Effects Of Protein And Nonstructural Carbohydrate With Different Sources On The Rumen Microbial Enzymatic Activities Of Lactating Dairy Cows

The activities of rumen microbial enzymes were affected by protein and carbohydrate with different sources in ruminant diets. The experiment was conducted to examine the effects of different protein and nonstructural carbohydrate sources on the rumen microbial enzymatic activiy of lactating dairy cows with Artificial Rumen Simulation Instrument and.to explone the mechanism of protein and carbohydrate with different sources degraded and utilized by microbe in rumen of lactating dairy cow. The results provided the academic basis for exploiting feed sources of dairy cows, utilizing feed resources, optimizing feed formulation and improving the efficiency of feed resourse.The first part of this study was mainly conducted to study the effects of four diets with different protein sources on the rumen microbial α -amylase, neutral protease, endo-glucanase, FPaser, endo-xylanase and β -glucosidase activities of lactating dairy cows. Four diets were formulated according to their which contain soybean meal, soybean meal and cottonseed meal and rapeseed meal, fish meal and cottonseed meal and rapeseed meal, roasted soybean. The results showed that there were significant effects on the α-amylase (p<0.01) and FPase (p<0.01) , and the endo-glucanase activiy of rumen microbe (p<0.05);wherease there were no effects of the diets on the neutral protease, β-glucosidase and endo-glucanase activities of rumen microbes (p>0.05). The α-amylase activiy of rumen microbe in the diet of with soybean meal as the main sources was significant lower than that in other diets;and the highest α-amylase activity of rumen microbe was found in diet with roasted soybean meal sources as the main source. The FPase of rumen microbe with diet of main roasted soybean meal sources was significant higher than that of other diets. The endo-xylanase activiy of rumen microbe with diet of fish meal and cottonseed meal and rapeseed meal was significant higher than that of other diets.The second part was mainly conducted to study the effect of synchronization of nonstructure carbohydrates (corn, wheat) and protein (soybean meal, roasted soybean) on rumen microbial enzymatic activities of lactating cows. The result showed that there were nonsignificant effects of diets with nonstructure carbohydrates of different sources and their synchronizing ferment with protein on the activities of α-amylase, neutral protease, endo-glucanase, FPase and β-glucosidase of rumen microbe (p>0.05);but the significant effects were found of endo-xylanase activiy of rumen microbe (p<0.05), The endo-xylanase activiy of rumen microbe with diet of rapidly synchronizing ferment (wheat and soybean meal ) was significant higher than diet of slowly synchronizing ferment (corn and roasted soybean).