Animal Nutrition• All animals must eat. Whether a herbivore, carnivore, or an omnivore the

ingestion of nutrition and calories must satisfy the following needs:• fuel -cellular need for energy (ATP)

– carbs 1st, fats 2nd, protein 3rd • Organic molecules used for biosynthesis

– Essential materials (vitamins and minerals) and raw material (essential amino acids) that an animal cannot make for themselves

• malnourishment- a diet deficient in one or more essential mineral or compound

Essential materials• those amino acids that

cannot be produced by an individual are considered to be essential – 9 essential AA in humans

• Deficiency causes kwashiorkor - protein deficiency with adequate calories

• meat is best source but can also obtain through food combining (whole grain +legume)

• minerals - inorganic cofactors – Ca (bone & muscle fx), P

(nucleic acid & ATP), Mg (enzymes that split ATP), Fe (cytochromes used in cellular resp. & in Hb), I (thyroid hormones - lack gives goiter), Zn, Na, K, Cl

Vitamins• vitamins -used as cofactors used in metabolic

pathways – 13 are essential

Fat Soluble Vitamin Used For Deficiency Causes

A component of eye pigments

vision, skin, liver & bone damage

D calcium absorption Rickets - bone deformation

E antioxidant Blood clotting problemsK Blood clotting factor bleeding, liver damage

VitaminsWater Soluble Used For Deficiency Causes

B1 (thiamine) Coenzyme - removing CO2 from organic compounds Beriberi - nerve disorder

B2 (riboflavin) Component of coenzyme - FAD Skin lesions - cracks corner of mouth

Niacin Component of coenzyme - NAD & NADP

Skin & gastrointestonal lesions / nervous dissorders

B6 (pyridoxine) coenzyme used in amino acid metabolism irritability, convulsions, twitching

Pantothenic acid Component of coenzyme A Fatigue, numbness, tingling of hands & feet

Folic Acid coenzyme in nucleic acid and amino acid metabolism

anemia, gastrointestinal problems / neural chord malformation in the fetus

B12coenzyme in nucleic acid metabolism & red blood cell maturation

anemia, nervous system disorders

Biotin coenzyme in the synthesis of fat, glycogen, and AAs

scaly skin inflammation, neural muscular disorders

C (ascorbic acid) collagen synthesis - antioxidant scurvy - degeneration of skin, teeth & vessels

Homeostatic Mechanisms• Glucose regulation

– excess glucose is stored in the liver and muscles in the form of glycogen • stimulated by the hormone insulin • when stores are full, excess glucose ingested is stored as fat

– release is promoted by hormone (glucagon) secretion • when caloric needs exceed ingestion of glucose, glycogen is removed from the

liver 1st, muscles 2nd, and fat 3rd. • deamination of protein for energy occurs after glycogen and fat stores have been

eliminated – gluconeogenesis

– when blood sugar is raised after feeding, appetite decreases

Homeostatic Mechanisms– homeostatic mechanism for the maintenance of

weight are located in the satiety center of the brain • hormones tell you when to start and stop eating

– leptin - secreted by fat cells suppresses appetite as fat is stored » fat bulk decreases leptin and increases appetite

– PYY - secreted by the small intestine to decrease appetite – ghrelin - secreted by the stomach at feeding times to increase

appetite – insulin - secreted by the pancreas

Caloric Imbalances• Undernourishment

– chronic energy imbalance created by the consumption of too few calories or essential calories

– usually present in times of drought, war, or where disruption of the food supply occur (poverty)

– after the glycogen and fat stores are used the body begins to eat protein from muscle tissue • may lead to protein imbalances in the brain • some of the damage may be irreversible even after recovery has occurred

Obesity• Obesity is considered an inherited

condition – fat storage and the craving of fatty foods

once served an evolutionary purpose as it would aid an animal in periods when food was scarce

– created by the chronic over consumption of calories • over consumption of carbohydrates leads to

hyper storage of fat

– now recognized as a global health problem by the World Health Organization (WHO) • ~ 30% of Americans are severely obese (nearly

doubled in the last decade) • ~35% are over weight • ~15% of children are obese • ~300,000 deaths/year associated with obesity

– obesity is associated with an increase in breast and colon cancers, diabetes, and cardiovascular disease