ANS Exam 3

What is animal science

Study of animals used for food, fiber, labor, and companionship (includes biology, nutrition, reproduction, management).

Why is animal science important?

Responsibility with the animals we use and resources that animals provide.

Consumption of animal products

Excellent source of protein, Vitamins (B), minerals (iron, zinc, and magnesium)

Examples of products that animals provide us with

leather, feathers, draft, fibers, fuel, biomedical research

How do livestock influence soil conservation?

Manure adds nutrients to soil
Grazing can reduce erosion if managed properly
Helps recycle nutrients

What is domestication?

The process of adapting wild animals from a natural state to live in close contact with people.

Domestication Steps

Close contact with humans and selection modification

How long does domestication take?

Takes many generations

Domesticated Animal

To adapt and live in intimate association with and to the advantage of humans

Wild Animals

Living in undomesticated state (no human control)

Feral Animal

Ancestors have been domesticated, reverted, and now live in a wild state

Tame Animal

used to humans but not genetically changed

Criteria for Domestication

temperament, utility to humans, diet, genetic flexibility, and growth rate

Three Pathways to Domestication

Commensal, Prey, and Directed

Commensal Pathway

Animals move into human area (animals benefit from humans:dogs)

Prey Pathway

Animals hunted to enhance yield (humans domesticate food animals: cattle and sheep)

Directed Pathways

Humans set out to domesticate species (horses)

Animal Rights Vs Welfare

Rights = animals should not be used
Welfare = animals can be used but treated humanely

Why is it important to correctly handle and retrain?

Safety

Productivity / product quality

What to consider when handling animals

Temperament

Flight Zone

Personal space

Point of Balance

line across the shoulder (controls forward/backward movement)

Field of Vision

wide angle (300 degrees) blind spot behind

Herd Behavior

Sheep, cattle, goats, and some birds work best as a group. At least 4 to handle

Handling Tools

Sheep hook, sorting pole, rattle paddle, sorting slate, hog snare, halter

Types of Fencing

Net wire

Electric

High tensile

Barbed wire

Types of Restraint

squeeze chute, Chin hold, Rear leg/flank

Low-stress system design

Curved chutes, Solid sides, Good lighting, Non-slip flooring, Quiet environment

Digestion

Process of converting complex nutrients into forms that can be

absorbed (End products: glucose, amino acids, fatty acids)

Absorption

Process by which digested nutrients cross gastrointestinal membranes

Based on diet

Herbivores – mainly cellulose and starch

Carnivores – mainly protein, fat and glycogen

Omnivores – combination of protein, fat and starch

Monogastric (non-ruminant)

Omnivores and carnivores. Ex: Dog, cat, pig

Ruminant

Herbivores. Ex: Goat, sheep, cow

Non-ruminant herbivore (hindgut fermenter)

Herbivores. Ex: rabbit, horse

Modified monogastric

Omnivores, carnivores and herbivores. Ex: all birds

Digestion start and end

Starts: mouth

Ends: large intestine/anus

mouth

• Prehension

• Mastication

• Saliva functions:

  • Lubricate food

  • Moisten mouth

  • Digestive enzymes

  • Buffer

Esophagus

• Tube connecting mouth to stomach

• Lined by muscle

• Monogastric: one way

• Ruminant: both ways (rumination

Stomach

• Chemical digestion

• HCl

• Pepsin (protein)

Small Intestine

• Chemical digestion

• Enzymes:

  • Amylases – starch

  • Proteinases – proteins

  • Lipases – fats

Pancreas

Secretes digestive enzymes

Gallbladder

Bile → aids fat digestion

large intestine cecum

• Water absorption

• Microbial digestion (varies by species)

Types of teeth and purpose

Incisors: cutting

Canines: tearing

Molars: grinding

Process and purpose of rumination

Rumination:

• Regurgitation and remastication of ingested food

• ~8 hours/day

Purpose: improve digestion of feed
Eructation: elimination of gases

Structures in each compartment of the rumen

Rumen - Vat for microbial digestion

Reticulum - Trap the bolus

Omasum - Retains water

Abomasum - True stomach and Chemical digestion

Nutrients Animals require:

Water, energy, protein, minerals, and vitamins

Classes of nutrients:

Water, carbohydrates, lipids, protein, minerals, and vitamins

Factors that Affect Water Intake

Physiological functions(e.g., lactation)

Physical activity

Diet composition

Feed intake

Water quality

Environmental temp

Water Sources

Drinking water - Must be available ad libitum

Water contained in feed

Metabolic water (water

of oxidation)

Monomers & digestion

• Carbs → glucose (enzymes, small intestine)

• Protein → amino acids (enzymes)

• Lipids → fatty acids (bile + enzymes)

Ruminant energy:

Ruminants don’t use sugar as their energy source:

Use volatile fatty acids (VFA’s)

Lipids vs carbs:

Lipids = more energy dense (2x)

Protein differences monogastric vs ruminants

• Monogastrics need essential amino acids in diet

• Ruminants use microbes to make protein

Macro-minerals

are needed in the diet in relatively large amounts (7)

(expressed as percentage or g per kg feed)

Micro-minerals

are needed in the diet in relatively small amounts (11)

(expressed as mg per kg of feed (ppm)

Vitamins

Fat-soluble: A, D, E, K (stored)

Water-soluble: B, C (not stored)

Factors affecting nutrition:

Age

Size

Production (growth, lactation)

Environment

Health