Download minerals

Principles of Animal Nutrition
Objectives:
 An understanding of basic nutrition concepts and
terminology
 Relationship between nutrition and animal function
 Sources of information
 Examples of nutrition application
Outline










Classification of nutrients and nutrient analysis
Feed classification and composition
Digestibility: measurement and variability
Energy requirement and feed energy utilization
Water as a nutrient and water quality
Carbohydrates
Lipids
Protein: monogastric animals and ruminants
Minerals: macro and micro
Vitamins: fat and water soluble
1
References:
Basic Animal Nutrition and Feeding. Pond, Church and Pond, John
Wiley, Fourth Edition 1995.
Applied Animal Nutrition; Feeds and Feeding. Cheeke, Collier
MacMillan, 2nd Ed, 1999.
Nutrient Requirements of Domestic Animals. National Academy of
Sciences, National Research Council (NAS-NRC), Washington, D.C.
Description graduate veterinarian requirement:
Veterinary Nutrition Education Program AVMA
(www.acvn.org)
On-line Glossaries:
Definitions of English terms in Animal Science and Agriculture
USA: http://www.epa.gov/agriculture/ag101/glossary.html
Canada: http://www.aps.uoguelph.ca/~gking/Ag_2350/glossary.htm
2
What to learn from Nutrition Lectures?
 How feeds are classified
 Differences in composition
 How types of feeds differ
 Digestibility concepts and influencing
factors
 Energy partition in the animal and feed
energy GE to NE
 Energy requirement estimation
 Carbohydrates as energy and gut
microbe modifiers
 Lipids as energy and fatty acid
sources
 Monogastric animal protein nutrition,
essential amino acids, protein quality
 Ruminant protein utilization, rumen
microbial protein, bypass protein,
Cornell fractions
3
 Under what circumstances may macro
and micro mineral deficiencies occur,
general signs of deficiencies,
appropriate supplements
 Be familiar with fat and water soluble
vitamins
 Basic nutrition vocabulary and
understanding of nutrition principles
Laboratories outcomes (not offered at CAU)
 Be familiar with feedstuffs and simple
methods of ration formulation
 Sensitivity to the possibility of inadequate
nutrition or toxicity of diet constituents in all
clinical cases
 Understand general ration characteristics,
digestibility / availability, nutrient
requirements and approaches to determining
requirements
 Some familiarity with feed processing and
equipment
4
NUTRIENT:
Any chemical element or compound in
the diet that supports life processes,
such as reproduction, growth, lactation,
draft power, and maintenance.
Classes of nutrients:
1. Water
2. Proteins and amino acids
3. Carbohydrates
4. Lipids
5. Vitamins
6. Inorganic elements
(minerals)
*Note energy is not considered a nutrient –
it is derived from nutrients: lipids,
carbohydrates and protein
5
6
Specialty terms:
Functional foods or nutraceuticals: These
are foods that have non-nutrient effects that
contribute to health
Pre- and pro-biotics:
Prebiotics are nutrients that specifically allow
growth of beneficial microbial populations in
the gut
Probiotics: are microbial communities/strains
included in feed (inoculation) to colonize the
gut and improve gut health of the host
*****************************************************
Energy: Not a nutrient in itself but fuel (ATP)
provided by lipid, carbohydrate, and carbon
skeleton of amino acids after removal of N.
Essential Nutrient:
Required in diet because it can not be
synthesized by the body in sufficient amounts
to satisfy metabolic needs.
7
Nutrition is an
Interdisciplinary Science
It involves the following science
disciplines:
Digestive physiology
Biochemistry
Analytical chemistry
Endocrinology and Metabolism
Microbiology
Pathology
Nutritional Genomics and Genetics
Animal behaviour and management
Environmental studies
Animal Nutrition also incorporates
economic considerations
8
Nutrition:
Purpose of Nutrition is to provide
Nourishment
It is the science (or study) of daily diet and
health
1. Nutrient requirements of animals
2. Content of nutrients in food or feed
3. The balancing (mixing in specific
amounts)of a mixture of feed
ingredients to meet the animal’s
nutrient requirement at lowest cost
4. Through computer models predict from
feed nutrient content the actual animal
performance that one can expect from
an animal fed a certain diet
9
The Application of Nutrition in
Feeding Animals (How to approach
feeding management in steps):
1. Q: What is the nutrient requirement of
class of animal for specific productive or
physiological function (look this up in
tables)?
 Note that these are minimum
requirements for typically healthy
animals under ideal conditions (thus not
very practical)
 They do not take into consideration
stress, disease or parasite conditions of
the animal
 Feed formulation must also be sensitive
to environmental considerations (low N
and P in urine and feces)
10
 Requirement vs allowance
Requirement is the minimum;
allowance is a practical approach
allowing a safety margin
2. Q: What is the nutrient content of feed
ingredients?
Preferably from chemical analysis, Near
Infrared Spectroscopy (NIR) or else from
tables and data bases;
11
and
a.Consider availability of nutrients
(digestibility)
b.Consider anti-nutritional factors
c. Consider antagonism between
nutrients and other factors (feed
matrix)
3. Formulate and balance a ration using
the feed ingredients available on a least
cost basis with set limits (parameters)
 Computer models
 Limits to production
 Animal health
12
Sequence of Events in Nutrient
Deficiency
The discovery of most of the nutrients
as essential dietary constituents has
been accomplished largely with farm
and laboratory animals. Regardless of
the nutrient deficiency the same
sequence of events prevails:
13
Nutrient deficiency
↓
Biochemical defect
↓
Functional defect
↓
Microscopic anatomical
defect
↓
Macroscopic anatomical
defect
↓
Morbidity (illness)
↓
Mortality (death)
14
Nutrition Affects Health Status
of Animals
Beef Cattle:
 Rumen Acidosis – amount and
form of carbohydrates
 Rumen Impaction – high fiber, low
energy and low protein roughage
 Low Fertility, Calving Difficulty –
over-fat cows
Dairy Cattle:
 Ketosis – body condition, feed
intake, liver metabolism (similar to
pregnancy toxemia in sheep)
 Fatty Liver Syndrome – body
condition and feed intake
 Low Milk Fat Syndrome – amount
and type of carbohydrate, low
rumen pH
15
 Milk Fever – calcium, acid base
balance
 Left Abomasal Displacement –
body condition, exercise
Llamas:
 Diarrhea – amount and frequency
of eating
 Constipation – amount and quality
of forage in young llamas
Swine:
 Poor Milk Production – excess body
condition
 Lameness – body condition, mineral
and vitamin D nutrition
 Obesity in Sows – feed energy
density, feeding system
16
Horses:
 Malnutrition- starvation
 Laminitis – carbohydrate overload
 Contracted tendons – minerals, rate
of growth
Reasons for Continued Nutritional
Study
1. Genetic improvement of animals
2. Increased artificial rearing
3. Environmental concerns and
Green House Gas emissions
4. Changing genetics of crops-feeds
5. Reduced use of multiple protein
sources; primarily reliance on a
few feedstuffs
6. Early weaning in swine
7. New feedstuffs
8. Changes in agronomic practices
9. Narrow profit margins
17
Reasons for Chemical Analysis of
Feeds and Feed Ingredients
 Ration formulation:
- Analyze feed samples for on farm
use
- To develop feed data bases on feed
composition
- Regional and company data bases
 To provide analyses for use in
estimating available energy use of
feedstuffs (TDN, Net Energy etc.)
 To provide information to solve a
production problem that may be feed
related
 To place a market value on a feed
 To verify a commercial guarantee
 For use in a feed quality competition
(forage quality)
18
Feed Sampling for Analysis:
 Sampling technique is the most
important cause of variation in
nutrient values
 Method is important to avoid error
Show slides here
Forage
Hay: Penn State core sampler
- 10-12 bales
Silage: grab samples
- 4 to 6 250 ml samples composited
and mixed
Feed in bags
Core samples from 5 bags
Bulk feed in a bin
10 samples from different areas
- Mix on a flat surface on paper
19
- Store in a tightly closed container
- Refrigerate if necessary
Nutrient Groups
We know which the nutrients are, but
how do we measure these chemically?
Chemical analysis using the Proximate
Principles ‘Weende System’
 Water
 Crude Protein (CP; assumes 16%
nitrogen in crude protein)
100 ÷ 16 = 6.25 therefore N % x 6.25
= CP %
Crude  Non Protein N (NPN) and
true protein
[Melamine is a NPN]
 Ether extract (fat)
20
 Ash
 Crude fibre (older method)
 Nitrogen Free Extract (non-fibre
carbohydrate or starch)
In flow diagram next page:
Ash is further analyzed for minerals by atomic
absorption spectrophotometry.
Fiber is measured as Acid Detergent Fiber (ADF)
and Neutral Detergent Fiber (NDF).
21
Flow diagram Proximate Analysis
22
FIBRE IN FEEDS
1. Old Measure: Crude Fibre (CF)
Indigestible by monogastric animals
2. Van Soest Fibre or Plant Cell Wall
method (for forages) slide
a.Neutral Detergent Fibre (NDF) includes
 Cellulose (beta glucose linkage)
 Lignin (phenolics)
 Hemicellulose (xylose, arabinose,
ribose)
b. Acid Detergent Fibre (ADF) includes
 Cellulose
 Lignin
c. Acid Detergent Lignin (ADL)
23
Example Dairy Feeding:
ADF 19-21% of DM
NDF 30-32% of DM (early lactation 28%)
NDF  digestible, slowly degradable
 More gradual organic acid
production
 Increased saliva flow  higher
HCO3- secretion  buffering
 Reduced risk of rumen acidosis
24
Other Typical Feed Analyses
 silage pH (3.8 – 5.0) and butyric acid
 bomb calorimetry for gross energy
(GE)
 amino acid analysis
 NIR: near infrared, estimates protein,
energy and fibre using equations
 feed microscopy, identify
ingredients and contaminants
25
WATER CONTENT OF FEEDS
1. Reported as “As Is” OR “As Fed” OR
“Air-Dry”
2. Standardized to 90% DM, is
also termed Hay Equivalent (HE) as
most hay has around 90% DM
3. Standardized to Dry Matter (DM) Basis
(0% moisture or 100% DM)
2 and 3 are done to standardize
comparisons of feed ingredients and
price
Remember: More water or moisture
in a feed dilutes the nutrient
content or density.
Less water concentrates the
nutrient content or density.
26
EXAMPLE : Dog food
as fed = 35% DM (65% water) and 3%
CP
Convert CP% to a dry 100% DM basis
= 3% CP X (100 % DM / 35 % DM) =
8.57% or
3% CP / (35 % DM / 100 % DM) =
8.57%
Hay and Hay Equivalent:
10% CP on a 87% DM basis = 10 x
90/87 = 10.34% CP as HE (90% DM)
(drier feed thus increasing nutrient
density)
27
LAB - FEED CLASSIFICATION
CONCENTRATES
High in energy, low in fibre content
high energy - (and can be high protein)

Cereal grains: barley, corn, oats, wheat

Grain milling by-products: wheat bran, rice bran

Food processing by-products; molasses, distillers and
brewers byproducts

Roots and tubers; turnips, potatoes, cassava
PROTEIN SUPPLEMENTS
Contain more than 20% protein

Oilseed meals; canola meal, soybean meal, cottonseed
meal, linseed meal

Grain legumes; peas, lentils, beans, lupins

Animal proteins; fishmeal, meat and bone meal, feather meal
nitrogen/protein for ruminants

