Dietary effects of Zinc-L-Methionine supplementation on the growth, nutritional performance and haematology of African Catfish Clarias gariepinus (Burchell 1822)

Abstract

Zinc-L-methionine represents an important advancement in aquaculture nutrition; the enhanced bioavailability of zinc-L-methionine compared to conventional inorganic zinc sources allows for superior absorption through amino acid transport mechanisms in the intestinal tract. However, the mechanisms of zinc-L-methionine in nutritional physiology of African catfish is still poorly understood. The present study assessed the dietary effects of zinc-L-methionine supplementation on growth performance, nutrient utilization and basic hematological profile of African catfish, Clarias gariepinus juveniles for 56 days. Six isonitrogenous diets were formulated to meet the 40% crude protein requirements of C. gariepinus juveniles. Fish were fed diets with different supplementation levels of zinc-L-methionine. The graded levels were 0.00g (control), 0.01g, 0.02g, 0.03g, 0.04g, 0.05g/100g for each diet denoted as T1, T2, T3, T4, T5 and T6 respectively. Key performance indicators, including weight gain, feed conversion ratio (FCR), protein efficiency ratio, (PER), specific growth rate (SGR) and basic hematology profile of African catfish juvenile were measured after the feeding trials. Results showed that fish fed diets with 0.03g/100g zinc-L-methionine supplementation demonstrated significant (P<0.05) improvements in weight gain, PER, FCR, SGR, an impressive growth rate and good hematological profile compared to the control and other groups. Additionally, the present study has proven that zinc-L-methionine at 0.03g/100g and 0.04g/100g inclusion levels have the potential of improving fish growth parameters and nutrient utilization for sustainable fish production without any detrimental effect on the basic health parameters.