animal nutrition - small and large animals at wcvm
TRANSCRIPT
VLAC 211 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
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.htmlCanada: http://www.aps.uoguelph.ca/~gking/Ag_2350/glossary.htm
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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 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
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
Nutrition is anInterdisciplinary 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 Economic Studies
Animal Nutrition also incorporates economic considerations
NUTRIENT:
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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. Water2. Proteins and amino acids3. Carbohydrates4. Lipids5. Vitamins6. Inorganic Elements (Minerals)
*Note energy is not considered a nutrient – it is derived from nutrients: lipids, carbohydrates and protein
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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
When fiber is added to water it forms a gel – this happens in the gut and then the microbes go and aggregate on it.
Energy: Not a nutrient initself but fuel (ATP) provided by lipid, carbohydrate, and carbon skeleton of amino acids after removal of N.
Essential Nutrient: Required in diet because it cannot be synthesized by the body in sufficient amounts to satisfy metabolic needs.
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.
What makes a good diet?
Must contain all the essential nutrients
And in the correct amounts and proportions
Must be palatable (taste good)
Cost - must be economical
Must be safe – no toxic substances
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Must meet functional food requirements as well. The Application of Nutrition in Feeding Animals (How to approach feeding management in steps):
1. Question: 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)
Requirement vs allowance Requirement is the minimum; allowance is a practical approach allowing for variabilityDogs: Requirements (NRC 2006)Allowance/practical applications AAFCO (2007)
2. Question: What is the nutrient content of feed ingredients?
Preferably from chemical analysis, Near Infrared Spectroscopy (NIR) or else from tables and data bases; and
a. Consider availability of nutrients (digestibility)b. Consider anti-nutritional factorsc. Consider antagonism between nutrients and other factors (feed matrix)
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3. Using Questions 1 and 2: 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
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:
Nutrient deficiency↓
Biochemical defect↓
Functional defect↓
Microscopic anatomical defect↓
Macroscopic anatomical defect↓
Morbidity (illness)↓
Mortality (death)
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 Milk Fever – calcium, acid base balance Left Abomasal Displacement – body condition, exercise
Swine: Poor Milk Production – excess body condition Lameness – body condition, mineral and vitamin D nutrition Obesity in Sows – feed energy density, feeding system
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Horses: Malnutrition - starvation Laminitis – carbohydrate overload Contracted tendons – minerals, rate of growth
Pets:Obesity, metabolic syndrome, etc.
Reasons for Continued Nutritional Study in livestock1. Genetic improvement of animals2. Increased artificial rearing3. Environmental concerns and Green House Gas emissions 4. Changing genetics of crops-feeds5. Reduced use of multiple protein sources; primarily reliance on a few feedstuffs6. Early weaning in swine7. New feedstuffs8. Changes in agronomic practices9. Narrow profit margins
Reasons for Chemical Analysis of Feeds and Feed Ingredients
For 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)
[For Lab presentation:]Feed Sampling for Analysis:
Sampling technique is the most important cause of variation in nutrient values Method is important to avoid error
ForageHay: Penn State core sampler - 10-12 balesSilage: grab samples- 4 to 6 250 ml samples composited and mixed
Feed in bagsCore samples from 5 bagsBulk feed in a bin10 samples from different areas
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- Mix on a flat surface on paper- 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 real protein) 100 ÷ 16 = 6.25
therefore N % x 6.25 = CP % Crude Non Protein N (NPN) + true protein[Melamine is a NPN]
Ether extract (fat)
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).
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Flow diagram Proximate Analysis
Crude fiber vs ADF and NDF (see next)
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FIBRE IN FEEDS (REALLY UNDERSTAND THIS).
Crude Fibre(CF) = indigestible by monogastric animals, but not in ruminants
Van Soest Fibre or Plant Cell Wall method (for forages)
VAN SOEST DETERGENT SYSTEM
Ground Forage Material Digest w/ neutral detergent ND solubles(cell content) + ND insoluble fiber (cell wall components).
ND insoluble fiber digest with acid detergent AD solubles (hemicellulose – cell wall with N) + Acid insoluble fiber (cellulose w/ lignin).
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Acid insoluble fiber digest w/ 72% sulfuric acid (H2SO4 – breaks down cellulose) Solubles (cellulose) + Acid insoluble lignin.
Used primarily for forages
Extraction with neutral or acid detergent solutions
Partitions the fiber component into soluble and insoluble carbohydrate
Fiber fractions are called neutral detergent and acid detergent fiber (i.e. NDF and ADF)
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)
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
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Other Typical Feed Analyses
silage pH (3.8 – 5.0) and C4 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
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WATER CONTENT OF FEEDS (IMPORTANT/CONFUSING SECTION – WILL BE A QUESTION ON THE FINAL EXAM – NEED TO KNOW HOW TO DO THESE CONVERSIONS).
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.
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)
LAB - FEED CLASSIFICATION
CONCENTRATES
High in energy, low in fibre contenthigh energy - (and can be high protein)
Cereal grains: barley, corn, oats, wheat
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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
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 or 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).
