Evaluation of dietary supplementation of L-lysine and phytase in corn gluten meal-soybean meal based diets for Pacific white shrimp Penaeus vannamei (Boone, 1931)

Abstract

An eight-weeks feeding trial was conducted to study the effects of dietary L-lysine and/or phytase supplementation in corn gluten meal-soybean meal (CGM-SBM) protein blend diets on the growth, apparent digestibility, whole body chemical composition and digestive enzyme activity of Pacific white shrimp Penaeus vannamei (Boone, 1931) juveniles. Five isonitrogenous and isolipidic diets were formulated viz., control diet (T0), with 20% fishmeal was compared against four CGM-SBM based diets, T1 with no supplementation, T2 supplemented with L-lysine, T3 supplemented with phytase and T4 supplemented with L-lysine + phytase. Dietary lysine supplementation had a significant effect (p<0.05) on growth performance and feed conversion ratio (FCR), while supplementation of dietary phytase had no effect on growth performance. Apparent digestibility coefficient (ADC) value for crude protein increased by 2.5 to 3% on supplementation of phytase (500 FTU kg^-1 feed) in the diets. The protein digestibility increased by 8 to 11% with the addition of dietary phytase than other treatment groups with no supplementation of phytase. The amylase and lipase enzyme activity of T3 and T4 supplemented with dietary phytase was higher than the groups that were not supplemented with dietary phytase. Higher protease activity was observed in T2 diet supplemented with dietary L-lysine. L-lysine and phytase supplementation in plant based CGM-SBM protein blend diets resulted in better growth performance of P. vannamei.

Keywords: Apparent digestibility, Corn gluten meal-soybean meal based diet, Digestive enzyme, Growth performance, L-lysine, Penaeus vannamei, Phytase,