Transcript Animal Nutrition - Santa Susana High School

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
• 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
Essential
materials
Vitamins
Fat Soluble Vitamin
• vitamins -used as cofactors used in metabolic
pathways
– 13 are essential
Used For
Deficiency Causes
A
component of eye
pigments
vision, skin, liver &
bone damage
D
calcium absorption
Rickets - bone
deformation
E
antioxidant
Blood clotting problems
K
Blood clotting factor
bleeding, liver damage
Vitamins
Water 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
B12
coenzyme 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 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
Obesity