ASC 378 EXAM 4 QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026

ASC 378 EXAM 4 QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026 Vitamins - Answers very diverse in fxn and structure organic substances required by animals in small amounts for normal metabolism. obtainable from diet or a precursor Are not synthesized within body at a rate adequate for normal metabolism Vitamins as organic compounds - Answers 1. component of natural food (CHO/fat/protein) 2. present in foods in very small amounts 3. essential for development of normal tissue for good health, growth and maintenance Vitamins are primarily required as a..... - Answers coenzyme in nutrient metabolism Fat-soluble vitamins - Answers A, D, E, K Water-soluble - Answers Vitamin C and B complex Provitamins - Answers compounds that give rise to the vitamins Antivitamins - Answers compounds that inhibit vitamins in some manner Vitamin deficiency - Answers inadequate supply that results in clinical signs/symptoms Minimal supply - Answers dietary level of sufficient to prevent clinical signs/symptoms. Growth is normal under ideal conditions. Optimal supply - Answers meet all needs for optimal growth and performance Specialized supply - Answers meets all metabolic needs under stressful conditions Cause of vitamin deficiency - Answers 1. inadequate level in diet 2. problems with absorption 3. inability to synthesize sufficient quantities by the animal, therefore must be obtained from the diet Cofactor - Answers non-protein molecule required for enzyme function Coenzyme - Answers cofactor that is an organic molecule Prosthetic group - Answers a cofactor that associates with an enzyme covalently or very tightly Vitamin A proper name - Answers retinol Vitamin D proper name - Answers cholecalciferol Vitamin E proper name - Answers a-tocopherol Vitamin K proper name - Answers K1= Phylloquione Vitamin B1 proper name - Answers Thiamin Vitamin B2 proper name - Answers riboflavin Vitamin B6 proper name - Answers pyridoxine Vitamin B12 proper name - Answers cobalamine Other water-soluble vitamins - Answers pantothenic acid niacin choline biotin folic acid Units of vitamins - Answers used because different sources have different biological activities IU= international unit USP = US Pharmocopeia units amount can differ fro supply of same vitamin based on what carrier it is paired with Vitamin A carriers - Answers active as alcohol, aldehyde, acetate, palmitate, and acid (many diff carriers) occurs ONLY in animals Retinoic acid and Vitamin A - Answers will not fulfill requirements for visual purple and reproduction Vitamin A palmitate - Answers most popular synthetic form Vitamin A form in plants - Answers carotenoids Highest vitamin A content - Answers highest found in liver fish liver oils are high colostrum contains 10X as much as other milk What improves vitamin A absoprtion? - Answers bile salts and dietary fat Vitamin A structure - Answers Functions of Vitamin A - Answers 1. Role in visual purple cycle 2. maintenance of normal epithelium 3. concerned in normal bone formation (slow osteoblast differentiation if diet is deficient) 4. nervous symptoms due to failure of spinal column and other bone developments 5. Maintenance of normal cerebrospinal fluid pressure 6. necessary for normal reproduction (can reverse infertitily) Vitamin A deficiency signs - Answers 1. night blindness 2. nervousness 3. reduced appetite 4. increased keratinization of epithelium which leads to increased invasion of infective organisms 5. noninfective changes 6. congenital malformations 7. liver and kidney damage 8. diarrhea 9. testicular degeneration Vitamin A deficiency diseases - Answers Xeropthalmia copious lacrimation Xeropthalmia - Answers dry condition of eye and ulcerations problem in children and rats Copious lacrimation - Answers runny eyes of cattle and sheep secondary infections Hypervitaminosis A signs - Answers 1. skin thickening 2. interference with bone development 3. prolonged prothrombin (blood clotting) time 4. increase in CSF pressure (hydrocephalus) 5. lowered plasma cholesterol in chicks 6. resorption of fetus 7. decreased appetite Carotene conversion in rats, sheep, goats, and pigs - Answers carotene not absorbed in blood stream but rather converted to vitamin A in intestinal wall Carotene conversion in cows and horses - Answers have considerable amounts in plasma, only part of carotene in feed is converted to Vit A in the intestinal wall, plasma may be stored in liver and fatty tissues of body Vitamin A storage - Answers main storehouse is the liver (70%-93%) the remainder is soft tissue depots liver acts as buffer against subsequent dietary inadequacies Problem with low carotene levels in beef cattle - Answers over wintering of beef cattle on low carotene forage will cause liver stores to maintain plasma A levels until they are depleted and drop rapidly Vitamin A preferred isomer - Answers trans Vitamin A preferred carotenoid - Answers B-carotene What process has the biggest effect (chemical change) on Vitamin A biological activity - Answers esterification Highest B-carotene level species - Answers horses Lowest B-carotene level species - Answers rat Vitamin A sources - Answers fish oils, egg yolk, liver, milk fat Carotene sources - Answers high in green leafy plants; green color or chlorophyll masks yellow of carotenes Vitamin A practical considerations - Answers easily destroyed due to various factors (accelerated at high temps) certain metals aid destruction of appreciable toxicity concern along with Vit D What species is vitamin A requirements being met especially important - Answers poultry, don't have a lot of access to grass Functions of Vitamin D - Answers 1. promotion of Ca and P absorption 2. thought of as a hormone 3. required for proper calcification Promotion of Ca and P absorption in vit D - Answers 1. synthesis of a Ca-binding 2. may raise