Study On The Digestibility Of Protein Of Feeds With Enzyme By A Pepsin-Pancreatin In Vitro Method

A two-step enzymatic method of pepsin-pancreatin was used to evaluate the digestibility of dry matter and protein of eight feeds(soybean meal, fish meal, cottonseed meal, rapeseed meal, corn, wheat-bran, piglet ration and meat-strain duck finished feed). The feeds were pretreated for 10 hours at 37癈, then pancreatin was added and incubated for 24 hours at 39癈. Three treatments were designed and six different enzyme preparations were used. The feeds without enzyme was the control group. Feeds with enzyme not pretreated for 1. 5 hours was experiment group I and feeds with enzyme pretreated for 1. 5 hours was experiment group II. After incubation, the digestibility of dry matter and crude protein of each group were calculated respectively. The results showed: (1) The digestibility of dry matter of all samples with enzyme were increased than the control group. The protein digestibility of cottonseed meal and rapeseed meal were increased after enzyme added, and the digestibility of group II were increased significantly compared to that of group I (p<0.05). The protein digestibility of soybean meal, fish meal , wheat-bran and corn were increased, too. The digestibility of piglet ration and meat-strain duck finished feed were decreased. The protein digestibility of all feeds except for cottonseed meal and rapeseed meal of group II was lower than that of group I, but there were no significant difference between them. (2) Supplement different enzymes, there were no significant difference in the protein digestibility of corn, piglet ration and rapeseed meal between each supplement enzymes in the two treatments(p>0. 05). The protein digestibility of soybean meal with enzyme D was the highest than all of the others. There was significant difference between the digestibility of soybean meal with enzyme D and with enzyme E and F(p<0. 05). The protein digestibility of cottonseed meal with enzyme C in group II was the highest and it is different significantly to that with enzyme A. (p<0. 05). After enzyme A was added to the fish meal and pretreated for 1.5 hours , the digestibility was the highest. There was significant difference between the digestibility of fish meal with enzyme A and with enzyme B, C and D. The protein digestibility of meat-strain duck finished feed with enzyme B was the highest, and the digestibility between enzyme B and enzyme E and F were different significantly (p<0. 05). After enzyme D was added to wheat-bran and not pretreated, the digestibility was the highest while with enzyme F, the protein digestibility was the highest after 1.5 hours pretreatment.