The supplementation of nutrient additives in broad bean‐based diet improved the growth of “crisped” grass carp, Ctenopharyngodon idellus

Abstract

AbstractTo investigate the effects of supplemental nutrient additives in broad bean‐based diets on growth, flesh quality, and collagen gene expression of grass carp, five diets were prepared, including complete formula diet (control), soaked broad bean (SBB), and three broad bean‐based diets containing 80% broad bean without (BBD1) or with the supplementation of methionine (BBD2), and methionine+vitamins+minerals (BBD3), and were fed to grass carp (171.9 ± 1.1 g), Ctenopharyngodon idellus, for 84 days. The results showed that broad bean‐based diets significantly increased weight gain (WG) and reduced the feed conversion ratio (FCR) of grass carp when compared to the SBB (p < .05). The BBD3 group reached levels similar to the WG and FCR of the control group (p > .05). Grass carp fed the BBD3 diet had lower steaming loss of flesh, higher muscle fiber density, and higher collagen content in muscle and skin than the control (p < .05). The relative expressions of COL1A1 and COL1A2 mRNA in muscle and skin were significantly higher in the BBD3 and SBB groups than in other groups (p < .05). In conclusion, the combination of methionine, vitamins, and minerals in broad bean‐based diets promoted the growth of “crisped” grass carp and improved flesh quality and collagen gene expression when compared to the control formula diet.