Evaluation Of Feed Amino Acids Digestibility In Small Intestinal In Dairy Cows

The study was to provide the Chinese Feed bank with intestinal digestibility (Idg) of crude protein (CP) and amino acids (AA) and find out the relationship between the contents of each protein fractions and the degradation and the digestibility of feeds common used in China. The mobile nylon bag technique was used to investigate the apparent small intestinal digestibility of CP and AA in soybean meal(SBM), cottonseed meal(CSM), rapeseed meal(RSM), peanut meal(PM), flaxseed meal(FSM), linseed meal(LSM), distillers dried grains(DDGS), expanded soybean(ES), corn grain(CG), brewer's grains(BG), alfalfa hay(AH), chinese wildrye(CW) and whole corn silage(WCS).Chemical contents were determined according to the methods provided by CNCPS Version 5.0.1. We can see that the content of each protein fractions of the feedstuff with same level CP were dissimilar, and the potential that can provide for animal with true protein were different.2. The CP intestinal digestibility of SBM, CSM, RSM, PM, FSM, LSM, DDGS, ES, CG, BG, AH, CW and WCS were0.91,0.80,0.71,0.92,0.64,0.79,0.96,0.70,0.89,0.61,0.61,0.61and 0.63,while the DM digestibility were 0.69,0.35,0.38,0.74,0.11,0.40,0.80,0.52,0.35,0.67,0.14,0.09 and 0.03, respectively.3. In our result, the disappearance of test protein feeds is higher than other feedstuff. The content of Met is higher than that of Lys in most feedstuffs residues after 16 h incubations in rumen.4. The content of undegraded protein after 16 h incubation was affected by the NDF and PB₃ fractions. The content of RUP have a high relationship with contents of the NDF and PA fractions.5. The absorbed DM increased while the feeds have less PA. The protein content absorbed in the intestine can be mainly predicted by the NDF and PA content. We can see that the intestinal absorbed DM and CP have a high relationship with the content of each protein fractions, the potential of each feedstuffs that can provide for animal intestinal protein were dissimilar, and the potential that can provide for animal with intestinal protein.