Study On Estimation Of The Yields And Absorption Rate Of Propionice Acid Originated From Fermentation Of Common-used Feeds For Sheep

This paper mainly studied the techniques for the measurement of glucose synthesized in the liver by propionic acid produced in the rumen (POEG) and the standardization of a methed for measuring the propionic acid yields and its absorption in the runen . With 24 feedstuffs, 5 sheep fed a basal diet were used and the data were obtained for establishment of metabolizable glucose (MG) database. This study includes three parts: Part 1.The development of mathematical models for estimating the propionic acid yields in the rumen from some feed nutrients parameters by in vitro technique. Experiment 1: Chemical analysis of the feedstuffs. Based on the feed protein and carbohydrate fractionation proposed by CNCPS ,4 kinds of 24 individual feeds were analysised for those components available for digestion in the rumen. Experiment 2: For development of In vitro regression equations among propionic acid yields and the feed components. 4 classes of feedstuffs were chosen to determine the propionic yields by in vitro technique; and the experimental procedures were standardized for measuring propionic acid yield of individual feeds.The propionic acid yields after 1 5h (for concentrates) or 24h (for roughages) incubations were as follows: (1) for energy feedstuffs, maize,wheat bran,barely,sorghum,wheat and orts were 0.41.. 0.44.. 0.41.. 0.41.. 0.57.. 0.44nimoll400mg, respectively. (2)for protein feedstuffs, soybean meal, flaxseed meal, sunfiowerseed meal, rapeseed meal,cottonseed meal and corn protein meal were 0.41. 0.32.. 0.38.. 0.34.. 0.16-.. 0.l7mmoIl400mmol,respectively. (3) for high quality roughages, Alfalfa hay, Astragalus absurgens, Wild pean stems ,Wheatgrass, Dahurian wildrye, Brome were 0.31 -. 0.27.. 0.21.. 0.22.. 0.33.. 0.29mmoIl400mg,respectively.(4)for low quality rourages :corn stovers, wheat straws, millet stalks, broomcom stalks,oat straws and potato stems were 0.07.. 0.09.. 0.14.. 0.17.. 0.25.. 0.39mmoIl400mg,respectively. Based on the data obtained from the experimental 1 and 2, the SAS multiregression procedure was used to develop a regressionship among propionic acid yield(Y) and feed components (Xi) . Regression equations obtained were showed as follows: For energy feedstuffs:Y0.005 1 CA-I-0.0037CB 1 +0.0043CB2+0.0 11 PA-0.00093PB 1-0.79 (R2=0999,n=6 p