ANSC 318 1st EditionExam # 1 Study Guide Lectures: 1 - 10Lecture 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 inefficientharvest of grains and oil seedsDescribe the Main Differences Between Plant and Animal Based Feeds.Plant-Based feeds have a higher carbohydrate content and a low fat content while animaltissue based feeds are high in fat content and low in carbohydratesHow 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 digestionWhat is a nutrient?Component of feed that aids in support of life: water, minerals, carbohydrates, lipids,proteins, and vitaminsLecture 2 (September 4) Review of Nutrition: CarbohydratesWhat 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 limitedfermentation in pigs.Starch CHO is mainly fermented in the rumen of cattle and turned to VFAs, while it isenzymatically digested in the small intestine of horses and pigs and turned to glucoseProtein is fermented in the rumen to microbial protein and in the small intestine to AAin cattle, while in pigs and horses it is enzymatically digested in the small intestine to AAsLipids are fermented in the rumen to long chain fatty acids in cattle with someenzymatic digestion in the small intestine to the same product, while all lipids areenzymatically digested to LCFAs in pigs and horsesWhat 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 wallReticulum  epithelial lining forms polygonal cells; honeycomb appearanceOmasum  longitudinal folds packed with finely-ground ingesta; separate largeparticles; not much in actual digestionAbomasum  “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 α-bonds and fiber CHOs have β-bonds; they aredigested 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. β-glucans from cell wallList the CHO Monosaccharides by carbon chain length.Hexoses (6 C’s)  glucose, fructose, galactose, mannosePentoses (5 C’s)  arabinose, xyloseWhat are the CHO Disaccharides? What are they made of? Bond Type?Sucrose: glucose – fructose; α-bondLactose: galactose – glucose; α-bondMaltose: glucose – glucose; α-bondCellubiose: glucose – glucose; β-bondWhich 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 topicalgrasses 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 + glucoseLactose –lactase glucose + galactoseSucrose –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 glucoseHemicellulose –hemicellulase mixed sugars  VFAsGlucose  2 acetate + CO2 +CH4 + HeatGlucose  2 propionate + H2OGlucose  1 butyrate + CO2 + CH4How are VFAs absorbed? Small molecule size allows passive diffusion through rumen wall.Which VFA is high in forage? Grain?Forage  acetateGrain  propionateWhat 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 thenVFAs. 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 alot 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 ProteinTrue/False: Lipids have the highest energy content.True, lipids are 2.25x more dense than CHOs and proteinWhat are the main differences between true fats and waxes?True fats have a glycerol backbone and are high energy while waxes have alcohols otherthan 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 moreHow can you estimate a fatty acid’s melting point?Saturated FAs  increase carbons = higher MPUnsaturated FAs  increase double bonds = lower MPDescribe 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 + LCFAGlycerol (3-C sugar) –fermentation VFAUnsaturated LCFA –biohydrogenation