Effect of different level of methionine on growth performance and body composition of juvenile of stellate sturgeon (Acipenser stellatus)

Methionine is an essential amino acid for fish, which deficiency of it reduces the growth and efficiency of the food. Methionine is usually the first essential limiting amino acid in many diets, especially those with high levels of plant proteins. This study aimed to investigate the effect of increasing the Methionine on growth, and body composition in juvenile of stellate sturgeon (Acipenser stellatus) during 8 weeks. A total of 200 fish were randomly distributed in 10 tanks. Fish were fed with diets containing different levels of the amino acid Methionine (0.5, 1.5, 2.5 percent and control diet). Growth and nutrition indices, including condition factor, body weight increasing, specific growth rate, food conversion ratio, body weight index, visceral index and carcass composition were evaluated. Based on the results, there was no significant difference in growth parameters between the experimental treatments, except for the feed conversion ratio, which had a significant difference (P <0.05). Accordingly, the highest performance of growth indices in the treatment contained 2.5 percent and the feed conversion ratio was related to the treatment of 1.5 percent methionine and the lowest was different in different treatments. On the other hand, the results showed that the presence of Methionine in the diet increases the amount of protein and fat in the treatment of 0.5 and 2.5 percent compared to the treatment of 1.5 percent. Therefore, it can be stated that the addition of the 2.5 percent Methionine in the diet of stellate sturgeon juvenile will improve growth performance.