FEED ADDITIVES
Mineral supplements, limestone, salt
Vitamin supplements
Amino acids
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Drugs; antibiotics, ionophores
Preservatives; antioxidants, mold inhibitors
Buffers; sodium bicarbonate
Flavors; anise, fenugreek, licorice
Pellet binders; lignosulfonate, bentonite
Silage process: (slide)
High quality silage low butyrate, high lactate and low pH
PHASES: I: Oxygen 12-24h II: Acetic acid 24-72hIII: low pH low acetic high lactate 3-4dIV: Preserved with lactateV: feed out with oxygen infiltration spoilage and mold formation
GENERAL RATION CHARACTERISTICS
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SWINE: Cereal grains 70-80% 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)
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 is not measured!)
Methods of Determining Digestibility
Measurement
Total collection
Indicator methods
Estimation
Chemical analysis ie. ADF, or more complete analysis
Enzyme laboratory methods
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
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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, 20-30 d for ruminants.
Must know amount and composition of feed consumed and amount and composition of feces voided.
Then calculate:
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:
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
FACTORS AFFECTING DIGESTIBILITY
Animal Factors
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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)
Effect of Environment
Temperature: low temperature increased feed intake 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 Trialso Growth (dietary amino acid level) o Biochemical or functional defect (Thiamin or Vitamin A) o Nutrient balance (protein, trace minerals)
2. Factorial Method (energy, protein)o Maintenanceo Growtho Production (milk, wool, activity)
3. Digestion Trialso Measures availability of nutrients in feedso Whole digestive tract or part of the tract in surgically altered animals, rumen
fistula, or duodenal canula
4. Clinical-metabolic evaluationo Biochemical, function, microscopic-macroscopic defects
5. Use of statistical analysis
EXAMPLE OF DIGESTIBILITY BY TOTAL COLLECTION19
• Steer 300 kg live weight. • 14 day adjustment period on experimental ration • 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% CP 30 kg X 15%
• Digestibility of other nutrients
Gross energy; DE, kcal/kg Ether extract ADF, NDF Starch or nitrogen free extract
ENERGY
Required by all animals for:
Maintenance, growth, physiological functions of living tissue
Thermoregulation
Locomotion
Energy Measurement: Calorie
“Quantitatively, energy is the most important element of diet.”
Source: CHO, Lipids (fats) (protein)
- Animal will eat to satisfy its energy requirement !!!!!!!
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- Determines the daily intake of feed (the energy level of the food will determine how much food the animal will eat) subject to physical capacity
- Thus energy level determines the overall intake of all nutrients
- Other nutrients like protein must be balanced to the energy intake. For pets often concentrations are expressed per 100 Kcal ME, such as g protein per 100 Kcal ME
- Therefore a diet with high energy content must also have higher levels of other nutrients to ensure the animal will receive the daily requirement (such as grams per day) for all nutrients (because the animal will eat less)
- A diet with lower energy content will cause the animal to eat more feed, and therefore other nutrients can be at a lower level also. But physical capacity of the GI tract will limit how much feed the animal can eat (upper limit). Chemostatic control vs physical control.
BIOENERGETICS- Energy sources, utilization and metabolism
All animal functions and biochemical processes require a source of energy
ENERGY TERMINOLOGYCalorie (CAL) = energy to raise 1 g water from 14.5 to 15.5 C
Kcal = 1000 calories
Mcal = 1000 kcal (also called a therm) = 1000000 calories
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.
GROSS ENERGYHeat released from complete oxidation of a feed can be measured in an oxygen bomb calorimeter
Nutrient Kcal /g Carbohydrate mean 4.20
Protein mean 5.6521
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 3.49Propionic acid 4.96Butyric acid 5.95
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
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Gross Energy of Feed (GE) (Heat of Combustion)
Fecal Energy (FE) (30%)1. Undigested feed2. Enteric microbes & their products3. Excretions into the GI tract4. Cellular debris from the GI tract
Digestible Energy (DE) (70%)
Urinary Energy (UE) (5%)Gaseous Products of Digestion (methane) (5%)
Metabolizable Energy (ME) (60%)
Heat Increment (heat of nutrient metabolism) Heat of Fermentation (from the rumen, cecum, large intestine)
Net Energy (NE) (40%)
Maintenance Energy Productive or Recovered Energy 1. Basal Metabolism 1. Tissue Energy (muscle, fat)2. Voluntary Activity 2. Lactation (milk)3. Thermal Regulation 3. Conceptus4. Product Formation 4. Wool, Hair5. Waste Formation and 5. Work
Excretion
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Digestible Energy (DE)
DE = Gross Energy – Fecal Energy
DE/GE = 80% for pigs and poultry (& dogs/cats)
DE/GE = 70-80% for ruminants fed concentrates (on grain based diets)
DE/GE = 50-60 % for ruminants fed roughages (hay)
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.
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 non-ruminants
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
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Increase in Heat Production Following Eating When the Animal is in a Thermo-Neutral Environment.
Work of Digestion = 5 %
Heat of Fermentation = 15 %
Nutrient Metabolism = 80 %
Factors Affecting Heat Increment
Digestibility of ration high then lower HI
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 FeedingHigher frequency, lower HI
Injury or infection (30-40%)
NE - MAINTENANCE NE - PRODUCTION
BASAL METABOLISM GROWTH
HEAT TO KEEP BODY WARM FAT DEPOSITION
VOLUNTARY ACTIVITY ASSOCIATED WITH MAINTENANCE
REPRODUCTIVE PRODUCTS
MILK
WORK
Maximum Level of Energy Intake
For growth in most species = twice maintenance
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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
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.