Non protein nitrogen; urea, ammonium phosphate

Rumen bypass protein; dehydrated alfalfa, corn gluten
meal
28
Roughages
Bulky material with high fibre content and low nutrient
density. Protein and mineral content varies widely
 Pasture
 Silage (see next page)
 Hay
 Straw
Roughages can be legume of non-legume
Legume is a N fixator and has higher protein
content – clover, alfalfa (lucerne)
Non-legume – grass silage, barley silage, corn
silage, grass hays (bluegrass, timothy).
29
FEED ADDITIVES
 Mineral supplements, limestone, salt
 Vitamin supplements
 Amino acids
 Drugs; antibiotics, ionophores
 Preservatives; antioxidants, mold inhibitors
 Buffers; sodium bicarbonate
 Flavors; anise, fenugreek, licorice
 Pellet binders; lignosulfonate, bentonite
Silage process: (slide)
30
High quality silage  low butyrate, high lactate and low
pH
PHASES:
I: Oxygen 12-24h II: Acetic acid 24-72h
III: low pH low acetic high lactate 3-4d
IV: Preserved with lactate
V: feed out with oxygen infiltration spoilage and mold
formation
31
GENERAL RATION CHARACTERISTICS
SWINE:
Cereal grains 7O-80%
OiI meals (soy or canola meal)
Mineral-vitamin supplements
Synthetic amino acids
DAIRY COWS:
Forages (hay-silage) 40-95%
Cereal grains
Oil meals and byproduct feeds
Proteins not degraded in the rumen ie.
blood meal, various heated proteins
Mineral-vitamin supplements
Buffers (sodium-bicarbonate)
32
Lecture Digestibility:
The proportion of the feed not excreted
in the feces, and which is therefore
assumed to be absorbed (it is implied
that nutrients which disappeared from
the gut were absorbed in a useful form,
but this was not measured!
Methods of Determining Digestibility
 Measurement
 Total collection
 Indicator methods
 Estimation
 Chemical analysis
ie. ADF, or more complete
analysis
 Enzyme laboratory methods
33
 Artificial rumen (in vitro)
 Rumen nylon bag (in sacco)
 Mobile nylon bag; moves through
part or all of the intestine in
surgically altered animals (pigs)
Total Collection Method
Animals are fed a single feed or a diet
of known composition for a number of
days and during the latter part of the
period all feces are collected;
After 10-14 days for monogastrics, 2030 d for ruminants.
Must know amount and composition
of feed consumed and amount and
composition of feces voided.
Then calculate:
34
Apparent Digestibility, %
Nutrient intake - Nutrient in feces x 100
Nutrient intake
True Digestibility, %
Correct for endogenous excretion
Nutrient intake - (Nutrient in feces - endogenous nutrient) x 100
Nutrient intake
True digestibility is used mainly for
protein and fat. Can also be used for
minerals.
Index or indicator method
An indicator substance is mixed with
the diet or given by bolus:
Bolus characteristics:
35
 Not absorbed (No effect on the
animal)
 Not altered in the gut
 Excreted uniformly in the feces
 Readily measured
Example:
Chromium Sesquioxide (Cr203) green
color
36
FACTORS AFFECTING DIGESTIBILITY
Animal Factors
 Type of Digestive Tract
 Low digestibility of plant cell walls
(fiber) by monogastrics
 Age of animal
 Level of feed intake
 Health status
Feed Factors
 Feed composition (type of plant, stage
of maturity, amount and type of fibre)
 Processing of feed, fine particle size,
part of plant
 Additives, enzymes
 Associative or Matrix effects (one feed
changing the digestibility of others)
37
Effect of Environment
Temperature: low temperature, faster rate
of passage, lower digestibility (ruminants)
********************************************************
***********************************************
OTHER METHODS USED TO EVALUATE
FEEDS AND DETERMINE NUTRIENT
REQUIREMENTS
Used in combination, may overlap
1. Dose-Response Trials
Growth (dietary amino acid level)
Biochemical or functional defect
(Thiamin or Vitamin A)
Nutrient balance (protein, trace
minerals)
2. Factorial Method (energy, protein)
Maintenance
38
Growth
Production (milk, wool, activity)
3. Digestion Trials
Measures availability of nutrients in
feeds
Whole digestive tract or part of the
tract in surgically altered animals,
rumen fistula, or duodenal canula
4. Clinical-metabolic evaluation
Biochemical, function, microscopicmacroscopic defects
5. Use of statistical analysis
39
EXAMPLE OF DIGESTIBILITY BY TOTAL COLLECTION
• Steer 300 kg live weight.
• 14 day adjustment period on experimental ration
• 5 day fecal collection
• 5 day feed intake, DM; 6 kg/day x 5 days = 30 kg
• 5 day fecal collection; Total wet feces = 40 kg
DM % in feces = 30%
Total dry feces = 30% of 40 kg = 12 kg
• Dry matter digestibility =
30kg DM intake - 12 kg DM in feces x 100 = 60% DM Dig.
30kg
• Crude protein digestibility =
15% CP in feed DM
17% CP in fecal DM
CP digestibility =
(30 kg x 15%) - (12 kg x 17%) X 100 = 55.6%
30KG X 15%
• Digestibility of other nutrients
Gross energy; DE, kcal/kg
Ether extract
ADF, NDF
Starch or nitrogen free extract
40
ENERGY
Required by all animals for:

Maintenance, growth, physiological functions
of living tissue

Thermoregulation

Locomotion
Measurement:
Calorie
“Quantitatively, energy is the most important
element of diet.”
Source: CHO, Lipids (fats) (protein)
-
Animal will eat to satisfy its energy
requirement
-
Determines the daily intake of feed
-
Thus determines the overall intake of all
nutrients
-
Nutrients musts be balanced to the energy
intake
41
BIOENERGETICS
- Energy sources, utilization and metabolism
All animal functions and biochemical
processes require a source of energy
ENERGY TERMINOLOGY
Calorie (CAL) = energy to raise 1 g water
from 14.5 to 15.5  C
Kcal = 1000 calories
Mcal = 1000 kcal (also called a therm)
Joule (J) = 4.184 cal
BTU = 252 cal (not used in animal nutrition)
Calorie system: North American feed
industry, US research
Joule system: UK Feed industry and
research and Canadian research
publications.
42
GROSS ENERGY
Heat released from complete oxidation of a
feed can be measured in an oxygen bomb
calorimeter
Nutrient
Kcal /g
Carbohydrate mean
4.20
Protein mean
5.65
Fat mean
9.30
Ash (minerals)
0
Water
0
Glucose
3.78
Glycine
2.04
Lysine
4.84
Ethyl alcohol
7.11
Methane
13.3
Acetic acid
3.49
Propionic acid
4.96
Butyric acid
5.95
43
Gross energy is influenced mainly by water,
fat and ash content of a feed and to a lesser
extent by the type of carbohydrate, fat and
protein
44
Gross Energy of Feed (GE) (Heat of Combustion)
Fecal Energy (FE)
1. Undigested feed
2. Enteric microbes & their products
3. Excretions into the GI tract
4. Cellular debris from the GI tract
Apparent Digestible Energy (DE)
Urinary Energy (UE)
Gaseous Products of Digestion (primarily methane)
Metabolizable Energy (ME)
Heat Increment (heat of nutrient metabolism)
Heat of Fermentation (from the rumen, cecum,
large intestine)
Net Energy (NE)
Maintenance Energy
1.
Basal Metabolism
2.
Voluntary Activity
3.
Thermal Regulation
4.
Product Formation
5.
Waste Formation and
Excretion
Productive or Recovered Energy
1. Tissue Energy (muscle, fat)
2. Lactation (milk)
3. Conceptus
4. Wool, Hair
5. Work
Heat Production
45
Digestible Energy (DE)
DE = Gross Energy – Fecal Energy
DE/GE = 80% for pigs and poultry
DE/GE = 70-80% for ruminants fed
concentrates
DE/GE = 50-60 % for ruminants fed
roughages
Metabolizable Energy (ME)
Takes into account additional losses arising
from the absorption and metabolism of the
feed, such as energy loss in urine and energy
lost in gaseous products of digestion.
ME = DE – (UE + GPD)
ME is usually in the range of 82 % of DE in
ruminants and 92 % in pigs
GPD - Gaseous Products of Digestion:
Results from fermentation in the digestive
tract. The gases produced contain energy
and thus result in energy loss.
46
Methane, Hydrogen and Hydrogen Sulfide
Non-ruminants: <1 %
Ruminants 5 – 15 % (significant)
Efficiency of ME use:
 ME use for maintenance, 65 % in
ruminants
 ME use for lactation, 65 % in
ruminants
 ME use for growth and fattening,
45 % in ruminants, 70 % in nonruminants
47
Net Energy
Net energy refers to the part of the feed
that is completely useful to the animal to
maintain itself or to produce growth, milk,
eggs, etc.
NE = ME – Heat Increment
HI - Heat Increment
Increase in Heat Production Following
Eating When the Animal is in a ThermoNeutral Environment.

Work of Digestion =
5%

Heat of Fermentation =
15 %

Nutrient Metabolism =
80 %
Factors Affecting Heat Increment

Digestibility of ration high then lower
HI
48

Makeup of Ration
Forages have higher HI than
concentrates (more heat of
fermentation and C2)

Level of Feeding

How the Feed is Utilized
(In ruminants the C2:C3 ratio, with C3
more efficient metabolism)

Amino Acid Balance (40%)

Nutrient Deficiency

Frequency of Feeding
Higher frequency, lower HI

Injury or infection (30-40%)

Genetics
49
NE - MAINTENANCE
NE - PRODUCTION
BASAL METABOLISM
GROWTH
HEAT TO KEEP BODY
WARM
FAT DEPOSITION
VOLUNTARY ACTIVITY
ASSOCIATED WITH
MAINTENANCE
REPRODUCTIVE
PRODUCTS
MILK
WORK
50
Maximum Level of Energy Intake
 For growth in most species = twice
maintenance
 For work in most species = twice
maintenance
 For lactation = two to four times
maintenance
(dairy cows can take in 4x maint.)
Estimate of Feed intake kg DM/d:
 Look up in NRC tables
 Rough guide – express as % of
Body Weight (BW)
Maintenance ~1.8 - 2.0 % BW
Peak lactation ~ 3.5-3.8% BW
Growth ~ 2.8-3.0 % BW
51
Determination of Net Energy
Requirements and Feed Values

Feed values can be determined by
measuring or estimating the various
components of energy partition. The
difference between gross energy and the
components gives an estimate of NE.

Requirements can be estimated from
energy stored in products (gain or milk)
when a known amount of feed is
consumed.
Stored energy (gain) can be obtained from
slaughter trials and carcass analysis or
various estimates of carcass composition:


Specific gravity

Ultrasound

Isotope dilution techniques
Combinations of methods can be used for
both feed values and requirements.
52
Other energy systems:
Physiological Fuel Values (PFV)
(or Atwater or 4-9-4 or ME)
A form of ME where gas loss is ignored
(used in dogs, pigs and people)
Nutrient
Protein
NFE (CHO)
Fat
GE (kcal/g)
5.65
4.15
9.4
Urine
1.25
-----
Dig Factor
92
4.0
98
4.0
95
9.0
Measured as kcal/g
Example:
Bread, 100g of DM: 12.2 g CP, 2.3 g fat,
66 g of NFE
(12.2 x 4) + (2.3 x 9) + (66 x 4) = 334
kcal ME
53
For pet foods
• Modified Atwater factors for processed diets
▫ Carbohydrate: 3.5 kcal/g
▫ Protein: 3.5 kcal/g
▫ Fat: 8.5 kcal/g
54
55
56
57
Calculating Maintenance
Energy Requirement
Basal Metabolic Rate (BMR) or Basal
Energy Requirement (BER)
70 X BW kg 0.75 (ME kcal/day)
Fasting (in monogastric animals)
At rest
Thermoneutral
Brain, liver, heart and kidneys make up
about 5 % of body weight, but account for
60 % of basal oxygen consumption.
Muscle makes up about 40 % of body
weight, and accounts for 25 % of basal
O2 consumption in monogastrics.
In ruminants, Resting (fed and not
fasting) Metabolic Rate is used (RMR):
77 X BW kg 0.75 (ME kcal/day)

