Transcript FARM ANIMAL NUTRITION

FARM ANIMAL NUTRITION
ANIMAL SCIENCE 110
Fall 2001
NUTRIENTS
• A nutrient is any feed constituent that
functions in support of life.
• Structural components of cells and organs.
• Sources of energy for maintenance &
production.
• Regulation of body processes.
• Accessory functions such as growth,
reproduction, lactation, etc.
SIX CLASSES OF NUTRIENTS
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WATER
CARBOHYDRATES
FATS
PROTEINS
MINERALS
VITAMINS
WATER
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Transport of other nutrients
Temperature regulation
Gives body shape or form
Involved in most biochemical reactions
Clean fresh water is essential for all animals
Embryo is 90% water, newborn is 70% water and
market animal is 50% water
• Several factors affect water intake
CARBOHYDRATES
• “CH2O”
• Monosaccharides
– Glucose, Fructose & Galactose
• Disaccharides
– Sucrose, Maltose & Lactose
• Polysaccharides
– Starch, Glycogen, Hemicellulose & Cellulose
– Lignin (Indigestible & not a true carbohydrate)
FATS
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Energy – 2.25 times the energy of CH2O
Most are triglyceride (glycerol + 3 fatty acids)
Saturated – no double bonds – animal origin
Unsaturated & polyunsaturated – plant origin
Precursors of cholesterol, prostaglandin and
structural components of cells
• Some vitamins are fat soluble
PROTEINS
• Contain nitrogen – long chain amino acids
• Average 16% N (100/16 = 6.25)
• Plants synthesize amino acids from
elements in the environment
• Animals require a dietary source of amino
acids
• Rumen microorganisms can synthesize
amino acids and protein
PROTEINS
• An essential amino acid is one that can not be
synthesized at a rate which would provide normal
growth
• Nonessential amino acids can be synthesized from
other amino acids
• A limiting amino acid is one present in the lowest
amount relative to the requirement
– Lysine, methionine & tryptophane are likely to be
limiting in diets for monogastric animals
ESSENTIAL AMINO ACIDS
• Phenylalanine
• Valine
• Threonine
• Methionine
• Arginine
• Tryptophane
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Histidine
Isoleucine
Leucine
Lysine
NONESSENTIAL AMINO
ACIDS
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Alanine
Aspartic Acid
Citrulline
Cystine
Glutamic Acid*
* Required by chick for
optimal growth
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Glycine*
Hydroxyproline
Proline*
Serine
Tyrosine
MINERALS
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Inorganic elements
Structure – skeleton & teeth
Acid – base balance in body fluid
Osmotic pressure in cells
Maintain acidity of digestive juices – most
enzymes are pH specific
• Muscle contraction & CNS
• Interact with vitamins (Se-Vit E)
MINERALS
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MACRO
Calcium
Phosphorous
Sodium
Chlorine
Sulphur
Potassium
Magnesium
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MICRO
Iron & Copper
Iodine & Fluorine
Cobalt
Manganese
Molybdenum
Selenium
Zinc
VITAMINS
• Organic compounds which function as
metabolic regulators
• Fat soluble vitamins
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“A” maintenance of epithelial tissue
“D” calcium & phosphorous metabolism
“E” antioxidant – (selenium)
“K” blood clotting
WATER SOLUBLE VITAMINS
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B1- Thiamine
B2- Riboflavin
B6- Pyridoxine
Pantothenic Acid
Folic Acid
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Niacin
B12- Cyanocobalamin
Choline
Biotin
C - Ascorbic Acid (not
in livestock)
CONCENTRATES vs
ROUGHAGES
• Concentrates include cereal grains, oil
meals, molasses and dried milk products
• They are high in energy, low in fiber and
highly digestible (80% to 90%)
• Roughages include hay, straw, silages, green
chopped forage and pasture
• They are 50% to 60% digestible except for
straw which is lower
PROXIMATE ANALYSIS of
FEEDS
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Moisture or dry matter – oven
Crude Protein – Kjeldahl procedure
Crude Fat – ether extract
Crude Fiber – acid/base digestion
Mineral – ash
Nitrogen Free Extract – determined by
difference (primarily starch & sugar)
VAN SOEST & Other Procedures
for Fiber Analysis
• Neutral Detergent Fiber (NDF) – plant cell
walls [hemicellulose, cellulose & lignin]
• Acid Detergent Fiber (ADF) – cellulose &
lignin
• NDF-ADF = hemicellulose
• Acid Detergent Lignin (ADL)
• Near-infrared Reflectance (NIR) –
spectrometer to predict forage quality
TOTAL DIGESTIBLE
NUTRIENTS (TDN)
• Chemical analysis does not indicate
availability of nutrients to animal
• Apparent Digestibility
– [(Nutrient in Feed – Nutrient in Feces)/
Nutrient in Feed] x 100
• TDN = [Dig.Protein + Dig.Crude Fiber +
Dig.NFE + (Dig.EE x 2.25)] x 100
ENERGY DEFINITIONS
• Calorie – Amount of heat energy required to
raise 1 gm of water 1oC (14.5o to 15.5oC)
• Kilocalorie – 1000 calories
• Megacalorie – 1000 Kilocalories
NET ENERGY SYSTEM
• Gross Energy (GE) = Total heat of
combustion
• Digestible Energy (DE) = GE – Fecal
Energy. DE is similar to TDN
• Metabolizable Energy (ME) = DE – Urine
& Gas Energy
• Net Energy = ME – Heat Increment
• Nem or NEg or NEl