ANSC 303 1st Edition Lecture 15Outline of Last Lecture I. VFA FormationII. Uses of VFAIII. VFA Production – Molar RatioIV. Importance of Rumen pHa. Influenced by:b. Determines:Outline of Current Lecture I. Rumen FermentationII. Glucose RequirementsIII. Metabolism – Fate of Absorbed Glucose/VFAIV. Carbohydrate ComparisonA. Extent of glucose from absorption from the gut? B. Primary energy substrate?C. Cellular demand for glucose?D. Importance of gluconeogenesis?E. Primary substrate for fat synthesis?V. Carbohydrates OverviewA. Monogastrica. Stomachb. Small Intestinei. Amylopectinii. Cellulosec. Large IntestineB. Ruminanta. Rumeni. Amylopectinii. Celluloseiii. VFAsCurrent LectureThese 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.I. Rumen FermentationA. Gases are primary byproducts of rumen fermentationa. Carbon dioxideb. MethaneB. Usually these gases are eructateda. If not, leads to bloatb. Rumen is on the left, the left side will be distendedi. Severe distension on left side of the ruminantii. Can result in death II. Glucose RequirementsA. Ruminant animals are different from monogastricsa. They have a lower fasting blood glucose (40 - 60 mg/dl)b. Less fluctuation i. Constant intakeii. Continuous VFA production A. VFA travels directly out of rumen into bloodstreamiii. Continuous digesta flowiv. Continuous gluconeogensisA. Increases post-mealB. Keeps levels constantC. Uses propionate B. Ruminant animals need to make their own a. Propionate is importantb. Therefore, propionate is very prevalent right after feedingC. Less meal dependentD. Ruminants are continuous eatersIII. Metabolism - Fate of Absorbed Glucose/VFAA. Ruminants are very stingy with glucoseB. Glucosea. 1st priority - glycogen storageb. 2nd priority - provide ATP i. Brain ii. Central nervous system iii. Red blood cellsc. 3rd priority - the ruminants DO NOT store glucose as fati. This is blocked in the ruminant system ii. Waste of glucoseiii. Lack enzymes to convert glucose to fatC. VFAa. Acetatei. Fatii. ATP b. Propionate i. Gluconeogensisii. ATP c. Butyratei. ATP IV. Carbohydrate Comparison A. Extent of glucose from absorption from the gut?a. Non-Ruminant: high b. Ruminant: lowi. Converts glucose to VFAii. No glucose to absorb B. Primary energy substrate?a. NR: glucoseb. R: VFAC. Cellular demand for glucose?a. NR: high i. Demand is easily metii. Brain, CNS, RBCb. R: Highi. Difference is what is absobed and what you wantii. Brain, CNS, RBCD. Importance of gluconeogenisis?a. NR: minimal b. R: very important i. Need glucose somehowii. Continuous iii. FastE. Primary substrate for fat synthesis?a. NR: glucose b. R: acetatei. NOT GLUCOSEii. There are no enzymes to store as fat V. Carbohydrates OverviewA. Monogastric (pig)a. Stomach i. Amylopectin and cellulose travel straight to the small intestineb. Small Intestinei. AmylopectinA. Non-structuralB. PolyC. Glucose-glucoseD. A 1-4 and a 1-6E. Breaks down poly to di F. Pancreatic a-amylase breaks a 1-4 bondsG. Maltose a 1-4 and isomaltose a 1-6 leftH. Isomaltosea. Needs isomaltaseb. Brush border enzymec. Two glucose left overI. Maltosea. Break down needs maltaseb. Maltase found in brush borderc. 2 glucose resultedJ. How is glucose passed into the bloodstream?a. Look at cellular levelb. SGLT-1c. Na/K ATPase passes Na out of the cell d. Na and glucose attach e. SGLT-1 allows Na and glucose to pass without the need for ATP ii. CelluloseA. Structural B. Poly C. Glucose-glucoseD. B 1-4E. Not broken down F. No cellulase producedc. Large Intestinei. Species dependentii. CelluloseA. Need cellulaseB. ^ produced by cellulolytic bacteriaC. Not 100% will be broken down a. Depends on the number of bacteria there areD. Broken down to glucoseE. Glucose broken down to VFAsF. VFAs passive diffuse to the bloodstreamB. Ruminanta. Rumeni. AmylopectinA. <6 hours to digestB. Grain or concentrationC. Lowers pHD. AcidosisE. Amylopectin needs amylasea. Breaks both a 1-4 and a 1-6 bondsb. Leds to glucose and then VFAsF. VFAsa. Propionateb. Butryatec. Lactate (only possibility)ii. CelluloseA. FedB. Slow response - 12-24 hoursC. Needs cellulaseD. Leads to glucose and then to VFAsE. VFAs = acetatea. Used for fat storageiii. VFAsA. The VFAs pass to the bloodstream through passive diffusionB. Butryate most likely to be left behind because the cells like it for