Effects of dietary yeast hydrolysate on the growth performance, intestine health and digestion of juvenile yellow catfish (Pelteobagrus vachelli ♂ × Pelteobagrus fulvidraco ♀)

Abstract

The effects of dietary yeast hydrolysate on the growth performance, gut health, and digestion of juvenile yellow catfish were evaluated throughout a 62-day feeding trial. Isonitrogenous and isoenergetic experimental diets were prepared. The positive control fishmeal (FM) diet contained 40 % FM. The negative control plant protein diet (PM group) contained 18 % soybean meal (SBM) and 18 % rapeseed meal (RSM). In other two test diets, 1 % and 5 % of yeast hydrolysate (1 % YH and 5 % YH group) were used to replace SBM and RSM (1:1) of PM group, respectively. The results showed no significant differences in the growth performance of yellow catfish among all groups. However, daily food intake was significantly increased in 5 % YH compared with the control PM. Besides, the apparent digestibility coefficient (ADC) of dry matter improved in 1 % YH, compared with FM. And the YH groups had significantly higher total EAA concentrations in plasma than PM group. The 1 %−5 % YH supplement in plant protein diet could improve the length of gut villi and density of distal intestinal microvilli, and enhance the antioxidant capacity of mid intestine and distal intestine. Compared with PM, YH groups increased the digestive capacity of proximal intestine and mid intestine. It is concluded that 1 %−5 % of dietary yeast hydrolysate improved intestine health, food consumption and absorptive ability of yellow catfish.