Other Energy Measuring 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)
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Nutrient GE (kcal/g) Urine Dig Factor Protein 5.65 1.25 92 4.0
NFE (CHO) 4.15 --- 98 4.0
Fat 9.4 --- 95 9.0
Measured as kcal/gExample:
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
For pet foods:
• Modified Atwater factors for processed diets
▫ Carbohydrate: 3.5 kcal/g
▫ Protein: 3.5 kcal/g
▫ Fat: 8.5 kcal/g
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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
Waste formation and excretion
Maintenance Estimate
Is BMR X 1.2 to 1.8 depending on activity
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Canine (dog) daily energy requirements (ACVN)Unit: In Kcal ME/kg BW
Resting Energy Requirement (RER) = 70 x Wkg0.75
OR 30(BW) + 70 (for dogs between 2 and 45 kg)
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Maintenance (0.8 to 1.6 x RER): Healthy, neutered adult 1.6 x RER
Intact adult 1.8 x RER
Obese prone 1.4 x RER
Weight loss 1.0 x RER
Geriatric 1.1 x RER
Work:
Light 2 x RER
Moderate 3 x RER
Maximum 4-8 x RER
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 1.2 x RER
Intact adult 1.4 x RER
Active adult 1.6 x RER
Obese prone 0.8 x RER
Critical care 1.0 x RER
Geriatric 1.1 x RER
Lactation 2-6 x RER
Growing kittens 2.5 x RER
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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
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A Periodic Diet that Mimics Fasting Promotes Multi- System Regeneration, Enhanced Cognitive Performance, and
Healthspan
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Highlightsd FMD rejuvenates the immune system and reduces cancer
incidence in C57BL/6 mice
d FMD promotes hippocampal neurogenesis and improves cognitive performance in mice
d FMD causes beneficial changes in risk factors of age-related diseases in humans
In BriefBrandhorst et al. develop a fasting mimicking diet (FMD) protocol, which retains the health benefits of prolonged fasting. In mice, FMD improved metabolism and cognitive function, decreased bone loss and cancer incidence, and extended longevity. In humans, three monthly cycles of a 5-day FMD reduced multiple risk factors of aging
CARBOHYDRATES IN NUTRITION
Carbohydrate is a translation of the French term “Hydrate de Carbone”
o 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
FUNCTIONS OF CARBOHYDRATES
Energy Source
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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) –Makes food Sweet
Structure, water holding capacity in processed foods and feeds
Pre-biotic
CLASSIFICATION Monosaccharides (5 and 6 carbon)
Disaccharides
Trisaccharides
Polysaccharides
Pentosans
Hexosans
Mixed Polysaccharides
CARBOHYDRATES Large amounts in plants
o Starch (65%-70% of cereal grain)
o Cellulose (up to 40% of forages)
o Hemicellulose
o Pectin
Small amounts in animals
o Glycogen
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o Glucose
o Chitin (long-chain polymer of N-acetylglucosamine)
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
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
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
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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
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
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
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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
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 i
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Major Components of Lignocellulosic Biomass (Department of Energy USA)
Example of composition of wood
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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 05-30%
Dog 10-30%
Human 25-40%
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Nutritional Classification of Starch Non ruminant (monogastric) 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 granulesRetrograde starch (Amylose), B type granules
Glycemic Index: Rise in blood glucose after a test food is consumed
High GI Low GI
White Bread 100 Skim Milk 46
Glucose 140 Oatmeal 87
Instant Rice 124 Pasta 40-70
French Fries 107 Apple 34-76
Sucrose 83
DIGESTION IN RUMINANTSReticulum Rumen Omasum Abomasum
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:
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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)
Abomasum: Analogous to gastric stomach in non-ruminants
True Stomach
Digestive secretions (host)
Digestion of Carbohydrates by Ruminants
A. Ruminant’s saliva is different from the non-ruminants.
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
C. Microbial enzymes break glycosidic bonds of fiber and starch
Bacterial cellulase and hemicellulase are capable of breaking the alpha or beta 1,4 bonds between CHO of cellulose and hemicelluloses
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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 end-products called volatile fatty acids. These include ACETIC (C2), PROPIONIC (C3), BUTYRIC (C4) 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.
