Supplemental bile acids in low fishmeal diet improved the growth, nutrient utilization of Pacific white shrimp (Litopenaeus vannamei)

This study was conducted to investigate the effects of adding bile acids to low fishmeal diet on the growth, nutrient utilization and serum biochemical parameters of Pacific white shrimp, Litopenaeus vannamei. First, a positive and a negative control diet were formulated to contain 200 g/kg fishmeal (FM20) and 140 g/kg FM (FM14), respectively. Then, bile acids were added to FM14 diet at the inclusion levels of 75 (BA75), 150 (BA150) and 300 (BA300) mg/kg. The five isoproteic and isolipidic diets were fed to shrimp with initial weight of 1.09 +/- 0.01 g for 56 days. The results showed no significant difference in survival among all the groups (>90 %). Compared to FM20 group, the weight gain (-12.9 %), body crude protein content, apparent digestibility of dry matter and protein, bile acid content in hepatopancreas and serum were decreased significantly, while feed conversion ratio (FCR) was increased by 0.17 in FM14 group (P < 0.05). The addition of bile acids to FM14diet tended to increase the weight gain, body crude protein content, apparent digestibility of dry matter and protein (P > 0.05), reaching the similar levels to FM20 group (P > 0.05). Especially, the FCR of BA150 group was significantly lower (-0.16) than that of FM14 group (P < 0.05). Compared to FM14 group, the addition of bile acids (75-300 mg/kg) significantly reduced serum glutathione transaminase activity and increased alkaline phosphatase activity (P < 0.05). In addition, the supplementation of 300 mg/kg of bile acids significantly reduced serum glutathione transaminase activity and increased hepatopancreatic protease activity and serum bile acid content (P < 0.05). In conclusion, the addition of 150 mg/kg bile acids to low fishmeal diet (140 g/kg FM) could improve the growth performance and nutrient utilization of white shrimp.