抄録
The development of proteases, maltase and amylase activities in the digestive organs of rainbow trout, Salmo gairdneri, after hatching was investigated, and the responses of these enzymes to four kinds of experimental diets were also studied for 40 days in the juvenile stage of this fish. The results obtained are as follows.
Proteolytic activities of both pepsin-like and trypsin-like enzymes, and activities of maltase and amylase increased greatly during the 20 days after hatching, and 40-60 days after hatching these enzymes reached the activity level of young rainbow trout.
The activities of these four digestive enzymes in the juvenile rainbow trout fed various diets were all highest in the high-protein diet group (80% fish meal diet) and were generally proportional to the protein content. The growth rate paralleled the changes in enzyme activities. The results obtained with the juvenile rainbow trout were different from those found previously in the young carp.