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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
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
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5. Presence of rumen modifiers in the diet (lonophores) increased C3 (proprionic acid)
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
Lower milk fat – higher body fat
Lower rumen pH (higher acidity; 5.5 – 5.8)
Alteration of the PHYSICAL FORM of the diet:
oGrinding and pelleting generally increase reactions which produce more Propionic acid (more rapid fermentation) and lower pH
Classification of Carbohydrate Fractions in Feed for CattleCornell - 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
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CLASSIFICATION OF THE LIPIDS
Simple lipidsFatty 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 LipidsGlycolipids, Liproproteins,
Androgens, Estrogens
Chylomicrons, HDLs, LDLs, VLDLs
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CLASSIFICATION OF LIPIDS
Lipid = All Ether Extractable material
1. SIMPLE LIPIDS-Esters of FA and Alcohols (mainly Glycerol)
FATS OILS
(SOLID AT RT) (LIQUID AT RT)
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. Such as:FATTY ACIDS
ALCOHOLS (EG. GLYCEROL)STEROLS AND CHOLESTEROL
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THE ROLE OF LIPIDS IN NUTRITION
Source of dietary energy (2.25 x carbohydrate)
Low heat increment - Minimize heat stress
Source of essential fatty acidso Linoleic (C18:2) and Linolenic (C18:3) Source of omega-3 fatty acids
Carrier of fat soluble vitaminso A, D, E, K
Cell structure and metabolic role
Feed/Food flavor (palatability)
Dust control, food/feed consistency,o Physical characteristics
Minimizes wear on feed handling equipment
LIPID CONTENT OF COMMON FEEDSTUFFS
Feed Lipid Linoleic % of DM % of Lipid
Alfalfa hay 2.7 16Barley silage 3.0 ----Brome grass hay 2.2 ----
Barley grain 1.9 42Corn grain 3.8 56Oat grain 4.5 33Wheat grain 1.6 40Wheat bran 6.0 55
Canola seed 40 65
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Canola meal 3.5 ------Soybeans 18 45Soybean meal 1.0 40
Meat meal 9.0 2Fish meal 9.0 2Milk, whole 30 3Lard 98 11
FUNCTIONS OF BODY FAT
1. Energy Reserve: can be used during energy intensive processes (ie.
Lactation).
2. Insulation
3. Protection and Cushioning
4. Cell Membranes
5. Steroid Hormones
6. Bile Acids
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).
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o (∆ 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 (∆ delta)).
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
Omega 6 (n-6) (means the first double bond is 6C from the terminal CH3):Linoleic acid (C18:2)Gamma Linolenic acid (C18:3) = GLAArachidonic acid (C20:4)
Omega 3 (n-3) (means the first double bond is 3C from the terminal CH3):Alpha Linolenic acid (C18:3) ALA PlantsEicosapentaenoic acid (C20:5) EPA FishDocosahexanoic acid (C22:6) DHA Fish
EPA and DHA melting point = -54°C!
Omega-6 Omega-3Gamma-linolenic (GLA) Alpha-linolenic ALA
↓ ↓↓ ↓
Arachidonic acid EPA↓ ↓
PGE2 DHA↓ ↓↓ PGE3
Inflammatory Anti-inflammatory
EFA: Need as 1% of calories
WHO/FAO: omega 6 : omega 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
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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) inhibits the synthesis of prostaglandins from
arachidonic acid
Some important fatty acids of refined vegetable oils in Canada (w/w %)
Fatty Acid
Flax Canola Soybean Corn Peanut Sun-flower
Olive Palm
16:0 6 4 9 11 11 7 14 4218:0 3 2 5 2 3 5 2 418:1 17 55 45 27 46 19 64 3818:2 16 26 37 59 29 66 16 918:3 56* 10* 3* 1 1 Tr Tr20:1 2 Tr Tr Tr Tr Tr22:1 Tr Tr Tr Tr
* α-linolenic acid (omega 3) Fish oil, flax, canola/rapeseed, walnuts, soy sources of α-linolenic acid
Canola oil positive factors: High in C18:1;LA (omega 6) : ALA (omega 3) = 2:1
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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(HUMAN DIET)
Ratio more important than absolute amounts
Essential fatty acids for cats and dogs
Essential fatty acid (g)
Growing puppies allowance (per kg BW0.75)
Adult dogs recommended allowance (per kg BW0.75)
Bitches late gestation and peak lactation allowance (per kg BW0.75)
LA 0.8 0.36 1.6ALA 0.05 0.014 0.10AA 0.022EPA + DHA 0.036 0.03 0.06
Essential fatty acid (g)
Kittens allowance (per kg BW0.75)
Adult cats allowance (per kg BW0.75)
Queens late gestation and peak lactation allowance (per kg BW0.75)
LA 0.29 0.14 0.3ALA 0.01 0.011AA 0.01 0.0015 0.011EPA + DHA 0.05 0.0025 0.0044
Source: Nutrient Requirements of Dogs and Cats. 2006. National Research Council (U.S.)
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Fatty acids are not a source of energy for microbes.
Minimal degradation of long-chain fatty acids in the rumen.
Long chain fatty acids not absorbed from the rumen (VFAs are)
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 is consumed by the animal
Lipids leaving the rumen:
80 to 90% free fatty acids attached to feed particles and microbes About 10% microbial phospholipids Some undigested feed fat bypasses rumen
Diagram of the molecular structure of different fatty acidsSaturated fat Cis-unsaturated fatty acid Trans-unsaturated fatty acid
saturated carbon atoms (each with 2 hydrogens) joined by a
single bond
unsaturated carbon atoms (each with 1 hydrogen) joined
by a double bond. Cis configuration.
unsaturated carbon atoms (each with 1 hydrogen) joined
by a double 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 55-80% of olive oil.Elaidic acid is a trans unsaturated fatty acid often found in hydrogenated vegetable oils.
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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)
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 - A novel nutraceutical 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
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CLA content in some foods
Food CLA isomers cis 9, trans 11mg/g fat %
Beef 4.3 85Pork 0.6 82Chicken 0.9 84Milk 5.5 92Colby cheese 6.1 92Corn oil 0.2 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.
