Effect of graded levels of taurine supplementation to non-fishmeal diet on growth, nutrient digestibility, intestinal morphology and cytokines gene expression of juvenile red seabream,Pagrus major

摘要

Red seabream (5.4 土 0.03 g) were fed one of the four isonitrogenous (46% crude protein) and isolipidic (12% crude lipid) diets formulated with 50% fishmeal diet (FM, control) or soy and corn protein based non fishmeal diets supplemented with 1.0-2.0%taurine (NFM+T1.0, NFM+T1.5 and NFM+T2.0) for10 weeks. Significantly higher weight gain and specific growth rate were observed in the FM group than the NFM groups (尸く 0.05). Significantly better feed utilization were observed in FM group than NFM+1.0Tand NFM+1.5T groups (P< 0.05). Apparent digestibility coefficient of protein and lipid were significantly higher in FM group than NFM+1.0T group but not NFM+1.5T and NFM+2.0T groups. Typical pathological change for soybean enteropathy such as neutrophilinfiltration was observed in intestinal submucosa of fish fed NFM-based diets. Inflammatory cytokine genes were significantly up-regulated in intestine of NFM groups than FM group. However, the gene expression levels signifinantly decreased with increasing taurine supplementation levels in the NFM groups. These results demonstrated that the complete replacement of fishmeal by plant protein caused growth retardation, pathological changes and high expression of cytokine genes in the intestine but these changes can be ameriolated by taurine in red seabream.