Effect Of Different Carbohydrate Sourse On Fermentation And Amino Acid Composition Of Rumen Microorganisms

Four Xuhuai wethers fitted with permanent ruminal cannulas were used in this study. Different acetate to propionate ratio (0:100, 30:70, 50:50, 70:30, 100:0) and different ratio of nonstructural and structural carbohydrates (0.33, 0.63, 1.17, 2.18) were used as substrates to determine the effect of different Carbohydrate sources on rumen fermentation pattems and microbes community. A 4×4 Latin Square experiment was carried out to study the effect of NSC/SC diet on rumen fermentation pattems and the amino acid composition of rumen microbes. PCR-SSCP techniques were used to monitor the dynamics of rumen microbial community. The results of the study showed:1. Different acetate to propionate ratio affected rumen fermentation pattems significantly. The pH of 50:50 group was higher than 0:100 and 30:70 group (P<0.05). The NH3-N concentration of 30:70 group was significantly higher than 50:50, 70:30 and 100:0 group (P<0.01). AA-N concentration of rumen microbes, the index of protozoa to bacteria ratio (P/B) were highest in 50:50 group, and AA-N/Total-N was lowest.2. Effect of different NSC/SC substracts on fermentation pattems were investigated. With the increase of NSC/SC, rumen pH decreased, the NH3-N concentration increased from 0.63 group to 2.18 group. The acetate concentration was highest in 0.33 group, and lowest in 1.17 group. The propionate concentration was highest in 2.18 group, and lowest in 1.17 group. The percent of acetate decreased, propionate increased with the increase of NSC/SC from 0.63 group. Microbial production decreased with the increase of NSC/SC, P/B decreased from 0.63 group, and AA-N/Total-N of protozoa increased with the increase of NSC/SC. Different Carbohydrate sourse induced different AA-N concentration.3. With the increase of NSC/SC, rumen pH decreased, NH3-N concentration increased, the percent of acetate decreased, the percent of propionate increased, and the ratio of acetate to propionate decreased. The acetate concentration of 0.33 group is significantly higher than 1.17 group and 2.18 group (P<0.01). The propionate concentration of 0.33 group is significantly lower than 1.17 group and 2.18 group (P<0.01). The butyrate concentration increased from 0.33 group to 1.17 group, but decreased in 2.18 group. Some amino acids concentration of rumen bacteria varied significantly, such as Asp, Ser, Gly, Val, Met, Leu, Phe, His, Arg, Pro. Different NSC/SC ratios also affected some protoza AA, such as Asp, Ala, Leu, Phe, Lys, His, Arg, Pro. Different Carbohydrate sourse induced different amino acid composition of rumen microbes.4. It was obviously that the SSCP profile varied with treatments. The kinderd index was also widely different among all groups, and emerged dominant bands and peculiar bands under given treatment. Acetate/propionate ratios had effections on microbes community. The kindred index of bacteria was similar between 30:70 group and 50:50 group. The diversity of SSCP fingerprint was also showed under the different NSC/SC substrates. Number of bands on SSCP profile of bacteria is least in 0.33 group. With the increase of NSC/SC, the bands number of 0.63 group and 1.17 group increased. Different Carbohydrate sourse induced different microbes communities.