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 FermentationUpper 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)
PUFA may change redox conditions in cells, oxidation stress
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- PUFA oils are more inhibitory than saturated fats
- Feeding whole oil seeds with high PUFA content less inhibitory due to
lower availability
Consequences:
Reduced feed intake
Reduced fiber digestion! (reduced fermentation activity) Reduced milk fat
Increase propionate/acetate ratio
Fatty acids can be used to defaunate the rumen (protozoa very sensitive)
OXIDATIVE RANCIDITY
Auto-catalytic reaction in unsaturated fatty acids with generation of oxygen
radicals and potentially leading to spontaneous combustion
Accelerated by pro-oxidants
• Heat
• U.V. Light
• Moisture
• Transition Metals eg Cu, Fe, Mn
Anti-oxidants
• Vitamin E (& A)
• Ethoxyquin (synthetic Vit E)
• Butyl Hydroxy Anisole (BHA)
• Selenium glutathione peroxidase
Cholesterol:Many important steroids are derived from cholesterol in animals, including:
HORMONES including androgens, estrogens, progestins, glucocorticoids, and mineralocorticoids
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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
WATER
Sources (3): Drinking water Water in feed (Eats). 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 L/day Dairy cow 160Beef cow 55Beef steer 35Feeder pig 7-10Ewe 2-7Laying hen 0.25
Water content of feeds:
Feed % waterCorn 12Barley 11Oats 9Hay 10 (8-15)Silage 70 (45-75)Beets 87Potatoes 75
Metabolic water formed from:
Carbohydrate 60%Protein 40%
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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
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 + MgVery hard = >800 mg/L Ca + MgMaximum for livestock = 1000 mg/L
Salinity: (salts, mainly NaCl) estimated from conductivity (EC) and may be expressed as TDS mg/L
TDS EC<1000 <1.5 Excellent for all types of livestock
1000 - 3000
1.5-5 Satisfactory for all livestock but may slightly reduce productivity, mild diarrhea, especially poultry
3000 – 5000 5-8 Acceptable except poultry. Will cause temporary diarrhea and may be refused at first
5000 - 7000 8-11 Usually safe for beef cattle, sheep, swine and horses7000 – 10,000
11-16 Not suitable for young, pregnant or lactating animals
>10,000 >16 Not recommended under any conditions
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Livestock water quality guidelines
Parameter mg/L (maxima) = PPM Calcium 1000Nitrate + nitrite 100Nitrite alone 10Sulfate 1000TDS 3000 (2000 for aquatics)
Aluminum 5Cadmium .02Copper 1 (cattle)
0.5 (sheep)5 (swine and poultry)
Fluoride 2Lead .1Mercury .003Molybdenum .5Selenium .05Zinc 50
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Common water quality problems
Sulfate >1000 mg/LSource: Calcium sulfate rock (gypsum)Effects: Reduces availability of Ca, Zn, Fe, Mn, Mo, CuAction: Improve water quality and/or provide additional trace minerals,
especially Cu
Nitrite > 10 mg/L OR nitrate + nitrite >100 mg/LSource: Fertilizer or animal wasteEffect: Formation of methemoglobin (brown blood), reduced vitamin A
utilization and absorptionAction: Prevent contamination
Iron > 2 mg/LNot 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
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 SolutionColiform count Chlorinate waterWater hardness Install softenerHigh nitrates or other minerals Ion exchange or RO systemIron FiltrationHigh water pH AcidificationHigh turbidity Coagulation
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Vulnerability of water supplies
1. Surface water2. Cisterns3. Natural springs4. Shallow hand-dug or sandpoint wells (<50 ft)5. Artesian wells6. Drilled wells7. 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 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.
Protein Nutrition
1. Introduction, general, classes of proteins, amino acids
2. Non-ruminant protein nutrition a. Quality:
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i. Protein digestibility: ileal vs. fecal Amino acid digestibility: ileal vs. fecalAmino acid balance, biological valueAssay for protein quality
b. Requirement:i. Maintenanceii. Production
3. Ruminant protein nutrition a. Versus non-ruminantb. Microbial fermentation:
microbial protein synthesisfrom non-protein nitrogen (NPN)energy interaction
quality of microbial proteinc. Feed protein:
Solubility of NDegradable protein Bypass protein
Protein:
1. Primary function : Source of amino acids for body protein orsource 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 pathwaysessential vs. non-essential amino acidsdifferent digestion coefficients between amino acidsrelative proportions of amino acids in feed matteroptimal relative proportions of amino acids change with physiological state
(growth, lactation, pregnancy, disease)very limited storage of amino acids
Protein turn-over g / day:
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Protein intake represents only 1/3 of total protein synthesis
Human: intake 100 g/dgut secretion 70 g/d
170 g/dfecal loss 10 g/dabsorbed 160 g/d
Protein turn-over:
Protein synthesis / day 300 gProtein intake / day 100 gAmino acids re-used daily 200 g
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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.
Forms of proteins:
1. Fibrous : collagen, elastins, keratins2. Globular : albumins, globulins, glutelins, histones, prolamines, protamines3. Conjugated : nucleoproteins, mucoproteins, glycoproteins, lipoproteins,
hemoproteins, metalloproteins4. 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.
