ANSC 221 Exam 2 Questions With Verified Answers

ANSC 221 Exam 2 Questions With Verified Answers Where is fat digested, primarily, and how? What is needed to do a good job? - answerOccurs in small intestine Bile is needed to emulsify fat to be digested by enzymes Why don't the protein digesting enzymes digest the cells that make them? - answerPepsin is in the inactive form when secreted How is digestion of carbohydrate different in the ruminant animal (cow) than the nonruminant? - answerRuminant - digested by bacteria into VFA's Non-ruminant - broken into glycogen; used for blood sugar or converted to ATP, stored as fat Bicarbonate in cow vs pig vs horse - answerBicarbonate from pancreas in both, secreted from different locations Where do cows vs pigs get glucose - answerAll animals need glucose Cows - milking get glucose from lactose; glucose eaten is broken down by microbes, so need to make their own - glycogenesis Pig - break down glucose from feed Non-ruminant - glucose from diet, break down carbs and can make glucose from other things (amino acids) Why do protein digesting proteins digest themselves - answerProtein digestive enzyme is made in an inactive form Pepsinogen (inactive) is secreted, becomes active (pepsin) with HCl Protein digestion in ruminant - answerBacteria break down DIP to make bacterial protein, which is later digested with UIP in small intestine, where amino acids are absorbed. VFA's can be absorbed in rumen wall Degradable Intake Protein (DIP) vs Undegradable Intake Protein (UIP) - answerDIP is what microbes get to first, bacteria take it to make proteins UID passes through rumen untouched and ends up in small intestine, where digestive enzymes can digest it If you feed proteins easier to break down, it will break down. If less digestible, more lysine can get to animal (more UIP) Digestion of protein in non-ruminant - answerAmino acids enter bloodstream and supply cells w/ amino acids for protein synthesis; the amino acids not used are deaminated and used for energy NPN is not useful bc there are not microbes to break it down for use. Broken down by enzymes into amino acids, absorbed in small intestine How do we determine the value of a feedstuff? How do we determine the value of its protein? of its energy? - answerAnalyze and run trials to evaluate the protein amount, value, energy value, etc (like the homework) What is meant by: protein digestibility, nitrogen balance, nitrogen retention, biological value, true digestibility or BV vs apparent digestibility or BV? HW3 - answerProtein digestibility - amount of usable protein Nitrogen balance - amount of available nitrogen Biological value - proportion of nitrogen retained True vs apparent BV - true is what's retained, apparent is what's taken in What losses of nitrogen occur from the body? - answerUrine and feces Why is the digestibility of nitrogen and the digestibility of protein the same thing? - answerMeasure protein as crude protein (N*6.25) What does 'endogenous' mean? How could you determine the endogenous secretion? What are the 2 different energy systems? - answerMeans the nitrogen is coming out from the body instead of the evaluated feed Determine the secretion by not feeding any protein, and see the amount of protein secreted (assuming rate of secretion doesn't change) - can also use isotopes The two energy systems - answerTDN - older system to estimate energy on hydrocarbon basis Choleric system to measure energy based on intake (kcal) for digestible and metabolized energy - more complicated