Voluntary activity

Body temperature regulation
58

Waste formation and excretion
Maintenance Estimate
Is BMR X 1.2 to 1.8 depending on activity
_____________________________________
Canine (dog)daily energy requirements
(ACVN)
In Kcal ME/kg BW
Resting Energy Requirement (RER)
= 70 x Wkg0.75 or 30(BW) + 70 (between 2 and 45
kg)
Maintenance (0.8 to 1.6 x RER):
 Healthy, neutered adult
 Intact adult
 Obese prone
 Weight loss
 Geriatric
1.6 x RER
1.8 x RER
1.4 x RER
1.0 x RER
1.1 x RER
Work:
 Light
2 x RER
 Moderate
3 x RER
 Maximum
4-8 x RER
59
Growth:
 Under 4 months
3 x RER
 4 months to adult
2 x RER
Lactation: 4 – 8 x RER or free choice feeding
Feline (cat) daily energy requirement
Same basis as for dogs
Resting Energy Requirement (RER)
= 70 x Wkg0.75 or 30(BW) + 70 (between 2 and 45 kg)
Average, neutered healthy adult
Intact adult
Active adult
Obese prone
Critical care
Geriatric
Lactation
Growing kittens
1.2 x RER
1.4 x RER
1.6 x RER
0.8 x RER
1.0 x RER
1.1 x RER
2-6 x RER
2.5 x RER
60
Caloric Restriction and Longevity
 Caloric restriction of 10-30% below ad
libitum extends life span and health span,
including brain and behavioural function.
First reported by McCay, 1935. J of Nutrition,
10: 63
 This has been found with many species:
dogs, rodents, fish, nematodes, spiders,
flies, protozoa, primates including humans
Many theories:
 Reduced growth rate
 Reduced body adipose tissue
 Lower metabolic rate
 Reduced plasma glucose-insulin
fluctuation??
 Less oxidative cell damage from hydroxyl
radicals, peroxides, etc. (mitochondrial
membrane)
 Protection from acute stressors or the
general protective action hypothesis
61






2007Reduced incidence of various diseases
Improved disposition to resist disease
Aging at a slower rate
Protection against neurotoxic insult and
reduced age-related neuronal loss
Increased cellular stress resistance and
adaptive cellular stress response
Cyto-protective proteins, growth factors,
antioxidant enzymes
 Exercise – caloric restriction interaction?
 Phytochemicals?
 Effect can be induced with alternating
fasting and feeding periods with normal
calorie intake, which suggests that induction
of protective mechanisms may be important
62
CARBOHYDRATES IN NUTRITION
 Carbohydrate is a translation of the French
term
“Hydrate de Carbone”
-They contain H and O in the proportion found
in water
 They are the primary product of
photosynthesis in plants
 There is no specific individual carbohydrate
requirement for animals but some
carbohydrate is needed for metabolic
functions
 Dietary carbohydrate type and amount are
related to health
63
FUNCTIONS OF CARBOHYDRATES
 Energy Source
 Structural component of other compounds
-non essential amino acids
-lipids (glycerol synthesis)
 Anti - ketogenic (prevents breakdown of fat
and generation of ketones)
 Protein sparing effect
 Bulk (fiber)
 Palatability (or influence food preference)
Sweetness
 Structure, water holding capacity in
processed foods and feeds
 Pre-biotic
64
CLASSIFICATION
 Monosaccharides ( 5 and 6 carbon)
 Disaccharides
 Trisaccharides
 Polysaccharides
Pentosans
Hexosans
Mixed Polysaccharides
CARBOHYDRATES
Large amounts in plants
Starch (70% of cereal grain)
Cellulose (up to 40% of forages)
Hemicellulose
Pectin
-
Small amounts in animals
Glycogen
Glucose
Chitin
65
HOMOPOLYSACCHARIDE: CHO contains only
ONE TYPE of saccharide unit
1.
STARCH: slides
 basic unit: alpha-D-glucose
 principal starch form in CEREALS (seed energy
storage)
 two (2) forms of starch exist: AMYLOSE and
AMYLOPECTIN
a. AMYLOSE:
 alpha 1,4 linkage only – straight chain
 15 – 30 % of total starch in most plants
 soluble in water
 molecular wt: 10,000 – 100, 000 (glucose =
180)
 exists in alpha-helical coil: retains IODINE –
blue color
 degraded by both  and β – Amylase
 high amylose grains - lower glycemic index
66
b. AMYLOPECTIN:
 alpha 1,4 linkage with alpha 1,6 linkage at
branch points
 70 – 85% of total starch
 NOT soluble in water
 Molecular wt: > 1,000,000
 Limited coil – cannot retain iodine  red
purple color
 Lots of side chains = 19 – 20 glucose unit
 Degraded by  - Amylase only
2. GLYCOGEN: animal starch
 Basic unit: alpha – D – glucose
 Exists in small amount in LIVER and MUSCLE
 Similar to AMYLOPECTIN in structure
 Except HIGHLY BRANCHED – with shorter
side chains
 Water soluble
 NO helical coil  red color with iodine
67
3. CELLULOSE:
 Basic unit: β D – glucose
 With beta 1,4 linkage in straight chain
 Highly stable and crystalline: no animal
enzyme can digest it
 Microbial CELLULASE can degrade it
 COTTON is one of the purest form
 Most abundant CHO in nature
4. INULIN:




Basic unit: FRUCTOSE
High molecular weight, soluble in water
Found in roots and stems
Used extensively in metabolic studies
68
HETEROPOLYSACCHARIDE:
CHO contain more than one (2 – 6) types of
sugars
1. HEMICELLULOSE
 NOT ½ of a CELLULOSE
 It is plant glue - sticky
 β - 1,4 linked XYLOSE (a pentose)
branched
 complex mixture of glucose, mannose,
arabinose and galactose
 principal component of plant CELL WALL
 mammalian enzymes CANNOT degrade
this, however, microbial enzymes do
2. PECTIN
 mainly POLYMERS of alpha 1,4 linked
glucose
 but also contain D-galacturonic acid.
 Thus, no animal enzyme can break it
 However, readily available to ruminant
microbes
 Found primarily in the space between
CELL WALLS
 Soluble in water
69
Non-CARBOHYDRATE
LIGNIN:
 Polymers of PHENYL PROPANE
derivatives
 Encases the cellulose and hemicellulose
 As plant matures it becomes “woody”:
lignification
 Reduces digestibility of cellulose and
hemicellulose
 NO animal or anaerobic microbial enzyme
can break it
 SOME fungi and aerobic microbes can
digest it
70
Major Components of Lignocellulosic Biomass (Department of Energy USA)
Example of composition of wood
71
DIGESTIBILITY OF CARBOHYDRATES
STARCH
All species
80-100%
Cell Walls
Are in the Neutral Detergent Fiber (NDF)
fraction: hemicellulose, cellulose and lignin
Digestibility:
Ruminants
50-90%
Horse
35-50%
Poultry
25-35%
Pig
5-30%
Dog
10-30%
Human
25-40%
72
Nutritional Classification of Starch
Non ruminant system
Based on release of glucose from an in vitro assay
using a pepsin-carbohydrase enzyme cocktail
 Rapidly available glucose (RAG)
 Rapidly available starch (RAS) 20 min test
 Slowly digestible starch (SDS) 120 min test
 Resistant starch (may have similar effects as fibre)
Physically inaccessible (whole grain)
Resistant granules
Retrograde starch (Amylose), B type granules
Glycemic Index: Rise in blood glucose after a test
food is consumed
High
White Bread 100
Glucose 140
Instant Rice 124
French Fries 107
Sucrose 83
Low
Skim Milk 46
Oatmeal 87
Pasta 40-70
Apple 34-76
73
DIGESTION IN RUMINANTS
Reticulum:
 Receives feed from esophagus
 Pass feed to rumen and omasum
 Reticular groove reflex (suckling reflex) to
shunt liquids directly to abomasum (calf)
 Eructation and rumination
Rumen:
 Bulk of fermentation: bacteria, protozoa, fungi
 Digestion via microbial enzymes
 Some mineral absorption
 Volatile fatty acid absorption (extensive)
VFA’s are major end products of fermentation
and provide a major source of energy to
ruminants
Omasum:
 Regulates flow to lower gut: filter
 Water absorption
 Some mineral absorption (Mg)
74
Abomasum:
 Analogous to gastric stomach in nonruminants
 Digestive secretions (host)
Digestion of Carbohydrates by Ruminants
A. Ruminant’s saliva is different from the nonruminants.
 Saliva in the COW, SHEEP, and GOAT
does not contain AMYLASE
 Output of saliva in ruminants is very high. It
contains a lot of buffers Without it, rumen
pH would drop markedly
B. In the rumen conditions are ideal for
bacterial and protozoal growth:
 Fairly constant pH (pH 6)
 Anaerobic conditions
 Constant temperature
 Constant supply of nutrients
 Continuous removal of products of
microbial digestion
75
C. Microbial enzymes break glycosidic bonds of
fiber and starch
 Bacterial cellulase and hemicellulase are
capable of breaking the beta 1,4 bonds
between CHO of cellulose and
hemicelluloses
 Bacterial amylases also break starch into
maltose. Protozoa engulf starch and digest
starch inside their bodies.
D. Glucose is present in the rumen only
transiently
 Glucose is promptly used by microbes and
through their glycolytic pathway converted
into pyruvate.
 Pyruvate is further converted into endproducts called volatile fatty acids. These
include ACETIC, PROPIONIC, BUTYRIC
and other longer chain FATTY ACIDS.
 This process is called FERMENTATION.
 The VFAs are released from the microbes
(as end-products) and are then available for
absorption and utilization by various tissues.
76
RUMINANT DIGESTIVE PROCESSES:
1. Feed enters the foregut and it may
either be fermented by microbes or
bypass the foregut altogether
2. Hence, digesta entering the abomasum
included undigested feed and microbial
cell mass
3. The proportions of these two
components are extremely variable.
Highly soluble feeds are extensively
digested by microbes. Less soluble
feed constituents largely bypass
microbial degradation
4. Heat treated feed or feed treated with
formaldehyde or coated with oil, so that
high quality feed can escape the
microbes in the rumen and thus can be
break down in the abomasum and SI.
5. Ruminants absorb very little glucose
77
RUMEN FERMENTATION VS CECUM
FERMENTATION:
What is the difference??
 Major absorption site is at SMALL
INTESTINE
 Rumen is located before, and cecum is
located after the small intestine
FACTORS DETERMINING AMOUNTS &
PROPORTIONS OF RUMEN VFA
1. Level of feed intake
2. Frequency of feeding
3. Proportions of starch and fibre
4.
Size of forage particles  small particle
size (finely ground) increases C3
5. Presence of rumen modifiers in the diet
(lonophores)  increased C3
78
Alteration of ROUGHAGE : CONCENTRATE
RATIO:
o Increased roughage intake results in
 high acetic acid level
 high milk fat
 high methane production
 higher rumen pH (lower acidity; 6.1 – 6)
o
Increased concentrate intake results in:
 High propionic acid level
 High body fat
 Lower rumen pH (higher acidity; 5.5 –
5.8)
Alteration of the PHYSICAL FORM of the
diet:
o Grinding and pelleting generally increase
reactions which produce more Propionic
acid (more rapid fermentation) and lower
pH
79
Classification of Carbohydrate
Fractions in Feed for Cattle
Cornell - Penn State System
Fraction CHO type
Rate of rumen
utilization, % /h
A
Soluble sugars
150-350
B1
Starch, pectin,
beta-glucans
10-50
B2
Fermentable cell
wall (NDF)
2-10
C
Unavailable cell
wall
0
80
CLASSIFICATION OF THE LIPIDS
Simple lipids
Fatty acids:
C2 to C24, saturated and unsaturated
Monoglycerides:
monoacylglycerol
Diglycerides:
diacylglcerol
Triglycerides:
triacylglycerol
Cholesterol:
cholesterol esters
Bile acids:
cholic acid, taurocholic acid, glycocholic acid, etc.
Vitamin A:
vitamin A esters
Waxes:
esters of alcohols other than glycerol
Prostaglandins:
hormones, essential fatty acids
Compound lipids: derivatives of phospatidic acid
Phosphatidylcholine (lecithin)
Phosphatidylethanolamine
Phosphatidylserine
Phosphatidylinositol
Sphingolipids
Other Lipids
Glycolipids, Liproproteins,
Androgens, Estrogens
Chylomicrons, HDLs, LDLs, VLDLs
81
CLASSIFICATION OF LIPIDS
Lipid = All Ether Extractable material
1. SIMPLE LIPIDS
-Esters of FA and Alcohols (mainly Glycerol)

