Animal Nutrition Exam: Amino Acids, Protein, and Nitrogen Metabolism, Exams of Animal Biology

Download Animal Nutrition Exam: Amino Acids, Protein, and Nitrogen Metabolism and more Exams Animal Biology in PDF only on Docsity! ANS 313 Exam 3, October 18, 1999 Name: ___________________________ Lab: ____ 2 points per question True/False 1. T F Generally, we consider that there are ten AA which are “essential” and are needed in an animal’s diet; however, in some young animals, there might actually be more than ten that are “essential”. 2. T F Collagen is a structural protein in muscle that increases with age. It makes meat tough. 3. T F “Non-essential” AA are those with no nutritional value. 4. T F The final end product of protein catabolism in a turkey is urea. 5. T F What an animal eats has almost nothing to do with the amino acid profile and 3-dimensional structure of muscle protein—these are determined by the genetic code. 6. T F The branched-chain AA are important parts of the hydrophobic regions in a protein that interact with lipids. 7. T F If you fed 30% alfalfa to an adult pig, the AA balance of the alflalfa would not be very important to you because most of the cell wall in the alfalfa would be fermented in the hindgut anyway and microbial protein has a fairly consistent AA profile. 8. T F Bypass protein is more important for a young growing beef steer than for a mature beef cow in mid-gestation and not lactating. 9. T F Animals use the L-form of amino acids in protein synthesis. Therefore only half of the methionine from chemically-synthesized, commercially-available, D,L-methionine is useful. 10. T F Heating a feedstuff will generally make protein less degradable in the rumen. This is good for a high-producing dairy cow unless it also makes the protein less digestible. 11. T F If feed intake of a cow is increased, microbial protein yield will increase. 12. T F If the rumen pH drops below 6, microbial protein yield will increase. 13. T F Animal proteins usually have higher biological values than the proteins of cereal grains. Multiple Choice (only one best answer per question) 14. ____ When protein is overfed, most of the excess N: a. is stored in liver or muscle. b. is lost from the body in the feces. c. is lost from the body in liver secretions. d. is lost from the body as urinary N. 15. ____ What would likely limit microbial protein production in a dairy cow fed a diet with lots of corn silage and high-moisture corn grain with most of the supplemental protein coming from heat- treated soybean meal and bloodmeal? a. the amount of rumen-degraded protein b. the amount of encapsulated lipid c. the amount of fermented organic matter d. the amount of digested feed 16. ____ Farmer VanDyk feeds his beef steers (~900 lb body weight---close to market weight) a completely mixed diet of high-moisture ensiled corn and corn silage. What would be a good protein supplement to mix with the diet? a. urea b. soybean meal c. bloodmeal d. rumen-protected methionine 1 32 17 Pig A is fed a corn-soy diet containing 18% protein and grows 650 g / day. Pig B is fed a base diet of 12% CP with added lys, met, and trp and grows at 620 g / day. Which pig will likely have the higher blood urea N (BUN) concentrations? a. Pig A because it is growing at a faster rate b. Pig B because it is growing at a slower rate c. Pig B because it is eating more free AA which will be rapidly catabolized d. None of the above 18. The efficiency of capturing dietary N in a young growing pigs is usually about: a. 10% or less b. 20 - 30% c. 50 - 60% d. 70% or more 19. About what percentage of feed protein is normally degraded in the rumen of a lactating cow? a. 20% b. 40% c. 60% d. 80% 20. ____ The source of most of the amino acids in blood is: a. absorption from the small intestine b. amination in the liver c. proteolysis of skeletal and smooth muscle proteins and other body proteins d. none of the above 21. ____ Regarding N cycling in a ruminant: a. it is generally considered useful to a high-producing dairy cow eating a high protein diet b. it is generally considered useful to a maintenance ruminant eating a low protein diet c. running the N cycle is always a waste of energy d. all of the above 22. ____ Of the following AA, which would be considered the "most limiting AA"? a. AA1: Animal requires 20 g. Diet supplies 22 g. b. AA2: Animal requires 40 g. Diet supplies 42 g. c. AA3: Animal requires 10 g. Diet supplies 15 g. d. None of the above are limiting production, so there is no "most limiting AA". Match the compound with its description (one best answer per blank) 23.___ Used to make thyroid hormones a. taurine 24.___ Cats require more of this than other species b. gossypol 25.___ Toxic glycoprotein in cottonseeds c. tyrosine 26.___ Not required by mammals but may be required by poultry d. proline 27.___ The reason that raw soybeans should not be fed to pigs e. purine f. trypsin inhibitor Fill-in-the-Blank (write neatly and spell correctly) 28. __________________ In addition to C, H, and O, all amino acids also contain N. We multiply %N times what number to determine %CP? 29. __________________ Methionine and cysteine are unique because they contain another element in addition to C, H, O, and N. What is it? 30. __________________ In general, muscle tissue is what % water? 31. __________________ The final end product of protein catabolism in a thoroughbred race horse that is excreted in the urine. 32. __________________ The function of this organ or tissue is impaired by high blood ammonia concentrations and consequently visible signs of toxicity can be seen. 2 32