ANSC 318 1st Edition Lecture 2 Outline of Last Lecture I. Demand for Meat Will rise in the Future; Composition of Feedstuffs and Animal ProductsOutline of Current Lecture II.Compare how Nonruminants, Ruminants, and Hindgut Fermenters Digest Nutrientsa.Percentage Make-ups of Each Digestive TractIII.Importance of Watera.Water Sourcesb.Effects on Moisture Intake from Water in Forage and TemperatureIV.Carbohydratesa.Definition and Purpose of Carbohydratesb.Plant Carbohydratesc.Monosaccharides, Disaccharides, Polysaccharides, and Mixed Polysaccharidesd.Digestion in RuminantsV.Starch Carbohydrate Digestiona.Ways Starch is Digested Throughout Each Gastrointestinal Systemb.Enzymes Utilized During Starch DigestionVI.Fiber Carbohydrate Digestiona.Enzymes Used During Fiber DigestionCurrent LectureComparative Nutrition- Nonruminant vs hind-gut fermenter vs ruminant animalsNutrient Pig Horse CowFiber CHO Limited fermentation inlarge intestine (VFA)Fermentative in large intestine (VFA)Fermentative in rumen (VFA)Starch CHO Enzymatic in small intestine (glucose); some fermentative in large intestine (VFA)Enzymatic in small intestine (glucose); some fermentative in large intestine (VFA)Fermentative in rumen (VFA); some enzymatic in small intestine (glucose)Protein Enzymatic in small intestine (amino acids)Enzymatic in small intestine (amino acids)Fermentative in rumen (microbial protein); These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.enzymatic in small intestine (amino acids)Lipid Enzymatic in small intestine (long chain fatty acids)Enzymatic in small intestine (long chain fatty acids)Fermentative in rumen;some enzymatic in small intestine (long chain fatty acids)Nonruminant Gastrointestinal Tract (GIT):-29% stomach (1/3) ***** (know this)-35% small intestine-7% cecum-29% large intestineRuminant GIT:-68% stomach (2/3) ***** -Rumen: papillae on wall that vary in size; largest part of stomach-Reticulum: epithelial lining forms polygonal cells; gives honeycomb appearance-Omasum: longitudinal folds, filled with ground digesta; separate large particles, not much in digestion-Abomasum: “true stomach”-20% small intestine-3% cecum-9% large intestineHindgut Fermenter GIT:-8% stomach-27% small intestine-18% cecum ***-47% large intestine *****-Hindgut (cecum + large intestine) does not use enzymatic digestion, only fermentativeWater:-quality in important! Animals don’t like taste  drink less  eat less  decrease in performance-essential nutrient to support metabolism and temperature regulationSources of Water:1. Drinking Water2. Water in feed – mainly grazing animals; when moisture in forage increases, drinking water intake decreases3. Metabolic water – water of oxidation-if temperature increases  water intake increases-to increase milk production  increase water consumptionCarbohydrates:-2/3 of dry matter (50-85%)-tells nutritional content-main storage of photosynthetic energy in plants-organic molecule; 1:2:1 ratio of C:H:O-nutrient value is dependent upon the animals ability to cleave glycosidic bonds between sugar molecules-Glycosidic bonds tell with carbohydrate cell type a molecule is (they are digested differently)-Starch Carbohydrates (alpha bonds, α)-Fiber Carbohydrates (beta bonds, β)Plant Carbohydrates:-Cell Contents: organic acids, sugars, starches, fructans-Cell Wall + lignin: Pectins and β-glutans, hemicellulose, cellulose-lignin is like bailing wire in plants-the cell contents, pectins, and β-glutans are all nonstructural carbohydrates and are easily digested-hemicellulose and cellulose are fiber (structure) carbohydrates and harder to digestCarbohydrate – Monosaccharides: “Building Blocks”-Hexoses (6-Carbon sugars) ******1. Glucose2. Fructose3. Galactose4. Mannose-Pentases (5-Carbon sugars) ******1. Arabinose2. XyloseCarbohydrate – Disaccharides:-Alpha bonds:1. Sucrose (Glucose + Fructose)2. Lactose (Galactose + Glucose)3. Maltose (Glucose + Glucose) w/ α-glucosidic linkage-Beta bonds4. Cellobiose (Glucose + Glucose) w/ β-glucosidic linkageCarbohydrate - Polysaccharides:1. Araban: Arabinose sugar molecules (5 C’s)2. Xylan: xylose sugar molecules (5 C’s)3. Starch: glucose sugar molecules (4 C’s)4. Glycogen: glucose sugar molecules; found in animal tissue5. Fructans: fructose sugar molecules6. Cellulose: glucose sugar molecules-Starch and Cellulose are extremely similar; starch has α-bonds (all bonds go up or down) and cellulose has β-bonds (bonds alternate up, down, up, down, etc.)Starch Carbohydrate Digestion: *****I. Mouth: Salivary amylase (only in cattle) ***II. Stomach: Starch Carbohydrate is ONLY digested in the stomach in cows **III. Small intestine: only enzymatic digestion in all species-pancreatic amylase-maltase-sucrase-lactaseIV. Large intestine/cecum: fermentative digestion only; limited fermentation of starch carbohydrate in all species-too much starch in hindgut of a horse and acidosis occurs, causing colic and founder-nonruminants digest most starches in the small intestine with a small amount in the hindgut-ruminants digest most through enzymatic digestion, hindgut gets a small amount-Fiber will NEVER be digested enzymatically in small intestine (only in hindgut) *******I. Enzymatic digestion of starch carbohydrate in small intestine of nonruminants and hindgut fermenters:**Starch –amylase dextrinsDextrins –amylase maltoseMaltose –maltase 2-glucoseLactose –lactase glucose + galactoseSucrose –sucrase glucose + fructose**II. These enzymes also digest the starch carbohydrate in the small intestines that bypasses the stomach of ruminant animals-very important in horse and pig (cows have rumen)Fiber Carbohydrate Digestion: ******** (know this)I. Fiber carbohydrate can ONLY be digested by fermentationII. A lot of fiber digestion occurs in the stomach of ruminants and the large intestine of hindgut fermenters; broken down by anaerobic microbesCellulose –cellulase—glucoseHemicellulose –hemicellulase mixed sugarsGlucose  2-acetate + CO2 +CH4 + HeatGlucose  2-propionate +H2OGlucose  1-butyrate + CO2 + CH4-acetate (2 C’s), propionate (3 C’s), and butyrate (4 C’s) are volatile fatty acids (VFAs); they are the end-product of CHO fermentation; because of small particle size, they can be absorbed through passive diffusionIII. limited amount of fiber carbohydrate digestion also