FATS
OILS
(SOLID AT
(LIQUID AT
ROOM TEMP)
ROOM TEMP)
ESTERS OF FA AND OTHER ALCOHOLS: WAXES
2. COMPOUND LIPIDS
- Esters of FA and Glycerol containing 2 FA residues and another
chemical grouping (eg. Choline linked through phosphoric ACID:
Lecithin)
3. DERIVED LIPIDS
-Substances derived by hydrolysis
EG. FA
ALCOHOLS (EG. GLYCEROL)
STEROLS AND CHOLESTEROL
82
THE ROLE OF LIPIDS IN NUTRITION
 Source of dietary energy
2.25 x carbohydrate
 Low heat increment - Minimize heat stress
 Source of essential fatty acids
Linoleic C18:2 and Linolenic C18:3
Source of omega-3 fatty acids
 Carrier of fat soluble vitamins
A, D, E, K
 Cell structure and metabolic role
 Feed/Food flavor (palatability)
 Dust control, food/feed consistency,
Physical characteristics
 Minimizes wear on feed handling
equipment
83
LIPID CONTENT OF COMMON FEEDSTUFFS
Feed
Lipid
% of DM
Linoleic
% of Lipid
Alfalfa hay
Barley silage
Brome grass hay
2.7
3.0
2.2
16
-------
Barley grain
Corn grain
Oat grain
Wheat grain
Wheat bran
1.9
3.8
4.5
1.6
6.0
42
56
33
40
55
Canola seed
40
65
Canola meal
3.5
------
Soybeans
18
45
Soybean meal
1.0
40
Meat meal
9.0
2
Fish meal
9.0
2
Milk, whole
30
3
Lard
98
11
84
FUNCTIONS OF BODY FAT
1. Energy Reserve
2. Insulation
3. Protection and Cushioning
4. Cell Membranes
5. Steroid Hormones
6. Bile Acids
85
Essential Fatty Acids (EFA)
 Animals and people cannot synthesize
EFAs, so these must be provided in the diet
 EFAs are precursors for C20 compounds
(eicosanoids) prostaglandins,
thromboxane’s and leukotrienes 
intracellular messengers only (not
transported in blood)
 Most common mono-unsaturated FA in
animals are: oleic (18:1c∆9) and palmitoleic
(16:1c∆9). (∆ delta, counted from COOH)
 In animals and humans microsomes contain
four Fatty Acid Desaturase enzymes, which
can introduce desaturation at (Carbon) C4,
C5, C6 or C9 (only up to C9).
 Linoleic acid 18:2c∆9,12 or linolenic acid
18:3c∆9,12,15 cannot be synthesized as
they require desaturation beyond C9. These
must be provided in diet: Thus are Essential
Fatty Acids
86
Omega 6 (n-6) (means the first double
bond is 6C from the terminal CH3):
Linoleic acid (C18:2)
Gamma Linolenic acid (C18:3) = GLA
Arachidonic acid (C20:4)
Omega 3 (n-3) (means the first double
bond is 3C from the terminal CH3):
Alpha Linolenic acid (C18:3) Plants ALA
Eicosapentaenoic acid (C20:5) EPA Fish
Docosahexanoic acid (C22:6) DHA Fish
EPA and DHA melting point = -54°C!
Omega-6
Omega-3
Gamma-linolenic (GLA) Alpha-linolenic ALA
↓
↓
↓
↓
Arachidonic acid
↓
PGE2
EPA
↓
DHA
↓
PGE3
Anti-inflammatory
Inflammatory
87
EFA: Need as 1% of calories
WHO/FAO: n-6 : n-3 PUFA ratio from 4:1 to 10:1
Deficiency omega-6:
Reduced growth, reproduction
Skin lesions, dermatitis, impaired wound healing
Edema, subcutaneous hemorrhage
Reduced Inflammatory response
Mechanisms of action for omega 3 FAs:
 Anti-arrhythmic
 Anti-thrombotic
 Anti-atherosclerotic
 Anti-inflammatory
 Improved endothelial function (vasomotor
function/dilation)
 Lowers blood pressure
 Lowers triglyceride level
Aspirin:
• "non-steroidal anti-inflammatory drugs" (NSAIDs)
(aspirin, ibuprofen, acetaminophen)
• inhibit the synthesis of prostaglandins from
arachidonic acid
88
Some important fatty acids of refined vegetable oils in
Canada (w/w %)
Fatty
Acid
16:0
18:0
18:1
18:2
18:3
20:1
22:1
Flax Canola Soybean Corn Peanut
6
3
17
16
56*
4
2
55
26
10*
2
Tr
9
5
45
37
3*
Tr
Tr
11
2
27
59
1
Tr
Tr
11
3
46
29
1
Tr
Tr
Sun- Olive Palm
flower
7
14
42
5
2
4
19
64
38
66
16
9
Tr
Tr
Tr
Tr
* α-linolenic acid (omega 3) Fish oil, flax, canola/rapeseed,
walnuts, soy sources of α-linolenic acid
89
Canola oil positive factors:
High in C18:1 and LA (omega 6) : ALA
(omega 3) = 2 : 1
Health Canada
Diet Target ω 6 : ω 3 = from 4:1 to 10:1
US: 2.5 : 1 as ideal; 250 mg/d (2011)
Common: 20:1
90
Essential fatty acids for cats and dogs
Essential
fatty acid
(g)
LA
ALA
AA
EPA +
DHA
Essential
fatty acid
(g)
LA
ALA
AA
EPA +
DHA
Growing
puppies
allowance
(per kg
BW0.75)
0.8
0.05
0.022
0.036
Adult dogs
recommended
allowance (per kg
BW0.75)
Bitches late
gestation and peak
lactation allowance
(per kg BW0.75)
0.36
0.014
1.6
0.10
0.03
0.06
Kittens
allowance
(per kg
BW0.75)
0.29
0.01
0.01
0.05
Adult cats
allowance (per kg
BW0.75)
Queens late
gestation and peak
lactation allowance
(per kg BW0.75)
0.3
0.011
0.011
0.0044
0.14
0.0015
0.0025
Source: Nutrient Requirements of Dogs and Cats. 2006. National Research Council (U.S.)
91
92
Fatty acids are not a source of energy to
microbes.
There is minimal degradation of long-chain fatty
acids in the rumen.
No absorption of long chain fatty acids from the
rumen
Active hydrogenation of unsaturated fatty acids
Microbial synthesis of long-chain fatty acids in
the rumen (15g/kg nonfat org matter fermented)
More fat leaves the rumen than consumed by the
animal
Lipids leaving the rumen:
 80 to 90% free fatty acids attached to feed
particles and microbes
 ~10% microbial phospholipids leave the
rumen
 Small quantity of undigested fats in feed
residue
93
Diagram of the molecular structure of different fatty acids
Saturated fat
saturated carbon atoms (each with 2
hydrogens) joined by a single bond
Cis-unsaturated fatty acid
Trans-unsaturated fatty acid
unsaturated carbon atoms (each with unsaturated carbon atoms (each with
1 hydrogen) joined by a double
1 hydrogen) joined by a double
bond. Cis configuration.
bond. Trans configuration.
Oleic acid (C18:1 cis 9)
Elaidic acid (C18:1 trans 9)
Oleic acid is a cis unsaturated fatty acid that comprises Elaidic acid is a trans unsaturated fatty acid often found
55-80% of olive oil.
in hydrogenated vegetable oils.
These fatty acids are geometric isomers (chemically identical except for the arrangement of the double bond).
Trans fat not usually present in food unless use of
hydrogenation process of PUFA oils  high trans fat
content. Small amounts of trans fats found in ruminant
produced food (rumen microbial hydrogenation)
94
Conjugated Linoleic Acid (CLA)
Present in ruminant fat, and produced in rumen
fermentation by microbial saturation of UFA
Linoleic acid (cis-9, cis-12 C18:2) hydrogenated to
several trans forms including CLA (cis-9, trans-11
C18:2)
POSITIVE HEALTH EFFECTS OF CLA
o Anti-carcinogenic
o Anti-atherogenic
o Anti-obesity (nutrient partitioning)
o Enhanced immune system
o Prevents or delays diabetes
Milk fat contains 3.5 to 7 mg CLA/g fat
95
CLA content in some foods
Food
CLA isomers
mg/g fat
Beef
4.3
Pork
0.6
Chicken
0.9
Milk
5.5
Colby cheese 6.1
Corn oil
0.2
cis 9, trans 11
%
85
82
84
92
92
39
Increasing CLA isomers in foods produced
by ruminants:
 Grass pasturing
 Feeding unsaturated vegetable oils: fish oil, flax
oil, canola oil.
 Can increase CLA content from typical 3-4 mg
CLA/g fatty acids to 5-25 mg in milk.
96
 Feeding unsaturated oils with high concentrate
diet (low rumen pH)  trans-10, cis 12 CLA
isomer  inhibits milk fat synthesis  low milk
fat
Effects of Fats on Rumen Fermentation
Upper limit is around 7-8% fat in diet. Typical is
about 3% fat in diet ingredients and then one can
add up to 3% from a fat source.
Lipid-coated feed particles: interferes with
attachment of microbes and enzymes to feed
Cytotoxic to rumen microbes (cell membranes):
 FA associate with cell membranes masking
cell membrane receptors and enzyme
secretion
 Become incorporated in cell membranes and
changing fluidity (electrolyte transport)
97
 PUFA may change redox conditions in cells,
oxidation stress
-
PUFA oils are more inhibitory than saturated
fats
-
Feeding whole oil seeds with high PUFA
content  less inhibitory
Consequences:
 Reduced feed intake
 Reduced fiber digestion!
 Reduced milk fat
 Increase propionate/acetate ratio
Fatty acids can be used to defaunate the rumen
(protozoa very sensitive)
98
OXIDATIVE RANCIDITY
 Auto-catalytic reaction in unsaturated fatty
acids with generation of oxygen radicals
and potentially leading to spontaneous
combustion
 Accelerated by pro-oxidants
o - Heat
o - U.V. Light
o - Moisture
o –Transition Metals eg Cu,Fe, Mn
 Anti-oxidants
o -Vitamin E
o -Ethoxyquin
o -Butyl Hydroxy Anisole (BHA)
99
Cholesterol:
Many important steroids are derived from
cholesterol in animals, including:
 HORMONES including androgens,
estrogens, progestins, glucocorticoids,
and mineralocorticoids
 BILE ACIDS which are detergent
molecules secreted in bile from the
gallbladder that assist in the
absorption of dietary lipids in the
intestine
Animal products are a source of
cholesterol- important in human
nutrition
Normally not considered in animal
nutrition as the diets are mostly made
up of plant ingredients
100
WATER
Sources (3):
 Drinking water
 Water in feed
 Metabolic water
Functions of water:
 Solvent, GIT
extra- and intra-cellular and for excreta
 Chemical reactions – Synthesis of urea,
protein hydrolysis
 Lubricant and solvent for lubricants
 Temperature regulation
 Physical protection, cushions organs and
nerve tissue
Average daily water requirements
Class of livestock
Dairy cow
Beef cow
Beef steer
Feeder pig
Ewe
Laying hen
L/day
160
55
35
7-10
2-7
0.25
101
Water content of feeds:
Corn
Barley
Oats
Hay
Silage
Beets
Potatoes
% water
12
11
9
10 (8-15)
70 (45-75)
87
75
Metabolic water formed from:
Carbohydrate
60%
Protein
40%
Fat
100% (1 g water per 1 g fat)
Factors affecting water requirement:






