Animal Nutrition Exam 3

Gastrointestinal tract (GIT)

Passage from mouth to anus through which feed passes after consumption

Prehension

Taking in food/water

Mastication

Chewing

Regurgitation

Bringing swallowed but undigested foodstuffs back up esophagus and into mouth; passive

Digestion

Breakdown of feed particles into suitable products for absorption

Absorption

Transfer of substances from GIT to blood or lymph system

Excretion

Removal of waste products

Rumination

Process that allows the animal to ingest forage/feed rapidly and complete the chewing process at a later time

Dental pad

Palate present in ruminants in place of upper incisors

Salivary glands

Provide moisture, lubrication, digestive enzymes, buffers, and antimicrobial factors in the mouth during mastication

Vomiting

Bringing digested contents of the stomach and small intestine back up

Rumen

Largest compartment of ruminant stomach that ferments foodstuffs

Propionate for rumen development

Lower concentration causes more papillae and thus more efficient use of feedstuffs

Esophageal groove

Shunt in young ruminants that bypasses the rumen and brings milk straight to the abomasum; triggered by suckling

Reticulum

Compartment of ruminant stomach that holds ingested feed, traps foreign objects, and moves feed back and forth to the rumen for fermentation

Omasum

Compartment of the ruminant stomach that absorbs water-soluble nutrients and has many folds

Abomasum

Compartment of the ruminant stomach considered to be the “true stomach” because it breaks down food through acidic (HCl) and enzyme secretions

Ruminant hindgut

Cecum has little to no function, colon absorbs water and stores undigested chyme

Sacculated stomach

Compartmentalize functions for prolonged storage of feed and utilization of bacterial fermentation; degree of sacculation related to importance of fiber digestion and fermentative capacity

Vampire bat nutritional adaptation

Stomach becomes voluminous for storage of large amounts of blood

Carnivore

Consumes animal products

Herbivore

Consumes plant products

Omnivore

Consumes plant and animal products

Pregastric fermentation

Done by ruminants, more effective fermentation

Cecal fermentation

Type of postgastric fermentation; rodents, rabbits, other small herbivores

Colonic fermentation

Type of postgastric fermentation; true herbivores, omnivores, carnivores

Rabbit GIT

Similar to horses where the cecum breaks down fiber and has some volatile fatty acid production

Pig GIT

Monogastric omnivore with limited postgastric fermentation; similar to human

Rat GIT

Monogastric omnivore with larger cecum allowing for fermentation

Human cecum

Small, absorbs salt and liquid, mixes food with mucus

Kangaroo GIT

2-chambered stomach where first chamber ferments via microbes and second chamber digests like a normal stomach; monogastric omnivore with limited pregastric fermentation; sacculated stomach capable of utilization of high fiber diets

Crop

Enlarged area of esophagus in birds that stores and softens feed prior to it entering the stomach

Proventriculus

Glandular stomach in birds that secretes HCl and pepsinogen

Gizzard

Muscular stomach in birds that has a similar function to teeth in mammals

Monotreme and insectivore GIT

Primitive tract, simple stomach with little or no division between small and large intestine, non-sacculated colon

Minerals

Inorganic elements essential to bodily function when removal results in an abnormality that disappears when added back

Mineral functions

Bones and teeth, expression of genes, activation of vitamins, immune function, acid-base/water balance

Macro elements

Calcium, magnesium, sulfur, phosphorus, potassium, chlorine, sodium

Factors affecting mineral requirements

Species or breed, rate of growth or physiological state, chemical form of mineral, levels of other minerals

Mineral excretion

Urine excretes absorbed minerals filtered by the kidneys, feces excretes some absorbed minerals

Mineral secretion

Milk and eggs, sweat secretes Na and Cl

Mineral digestion

Cannot be broken down by heat, acid, or air; extracted from food

Transcellular absorption

Active transportation, mineral is transported through/across cell and exported into extracellular fluid and blood

Paracelluar absorption

Passive transportation, mineral able to move through small gaps between basolateral cells

Calcium

Most abundant mineral in animal tissues, active or passive absorption dependent on vitamin D

Calcium functions

Bone structure, nerve function, blood clotting, muscle contraction, cellular metabolism

Vitamin D3 from kidney

Increases plasma calcium

Parathyroid hormone

Increases plasma calcium

Calcitonin from thyroid

Decreases plasma calcium

Calcium deficiency causes

Low intake/absorption, abnormal ratio with phosphorus, vitamin D deficiency

Calcium deficiency

Rickets, osteoporosis, milk fever (hypocalcemia)

Phosphorus

Active and passive absorption, regulated by vitamin D (increases plasma P) and parathyroid hormone (decreases kidney reabsorption)

Phosphorus functions

Component of bones and teeth, energy metabolism, acid-base balance, regulation of metabolism through phosphorylation

