Effect of replacing fish meal by yeast hydrolysate on growth and intestinal function of| juvenile Jian carp (Cyprinus carpio var. jian)

Abstract

This experiment was performed to investigate the effects of replacing fish meal in the diet of Cyprinus carpio var. jian (average weight 19.44±0.06 g) by yeast hydrolysate (YH), on growth, intestinal histology and function. Six hundred fish were assigned into five groups and fed with five isonitrogenous and isocaloric diets replacing fishmeal by 0% (G1), 1% (G2), 3% (G3), 5% (G4) and 7% (G5) YH. YH supplementation at 3% level significantly increased average body weight, daily growth index, feed intake, condition factor, specific growth rate, intestinal villi length and digestive and brush-border enzymes activity compared to the control group (p<0.05). Moreover, YH supplementation significantly increased (p<0.05) intestinal lipase, γ-GT, Na+/K+-ATPase and AKP expression levels. Intestinal Claudin-7 and Occludin mRNA levels in fish of dietary group G5 were significantly higher (p<0.05) than that in the control group. Replacing fish meal with 3% YH increased growth performance, intestinal digestion and absorption, as well as improved intestinal villi length without triggering any negative effects on intestinal tight junction structure. Keywords: Enzyme activities, Growth, Intestinal histology, Jian carp, Tight junction structure, Yeast hydrolysate