Use of D and L amino acids by non-ruminants:
Amino acid D form relative to LMET (hionine) =PHE (nylalanine) =PRO (line) =LEU (cine) < slightlyVAL (ine) ½TRY (ptophan) limitedISO (leucine) limitedHIS (tidine) limitedLYS (ine) 0 (negative effect)THRE (eonine) 0ARG (inine) 0
Classification of amino acids:
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Essential (EAA; 10) Non-essentialArg (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 non-nutritional effect (functional food)
Cats (carnivore): Taurine is an Essential AA (present in meat)
Specific amino acid relationships:Methionine: Requirement only met by MetCysteine: Requirement met by Cys or Met
Phenylalanine: only met by PheTyrosine: 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 are used mainly in research and by feed companies for quality control. Expensive and not used in routine ration formulation.
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Monogastric protein nutrition(pigs, poultry, cat, dogs, humans)
Protein quality measurements:
Digestibility:
Apparent: P intake - P outputP intake
True: P intake - (P output - MFP)P intake
MFP = Metabolic Fecal Protein = MFN x 6.25MFN = 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
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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
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
Ileal Fecal Apparent digestibility % 60.4 71.1True digestibility % 69.0 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 Fecal
Lysine 73.4 77.8Methionine 77.6 76.5Phenylalanine 71.5 81.1Valine 72.6 80.2
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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)
Raw HeatedFecal Ileal Fecal Ileal
Lys 71.9 44.2 87.3 84.9Met 61.0 46.7 82.5 83.0Cys 77.7 35.2 87.0 74.1Thr 65.2 32.2 83.0 71.5Tryp 75.4 24.8 86.8 72.3
Are amino acid digestibility’s 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.
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 proteinPoor match low quality protein
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Deficiency of 1 amino acid will stop protein synthesis. Animal uses protein for energy and fat synthesis. Some will be cleared as urea/nitrogen in the urine.Which could signify that the animal is getting too much protein or a protein of poor quality.
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
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 for an ideal balance of A.A. in the feed.- match with what is digested from the ileol-cecal method.2. Fast growth ---- lean tissue amino acid composition is the requirement.3. Ideal protein concept
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Measuring protein quality
1. Ideal protein = ideal AA pattern concept
Liebig’s “Law of Minimums"
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Undersupply of one single essential amino acid will inhibit the use of those in adequate supply
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.
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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
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
Quality is measured in terms of growth only, not great for lactation or pregant animals. 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.
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Nitrogen BalanceTrue Biological Value: NI – (FN - MFN) – (UN - EUN) x 100
NI – (FN – MFN)
Measures N retained as a % of N absorbedClassic test
Biological value of proteins for growing and adult ratsProtein Growing Adult
Egg albumin 97 94
Beef muscle 76 69
Meat meal 72-79 -
Casein 69 51
Peanut meal 54 46
Wheat gluten 40 65
Many other tests including: Available lysine (color reaction) to test for Maillard reaction products In vitro (testubes) to simulate protein digestion
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)
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Modern protein classification based on:
1. Solubility in rumen:Totally and fast degraded to NH3
True protein and NPNDetermined 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 (passive/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.
3. RUMINANT PROTEIN NUTRITION 1. OPTIMIZE MICROBIAL PROTEIN OUTPUT
2. OPTIMIZE BYPASS PROTEIN / FEED PROTEIN TO MEET NEEDS OF
THE ANIMAL
3. MINIMIZE LOSS OF NH3 (COST AND BAD 4 ENVIRONMENT)
3.1 MICROBIAL PROTEIN :3.1.1 QUALITY
REL UNAFFECTED BY DIET
Biological Value = 80% (BACTERIA + PROTOZOA)
TRUE DIGESTIBILITY:
PROTOZOA 88%
BACTERIA 66%
PROTOZOA ON ROUGHAGE DIET
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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
3.1.2 QUANTITY OF PROTEIN SYNTHESIS IN RUMEN by microbes1. 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
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Super Important Figure to Study for Exams.
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Factors affecting the amount of microbial protein synthesis
1. Rumen nh 3 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
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3. DIETARY ENERGY LEVEL (need energy to drive microbial growth)
Microbial Protein % TDN Produced g/KG DM
> 75% 51.265-75% 38.4< 65% 26.0
UPPER LIMIT OF NON PROTEIN NITROGEN UTILIZATION WHEN
SUPPLEMENTING UREA (FERMENTATION POTENTIAL)
% PROTEININ RATION % TDN (DM)BEFORE NPN IS ADDED
60-65 65-70 70-75 75-80
MAX CP AT WHICH NPN IS USED8 % 10 10.5 10.9 11.210 % 10.8 11.3 11.7 12.0
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 WITH MOLASSES
4. RATE OF FERMENTATION OF CARBOHYDRATE
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SYNCHRONIZE PATTERNS OF NH3 AND ENERGY SUPPLY Molasses: too fast – very fast energy release
Straw: too slow – highly undigestible
Cereal starch acceptable
CEREAL STARCH: IS ACCEPTABLE
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5. OTHER NUTRIENTS? sulphur S : N = 1 : (10 - 12)
for de novo synthesis of S A.A.
6. RUMEN DILUTION RATE rate of flow of digesta out of rumen (Units: % / hour)
slow residence time of bacteria in rumen maintenance energy energy for
growth
DILUTION RATE (% / h)
dil. rate maintenance expense energy for bacteria growth of bacteria
bacterial protein available to host
YIELD
MAINTENANCE
5
10
20
15
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MAX (THEORETICAL)
ENERGY EFFICIENCY OF BACTERIA GROWTH (bacteria mass/ATP)
2 4 6 8 100
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.
