Comparisons of Corn Gluten Meal and Fish Meal Digestion in Yellowtail (Seriola quinqueradiata) by In vivo and In vitro Approaches

摘要

The lower digestibility of corn gluten meal (CGM) has been reported in yellowtail (Seriola quinqueradiata), This paper studied the factor (s) involved in such low digestibility both in vivo and in vitro, The post-feeding profiles of pepsin and trypsinsecretion, and trypsinogen activation were investigated in vivo by feeding yellowtail (average body weight, 720 g) either a fish meal-based diet (FMD) or a diet containing CGM (CGMD). The activities of pepsin and trypsin in CGMD-fed fish were not significantly different from those in FMD-fed fish. On the other hand, the in vitro study revealed that the catalytic ability of stomach and pyloric caeca extracts to digest CGM were lower than in FMD digestion, These results suggested that the lower digestionof CGM compared to fish meal was attributed to the lower catalytic ability of digestive proteases to CGM and not to a lower secretion volume or activation rate of proteases such as pepsin and tr ypsin.