Animal Science 118
Nutrition
Chris Ellason
Nutrient Classes
Water
 Carbohydrates (CHO)
 Lipids (Fat or Ether Extract)
 Protein
 Minerals
 Vitamins

Water


The most important but most taken for granted
nutrient
Cheapest most abundant nutrient



Animals will die faster due to lack of water than any
other nutrient
65 - 85% of animal weight at birth 45 - 60% at
maturity
Percentage decreases as percent fat increases
Water
Makes up 90 - 95% of blood
 3 Locations of water in body tissue

 Intracellular
 Greatest
water
% of body water (40%)
 Extracellular
water
 Water in urinary and GI tract
Water Functions
Transportation of nutrients and excretions
 Chemical reactions
 Body temperature regulation
 Lubrication of joints and organs in body
cavity

Water Intake

Water Consumption of Unstressed animals
 Swine
- 1.5 to 3 gal/hd/d
 Sheep - 1 to 3 gal/hd/d
 Cattle - 10 - 14 gal/hd/d
Water Turnover



In ruminants, body water turnover is
about 7 days
Nonruminants have a more rapid turnover
due to less water in the GIT
Slower turnovers are seen in very tolerant
animals such as camels and some sheep
Carbohydrates (CHO)



Made up of C, H and O
Makes structural components of plants
Formed by Photosynthesis
6CO2 + 6H2O + 686kcal = C6H12O6 + 6O2

Generally provide 50 to 75% of dry matter
of food in an animals diet
CHO




Sugars, starches, & cellulose
Simple CHOs, such as Starch, are easily
digested and supply the major source of
energy for swine and poultry
More complex CHO, such as cellulose, are
not easily digested and require a microbial
interaction for effective utilization
Grazing ruminants can make the most
effective use of forages
CHO

2 classes

Fibrous (contains cellulose)


Coastal Hay, alfalfa, cottonseed hulls
Readily available

Milo, Corn, Barley, Wheat
Carbohydrate Classification

Monosaccharides: simple sugars
 Hexoses
(6 C)
 Glucose
 Fructose
 Galactose
 Mannose
 Pentoses
(5 C)
 Arabinose
 Xylose
Carbohydrate Classification

Disaccharides: 2 sugar molecules linked
together
Sucrose (glucose & fructose)
 Maltose (2 glucose)
 Lactose (glucose & galactose)


Polysaccharides: Many sugars linked together
Starch: readily digestible
 Cellulose: requires bacterial action to break down

Carbohydrate Digestion

Only Monosaccharides can be
absorbed
Nonruminant CHO Digestion
Salivary Amylase
 Pancreatic Amylase
 Other Carbohydrases - cannot breakdown
Cellulose because of glucose-4--glucoside
linkage

 When
the –OH group on the anomeric carbon
is on the same side of the ring as the terminal
–CH2OH
Alpha vs beta linkage
Nonruminant CHO Absorption
Glucose and Galactose are readily
absorbed
 Most monosaccharides are converted to
glucose in SI mucosa
 Very high percent of absorption occurs in
first two sections of SI

Ruminant CHO Digestion

What’s the difference from nonruminants?
Ruminant CHO Digestion
Very little if any Salivary Amylase
 Lower amounts of Pancreatic Amylase
 Bacteria in rumen have cellulase
 Conversion of CHO to VFAs
 75 - 80% of ruminant energy is from VFAs

VFA Metabolism

There are 3 major VFAs
 Acetate
 Propionate
 Butyrate

They occur in concentration as listed
above
VFA Metabolism

How do the relative concentrations of
these change?


As grain increases in the diet, propionate
increases
As fiber increases in the diet, acetate and
butyrate increase
Fat or Lipid Metabolism
Fatty Acids can range from 2 to 24 C in
length
 Saturated Fatty Acids

 No
double bonds in the chain
 Solid at room temperature
 Butyric Acid
 Stearic Acid
Lipid Metabolism

Unsaturated Fatty Acids
 One
or more pairs of C have double bonds
 Liquid at room temperature
 Number of double bonds denoted in name
 Oleic Acid (C18:1)
 Linoleic Acid (C18:2)
Lipid Functions
Supply Energy
 source of essential fatty acids
 carry fat soluble vitamins
 cell membrane structure
 hormone precursor

Lipid Metabolism
As saturation increases melting point
decreases
 Iodine number denotes degree of
unsaturation

 Ex
C18:1
Lipid Metabolism
Upper Small Intestine is major site of
absorption
 Differences in Ruminant and nonRuminant

 Lypolysis
occurs further up the tract in the
ruminant
 In nonruminant occurrence is in small
intestine
 Fatty acids are neutralized in the rumen
Lipid Metabolism
Ruminants utilize essential fatty acids
much more efficiently than nonruminants
 This is important due to extreme
hydrolysis happening in the rumen
 Ruminants store 27 to 29% of fat as 18:0
 This % is only about 5 in nonruminants

Lipid Metabolism

Essential Fatty Acids
 Linoleic
acid (C18:2)
 Linolenic acid (C18:3)
 Arachidonic acid (C20:4) - Can be synthesized
from linoleic therefore only required if linoleic
is absent
Protein
Structure
 Classification
 Terminology
 Protein Quality
 Protein Quality Ruminants
 Digestion and Metabolism

Protein Structure
All proteins have one common property
 All are made up of chains of amino acids

Essential Amino Acids
22 Amino Acids total
 10 are Essential
 Pvt Tim Hall

Essential Amino Acids
Phenylalanine
 Valine
 Threonine
 Tryptophan
 Isoleucine






Methionine
Histidine
Arginine
Leucine
Lysine
Protein Classification

Simple Proteins: Those yeilding only
amino acids
 Albumins:
soluble in water
 Globulins: soluble in dilute neutral solutions
salts
Protein Classification

Fibrous Proteins: Constitutes about 30%
of total protein in animal body; connective
tissue
 Collagens:
insoluble in water; become
digestible after conversion to gelatin in dilute
acids or bases
 Elastins: similar to collagens but cannot be
converted to gelatin
Protein Classification

Conjugated Proteins: those in which
proteins are combined with a nonprotein
radical
 Glycoproteins:
contain CHO
 Phosphoproteins: contain phosphorus
 Lipoproteins: contain lipids
Protein Terminology




True Protein: composed only of amino acids
Nonprotein Nitrogen: not true protein in nature
but contain N and can be converted to protein
by bacterial action
Digestible protein: portion of the crude protein
which an animal can digest
Absorbable protein (Metabolizable Protein):
accounts for the quality and quantity of protein
leaving the rumen
Protein Quality

Biological value: measure of the
relationship of protein retention to protein
absorption
BV (%) = N intake – (Urinary N + Fecal N)
X 100
N intake – Fecal N

Protein efficiency ratio: Protein sources
are compared in terms of gain in animal
weight per gram of protein or N fed
Ruminant Protein Quality
Microbial Protein: Poor quality proteins &
NPN can be upgraded by rumen
fermentation to microbial protein
 Bypass Protein: Proteins that bypass
rumen fermentation and go directly into
the omasum

 Can

be used more effeciently
Protected Protein
Digestion and Metabolism

Fate of Amino Acid Breakdown
 Tissue
protein synthesis
 Synthesis of enzymes, hormones
 Energy