Application in computer models – Cornell SystemProtein 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 100-350% 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.
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B3 This is slowly degradable cell wall protein that may be increased in heat
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.
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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
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 re-used AA
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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
Amino acid imbalance with adequate energy intake limits use of protein / amino acids for
muscle protein synthesis Deamination and use of aa for energy not used for protein,
but for fat tissue synthesis.
Outcome: growth with reduced muscle mass and increased fat deposition
% CPCP LIMITS GROWTH
CP ENERGYE LIMITS GROWTH
METABOLIC LIMIT
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GROWTH
B. Protein or aa deficiency
No particular signs: poor growth and poor performance
More extreme: anemia, low blood protein, edema, reproduction
KWASHIORKOR = PROTEIN in MAN
MARASMUS = ENERGY in MAN
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
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MINERALS
INTRODUCTION:
26/90 elements are essential (required to maintain life)
Major or macro (measured in %): S, Ca, P, K, Na, Cl, Mg, Fe
Minor or trace (measured in mg/kg, ppm or ppb): I2, Cu, Zn, Mn, Co, Ni, Mo, Se, Cr, F, Sn, Si, V, As
Modern definition of essential: Consistently impaired function when deficient Supplementation of the mineral prevents or cures symptoms >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
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Fig. 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 (sub-clinical) leading to marginally
reduced animal performance on a large scale ------ high $ impact Clinical deficiency is only tip of the iceberg and easily corrected
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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 effectLesion elsewhere non-specific
2. Tyrosinase converts tyrosine to melanin (pigmentation) & requires Cu as a catalyst.
Cu deficiency: First sign = depigmentation
3. Lysyl oxidase connective tissue synthesisTropoelastin elastinCu deficiency connective tissue disorders, and cardiovascular disorders
Functions fail at different times and therefore symptoms may indicate severity of deficiency or toxicity
Separate graphs: Depletion phase in terms of pools and elements
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Length of depletion phase can be variable depending on complicating factors such as chelators (molybdenum and sulfur), stress, disease, genetics
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Depletion rate is a function of: Reserve pool Rate of mobilization Requirement
Length depletion phase can be variable depending on complicating factors
Homeostatic control: WHY???
Large variation of levels of minerals in feeds; even within plant species
Factors responsible:
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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 concentration10 fold differences in concentration within species
Degree and method of homeostasis vary
Rejection of excess is as important as absorption and retention:Earth’s crust Mn 15X in conc than ZnForages Mn about same conc as ZnBody Mn about 1% of Zn conc
Homeostatic control routes:1. % absorbed2. Excretion via urine3. Tissue deposition in harmless and /or mobilizable forms4. Secretion into milk5. 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
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Calcium and Phosphorus nutrition:
inter-related both need to be in adequate amounts Ca:P ratio important dependence on vitamin D
Bone: 25% ash (fresh)45% water10% fat20% protein
Bone (dry-matter basis 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, amorphous2. Long: harder, static, crystalline
Bone is characterized by active metabolism and constant turn-over. Ca and P exchange occurs across bone – blood barrier.
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:
RicketsOccurs 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 by supplementing Ca, P and vitamin D in early stage.
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Osteomalaciaas 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 and laying hens
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 parahyperthyroidism (PTH) AKA 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 occurs when horses are fed grain rations without supplements
Function in soft tissues:
Ca: Blood clotting (thrombin) Enzyme function: lipase, ATPase Nerve function: nerve/muscle action potential Insulin release beta-cells pancreas
P: Energy metabolism Acid-base balance
Deficiency (not enough):
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
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Skeletal
Toxicities (too much):
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
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.
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2. Produce transgenic grains and canola incorporating a microbial phytase gene.
- Increases availability of phytate P- Reduces the need for P supplementation in rations– 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
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 (Intracellular fluid – highest [ ] after potassium)- 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
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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
o Can infuse animal via IV fluid or by sprinkling it on their pasture.
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Na, K, Cl:
Required for: 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
o Red Salt – NaCl + iodineo Blue Salt – NaCl + iodine + cobalt
K deficiency:- K is high in forages and low in grains and concentrates.- 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- measured as (Na+ + K+ - Cl-) ~ 25 milliequivalents / 100 g feed (250 mEq/kg)- 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 de novo amino acid synthesis in rumen.
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- 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 selenium - retention of both calcium and phosphorus is reduced by the addition of sulphate
to diets - 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 of the brain. -aimless wandering-head pressing -hyperexcitability -rigidity -opisthotonos
- 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):
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- 70% is in hemoglobin & myoglobin (gives meat red colour)- gut mucosal cells, liver, spleen and marrow are storage sites- present in plasma as transferrin- component of oxidation-reduction enzymesStorage of Fe in proteins:1. Ferritin = protein with 20% Fe content and soluble2. 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.
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.
Ceruloplasmin requires Cu for enzymatic activity, and this explains why anemia can be symptom of Cu deficiency.
Efficiency of Fe absorption:
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- 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 efficiencyNormal: 20 % (on which requirement is based)
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 birth2. 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.Farmers used to throw grass sod in pen for this purpose.
White veal production (Europe):- 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.