DM intake. Water intake is 3x DM intake
Composition of feed. Increased by salts and
minerals
Physiological state: lactation, pregnancy
Ambient temperature and relative humidity
(RH)
Temperature of drinking water
Frequency of watering. Most species require
at least 3/day or DM intake is reduced
102
Water quality
Good water:
 Clear and colorless
 Low total solids
 No disease organisms, pesticides
 No undesirable flavour or odor
 No objectionable gases
Quality considerations TDS = Total
dissolved solids, mg/L
Hardness:
Soft water = <60 mg/L Ca + Mg
Very hard = >800 mg/L Ca + Mg
Maximum for livestock = 1000 mg/L
Salinity: (salts, mainly NaCl) estimated
from conductivity (EC) and may be
expressed as TDS mg/L
103
TDS
<1000
EC
<1.5 Excellent for all types of livestock
1000 3000
1.5- Satisfactory for all livestock but
5
may slightly reduce productivity,
mild diarrhea, especially poultry
3000 - 5-8 Acceptable except poultry. Will
5000
cause temporary diarrhea and
may be refused at first
5000 - 8Usually safe for beef cattle,
7000
11 sheep, swine and horses
7000 – 11- Not suitable for young, pregnant
10,000 16 or lactating animals
>10,000 >16 Not recommended under any
conditions
104
Livestock water quality guidelines
Parameter
Calcium
Nitrate + nitrite
Nitrite alone
Sulfate
TDS
mg/L (maxima) = PPM
1000
100
10
1000
3000 (2000 for aquatics)
Aluminum
Cadmium
Copper
5
.02
1 (cattle)
0.5
(sheep)
5 (swine and poultry)
2
.1
.003
.5
.05
50
Fluoride
Lead
Mercury
Molybdenum
Selenium
Zinc
105
Common water quality problems
Sulfate >1000 mg/L
Source:
Calcium sulfate rock (gypsum)
Effects: Reduces availability of Ca, Zn, Fe, Mn,
Mo, Cu
Action: Improve water quality and/or provide
additional trace minerals, especially Cu
Nitrite > 10 mg/L
OR nitrate + nitrite >100
mg/L
Source: Fertilizer or animal waste
Effect: Formation of methemoglobin (brown
blood), reduced vitamin A utilization and
absorption
Action: Prevent contamination
Iron > 2 mg/L
Not a nutritional problem. Causes scale formation
in pipes; may form slimy bacterial films, poor taste.
Can chlorinate and filter to remove iron
Fecal contamination:
Coliform count should not exceed 10 CFU/ml.
Cryptosporidium, enterotoxigenic E. Coli,
Salmonella, Leptospira, protozoa, round worms
106
Biochemical Oxygen Demand (BOD):
Organic content of water - Chemical measure for
estimating the amount of dissolved oxygen
needed by aerobic biological organisms in a body
of water to break down organic material present in
a given water sample at a certain temperature
over a specific time period.
BOD of 3-5 mg O2/L water is maximum for aquatic
life. Poor taste at 1-3 mg O2/L water
Blue-Green Algae (cyanobacteria):
Unpalatable and may contain toxins
Suggested water treatments:
Problem
Solution
Coliform count
Chlorinate water
Water hardness
Install softener
High nitrates or other
Ion exchange or RO
minerals
system
Iron
Filtration
High water pH
Acidification
High turbidity
Coagulation
107
Vulnerability of water supplies
1. Surface water
2. Cisterns
3. Natural springs
4. Shallow hand-dug or sandpoint wells (<50 ft)
5. Artesian wells
6. Drilled wells
7. Public water supplies
Small Animals
Water requirement for dogs and cats is
linked to energy consumption
(water : calorie ratio).
Water (ml per day) : ME (kcal per day) =
1:1
Dog example: 10 kg adult dog
 Maintenance requirement is
132 x BW0.75 = 742 kcal ME
 Water : energy ratio is 1:1
 Water requirement = 742 ml
108
 Of that 742 ml about 74-119 ml is
generated from metabolic water.
 Required water intake from water
and feed then is ca. 642 ml per
day.
Cats:
Same ratio, but it is recommended to
double the volume to allow for lifestage,
environment, work activities.
For both cats and dogs the
recommendation is to allow animals to
self regulate as opposed to working with
required intake of water.
109
Protein Nutrition
1. Introduction, general, classes of proteins,
amino acids
2. Non-ruminant protein nutrition
a. Quality:
i. Protein digestibility: ileal vs. fecal
Amino acid digestibility: ileal vs. fecal
Amino acid balance, biological value
Assay for protein quality
b. Requirement:
i. Maintenance
ii. Production
3. Ruminant protein nutrition
a. Versus non-ruminant
b. Microbial fermentation:
microbial protein synthesis
from non-protein nitrogen (NPN)
energy interaction
quality of microbial protein
c. Feed protein:
Solubility of N
Degradable protein
Bypass protein
110
Protein:
1.Primary function:
Source of amino acids for body protein or
source of Nitrogen for ruminants
2.Secondary function:
Source of energy during:
- consumption of excess protein
- consumption of poor quality protein
Lower efficiency of energy utilization (only
70-75 % vs carbohydrate 95%) due to
energy cost required for clearance of NH2
Urea cycle and uric acid production require
energy
Protein nutrition is complex:
 chemistry (23 amino acids)
 more metabolic pathways
 essential vs. non-essential amino acids
 different digestion coefficients between
amino acids
111
 relative proportions of amino acids in feed
matter
 optimal relative proportions of amino acids
change with physiological state (growth,
lactation, pregnancy, disease)
 very limited storage of amino acids
Protein turn-over g / day:
Protein intake represents only 1/3 of total
protein synthesis
Human:
intake
gut secretion
fecal loss
absorbed
100 g/d
70 g/d
170 g/d
10 g/d
160 g/d
Protein turn-over:
Protein synthesis / day
Protein intake / day
Amino acids re-used daily
300 g
100 g
200 g
112
Protein:
 highest concentration in muscle (apart
from water)
 important in tissue growth
 animals have limited ability to synthesize
protein: from amino acids only, and not
from NH2
 of all nutrients protein deficiency or
imbalance between amino acids has the
most pronounced negative effect on
carcass quality
Conclusion: Protein is an essential
component in the diet.
113
Forms of proteins:
1. Fibrous: collagen, elastins, keratins
2. Globular: albumins, globulins, glutelins,
histones, prolamines, protamines
3. Conjugated: nucleoproteins,
mucoproteins, glycoproteins, lipoproteins,
hemoproteins, metalloproteins
4. Derived: poorly defined, product of
degradation
Amino acids:
 Primarily used in the L- form, with a few
exceptions
 Some OH analogs may substitute such as
methionine hydroxy analog. Done for
economic reasons.
114
Use of D and L amino acids by nonruminants:
Amino acid
MET (hionine)
PHE (nylalanine)
PRO (line)
LEU (cine)
VAL (ine)
TRY (ptophan)
ISO (leucine)
HIS (tidine)
LYS (ine)
THRE (eonine)
ARG (inine)
D form relative to L
=
=
=
< slightly
½
limited
limited
limited
0 (negative effect)
0
0
115
Classification of amino acids:
Essential (EAA; 10) Non-essential
Arg (inine)
Ala (nine)
His (tidine)
Asp (artic acid)**
Iso (leucine)
Cys (teine)
Leu (cine)
Gly (cine)**
Lys (ine)*
Ser (ine)
Met (hionine)*
Tyr (osine)
Phe (nylalanine)
Pro (line)**
Thre (onine)*
Glu (tamic acid)**
Try (ptophan)
Val (ine)
* Not present in adequate quantity in grains
** Essential in some cases or may have nonnutritional effect (functional food)
Cats (carnivore): Taurine is an EAA
(present in meat)
Specific amino acid relationships:
Methionine: Requirement only met by Met
Cysteine: Requirement met by Cys or Met
116
Phenylalanine: only met by Phe
Tyrosine:
met by Tyr or Phe
Gly and Ser:
interchanged
Protein analysis:
Normally Crude Protein (CP)
 Uses the Kjeldahl procedure and is a
measure of total N in sample.
o Non-protein nitrogen (NPN) is also
converted to N and measured as N
 Use Kjeldahl factor to determine protein
based on N being constant in feeds at 16
% of total protein (100/16 = 6.25)
 The factor can differ between some foods
(milk = 6.38; feed = 6.25)
Amino acid analyses is used mainly in
research and by feed companies for quality
control. Expensive and not used in routine
ration formulation.
117
Monogastric protein nutrition
Protein quality measurements:
Digestibility:
Apparent:
True:
P intake - P output
P intake
P intake - (P output - MFP)
P intake
MFP = Metabolic Fecal Protein = MFN x 6.25
MFN = Metabolic Fecal Nitrogen
MFN is determined by:
1. Feeding a protein free diet and measure
N in feces.
2. Feed different levels of protein in diets,
measure N in feces, and extrapolate N
back to a 0% protein diet.
Does not work in poultry because urine
contaminates the feces
118
Digestibility of protein is affected by a wide
range of factors:
1. Heat damage of protein (enzymatic
browning or Maillard reaction: formation
of aminosugar complexes (Lys)).
2. Level of feed intake.
3. In forages age of plant at harvest (%
fiber).
4. Anti-nutritive factors:
- Trypsin inhibitor in raw soybean
- Gossypol interferes with Lys
- Lectins interfere with amylase
- Tannins are complexing agents
Which method of measuring digestibility is
more reliable to estimate true nutrient
absorption?
Use composition of the feces or of the
digesta at the ileal-caecal junction (Ileal vs.
fecal method)?
Consider interference by fermentation and
metabolism in the caecum and large intestine:
NH3 is generated, absorbed into the blood
stream and excreted in urine
119
Remember that digestibility measures
disappearance of N or protein (N x 6.25) from
the G.I. Tract and not absorption)
Example:
Sorghum protein for pigs
Apparent digestibility %
True digestibility %
Ileal
60.4
69.0
Fecal
71.1
78.4
Does CP digestibility reflect digestibility of all
amino acids in the crude protein?
No
Use ileal or fecal method for estimating
digestibility of amino acids? Ileal method.
True digestibility AA (%)
Ileal
Lysine
73.4
Methionine
77.6
Phenylalanine 71.5
Valine
72.6
Fecal
77.8
76.5
81.1
80.2
120
Example of fecal vs. ileal measurement
Comparison of ileal and fecal digestibilities of
raw and heated soybean meal (SBM) (heat
treatment inactivates the trypsin inhibitor in
soybeans)
Lys
Met
Cys
Thr
Tryp
Raw
Fecal
Ileal
71.9
44.2
61.0
46.7
77.7
35.2
65.2
32.2
75.4
24.8
Heated
Fecal
Ileal
87.3
84.9
82.5
83.0
87.0
74.1
83.0
71.5
86.8
72.3
Are amino acid digestibilities constant for
each feed or do they change with different
feeds used in a feed formulation (matrix effect
of ingredients)?
Not constant due to matrix effects.
121
122
Protein quality - Amino acid balance in
feed
= concentration of amino acids in feed in
relation to physiological needs: growth,
lactation, pregnancy, eggs, wool
Close match  high quality protein
Poor match low quality protein
Identify limiting amino acid(s) in poor quality
protein. 1st, 2nd, 3rd
Poor amino balance growth response to the
addition of limiting AA.
Ie. Zein (corn protein) - poor quality
- growth –ve
123
Growth in rats fed zein, or zein supplemented
with tryptophan or with tryptophan and lysine
Osborne and Mendel 1914
Lys 1st limiting; tryp 2nd limiting
1. Aim at ideal balance.
2. Fast growth ---- lean tissue amino acid
composition is the requirement.
3. Ideal protein concept
124
125
Measuring protein quality
1. Ideal protein = ideal AA pattern concept
Liebig’s “Law of Minimums"
Undersupply of one single essential amino acid will
inhibit the use of those in adequate supply
126
Ideal protein:
Established ideal pattern (balance) of digestible
essential amino acids for lean meat deposition
(protein accretion), when supplied with sufficient
nitrogen for the synthesis of non-essential amino
acids.
No excess, no deficiency and as little conversion
of amino acids for energy is desirable. N excretion
is minimized.
The assumption is that the pattern of amino acids
required does not change relative to the amount
of lean tissue deposition, but the absolute amount
of amino acids or ideal protein required does.
The level of individual amino acid required is
expressed on a ratio basis to lysine, which serves
as the reference amino acid.




