The Study On Fiber And Protein Degradability Of Main Feeds In Rumen Of Dairy Cows

Three good body condition China Hositan cows, weight, age, parity is similar and with permanent rumen fistula were chosen for this study(body weight approximately 600㎏, milk production quantity about 13㎏). Rumen dynamic degradability and effective degradation rate of dry matter, fiber matter (NDF, ADF) and protein of main roughages, protein feeds, grains, brans and distillers were estimated by nylon bag technique. The results are as follows:1.Among all roughages, the effective degradation rate of DM,NDF, ADF and CP of alfalfa hay, whole-crop corn silage and rye hay are higher, the effective degradation rate of DM are above 50%, the effective degradation rate of NDF and ADF about 40% (Alfalfa hay about 30%), the effective degradation rate of CP are above 60%. Oat hay, leymus chinensis and cornstalk silage are middle level,the effective degradation rate of DM are above 40%, the effective degradation rate of NDF and ADF are about 30%, the effective degradation rate of CP are above 45%. millet straw and cornstalk are lowest, the effective degradation rate of DM are about 40%, the effective degradation rate of NDF and ADF are about 30%, the effective degradation rate of CP are about 40%.2.Among all protein feeds, the effective degradation rate of DM,NDF,ADF and CP in full-fat soybeans are highest, which are 72.37%,74.36%,69.01% and 74.61% respectively. The effective degradation rate of protein are higher in soybean, cottonseed, whole cottonseed and barley malt sprouts above 60%, The effective degradation rate of protein are lowest in rapeseed meal and DDGS (lower 30%),the others'are 37%～50%. The effective degradation rate of DM are higher in soybean, corn gluten meal and barley malt sprouts above 50%, The effective degradation rate of DM are lower in cottonseed, rapeseed meal, DDGS, brewers dried grain, sesame meal and whole cottonseed (34%～50%), The effective degradation rate of NDF and ADF are higher in corn gluten meal, which are 83.69% and 63.80% respectively. the others'are all lower than 30% expect full-fat soybean and soybean.3.Among all grains, brans and distillers, the effective degradation rate of DM,NDF,ADF and CP of corn are 50.93%,50.74%,49.48% and 52.33% respectively. The effective degradation rate of CP of wheat middling and reddog, corn bran and wheat bran are higher, about 80%;the effective degradation rate of CP of apple waste are lowest (27.49%), the others'are 50%～55%. the effective degradation rate of DM of wheat middling and reddog are highest among all grains, brans and distillers, which are 72.43%;the effective degradation rate of DM of soybean hulls are lowest(38.83%), the others'are about 50%. The effective degradation rate of NDF and ADF of soybean hulls and apple waste are lower, which are 30.97% and 24.21%,28.63% and 26.17% respectively.