DefinePK

Abstract

ABSTRACT This study aimed to assess the benefits of incorporating an exogenous enzyme (Lysine) and replacing soybean meal (SBM) with cottonseed meal (CSM), with or without lysine supplementation, in Thalia (Catla catla) diets. A total of 225 fish were divided into five groups: Control, 75CSM, 75CSM+Lys, 100CSM, and 100CSM+Lys, with 15 fish per group (Three replicates each). The control group received a CSM-free diet, while CSM replaced SBM in the other groups. Survival rates were unaffected by dietary changes. Growth performance in the 75CSM+Lys group matched the control, but 100% CSM substitution, with or without lysine, negatively impacted growth. Body composition and muscle amino acids were largely unaffected, except for higher arginine and total amino acids in the control. Amylase and lipase activities decreased with CSM replacement, with the highest levels in the control, while protease activity remained same. Replacing SBM with CSM significantly increased blood ALT and AST levels but left ALP levels unchanged. Antioxidant enzyme activities (MDA and CAT) decreased with CSM substitution while SOD remained unchanged. Ratio of villus length/villus width of 75CSM+Lys group was same with respect to control group but other CSM groups showed significant decrease, similarly Tunica muscularis significantly decreased in all dietary groups as compared to control. . In conclusion CSM can be substituted with SBM up to 75% with the supplementation of lysine to balance its level without affecting the growth performance, proximate composition, digestive enzymes activity, antioxidant status and gut morphology of C. catla.