Lysine is 1st or 2nd limiting amino acid.
Simple chemical analysis in feeds.
Lysine is used primarily for protein accretion.
A lot of information on lysine requirements is
available.
 Synthetic lysine is cheap
127
Ideal Protein:
 Is a perfect balance of amino acids that
will cover the requirement of the animals
 Lysine is always set at 100% - all other
amino acids are set as a % of lysine
 Allows for the calculation of the
requirement of all amino acids if the lysine
requirement is known
2. Biological assays
Protein Efficiency Ratio PER (dates back to
1919):
 Feed efficiency measured on a protein
level basis
 10% CP in ration, 28d period
 Reference protein is casein
 Measure g gain/g protein consumed
 Rats or chicks
128
Quality is measured in terms of growth only,
not lactation or pregancy. More applicable to
children. Used in human nutrition and is a
simple and cheap testing method.
The test is highly standardized by WHO.
Standard reference casein available for PER
tests.
129
Nitrogen Balance
True Biological Value:
NI – (FN - MFN) – (UN - EUN)
NI – (FN – MFN)
x 100
Measures N retained as a % of N absorbed
Classic test
Biological value of proteins for growing and
adult rats
Protein
Egg albumin
Beef muscle
Meat meal
Casein
Peanut meal
Wheat gluten
Growing
97
76
72-79
69
54
40
Adult
94
69
51
46
65
Many other tests including:
Available lysine (color reaction) to test for
Maillard reaction products
In vitro protein digestion
130
Feed Protein for Ruminants:
Quantity:
The quantity of protein to be fed depends on
the protein requirement of the ruminant and
on the quality of the protein in the feed.
Quality of Protein for Ruminants:
Digestibility: Traditional method which has
limitations as discussed. Digestibility of
protein in forages is lower than that of grains
and protein supplements.
Forage protein digestibility depends on:
- Forage species
- Forage maturity
- Weathering
- Heating (Maillard reaction)
131
Modern protein classification based on:
1. Solubility in rumen:
Totally and fast degraded to NH3
True protein and NPN
Determined in buffer
2. Undigestible N (bound protein):
ADF-bound; perform N assay on ADF
3. Degradability in rumen:
Protein to varying degree is broken down to NH3.
The rate of breakdown depends on physical
characteristics of the protein, and on physical
conditions in the rumen (dilution rate).
Measured by protein disappearance from porous
nylon bags hung in the rumen of fistulated
ruminants.
4. Bypass protein (escape/undegradable):
The protein is not broken down in the rumen and
arrives in the abomasum intact. Measured by
nylon bag technique. Useful to target limiting
amino acids to the S.I., and also to increase total
protein available to high producing ruminants.
132
3.
RUMINANT PROTEIN NUTRITION Three objectives
1. OPTIMIZE MICROBIAL PROTEIN OUTPUT
2. OPTIMIZE BYPASS PROTEIN / FEED PROTEIN TO
MEET NEEDS OF THE ANIMAL
3. MINIMIZE LOSS OF NH3 (COST AND ENVIRONMENT)
3.1 MICROBIAL PROTEIN:
3.1.1
QUALITY

REL UNAFFECTED BY DIET

BV = 80% (BACTERIA + PROTOZOA)

TRUE DIGESTIBILITY:
PROTOZOA 88%
BACTERIA
66%

 PROTOZOA ON  ROUGHAGE DIET

20% NUCLEIC ACIDS

INFERIOR TO HIGH QUALITY ANIMAL PROTEIN

SUPERIOR TO GRAIN PROTEIN

EQUAL TO SOYBEAN MEAL OR CANOLA MEAL
OR ALFALFA
NB
SOYBEAN MEAL = SBM
CANOLA MEAL = CM
RAPESEED MEAL = RSM
133
3.1.2 QUANTITY OF PROTEIN SYNTHESIS IN
RUMEN by microbes
1. INHERENT METABOLIC LIMITATIONS IN
BACTERIA AND PROTOZOA
2. PHYSICAL LIMITATIONS: SIZE OR
CAPACITY OF RUMEN; FLOW OF DIGESTA
3. ENERGY SUPPLY FOR PROTEIN
SYNTHESIS; OTHER NUTRIENTS
134
135
136
FACTORS AFFECTING THE AMOUNT OF MICROBIAL
PROTEIN SYNTHESIS
1. RUMEN NH3 CONCENTRATION
MAX RATE and EFFICIENCY OF
MICROBIAL PROTEIN SYNTHESIS IS
AT 5 MG NH3 /100 ml RUMEN FLUID
> 5 MG / 100 ML  NH3 TO BLOOD LIVER
 UREA LOSS
< 5 MG / 100 ML  N LACK
2. RUMEN pH
pH high  NH3
 DIFFUSION
pH low  NH4 +
 SLOW DIFFUSION
137
138
3. DIETARY ENERGY LEVEL (need energy to
drive microbial growth)
% TDN
MICROBIAL PROTEIN
Produced g/KG DM
> 75%
51.2
65-75%
38.4
< 65%
26.0
UPPER LIMIT OF NON PROTEIN NITROGEN UTILIZATION
WHEN SUPPLEMENTING UREA (FERMENTATION
POTENTIAL)
% PROTEIN
IN RATION
% TDN (DM)
BEFORE NPN IS ADDED
60-65
65-70
70-75
75-80
MAX CP AT WHICH NPN IS USED
8%
10
10.5
10.9
11.2
10 %
10.8
11.3
11.7
12.0
139
This example suggests that 3.2 % crude
protein can be added in the form of urea when
the starting CP is 8% and at 75-80 % TDN. If
more is added, the NH3 from urea will be lost in
urine as it cannot be used by microbes
UREA FEEDING RULES:
 Urea contains 45% N, thus 1% urea
contains 45/100 X 1 X 6.25 = 2.81 %
crude protein.
 LIMIT 1% OF GRAIN MIX; 0.5% TOTAL
DIET
 UREA IS NOT PALATABLE, MIX IN
FEED MIX WITH MOLASSES
140
4. RATE OF FERMENTATION OF
CARBOHYDRATE
SYNCHRONIZE PATTERNS OF NH3 AND
ENERGY SUPPLY
 MOLASSES: TOO FAST
 STRAW: TOO SLOW
 CEREAL STARCH ACCEPTABLE
141

CEREAL STARCH: IS ACCEPTABLE
142
5. OTHER NUTRIENTS?
SULPHUR
S : N = 1 : (10 - 12)
FOR DE NOVO SYNTHESIS OF S AA.
6. RUMEN DILUTION RATE
 RATE OF FLOW OF DIGESTA OUT OF
RUMEN % / HOUR
SLOW RESIDENCE TIME OF BACTERIA IN
RUMEN  MAINTENANCE ENERGY 
 ENERGY FOR GROWTH
143
BACTERIA MASS / ATP
MAX (THEORETICAL)
20
EFFICIENCY
OF BACTERIA
GROWTH
MAINTENANCE
15
YIELD
10
5
0
2
4
6
10
8
DILUTION RATE (% / h)
 DIL. RATE   MAINTENANCE EXPENSE
ENERGY FOR BACTERIA  GROWTH OF
BACTERIA   BACTERIAL PROTEIN AVAILABLE
TO HOST
144
Review again
Modern protein classification for ruminants is based on:
1. Solubility in rumen:
Totally and fast degraded to NH3
True protein and NPN
Determined in buffer in lab
2. Undigestible N (bound protein):
ADF-bound; perform N assay on ADF
3. Degradability in rumen:
Protein to varying degree is broken down to NH3. The rate of
breakdown depends on physical characteristics of the protein,
and on physical conditions in the rumen (dilution rate).
Measured by protein disappearance from porous nylon bags
hung in the rumen of fistulated ruminants.
4. Bypass protein (escape/undegradable):
The protein is not broken down in the rumen and arrives in
the abomasum intact. Measured by nylon bag technique.
Useful to target limiting amino acids to the S.I., and also to
increase total protein available to high producing ruminants.
145
Application example – Cornell System
Protein fractions in feed:
A
NPN that is soluble and available in the
rumen
B1
buffer soluble protein which is
precipitated by tungstic acid. This
fraction is made up of soluble and
degradable true protein which is
degraded in the rumen at a rate of 100350% per hour.
B2
This is the buffer insoluble protein that
is in the cell contents rather than in the
cell wall. It is degraded at an
intermediate rate of 5 to 15% per hour.
B3
This is slowly degradable cell wall
protein that may be increased in heat
146
processed feeds. The rate of
degradation of this fraction is less than
1% per hour.
C
This is cell wall protein and N which is
not fermented by rumen bacteria and is
not available post-ruminally. It consist
of N mainly associated with lignin,
tannins and Maillard reaction products.
147
148
Factors affecting protein degradability
 Solubility in the rumen
 Retention time in the rumen
 Tertiary structure on the protein
 Feed processing and storage (heat
damage etc.)
Treatments to increase escape potential
 Heat treatment of the feed
 Formaldehyde treatment
 Tannin treatment
 Encapsulation in a rumen inert
polymer
149
PROTEIN REQUIREMENT
 GRAMS OF CP / DAY = CRUDE
 SHOULD BE IN GRAMS OF DIGESTABLE AA /
DAY = LACK DATA!
A LARGE TURNOVER OF PROTEIN / DAY:
PROTEIN INTAKE REPRESENTS ONLY 1/3 OF
TOTAL PROTEIN SYNTHESIS.
INTAKE
100 g / day
GUT SECRETION
70 g / day
170 g
10 g fecal loss
160 g absorbed
TURNOVER
300 g synth daily
100 g intake
200 g re-used AA
150
B. PROTEIN – ENERGY INTERACTIONS
DEFICIENCY OF ENERGY WITH NORMAL
PROTEIN INTAKE: LIMITS USE OF PROTEIN –
AA converted to meet energy requirement; stunts
growth, reduced muscle mass but lean animal
GROWTH
METABOLIC LIMIT
E LIMITS GROWTH
CP ENERGY
% CP
CP LIMITS GROWTH
151
AMINO ACID IMBALANCE WITH ADEQUATE
ENERGY INTAKE  limits use of protein for muscle 
DEAMINATION AND USE OF AA FOR ENERGY 
NOT USED FOR PROTEIN, BUT FOR FAT TISSUE
SYNTHESIS,
GROWTH with REDUCED MUSCLE MASS AND FAT
DEPOSITION
152
C. PROTEIN OR AA DEFICIENCY
NO PARTICULAR SIGNS:
 POOR GROWTH
 POOR PERFORMANCE
MORE EXTREME:
 ANEMIA
 LOW BLOOD PROTEIN
 EDEMA
 REPRODUCTION
KWASHIORKOR
MARASMUS
=
=
 PROTEIN MAN
 ENERGY MAN
153
PROTEIN REQUIREMENT
REQUIREMENT: MINIMUM AMOUNT OF A
NUTRIENT NEEDED FOR A SPECIFIC
FUNCTION
ALLOWANCE:
AMOUNT PROVIDED IN DIET TO
SATISFY REQUIREMENT + MAY CONTAIN A
SAFETY MARGIN
REQUIREMENT
EMPIRICAL
THEORETICAL
(TESTS)
FACTORIAL OR
PARTITION APPROACH
LITERATURE VALUES OFTEN A COMBINATION of both
154
MINERALS
INTRODUCTION:
26 of 90 elements are essential
Major or macro (measured in %):
S, Ca, P, K, Na, Cl, Mg, Fe
Minor or trace (measured in ppm or ppb):
I2, Cu, Zn, Mn, Co, Ni, Mo, Se, Cr, F, Sn, Si, V, As
Essential: Required to maintain life
Modern definition of essential:
 Consistently impaired function
 Supplementation prevents or cures
 >1 Investigator
 >1 Species
Major advances in mineral nutrition research as a result
of new analytical equipment. Atomic absorption
spectrophotometer is the work horse.
New experimental conditions:
 ultraclean lab equipment and animal housing
 filtered air
 synthetic diets
1969: ration with 5 ppb Se showed Se deficiency
155
Dependence of biological function on tissue
concentration or intake of a nutrient
 Each element has its own specific curve
 Different tissues or enzymes will also have different
curves i.e. some enzymes in different tissues have
different sensitivities depending on essential nature of
enzyme function
 For each element there is a range of safe and
adequate exposures in which homeostasis is
maintained
 Every element is potentially toxic
 In practice marginal areas difficult to define (subclinical) leading to marginally reduced animal
performance on a large scale ------ high $ impact
 Clinical deficiency is only tip of the iceberg and easily
corrected
156
Single element can influence several
metabolic processes.
Example Cu
1. Cytochrome oxidase involved in ATP trapping
- affects all energy dependent processes
- affects a wide range of processes
- differences between tissues in terms of effects and
priority
Lesion: nervous tissue  specific effect
Lesion elsewhere  non-specific
2. Tyrosinase converts tyrosine to melanin
(pigmentation)
Tyrosinase requires Cu as a catalyst
Cu deficiency: First sign = depigmentation
3. Lysyl oxidase connective tissue synthesis
Tropoelastin  elastin
Cu deficiency  connective tissue disorders, and
cardiovascular disorders
Functions fail at different times and therefore symptoms
may indicate severity of deficiency or toxicity
157
Separate graphs: Depletion phase in terms of pools and
elements
Length of depletion phase can be variable depending on
complicating factors such as chelators, stress, disease
158
Depletion rate is a function of:
 Reserve pool
 Rate of mobilization
 Requirement
Length depletion phase can be variable depending on
complicating factors
159
Homeostatic control: WHY???
Large variation of levels of minerals in feeds; even
within plant species
Factors responsible:










