| The Physico-chemical characters of digestive enzymes and the in vitro digestibility, using crude enzyme and commercial enzyme, of the 9 feed protein ingredients were studied in this paper. The results are as follows.1. The concentration of substrate for protease was 2.0% casein; The optimum pH of protease activity for each digestive organ were 2.2 in stomach, 7.8 in liver, 7.4 in pylorus,7.8 in foregut, 8.2 in hindgut; and the protease activities were 67.66±3.04 in stomach, 10.78±0.82 in liver, 21.00±0.81 in pylorus, 31.83±0.83 in foregut and 27.51 + 1.05(U/g) in hindgut. The optimum temperature of protease activity for each digestive organ were 40℃in stomach, 30℃in liver, 30℃in pylorus, 35℃in foregut, 40℃in hindgut; and the protease activities were 69.40+2.43 in stomach, 13.24+1.67 in liver, 21.78±1.62 in pylorus, 30.85 + 0.46 in foregut and 28.23±1.45(U/g) in hindgut. In the results of the effects of season on protease activities, the protease activities in summer of all digestive organs were higher than in winter. In each digestive organ, the pylorus protease activity gained the biggest loss, which the protease activity in winter was only 13. 47% of the protease activity in summer. But the liver protease activity gained the smallest loss, which the protease activity in winter was 42.16% of the protease activity in summer. In summer, the protease activity ratio of each digestive organ was in the sequence of stomach> foregut > hindgut> pylorus > live, and in winter, which was in the sequence of stomach> foregut > hindgut > live> pylorus.2. The optimum pH of amylase activity for each digestive organ were 5.6 in stomach, 7.8 in liver, and 7.4 in pylorus, foregut, and hindgut; and the amylase activities were 1229.69±38.13 in liver, 588.32±17.79 in pylorus, 380.34±66.34 in foregut, 273.5±19.58 in hindgut, and 188.53±27.56(U/g) in stomach .In the results of the effects of season on amylase activities, the amylase activities in summer of all digestive organs were higher than in winter. In each digestive organ, the stomach protease activity gained the biggest loss, which the amylase activity in winter was only 52.58% of the summer. But the liver amylase activity gained the smallest loss, which the amylase activity in winter was 42.16% of the summer. In two seasons, the amylase activity ratio of each digestive organ was in the sequence of live> pylorus > foregut > hindgut>stomach..3. In the results of the effects of season on lipase activities, the lipase activities in summer of all digestive organs were higher than in winter, but there was no significant differences. In two seasons, the lipase activity ratio of each digestive organ was in the sequence of live > foregut > hindgut>> pylorus stomach.4. The in vitro digestibility of the nine feed protein ingredients (i.e. soybean meal, New Zealand red fish meal, rapeseed meal, expander soybean, meat and bone meal, New Zealand white fish meal, corn protein meal and kelp meal) for Channa argus were studied by means of the in vitro digestibility method using crude enzyme and commercial enzyme. The commercial enzyme was set two treatments, in treatment A, pepsin was added with concentration of 25mg/ml and pancreatin with 50mg/ml; in treatment B, pepsin was added with concentration of 50mg/ml and pancreatin with 25mg/ml; the other conditions were the same in the two treatments. The results showed there was difference in the protein digestibility within two treatments. The effect of the- pepsin was more than the pancreatin in the protein digestibility. The protein digestibility of two treatments were significant correlated with the crude enzyme; and the protein ingredients from animal gained higher digestibility than from vegetal protein feed protein. The linear equation was y=0.7296x+14.706 (R~2=0.7264) in treatment A; and y=0.8151x+4.2889 (R~2=0.7955) in treatment B. |
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