Performance, immune response, and oxidative stress parameters of Litopenaeus vannamei fed diets containing varying carbohydrate/protein, lipid/protein, and energy/protein ratios

The recent increase in aquaculture production has been possible because of production intensification, development of formulated feeds and feed management. However, increased intensification can cause oxidative stress and immune breakdown in shrimp, resulting in poor performance. The problems associated with increased aquacultural intensification can be managed with proper nutrition. Therefore, the objective of this study was to examine the effects of different dietary carbohydrate/protein and lipid/protein ratios on the growth performance, immune response, and oxidative parameters of Litopenaeus vannamei cultured under high stocking density. L. vannamei juveniles were randomly fed 20 experimental diets, comprising five carbohydrate/protein ratios (CBH:P; 0.6, 0.8, 1.1, 1.5, and 2.1) and four lipid/protein ratios (Lip:P; 0.2, 0.23, 0.3, and 0.36), for 49 days. Samples were collected from the shrimp at the end of the feeding trial for immunological, oxidative, and performance analyses. The results of the study showed that the weight gain, specific growth rate, protein efficiency, and nitrogen retention of the shrimp were significantly affected by dietary CBH:P ratios, and the best growth performance was observed in shrimp subjected to the 2.1 CBH:P and 0.3 Lip:P treatments. Similarly, the total hemocyte count of the shrimp was significantly affected by CBH:P treatment, with the highest value obtained in shrimp subjected to 2.1 CBH:P treatment. In contrast, the phagocytic index of the shrimp was not significantly affected by dietary CBH:P and Lip:P ratios. TBARS concentration and superoxide dismutase activity of the muscles were not significantly affected by the treatments; however, protein carbonyl concentration was significantly affected by the treatments. Overall, the findings of the study showed that high dietary CBH:P ratio improved the growth performance of the shrimp, while high dietary Lip:P ratio improved the oxidative status of the shrimp, with the best performance obtained in shrimp subjected to 2.1 CBH:P and 0.3 Lip:P treatments, respectively