Genus, species or strain of plant
Type of soil
Rate of plant growth
Climatic or seasonal conditions
Irrigation
Stage of maturity
Soil management (fertilizer, pH)
Herbicides
Environmental (acid rain, smelters, traffic pollution)
Harvesting of plants (leave loss; soil contamination,
equipment contamination)
50 fold differences in concentration common
10 fold differences in concentration within species
common
Degree and method of homeostasis vary
Rejection of excess is as important as absorption and
retention:
Earth’s crust
Mn 15X in conc than Zn
Forages
Mn about same conc as Zn
Body
Mn about 1% of Zn conc
160
Homeostatic control routes:
1. % absorbed
2. Excretion via urine
3. Tissue deposition in harmless and /or mobilizable
forms
4. Secretion into milk
5. Endogenous excretion via feces (bile)
Minor routes: exhalation, sloughing of cells
skin, hair, wool, perspiration
Mineral requirement:
Affected by:




Type, composition of product (physiological function)
Type of animal, species, breed, sex, age
Level and chemical form in diet
Amount and nature of feed consumed
Acidic; basic; chelating agents such as phytate,
oxalates
 Non-dietary environment
Stress affects homeostatic ability
161
162
Calcium and Phosphorus nutrition:
 inter-related
 both have to be in adequate amounts
 Ca:P ratio important
 dependence on vitamin D
Bone:
25% ash (fresh)
45% water
10% fat
20% protein
Bone (dry and fat-free basis):
ash 55%
protein 45%
Ca:P = 2:1
also contains Mg, Na, Sn, Pb, F, S, carbonate and citrate
Bone types:
1. Soft: readily mobilized, amorphous
2. Long: harder, static, crystalline
Bone is characterized by active metabolism and constant turnover.
163
Ca and P exchange occurs across bone - blood.
Deposition of salts depends on:
 concentrations of Ca and P
 solubility constant Ksp
 hormonal effects (calcitonin and PTH)
 weight stress leads to remodeling and strengthening
Abnormal bone conditions:
Rickets
Occurs in growing animals only
 inadequate calcification of growing bone
 occurs with low concentrations of Ca or P in feed
 occurs with low absorption efficiency of Ca or P
 Vitamin D deficiency or phytate or abnormal Ca:P
ratio
Symptoms of rickets:
 reduced ash content of bones
 rubbery bones and beaks
 enlarged joints
 bending of ribs
 bent legs, arched backs, lameness, bone fracture
Rickets can be corrected with Ca, P and vitamin D in
early stage.
164
Osteomalacia
as rickets, but occurs in mature animals
 sub-normal intake of Ca and P or reduced absorption
 high parathyroid hormone concentration in blood
 bone demineralization associated with pregnancy or
lactation
 bone fracture (pelvic at calving)
 higher incidence in dairy cows
Osteoporosis
 reduced absolute amount of bone, but with normal
composition
 high incidence in middle-aged females:
 long term sub-normal Ca intake
 increased bone resorption
 estrogen provides “protective” effect
Nutritional secondary hyperthyroidism
 also referred to as big head disease in horses
 low Ca and high P in diet >> Ca deficiency and
interference of Ca absorption by high P content
 low blood Ca >>> high PTH>>> bone mobilization
>>> normal to low normal Ca, but very high P in
blood
 connective tissue invades demineralized bone
resulting in deformity
165
 occurs when horses are fed grain rations without
supplements
Function in soft tissues:
Ca:
 Blood clotting
 Enzyme function: lipase, ATPase
 Nerve function: nerve/muscle action potential
 Insulin release beta-cells pancreas
P:
 Energy metabolism
 Acid-base balance
Deficiency:
Ca:
 Tetany (milk fever in dairy cows)
 Increased blood clotting time
 Reduced insulin release (could lead to ketosis)
 Skeletal
P:
 Reduced fertility!!!!!!!!!!!!!!!
 Reduced feed intake, pica
 Skeletal
166
Toxicities:
Ca:
 Excess mineralization (osteopetrosis)
- in soft and vascular tissues
- arthritis (ie high Ca diet breeding bulls results in
poor breeding performance)
P:
 Laxative
 Bone resorption (big head)
 Kidney stones
Ca and P Absorption: site and pH
Ca: duodenum, pH 6.5  favours increased Ca
absorption
P: ileum, pH 7-7.5  favours increased P absorption
Diet acidity:
 Increased acidity of diet favours increased Ca
absorption (dairy cows to prevent milk fever)
Ca:P ratio:
 High Ca in diet  CaP salt precipitation in ileum
 High P diet  CaP salt precipitation in duodenum
167
Chemical form of Ca and P and availability:
 Inorganic form is better available
 Organic form is often chelated and poorly available
Common chelating agents:
Phytate: chelates P, Ca and various trace metals and
amino acids
50-80% of P in grain is in the phytate form and only
0-30% available to monogastric animals
Phytate also widely present in other plant sources
Rumen microbes produce phytase, and this phytate P
is fully available to ruminants.
Use of feed biotechnology to reduce phytate
impact:
1. Produce phytase enzyme and supplement to diets
for pigs and poultry.
2. Produce transgenic grains and canola incorporating
a microbial phytase gene.
- Increases availability of phytate P
- Reduces the need for P supplementation in rations
168
– Overall less P excretion in manure and less impact
on environment
Oxalic acid:
Chelates a wide range of minerals, but especially Ca
Oxalic acid + Ca  Ca oxalate precipitates
Can lead to formation of calculi (kidney stones)
Oxalate commonly high in beet tops, rhubarb, spinach,
swiss chard, chocolate
Oxalate can be high in forages
Reported instances of oxalate-induced abnormal
skeletal development in foals, where oxalates bound the
equivalent of 0.8 % of dietary Ca.
Ration ingredients:
High fat diets  formation of Ca soaps
Diet mineral interactions: Fe, Al, Hg, Be, Sn
can all interfere with P absorption
Note:
Ca and P absorption is critically dependent on vitamin
D
169
Magnesium:
Function:
 Component of bones and teeth
 Catalyst of many enzymes, including
cholinesterase (nerve transmission) and
ATPase (energy metabolism)
 Component of chlorophyll in plants
Location of Mg in body:
60% in skeleton
40% throughout
Second highest cation concentration in
intracellular fluid
Absorption of Mg:
 Both diffusion and active transport
 Slower than that of Ca
 Affected by:
- NH4+
- K+
- Na, Ca, P, SO4, phytate, oxalate
170
High K+ (over 2%) 
1. High DCAB (450 vs 250 meq/kg) causes
alkalosis  reduced Ca and Mg
absorption  milk fever and grass tetany
2. In ruminant Mg mainly absorbed through
rumen wall (active through Na-linked
carrier. High K+ reduces transmembrane
potential of epithelial cells and thus Mg
absorption.
Mg deficiency:
 Hypomagnesemia
 Anorexia
 Grass tetany – grass staggers –
hypomagnesemic tetany
(reduced cholinesterase activity)
 Vasodilation
 Malformation teeth
Requirement:
0.3 % of Dry Matter
Use Mg sulfate or Mg oxide to supplement
171
Na, K, Cl:







