实用动物营养学

Lipids
Fat deposition in the body: Internal Intermuscular（肌间） – seam fat Subcutaneous – below skin surface Intramuscular （肌内）– “marbling” （大理石花纹，肥瘦相间的）


Less digestible Requires microbial digestion
Carbohydrates

Functions



Source of energy for bodily functions Carbon skeletons for building other nutrients Milk synthesis
Water

Dietary needs Cattle 10-20 gals/day Horses 10-20 gals/day Sheep 1-3 gals/day Swine 1-2 gals/day Poultry 2:1 water: dry feed ratio
Water

Source of dietary fatty acids
ቤተ መጻሕፍቲ ባይዱ
Lipids

Essential fatty acid = Those fatty acids that an animal requires, but which it cannot synthesize in adequate amounts to meet the animal’s need
Excessive Protein Intake



Nitrogen deaminated Remaining carbon skeleton used as energy source or stored as fat Expensive method of supplying energy to the animal

Linoleic C18:2 Linolenic C18:3 Arachidonic C20:4

Monogastric animals require a minimum of 1% of dietary essential fatty acids in the diet
Lipids






Calcium Phosphorus Magnesium Potassium Sodium Chlorine Sulfur
Minerals

Minor (micro or Trace elements)





Iron Copper Cobalt Fluorine Iodine Manganese Selenium Zinc

Intake increased by: Warm to hot temperatures High protein levels High salt levels High fiber levels High dry matter intakes
Water

Normal losses: Urine Feces Lungs Skin surface Milk
Water

Most vital nutrient ingested


Typically consume 2-4 times more water than dry matter intake Functions



Transport of digesta and nutrients Excretion of waste Lubrication, shaping and cushioning Substrate（基质） for chemical reactions
Proteins

Functions

Structure of organs and soft tissues Enzymes Hormones Antibodies Skin, Hair Milk synthesis
Dietary Essential Amino Acids

Concentrated source of energy

1 gram of lipid contains 9.45 kcal of energy as compared to 4.2 kcal of energy for carbohydrates and protein (2.25 times more energy)
Dietary Limiting Amino Acid

The essential amino acid that is present in the lowest quantity in the diet when expressed as a percentage of the animal’s amino acid requirement
Non Protein Nitrogen (NPN)

Nitrogen supplied to the animal in a non-protein state

Urea or Biuret（缩二脲）


Requires microbial synthesis (Ruminants) Crude Protein Equivalent
Water Quality

Good water quality = Less than 0.25% dissolved solids
Can measurably affect feed consumption and performance May reduce palatability or even may be toxic due to levels of heavy metals
Brief introduction to the nutrients
Water

Accounts for 70% or more of the composition of most plants and animals
Water

Most vital nutrient ingested


May lose 100% of body fat, 50% of body protein and live Lose 10% of body water, dehydration occurs and may result in death
Dietary Essential Amino Acids




Phenylalanine （苯丙） Valine（缬） Threonine（苏） Tryptophan（色） Isoleucine（异亮）
Methionine（蛋） Histidine（组） Arginine（精） Leucine（亮） Lysine （赖）

% Nitrogen from NPN times a factor of 6.25
Lipids (Ether extract)



Are made of carbon, oxygen and hydrogen, but Contain much larger proportions of carbon and hydrogen than carbohydrates do Organic compounds that are characterized by being insoluble in water, but soluble in organic solvents
Lipids

Feed application

Increase caloric density of diet Control dust Bind small particles Maintenance of equipment
Minerals

Major (macro-elements)
Protein Deficiency



Reduced appetite and feed intake Reduced birth weights and growth Reduced colostrum（初乳） and milk production Decreased hormonal production Decreased fertility
Water

Sources Drinking water Moisture content of feeds


As-fed（实样的） feed intake Dry matter feed intake
Water released through chemical reactions at the cell level
Proteins
Principal constituent of organs and soft tissues Highest concentration of any nutrient, except water, in all living organisms and animals Required for life Contain carbon, hydrogen, oxygen and nitrogen

Metabolic water

Metabolic Water



0.6 gram of water produced per gram of carbohydrate metabolized 0.4 gram of water produced per gram of protein metabolized 1.0 gram of water produced per gram of fat metabolized


Carbohydrates




Primary nutrient component of livestock feeds Structural and energy reserve of plants 70-80% of dry matter of plants are carbohydrates Less than 1% of animal composition

Blood glucose Muscle glycogen
Carbohydrates

Carbon:Hydrogen:Oxygen = 1:2:1 ratio
Classifications


Monosaccharides - Glucose, Fructose Disaccharides - Sucrose, Maltose, Lactose Polysaccharides - Starch, Cellulose
Functions

Dietary energy source Source of essential fatty acids Insulation(隔热、保温） Carrier of fat soluble vitamins Major factor in quality grading of beef

Amino acids required in the diet and cannot be synthesized at a rate sufficient to meet the nutritional requirements of the animal; therefore; must be supplied in the diet
Carbohydrates

Starch

Non-structural or non-fibrous polysaccharide


Extensively digested Enzymatic or microbial digestion
Carbohydrates

Cellulose

Structural or Fibrous polysaccharide