ANSC 318 1st Edition Exam 1 Study Guide Lectures 1 10 Lecture 1 September 2 Review of Nutrition What accounts for 2 3 of livestock production costs Feed Why do developing countries have a lower crop yield Developing countries have more trouble with post harvest losses due to inefficient harvest of grains and oil seeds Describe the Main Differences Between Plant and Animal Based Feeds Plant Based feeds have a higher carbohydrate content and a low fat content while animal tissue based feeds are high in fat content and low in carbohydrates How much is global meat demand expected to increase by the year 2020 Why 55 due to increased feed efficiencies of beef pork and poultry What is a feed Material that is capable of being absorbed and utilized by an animal after digestion What is a nutrient Component of feed that aids in support of life water minerals carbohydrates lipids proteins and vitamins Lecture 2 September 4 Review of Nutrition Carbohydrates What are the key similarities and differences between how fiber CHO starch CHO protein and lipids are digested in horses pigs and cattle Fiber CHO is fermented in the large intestine in horses and cattle but has limited fermentation in pigs Starch CHO is mainly fermented in the rumen of cattle and turned to VFAs while it is enzymatically digested in the small intestine of horses and pigs and turned to glucose Protein is fermented in the rumen to microbial protein and in the small intestine to AA in cattle while in pigs and horses it is enzymatically digested in the small intestine to AAs Lipids are fermented in the rumen to long chain fatty acids in cattle with some enzymatic digestion in the small intestine to the same product while all lipids are enzymatically digested to LCFAs in pigs and horses What percentage of the GIT does the stomach make up in pigs cattle and horses Pigs 29 1 3 Cattle 68 2 3 Horses 8 What percentage of a horses GIT is the hindgut 18 cecum and 47 large intestine 2 3 What are the parts of the ruminant stomach and their purposes Rumen largest part papillae of various sizes line the rumen wall Reticulum epithelial lining forms polygonal cells honeycomb appearance Omasum longitudinal folds packed with finely ground ingesta separate large particles not much in actual digestion Abomasum true stomach What is the most often overlooked nutrient What does it support Water It supports metabolism and temperature regulation What 3 ways can animals get water Drinking water moisture in feed grazing and metabolic water water from oxidation How are the nutritive value of CHOs determined By the ability of an animal to cleave glycosidic bonds between sugar molecules Why are glycosidic bonds so important to CHOs They tell cell type Starch CHOs have bonds and fiber CHOs have bonds they are digested very differently What part of the Plant has fiber CHO Starch CHO Fiber Structural CHO cell wall lignin hemicellulose cellulose and lignin Starch Nonstructural CHO cell contents and pectic S glucans from cell wall List the CHO Monosaccharides by carbon chain length Hexoses 6 C s glucose fructose galactose mannose Pentoses 5 C s arabinose xylose What are the CHO Disaccharides What are they made of Bond Type Sucrose glucose fructose bond Lactose galactose glucose bond Maltose glucose glucose bond Cellubiose glucose glucose bond Which polysaccharide is found in animal tissue Glycogen What are the main differences between the CHO content of cereal grains and topical grasses Cereal grains are much higher in starch CHO making them highly digestible while topical grasses are high in cellulose and hemicellulose both of which are fiber CHOs and less digestible Which species utilizes salivary amylase in starch CHO digestion Pigs Illustrate how starch is digested in the small intestine of nonruminants and hindgut fermenters Starch amylase dextrins amylase maltose maltase glucose glucose Lactose lactase glucose galactose Sucrose sucrase glucose fructose True False Fiber can be digested enzymatically in the small intestine False Fiber can only be fermented or digested enzymatically in the hindgut Illustrate how fiber CHO is digested Cellulose cellulase glucose Hemicellulose hemicellulase mixed sugars VFAs Glucose 2 acetate CO2 CH4 Heat Glucose 2 propionate H2O Glucose 1 butyrate CO2 CH4 How are VFAs absorbed Small molecule size allows passive diffusion through rumen wall Which VFA is high in forage Grain Forage acetate Grain propionate What are the key similarities and differences in Fiber CHO digestion between cattle and horses Both do not digest starch in the small intestine and convert fiber to sugar and then VFAs However cattle ferment fiber in the stomach while horses utilize fermentation in the hindgut What are the key similarities and differences in Starch CHO digestion between cattle and pigs Both species use limited fermentation in the large intestine However pigs only utilize a lot of enzymatic digestion to sugar in the small intestine and then use active transport from the lumen while cattle utilize a lot of fermentation from starch to sugar and then to VFAs in the stomach and have limited enzymatic digestion in the small intestine Lecture 3 September 9 Review of Nutrition Lipids and Protein True False Lipids have the highest energy content True lipids are 2 25x more dense than CHOs and protein What are the main differences between true fats and waxes True fats have a glycerol backbone and are high energy while waxes have alcohols other than glycerol and are less digestible Describe the lipid structure naming system and the difference between saturated and unsaturated fats of carbons of double bonds i e C18 1 18 carbons 1 double bond Saturated fatty acids have no double bonds while unsaturated FAs have 1 or more How can you estimate a fatty acid s melting point Saturated FAs increase carbons higher MP Unsaturated FAs increase double bonds lower MP Describe Enzymatic Lipid Digestion in all species Triglyceride lipase diglyceride LCFA Diglyceride lipase monoglyceride LCFA FAs absorbed into lymph system Describe Fermentative Digestion in Ruminants Triglycerides hydrolyzation glycerol LCFA Glycerol 3 C sugar fermentation VFA Unsaturated LCFA biohydrogenation saturated LCFA What are proteins made out of Amino Acids List the essential amino acids PVT TIM HALL Phenylalanine valine tryptophan threonine isoleucine methionine histodine arginine lysine leucine What are the proteolytic enzymes and where do they come from Pepsinogen inactive when secreted