Iodine:
Component of thyroid hormones T3 and T4
Three forms of thyroid iodine deficiency:
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1. Simple primary deficiency (not enough iodine in soil or feeds)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 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. soybean
Iodine deficiency signs:- Goiter - Low BMR, increased fat- Reduced fertility- High mortality at birth (fetus with goiter)- Myxedema (pooling of plasma)- Alopecia (hair loss)
Iodine requirement (normal conditions):- 0.2 to 0.3 ppm- 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.
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Normal intake of a dairy cow is between 5 and 15 mg/d and 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.
Human iodine requirement:Children 50 g/dAdults 120 g/d – 150 g/d
High iodine-milk consumption results in iodine intakes in children (0.5-1L/d) is more than 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
Manganese Mn:
Required for:- Enzyme function; oxidative phosphorylation, 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 -
contracted tendons- 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:
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- Is higher for reproduction in general and in poultry.- Range of 20-40 ppm, and 55 ppm in poultry.- Supplement with MnSO4, MnCO3, MnO.
ZINCComponent of many enzymes including RNA and DNA polymerases, carbonic anhydrase, alkaline phosphatase, LDH
Absorption: Primary interference by divalent cations Cu, Ca, Mg Phytate interference
Deficiency: Reduced growth - anorexia Hyperkeratinization of epithelium: parakeratosis Infertility in males Impaired wound healing Liver produces IGF-1 – mitogenic – increases growth (bone, muscle,
mammory)
Requirement:40-50 ppm; ZnO, ZnS04
COBALTDiscovered by E. Underwood around 1935Most commonly deficient in ruminants:
1. Rumen microbes + cobalt vitamin B12 cyanocobalamine2. 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 ppmCoO, CoS04, CoCI2, CoC03
Blue Salt: Co + Iodine + NaCIBulletsRange MixFertilizer
COPPERVery important in the prairiesOften deficient in cattle exposed to variable mineral intake:
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Breeding and pregnant most at risk
Copper Deficiency signs:1. Anaemia
a. Iron transport – ceruloplasminb. Indirect Fe deficiencyc. 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 synthesisLysyl oxidase is Cu dependent
5. Scouring or diarrhea6. Defective keratinization7. Hereford/Angus have lower copper requirement than the animals that
came from Europe like the charolais, symmental, etc.
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 analysis2. Liver Cu (invasive)3. Plasma ceruloplasmin4. Plasma Cu
Copper Deficiency in the Prairies:1. Simple Primary Deficiency:
Low Cu in Feeds < 5 mg/kg 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
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Cu and SULFATES: Source of S is ground water: Greater than 800 ppm is bad Mean sulphate in SK, AB, MB 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 (increases as you move from SK to MB – swan river, MB has Mo of 12 ppm)
With NORMAL S intake: 800 ppmCu: Mo = (2-3):1 Manageable - SK Cu: Mo = 1:1 Difficult – MB
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 absorption2. 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 – 25 ppm 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 blocksInjectables: Cu glycinate; Cu calcium EDTAOther: 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!
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Cattle tolerance: 100 ppmPig tolerance: 450 ppmBreed 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: 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: (ROS) hydrogen 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
Less Available - Salts: Sodium Selenite Sodium Selenate
Excretion: Lungs, urine, feces
SELENIUM DEFICIENCY: (Same for Vit E deficiency)1. Nutritional muscular dystrophy - white muscle disease (lambs and calves)
2. Hepatosis dietetica - mulberry heart disease (pigs)
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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 ppmEnvironment: 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
3. Loss of long hair (horses)
Se S interactions in disulphide bonds proteins – there is constant competition b/w them. Need to consider sulfur content in prairies as a parameter to decide if we need to increase/decrease Se supplement.
PREVENTION:1. High inorganic sulphate intakes
2. High dietary protein levels
3. Arsenic supplements
VITAMIN/MINERAL NUTRITION
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Critical to growth and health of animals. Grazing animals are of particular concern. It is important to know what role vitamins and minerals play in animal growth and physiology.
2 Types:
- Water Soluble Vitamins ( Thimin, Riboflavin, Niacin, Biotin, Folic Acid, Vit B12.
- Fat Soluble Vitamins (Vit A, E, D, K)
Groupinng of Vitamin and Minerals by Function.
Electrolytes (Na, K)Bones (Ca, P, Mg, Vit D, Vit K)Energy releasing vitamins (Thiamin, Riboflavin, Niacin, Biotin)Hematopoietic (Folate, B12, Fe, Cu)Antioxidant (Vit E, Vit C, Se, Vit A)Others (Vit A, I, Zn, Cr, Choline)
Vitamins: generally not synthesized by the body (when they are its from microbes) & must be supplied in the diet. These are organic nutrients required in small amounts for a variety of biochemical functions. Can account for some major diseases: scurvey, beriberi, rickets, pellagra.
First discovered vitamins (A and B) were fat and water soluble respectively.
Water Soluble – all absorbed by passive transport at high levels, and active transport at low levels (Except B12), excreted in the urine, toxicity rarely a problem, storage limited (Except B12 – in muscle). Vit C is good to prevent the common cold – but at high levels it can contribute to kidney stone formation.
Rumen bacteria can make B vitamins at levels that meet ruminant requirment.
In horses – can also make most B vitamins needed for their requirement so supplementation generally not needed.
Rabbits & Coprophagy – cecum fermentation – they reconsume soft feces that is high in microbial content – gives rabbit access to B-vitamins and microbial protein.
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