Strategic replacement of soybean meal with local cotton seed meal on growth performance, body composition, and metabolic health status indicators in the major South Asian carp Catla catla for aquaculture.

This study assessed the effect of substituting soybean meal (SBM) with cotton seed meal (CSM) on different biological traits in thaila (Catla catla). Fish (n = 225) with an average initial body weight of 41.53±0.68 g were shifted into hapas (3 (L) x 2 (W) x 1 (D) m) in triplicate (15 fish/replicate). Hapas were divided into five dietary groups: 0CSM, 25CSM, 50CSM, 75CSM, and 100CSM diet treatments were administered diets for a period of 90 days. SBM was replaced by CSM at the levels of 0, 25, 50, 75, and 100%. The results showed that fish survival and growth performance were not affected by the inclusion of CSM in the fish diet up to 50% as a replacement of SBM, but higher replacement levels showed a negative effect. Similarly, body composition and most of the muscle amino acid profiles were not affected significantly (P>0.05) by replacing SBM with CSM. Digestive enzyme activities were significantly (P<0.05) decreased by increasing the level of CSM in the fish diet. Alanine transaminase (ALT) and aspartate transaminase (AST) levels increased significantly (P<0.05) with increasing dietary CSM levels, while alkaline phosphatase (ALP) levels remained the same. Malondialdehyde (MDA) and catalase (CAT) activity decreased significantly (P<0.05), but superoxide dismutase (SOD) activity showed no change. For the intestine, the villus height to villus width ratio and thickness of Tunica muscularis were also better in 25CSM, and their values decreased as the CSM inclusion level increased in the fish diet. In conclusion, SBM could be replaced partially (up to 50%) with CSM without compromising growth performance, whole body proximate composition or immunity of C. catla. [ABSTRACT FROM AUTHOR]