Effects Of Corn Oil On The Rumen Fermentation, Nutrient Metabolism And Fatty Acid Contents In Sheep

The manipulation of rumen fermentation , digestibilty and fatty acid composition in sheep by adding corn oil was studied in this thesis. Nine mature half-sib wether sheep with permanent ruminal and proximal duodenum cannulas were divided into three groups ,and fed on 1.4M basal diets which had concentrate/roughage ratio of 4:6, and added with 0%,4%,and 8% corn oil.The results obtained showed that:1.The rumen fluid samples were collected in 0,2,4,6,8,10 and 12 h after morning feeding.Rumen pH was measured,and NH3-N,VFA,BCP were determined.The results showed that addition of 4% or 8% concentration corn oil significantly increased the rumen pH,did not influence the NH3- N and propionic acid concentration, significantly decreased the total VFA and the ratio of acetic acid to propionic acid.Addition of 4 % corn oil decreased the BCP concentration ,but 8 % corn oil significantly decreased butyric acid concentration, respectively.2.Corn oil supplement tended to decrease the flow of digesta, N in the duodenum(P<0.05), and higher level of corn oil supplement increased the flow of EE in the rumen and the duodenum. The percentage of C18:0 and TVA in the profiles of duodenal digesta fatty acids, and the flow of C16:0,C16:1,C18:0 and c9,t11-CLA were increased significantly (P<0.05), the flow of other fatty acids tended to increase by corn oil supplementation. Dry matter intake and N intake were lower, and dietary digestible N and N retention tended to be lower for the sheep supplemented with corn oil.3. The 4%, 8% group OM, ADF, NDF digestibility were lower, while the 8% group was less than 4% group,the difference was not significant.The digestibility of fat increased significantly from before do not add 60% up to about 90% after the addition,the difference was significant (P <0.01). Although the added corn oil have reduced dry matter intake and nitrogen intake trends, while reducing fecal nitrogen and urinary nitrogen emissions,and has no effect on N digestibility.4. The lower the sheep within the mesenteric fat C10: 0, C15: 0,C17: 0,C18: 0,C20: 0 and other content after the addition, increased t-C18 :1,C18: 2,c9,t11-C18: 2,C20: 5 and other unsaturated fatty acids. Within the subcutaneous fat,C16: 1,C17: 1,C18: 1 content increased, the c9, t11-C18: 2 content increased by a greater extent, C10: 0, C15 : 0, C16: 0, C17: 0, C18: 0 content decreased, especially C18: 0 had a bigger drop. Reduced sheep perirenal fat of C12: 0, C16: 1, C17: 1, C18: 3 content, etc., increased C14: 0, C15: 0, C17: 0 saturated fatty acids, etc., and t-C18: 1, C18: 2 unsaturated fatty acids. Within the omentum fat, saturated fatty acid C14: 0, C15: 0, C16: 0, C17: 0 and unsaturated fatty acid C16: 1, C17: 1 increased with the dietary fat content decreased, t-C18: 1 in content of dietary fatty acids with the increase.