permeability of mucosal cells to Ca and P 3. absorbed in intestine as Vit D Vitamin D as a hormone - Answers 1. active form is made by the kidney and travels to act on bone and intestines 2. there are feedback mechanism for controlling synthesis and secretion of the active form Species with highest requirements of Vit D due to its role in calicification - Answers 1. young and lactating animals 2. swine and poultry (fastest growing) 3. Wide Ca and P ratios Calcitonin - Answers lowers blood Ca levels puts Ca back into bone PTH - Answers raises blood Ca levels, take Ca out of bone Rickets - Answers disturbance of Ca and P metabolism - poor calcification of bones Pigeon breast - Answers softening of bones in the chest bowing of the chest Osteomalacia - Answers importance of D to adult, failure of bone matrix to be mineralized Where is vitamin D stored - Answers liver Vitamin D deficiencies in chickens - Answers 1. thin shells on eggs 2. decreased hatchability 3. decreased egg production Vitamin D deficiencies in dairy cows - Answers parturient paresis parturient paresis - Answers milk fever found in lactating cows 1-24 hrs after calving drain of blood Ca into milk parturient paresis symptoms - Answers 1. lack of appetite 2. dull and listless 3. struggling and unable to stand 4. low blood Ca and P 5. coma Vitamin D3 proper name - Answers cholecalciferol (preferred) Vitamin D2 proper name - Answers ergocalciferol Vitamin D structure - Answers Ergocalciferol structure - Answers Cholecalciferol structure - Answers Chemistry of vitamin D - Answers Ergosterol (plants) ----(irradiation)---- irradiated ergosterol 7-dehydrocholesterol ------(irradiation)---- irradiated 7-dehydrocholesterol Vitamin D assay - Answers biological assay mainly used vitamin D2 and D3 both effective for mammals (vit D3 is 30 times more effective than D2 for chicks) Curative method of vit D assay - Answers line test based on observation of epiphyseal cartilage in rats Preventative method of Vit D in assay - Answers % bone ash in chicks Vitamin D in foods - Answers no active vitamin D in growing plants (ergosterol ---- ergocalciferol) in animals - sunlight on skin (predominant provitamin ----- "active" cholecalciferol) received by eating vit D sources - rich in egg yolks, liver, fish oils, fish meals, and roughages Vitamin D is not readily secreted in.... - Answers milk Practical problems with Vit D - Answers effectiveness of sunlight depends on intensity of UV rays confinement in winter ruminant pre-intestinal destruction Overdosage of Vitamin D - Answers hypercalcemia, Ca deposits in soft tissues excess used in some rat poisons Vitamin D effects on diseases in humans - Answers accelerates resolution of inflammatory responses during tuberculosis treatment helps with lupus obesity in elderly daytime sleepiness uterine fibroids etc. Pyroxidine (B6) structure - Answers pyridoxal phosphate structure - Answers Pyridoxamine phosphate structure - Answers Functions of Vit B - Answers pyroxidal phosphate and pyridoxamine phosphate are the active forms after absorption are phosphorylated in the liver serves as a coenzyme in several enzyme systems concerned in protein/amino acid metabolism Vit B in transamination - Answers necessary for this process provides the synthesis of non-essential amino acids, involve transfer of amino group to keto acids Most abundant of transaminases - Answers catalyzes transamination of glutamic acid to oxaloacetic and pyruvic acids Decarboxylation reactions with pyridoxal phosphate - Answers serves as coenzyme and decarboxylates several amino acids. More abundant in microorganims than animal tissues B6 and synthesis of niacin - Answers synthesized from tryptophan in B6's absence, abnormal product xanthurenic acid is formed What is an indicator of B6 nutrition in pigs? - Answers level of xanthurenic acid in urine Vitamin B6 influences..... - Answers intestinal transport and tissue uptake of amino acids intestinal absorption of amino acids can be diminished with a deficiency of Vit B Antivitamins of Vit B - Answers desoxypyridoxine and isoniazid are antagonists and appear to compete with pyridoxal phosphate for the active site on the apoenzyme Deficiency of Vitamin B - Answers 1. growth failure 2. acrodynia in rats (dermatitis) 3. urinary calculi in cattle 4. anemia in dogs, pigs, rats 5. convulsions/seizures 6. suppressed appetite Acrodynia - Answers form of dermatitis in rats, characterized by dermatitis of tails, ears, mouth, and paws, accompanied by edema Urinary calculi - Answers due to defect in glycine metabolism glycine ---- glyoxal ------ oxalic acid ------ Ca------ calcium oxalate (forms calculi) Highly insoluble Ca oxalate precipitates as - Answers "stones" in kidney and urinary tract Vit B anemia cell size and concentration - Answers microcytic and hypochromic Sources of Vitamin B - Answers yeast, liver, muscle meat, milk, cereal grains, usual food supply so rich in vit B very unlikely to have deficiency 3 M's of niacin - Answers 1. meat 2. molasses 3. meal (corn) 3 D's of niacin - Answers 1. dermatitis 2. diarrhea 3. dementia Poultry conjugate how many molecules of nicotinamide with ornithine - Answers 2 Ruminants excrete what unchanged? - Answers nicotinic acid and nicotinamide Acid and amide structural components - Answers colorless crystalline substances readily soluble in water and alcohol Functions of niacin (B3) - Answers 1. present as pyridine nucleotides in animal tissues 2. component of two coenzymes: NAD and NADP NAD and NADP functions - Answers function in biological oxidation-reduction systems via ability to serve as hydrogen transfer agents ***NAD is specific for hydrogenases concerned in the TCA cycles, serves as electron acceptor Niacin structure - Answers Niacin deficiencies - Answers 1. black tongue in dog 2. pellagra in man 3. Casal's necklace Black tongue in dogs - Answers black colorization of tongue