The effect of dietary L-carnitine and lipid on growth performance, feed utilization and body composition of Nile tilapia, Oreochromis niloticus and common carp, Cyprinus carpio were evaluated in two separate 2×5 factorial experiments as well as the effect of dietary L-carnitine on cold tolerance of Nile tilapia was evaluated in a third experiment of the present study. The effect of L-carnitine was evaluated in five levels, 0, 300, 600, 900 and 1200 mg/kg diet at each of two lipid levels (5 and 10%), therefore ten isonitrogenous (30% CP) and isocaloric (3000 kcal ME/kg) diets were formulated and tested in two replicates with Nile tilapia (First experiment) and common carp (Second experiment). Another five isonitrogenous (30% CP), isocaloric (3000 kcal ME/kg diet) and isolipidic (5%) diets were formulated to contain increasing levels of L-carnitine, 0, 300, 600, 900 and 1200 mg/kg diet to study the effect of L-carnitine on cold tolerance of Nile tilapia (Third experiment). Results of the present study indicated that:
Dietary L-carnitine at any level significantly increased all growth parameters (body weight, body length, weight gain, specific growth rate) and improved feed conversion and protein efficiency ratio of Nile tilapia (first experiment) and the same trend was also observed with common carp (second experiment).
Compared to control group dietary L-carnitine supplementation significantly (P |