Osmotic pressure
Acid-base balance
Nervous function
Nutrient transport
Water metabolism
Enzyme function
HCl production stomach
Na deficiency:
Pica (depraved appetite), reduced appetite,
reduced growth.
Na is low in plants and Na supplementation (
as NaCl) of animals is always required
Feed NaCl (white salt): increase appetite and
palatability
K deficiency:
K is high in forages and low in grains and
concentrates.
172
Normally K intake is adequate, when a
substantial amount of forage is fed.
Dairy cattle with high milk yield (high K loss in
milk) and that are fed more grain and less
forage to meet the energy requirement for
milk production can become deficient in K.
Requirement is 0.8 %
There is some evidence to suggest that
feeding of a high K diet (1.5%) during a
limited period may be beneficial when animals
are stressed and have reduced feed intake.
 Heat stress
 Shipping stress
 Ration change
 Lactation
Electrolyte balance in feed:
- anion-cation balance
- alkaline alkalinity
- affects acid-base balance, performance,
and utilization of amino acids
173
- measured as (Na+ + K+ - Cl-) ~ 25
milliequivalents / 100 g feed
- optimal growth around 25 milliequivalents,
as less energy is expended on acid-base
balance and thus more is available for
growth (see graph)
Sulfur:
Required especially for ruminants to allow S
amino acid synthesis in rumen.
Recommended S : N = 1 : (10-12)
Also required for thiamine and biotin vitamins
In Western Canada we are mostly concerned
about high S intakes.
High S in ruminants 
- with Mo, formation of thiomolybdate and
decoppering effect; CuS.
- sulphate and thiosulfate inhibit the uptake of
selenate
- retention of both calcium and phosphorus is
reduced by the addition of sulphate to diets
174
- interference with ruminal thiamine
synthesis, resulting in primary thiamine
deficiency or secondary thiamine deficiency
(thiamine anti-metabolite formed in rumen).
In both cases abnormal glucose metabolism
in brain  cerebro-cortical necrosis, also
known as polioencephalomalacia (PEM)
- Clinical Features of S Induced PEM:
- Signs appear between the 3rd and 8th
week of exposure
- Initially affected animals exhibit transient
attacks of mild excitation, loss of appetite
and restlessness
- some affected animals may recover
spontaneously
- growth of these individuals is stunted
- Progression of clinical signs reflects
development of necrotic lesions in the
cerebral cortex
- aimless wandering
- head pressing
- hyperexcitability
- rigidity
- opisthotonos
175
- in severely affected animals the signs
reflect severe necrotic lesions in the
cerebral cortex
- recumbency
- violent convulsions
- coma and death
- Pathological Features of S Induced PEM
- Extensive necrotic lesions in the cerebral
cortex
- Polioencephalomalcia (softening of the
gray matter of the brain)
- Cerebrocortical necrosis
- Note that a diet with high content of simple
carbohydrates can also induce PEM
(through thiamine anti-metabolite formed in
rumen).
Iron:
Fe present in small amounts (4-5 g in
humans):
- 70% is in hemoglobin
- gut mucosal cells, liver, spleen and marrow
are storage sites
176
- present in plasma as transferrin
- component of oxidation-reduction enzymes
Storage of Fe in proteins:
1. Ferritin = protein with 20% Fe content and
soluble
2. Hemosiderin = protein with 35% Fe content
and insoluble
Fe absorption:
Active absorption:
First step in lumen: Fe3+  Fe2+
Diet Fe3+ (ferric) must be reduced to Fe2+
(ferrous) before it can be absorbed into
mucosal cells.
177
Vitamin C is a useful reducing agent.
Note that ferrous iron is again oxidized to
ferric iron in the mucosal cell. The enzyme
ceruloplasmin is an important oxidation
enzyme for this reaction.
178
Ceruloplasmin requires Cu for enzymatic
activity, and this explains why anemia can be
symptom of Cu deficiency.
Efficiency of Fe absorption:
- Fe status of animal and feedback inhibition
at gut level
- Low pH  increased absorption
- Vitamin C
- Chelating agents:
- his, lys increase absorption
- lactoferrin in human milk is positive
- phytates can reduce Fe absorption
- High P, Zn, Mn, Cu, Cd can reduce
absorption
Range of homeostasis: 5-60% absorption
efficiency
Normal: 20 % (on which requirement is
based)
179
Fe deficiency:
- Anemia
- microcytic (reduced cell size)
- hypochromic
(reduced hemoglobin)
Symptoms of Fe deficiency:
- Reduced activity (lethargy)
- Palor (paleness)
- Shortness of breath
Among farm animals baby pigs are most
susceptible to Fe deficiency.
Baby pigs:
1. Low body reserves at birth
2. High growth rate (1 to 18 kg in 6 weeks) 
high Fe requirement for increased blood
volume.
3. Sow’s milk contains little Fe.
4. Low feed intake.
Inject 100-200 mg iron dextran at birth.
Rooting behaviour of piglets on dirt floor or in
the wild would allow adequate iron intake.
180
Farmers used to throw grass sod in pen for
this purpose.
White veal production (EU):
Feed calves milk replacer with low Fe  low
myoglobin in muscle.
Major animal welfare concerns. Practiced
mainly in France and Italy, with some in
Quebec for French market.
181
Iodine:
Component of thyroid hormones T3 and T4
Three forms of thyroid iodine deficiency:
1. Simple primary deficiency
2. Competitive inhibition of iodide uptake in
thyroid gland (i.e. by thiocyanate)
3. Non-competitive inhibition through reduced
organification of iodide into thyroid hormone
(i.e. goitrin, oxazolidinethione (OZT))
1. Iodine content in feeds is low throughout
the world except in coastal areas. Therefore
to prevent primary deficiency iodine must
always be supplemented to animals and
humans (iodized salt – red salt for animal
supplements).
2. Presence of goitrogens is variable and
feedstuff dependent.
Glucosinolates are a class of goitrogens
that release thiocyanates (competitive
inhibition).
Goitrin is a non-competitive class of
182
goitrogens
3. Rapeseed is high in glucosinolates and
therefore the meal was not very suitable for
animal feeding.
Canola is a much improved low
glucosinolate rapeseed variety, and is very
suitable for feeding.
4. Goitrogens are found in a wide range of
plants (natural pesticide), including the
cruciferae family with cabbage, cauliflower,
brussels sprouts, mustard, horse radish,
broccoli.
Iodine deficiency signs:
- Goiter
- Low BMR, increased fat
- Reduced fertility
- High mortality at birth (fetus with goiter)
- Myxedema
- Alopecia
Iodine requirement (normal conditions):
0.2 to 0.3 ppm
183
0.5 ppm for dairy cattle (iodine is secreted
into milk at a high rate)
The feeding rate must be increased (2-3
times) when goitrogens are present in order
to compensate for competition.
Iodine supplements:
Salts: KI, KIO3
Ethylenediaminedihydroiodide (EDDI;
“organic” iodine) is also available. It is used
for the prevention of foot rot, but this
application is of questionable value.
The dosage of EDDI as iodine is very high
and raises concern about iodine toxicity in
animals and humans.
Normal intake of a dairy cow is between 5
and 15 mg/d.
Milk iodine normal range is 50-300 g/L.
EDDI feeding results in intake of 200 mg/d
and milk iodine levels up to 2000 g/L.
184
Human iodine requirement:
children
50 g/d
Adults
120 g/d
High iodine-milk consumption results in iodine
intakes in children (0.5-1L/d) in excess of 10x
requirement  toxicity concerns based on
milk intake alone. Also consider iodized table
salt, and salt in condiments, chips etc.
Dairy farm families are at greater risk than the
regular consumer, because they do not have
the benefit of the pooling effect (mixing of
high with low iodine milk) in case the on-farm
milk is high in iodine.
Iodine toxicity symptoms:
- Increased salivation and lacrimation
(symptoms are similar to those from IBR
(infectious bovine rhinitis))
- Reduced fertility
- Reduced productivity
- Immuno-suppression
185
Manganese Mn:
Required for:
- Enzyme function; oxidative phosporylation,
pyruvate carboxylase.
- Chondroitin sulfate formation (cartilage)
- Steroid synthesis from cholesterol
Deficiency signs:
1. Leg-bone:
- Newborn calves-lambs: weak or stillborn,
with twisted or knuckled over pasterns
- Lameness, short bowed legs
- Perosis or slipped tendon in poultry
(common symptom)
2. Reproduction:
- delayed or silent estrus
- reduced conception rates – embryonic death
– reduced libido
– reduced spermatogenesis
Requirement:
Is higher for reproduction in general and in
poultry.
186
Range of 20-40 ppm, and 55 ppm in poultry
Supplement with MnSO4, MnCO3, MnO
ZINC
Component of many enzymes including
RNA and DNA polymerases, carbonic
anhydrase, alkaline phosphatase, LDH
Absorption:
 Primary interference by divalent
cations Cu, Ca, Mg
 Phytate
Deficiency:
 Reduced growth - anorexia
 Hyperkeratinization of epithelium:
parakeratosis
 Infertility in males
 Impaired wound healing
Requirement:40-50 ppm; ZnO, ZnS04
187
COBALT
Discovered by E. Underwood around
1935
Most commonly deficient in ruminants:
1. Rumen microbes + cobalt  vitamin
B12 cyanocobalamine
2. Required for propionate metabolism
in TCA cycle: Impaired
gluconeogenesis
 Deficiency results in WASTING
DISEASE
 Feed is available but animal starves to
death
Requirement: 0.1 ppm
CoO, CoS04, CoCI2, CoC03
Blue Salt: Co + Iodine + NaCI
Bullets
Range Mix
Fertilizer
188
COPPER
Very important in the prairies
Often deficient in cattle exposed to
variable mineral intake:
Breeding and pregnant most at risk
COPPER DEFICIENCY SIGNS:
1. Anaemia
a. Iron transport – ceruloplasmin
b. Indirect Fe deficiency
c. RBC synthesis
2. Achromotricia (depigmentation)
Melanin synthesis tyrosinase - Cu
dependent
3. Neonatal ataxia
Swayback (Lambs) Reduced
cytochrome oxidase
4. Falling Disease (Sudden Death)
Bone deformities, reduced elastin
and collagen synthesis
Lysyl oxidase is Cu dependent
189
5. Scouring or diarrhea
6. Defective keratinization
ABSORPTION:
 Upper small intestine
 Plasma: RBC =1:1
 80% of Cu in plasma in
ceruloplasmin
Excretion:
Increased with Mo, Sulfur, Cd, Zn
Cu Status Measurement:
1. Feed analysis
2. Liver Cu
3. Plasma ceruloplasmin
4. Plasma Cu
Copper Deficiency in the Prairies:
1. Simple Primary Deficiency:
 Low Cu in Feeds < 5 mg/kg
190
 Depends on soil type,
management, etc.
 Throughout western Canada
2. Secondary Deficiency:
 Most important cause of Cu
deficiency
 Associated with high S and/or Mo
intake
Cu and SULFATES:
 Source of S is ground water:
 Greater than 800 ppm is bad
 Mean sulphate in Sask. is 1800 ppm
 Deep wells always suspect
 Shallow wells less
 Surface water acceptable ???
MOLYBDENUM:
 Mo levels in feeds depend on Mo in
soil: focus on Eastern Sask. and
Manitoba
191
With NORMAL S intake:
Cu: Mo = 1: (2-3) Manageable
Cu: Mo = 1:1
Difficult
With HIGH S intake:
The combination of Mo and S is
problematic  Formation of
thiomolybdates (TM) under
reducing conditions in the rumen:
1. TM chelation of Cu prevents
absorption
2. Thiomolybdates decopper
animal
RECOMMENDATIONS:
 Cu requirement is 5-10 mg/kg
 For most of the prairies with moderate
S (1800 ppm) and moderate Mo (1-2
ppm): 25 mg Cu/kg DM
192
 Pregnant animals up to 55 ppm
With elevated Mo and Moderate S:
 Undefined but probably 55 ppm
 Use of Cu injectables? Decoppering
effect?
SUPPLEMENTATION:
Salts: copper sulfate
Trace mineral mixes: force feed, free
choice, salt blocks
Injectables: Cu glycinate; Cu calcium
EDTA
Other: Drinking water supplement, wires,
degradable glass
COPPER TOXICITY:
 Sheep are very sensitive to Cu:
 Common cattle grain feed
supplements with 25 ppm Cu KILL
sheep!
193
Cattle tolerance: 100 ppm
Pig tolerance: 450 ppm
Breed and species differences exist
Symptoms of Cu chronic toxicity:
 Gradual build-up of Cu in liver up to
1000 ppm
 Acute release of Cu into blood
 Haemolytic crisis, renal and hepatic
failure, death
ACUTE TOXICITY:
 In sheep death within 24-72 hours
 Nausea, salivation, abdominal pain,
convulsions, paralysis, collapse
 Gastroenteritis, necrotic hepatitis,
splenic and renal congestion
Treatment of mild Cu toxicity at early
stages:
194
 Feed S and Mo to decopper ruminant
animal
 Infuse thiomolybdate in monogastric
animal
SELENIUM
 Component of glutathione peroxidase
present in a variety of tissues.
 Detoxifies peroxide radicals: peroxide,
superoxides
 Prevents peroxidation damage to lipid
membranes
 Protects unsaturated FA, including
EFA
 Vitamin E relationship
Se absorption:
Better for the organic forms:
 Selenomethionine
 Selenocysteine
195
Salts:
 Sodium Selenite
 Sodium Selenate
Excretion: Lungs, urine, feces
SELENIUM DEFICIENCY:
1. Nutritional muscular dystrophy white muscle disease (lambs and
calves)
2. Hepatosis dietetica - mulberry heart
disease (pigs)
3. Exudative diathesis - subcutaneous
haemorrhages (chicks)
4. Infertility - retained placenta
Conditions:
 Low in soil, northern areas
 Unavailable: Low pH, Fe complexing
Requirement: 0.25 - 0.50 ppm
196
Environment: PUFA and Vit E content of
diet influence requirement
Supplement:
 As Se salts in concentrate or free
choice injectables
 Focus on maternal nutrition to ensure
adequate mineral status neonate
Se TOXICITY
 10-15 fold safety range between
requirement and toxicity
 10-20 ppm for 8 weeks causes
subacute toxicity in cattle
 Se accumulator plants, e.g., milk vetch
(loco weed)
1. Blind staggers / Alkali disease
horses Sloughing of hoofs lameness - deformation
2. Reduced fertility
197
3. Loss of long hair (horses)
Se  S in disulphide bonds proteins
PREVENTION:
1. High inorganic sulphate intakes
2. High dietary protein levels
3. Arsenic supplements
198