Dietary Supplementation of Crystalline Amino Acid Improves Growth Performance and Health of Yellow Catfish That Reduced by Plant Proteins Replacement of Fishmeal

Abstract

To evaluate the growth and health of yellow catfish ( 5.50 ± 0.61  g) under the conditions of unbalanced and balanced amino acid composition, an 8-week growth experiment was conducted. Three isoenergetic and isonitrogenous diets were formulated with a graded level of fishmeal: control group was formulated with 560.00 g/kg fishmeal, and 25%PP group and 25%PP + AA group were formulated with 420.00 g/kg fishmeal (replace 25% of fishmeal with plant protein), and then 25%PP + AA group was supplemented with threonine, glycine, alanine, methionine, isoleucine, histidine, and lysine. Compared with control group, weight gain (WG), specific growth rate (SGR), and survival (SUR) in 25%PP group were significantly the lowest ( p < 0.05 ), but feed conversion ratio (FCR) was higher than those in control group ( p < 0.05 ). After supplementation of crystalline amino acid, the WG, SGR, SUR, and FCR in 25%PP + AA group were recovered to the level of control group ( p > 0.05 ). Compared with control group, the activities of trypsin and lipase were significantly increased in 25%PP group and 25%PP + AA group ( p < 0.05 ). Liver impairment was exhibited in 25%PP group, mainly manifested as significantly increased contents of aspartate aminotransferase (AST) and alanine transaminase (ALT) ( p < 0.05 ). Supplementation of crystalline amino acids based on a 25%PP diet significantly reduced activities of AST and ALT ( p < 0.05 ). In addition, total antioxidant capacity (T-AOC), superoxide dismutase (SOD), acid phosphatase (ACP), and alkaline phosphatase (AKP) activities in 25%PP group increased significantly ( p < 0.05 ). Data from 25%PP + AA group showed that crystalline amino acid supplementation ameliorated antioxidant (T-AOC and SOD) and immune (ACP and AKP) ( p < 0.05 ). One of the characteristics of intestinal damage is shortening of villi height, which was significantly reduced in 25%PP group ( p < 0.05 ). In short, unbalanced amino acid intake can impact growth, survival, and physiological status of yellow catfish. Diet supplemented with unbalanced amino acid can cause abnormal accumulation of amino acid content in muscle, resulting in unnecessary consumption of nutrients. Dietary supplementation of crystalline amino acid improves growth performance and health of yellow catfish that reduced by plant proteins replacement of fishmeal.