KATIE BELK Animal Nutrition
KATIE BELK
Animal Nutrition
Basic Terms
Nutrition: food being taken in, taken apart, and taken up
Herbivores: dine mainly on plants or algae For example: cattle, parrotfish, and termites
Carnivores: mostly eat other animals For example: sharks, hawks, and spiders
Omnivores: don’t eat everything, but they do regularly consume animals as well as plants of algae For example: bears
Essential Nutrients
Four classes: essential amino acids, essential fatty acids, vitamins, and minerals. Essential amino acids: cannot be synthesized by animals
and must obtain food in prefabricated form Essential fatty acids: ones that cannot be synthesized by
animals(unsaturated fatty acids) Vitamins: organic molecules with diverse functions that are
required in diet in very small amounts Minerals: inorganic nutrients are usually required in small
amounts-requirements vary among animal species
Dietary Deficiencies
Undernourishment: result of diet that consistently supplies less chemical energy than the body requires
Malnourishment: the long-term absence from the diet of one or more essential nutrients.
Both of these dietary deficiencies have negative impacts on the healthy and survival of animals.
Main Stages of Food Processing
First Stage Ingestion: actual act of
eating
Second Stage Digestion: food is broken
down into molecules small enough for body to absorb
Third Stage Absorption: animal’s cells
take up (absorb) small molecules such as amino acids and simple sugars
Fourth Stage: Elimination: completes
process as undigested material passes out of digestive system
Ingestion Organs
Sphincters, oral cavity, salivary glands, pharynx, and esophagus
Peristalsis, amylase, and bolus help with ingestion as well.
Digestion and Absorption Organs
Stomach, small intestine, duodenum, pancreas, liver, gallbladder, villi, microvilli, lacteal, large intestine, colon, cecum, and appendix
Others that help with digestion and absorption are gastric juice, chyme, pepsin, mucus, bile, and feces.
Adaptations
Dental Adaptations
Evolutionary adaptation of teeth for processing different kinds of food is one major reason mammals have been so successful Example:
poisonous snakes have fangs to inject venom into prey
Stomach and Intestinal Adaptations
The length and size (expandable) of the vertebrate digestive system is correlated with diet. A longer digestive
tract gives more time for digestion and more surface area for the absorption of nutrients.
Energy Sources and Stores
Most animals “burn” proteins only after exhausting their supply of carbohydrates and fats.
When animals take in more energy-rich molecules, such as fats, it breaks down and the excess are converted to storage molecules.
Overnourishment and Obesity
Overnourishment: the consumption of more calories then the body needs for normal metabolism
Overnourishment also causes obesity which is the excessive accumulation of fat Obesity contributes to a number
of health problems, including the most common type of diabetes (type 2), cancer of the colon and breast, and the cardiovascular disease that can lead to heart attack and strokes.