Phosphorus deficiency

Rickets, osteoporosis, pica, low production/growth

Magnesium

Absorbed mostly passively through ileum

Magnesium functions

Bone formation, enzyme activation, stabilizes DNA/RNA/ribosomes, ATP metabolism

Magnesium deficiency

Grass tetany (early lactating cows on grass), but adequate levels in most diets

Sodium and chloride

Electrolytes that balance acid-base concentrations and osmotic pressure, transmit nerve impulses, are present in gastric secretions, added to diets to increase palatability

Sodium and chloride deficiency causes

Lactation, rapid growth, high temperatures or hard work

Potassium

Generally high content in plants, third most abundant mineral in body

Potassium functions

Osmotic and acid-base balance, transmission of nerve impulses, cofactor for reactions in carb metabolism, function of heart muscle

Potassium deficiency

Distended abdomen, reduced appetite/growth, tetany, nervous disorders, organ degeneration, abnormal heart function

Potassium toxicity

Excess decreases magnesium absorption, which reduces potassium retention, inducing potassium deficiency

Sulfur

Component of feathers, wool, cartilage, skin; component of insulin, heparin, methionine, cystine; component of vitamins thiamin and biotin

Sulfur deficiency

Decreases feather and wool growth/general growth and weight gain

Iron

Hemoglobin and myoglobin, immune function, brain function; most common mineral deficiency worldwide

Iron deficiency causes

Anything that causes blood loss (menstruation, GIT parasites); newborn/young animals at risk

Iron deficiency

Anemia, poor growth, pale skin/ears, labored breathing, enlarged heart

Iron toxicity

Hemochromatosis (increases iron absorption), hemosiderosis (long-term overconsumption), dogs who eat prenatal vitamins/fertilizer/hand warmers

Copper

Red blood cell formation, component of enzymes, bone development, hair/wool pigmentation, myelin sheath of nerves

Copper deficiency

Vitamin C interferes with absorption; aortic rupture/cardiac issues, swayback, skeletal deformity, depigmentation of hair/wool

Copper toxicity

Sheep more susceptible; neurological symptoms, red urine, jaundice

Zinc

Component of DNA/RNA/peptidases/enzymes, synthesis of skin/keratin/collagen, bone/feather formation, T-cells in immune system

Zinc deficiency

Common in huskies and Nordic breeds; lesions of skin, hair/feather loss, impaired reproduction, delayed puberty, low white blood cells, night blindness

Manganese

Synthesis of bone matrix, bone health, lipid metabolism

Manganese deficiency

Poor absorption through diet; poor bone growth, perosis (slipped tendon in poultry), impaired reproduction

Cobalt

Component of vitamin B12

Cobalt deficiency

Mimics B12 deficiency in ruminants; anemia, defective DNA synthesis, nerve degeneration

Iodine

Component of thyroid hormones

Iodine deficiency

Goiter from enlarged thyroid, cretinism (deficiency in pregnancy causing stillborns and abortions)

Selenium

Prevents mastitis and scours, connected to fertility, immune function, growth

Selenium deficiency

Exudative diathesis (hemorrhagic disease in chicks), liver necrosis, white muscle disease

Vitamins

Essential organic micronutrient compounds that function strictly as individual units, regulate reactions, but do not provide energy

Vitamin synthesis

All vitamins are metabolically essential but may be synthesized in body from precursors; bacteria synthesize B vitamins in ruminants

Fat-soluble vitamins

Absorbed with dietary fat across small intestine which is typically regulated by need; transported in chylomicrons via blood and lymph; liver stores or repackages for delivery to other cells

Water-soluble vitamins

Absorbed across small intestine and regulated by other vitamins/binding proteins; transported in blood and typically not stored; excess filtered into urine

International Unit (IU)

Standard unit of potency for fat-soluble vitamins

International Chick Unit (ICU)

Unit of measure used to express vitamin D requirements for poultry

Weight units (mcg, mg, ng)

Units of measure for vitamins that are not fat-soluble

Retinal

Promotes vision by maintaining cornea

Carotenoids

Potent provitamin A that can be cleaved to yield 2 molecules of vitamin A after absorption; antioxidant activity

Retinoic acid

Helps with gene expression (switches genes on and off), affects differentiation of epithelial cells

Vitamin A deficiency

Night blindness, keratinization, reproductive failure, abnormal skeletal development

Vitamin A toxicity

Hypervitaminosis A in humans with self-medication and over-prescription, skeletal malformations, internal hemorrhages, birth defects/miscarriage

Vitamin D

Fat-soluble, body can make if exposed to enough sunlight; helps with bone development via calcium/phosphorus absorption, regulatory hormone of gene expression

Vitamin D deficiency in young animals

Rickets, bowed legs, knock-knees, outward bowed chest

Vitamin D deficiency in older animals

Osteomalacia, osteoporosis

Vitamin D deficiency in poultry

Decreased egg production/hatchability, thin-shelled eggs

Vitamin D toxicity

Calcification of soft tissue and arteries, stone formation in kidneys, lack of appetite, excessive thirst and urination

Vitamin E

Fat-soluble, interrelated with selenium, antioxidant/free radical scavenger