Comparison of partial replacement of fishmeal with soybean meal and EnzoMeal on growth performance of Asian seabass Lates calcarifer.

This study explored the impact of fishmeal replacement by commercial soybean meal (SM) and EnzoMeal (EZM) on Asian seabass Lates calcarifer growth performance using six diets. The six diets comprised two sources of plant proteins with three levels each, including 300 g kg-1 soybean meal (SM30), 300 g kg-1 EnzoMeal (EZM30), 400 g kg-1 soybean meal (SM40), 400 g kg-1 EnzoMeal (EZM40), 500 g kg-1 soybean meal (SM50), and 500 g kg-1 EnzoMeal (EZM50). The soybean level was shown to significantly affect the final fish weight, weight gain, specific growth rate (SGR), survival, feed intake, feed conversion ratio (FCR), and apparent digestibility coefficient (ADC). Further, the plant meal type significantly affected the final weight, weight gain, feed intake, ADC, and body lipid content. The highest final weight was observed in the SM30 group, and the lowest final weight was in the EZM50 group. Fish fed EZM had lower body weight than those fed soybean meal at the same inclusion level. However, once the fish had adapted to the EZM diet the fish weight variation was low. At the 300 g kg-1 and 400 g kg-1 inclusion levels the fish fed EZM showed significantly higher ADC than those fed soybean. The pepsin activity of fish fed EZM at 300 g kg-1 and 400 g kg-1 was higher than those fed soybean meal at the same levels. The enterocyte height in the hindgut of fish fed SM40 and SM50 was significantly higher than those fed EZM40 and EZM50, respectively. This study indicates that EZM could be a potential source of plant protein to replace fishmeal in fish feed as it contains high protein and low anti-nutritional factors. However, the major endpoint measurements on fish performance suggest that low feed intake constrains further EZM inclusion beyond 300 g kg-1 in the diet.