>2mm

secretions of the stomach

secretes HCl and pepsin for food digestion

pepsin

enzyme that breaks down proteins in the stomach

parietal cells HCl

lowers pH of digestsa to ~2.0, ideal for enzymes in the stomach to function

surface mucus cells (stomach)

mucus that protects stomach lining from acid and digestive enzymes

chief cells of the stomach

secrete pepsinogen and gastric lipase

pepsinogen

inactive form of pepsin

denaturation

loss of normal shape of a protein due to heat or other factor

B-complex vitamins that cause problems

Cobalamin (B12) or Thiamin (B1)

Haustra

small pouches that form in the large intestine when the longitudinal muscles are shorter than the colon.

What does the haustra do?

increases feed retention time and allows for more microbial fermentation

Urea

A chemical that comes from the breakdown of proteins

dental anatomy

cementum, alveolar bone

Why are chew toys bad for teeth

risk of excessive abrasion

Ruminal Bacteria

-50-80% of microbial mass
-activity towards many different substrates in feed

Ruminal Archaea

-1-2% of microbial mass
-produce methane

ruminal protozoa

- large
- 10-40% microbial mass
over 250 species
- activity towards many different substrates

Ruminal fungi

-5 to 10% of microbial mass
-Activity towards fiber.

Volatile Fatty Acids

acetate, propionate, butyrate

NPN

nonprotein nitrogen (free amino acids)

NH3

ammonia

Bacteria

60% protein

Duodenum

secretes juice rich in bicarbonate

Jejunum

middle section for both digestion and absorption

Ileum

joins the large intestine and is primarily for absorption

Enterocytes

epithelial cells that line the inner surface of the small intestine