Performance of Litopenaeus vannamei at different levels of daily protein intake and carbohydrate/protein ratios in low fishmeal content feeds

The increase in aquaculture production needs optimization of protein in feeds, which should aim to reduce production costs and environmental impact. The aim of this study was to determine the daily protein intake (DPI)  mathematical functions related to body weight, to evaluate diets with low inclusion of fishmeal that present the best performance in terms of protein efficiency and nitrogen retention. Two experiments were carried out, Juveniles of L. vannamei. First trial; feed with commercial diet at four DPI levels (80, 100, 120 and 140 %). In second trial, five diets with different CHO:Protein (2.1, 1.5, 1.1, 0.8 and 0.6) levels were evaluated, according to 120 % DPI level. DPI = 43.174 BW-0.684 was the best mathematical function found to represent the aquaculture feeding practices. A significant effect on weight gain, specific growth rate, feed conversion rate, protein efficiency and nitrogen retention were found due to DPI levels and CBH:P ratios, without any effect on survival. Growth parameters and feed conversion rates increase in both cases, protein efficiency and nitrogen retention diminish with DPI levels using similar protein level and CBH:P ratio but increases with CBH:P ratios at same DPI level using low fishmeal content in feeds.