纤维素分解菌对奶牛瘤胃发酵的影响

Effects of ruminal cellulose decomposing bacterium on rumen fermentation in dairy cows

为研究纤维素分解菌对奶牛瘤胃发酵的影响,选用3头体况良好,体重、日产奶量均相近,安装有永久性瘤胃瘘管的泌乳中期荷斯坦奶牛,采用3×3拉丁方试验设计,饲喂3种不同处理的日粮,纤维分解菌饲喂量分别为0(对照组)、0.7×1011cfu/d(试验1组)和1.4×1011cfu/d(试验2组)。试验分为3期,每期预试期15 d,正式期3 d。饲喂纤维分解菌后,测定瘤胃内pH、原虫数量、细菌总数、氨态氮浓度(NH3-N)、挥发性脂肪酸浓度(VFA)、菌体蛋白浓度。结果显示:两试验组瘤胃液pH(试验1组:6.49;试验2组:6.56)、氨态氮(试验1组:14.11;试验2组:14.64)、挥发性脂肪酸浓度(试验2组:101.76)、乙酸浓度(试验1组:67.38;试验2组:68.31)与对照组(pH:6.43、氨态氮:12.89、挥发性脂肪酸浓度:96.7、乙酸浓度:64.42)相比均显著提高(P<0.05),而瘤胃原虫数、丙酸浓度、丁酸浓度和乙/丙酸比值与对照组相比无显著差异(P>0.05)。

This experiment was conducted to study the effect of cellulose decomposing bacteria on rumen fermentation in dairy cow.Three Holstein cows with similar body weight,parity,milk yield and permanent rumen fistula were assigned to 3 treatments with different levels of sodium sulfate ：0（control）,0.7 ×10^11fu/d（treat 1 ）and 1.4 ×10^11fu/d（treat 2） by 3x3 Latin square design.The experiment was divided into 3 periods and each period lasted for 18 d,including 15 d pre-experiment and 3 d experiment.Rumen pH, the number of protozoa, total number of bacteria, the concentrations of am- moniaeal nitrogen（NH3-N）,volatile fatty acids（VFA）and bacterial crude protein（BCP）were determined.The results showed that ： the rumen pH （treat 1 ： 6.49 ; treat 2 ： 6.56 ）, NH3-N （treat 1 ： 14.11 ; treat 2 ： 14.64 ）, VFA concentrations （treat 2 ： 101.76 ） and acetic acid concentration （treat 1：67.38 ;treat 2：68.31 ）were significantly higher than those of the control （P 〈 0.05）, while the number of protozoa, propionic acid, butyrate,propionate and acetate to propionate ratios wasn＇t significantly affected（P 〉 0.05）.