Abstract
The poultry industry has traditionally been selecting animals for improved performance without consideration for the effect on fat deposition. Dietary L-carnitine can alter lipid metabolism; nevertheless, when combined with fat, the effects are not clear. This study shows the effect of different dietary levels of L-carnitine (0, 200 and 400 mg/kg) and fat (0, 2.5 and 5%) on growth performance and slaughter traits of commercial broilers (Ross 308; n=270). The groups received the following dietary treatments: 1) 0 mg/kg L-carnitine + 0% fat, 2) 200 mg/kg L-carnitine + 0% fat, 3) 400 mg/kg L-carnitine + 0% fat, 4) 0 mg/kg L-carnitine + 2.5% fat, 5) 200 mg/kg L-carnitine + 2.5% fat, 6) 400 mg/kg L-carnitine + 2.5% fat, 7) 0 mg/kg L-carnitine + 5.0% fat, 8) 200 mg/kg L-carnitine + 5.0% fat, and 9) 400 mg/kg L-carnitine + 5.0% fat. Feed conversion ratio, growth performance, blood biochemical parameters, carcass traits and body composition were measured and analyzed. Levels of fat with L-carnitine had significant effects on the European Performance Efficiency Factor, wings weight, intestine length and weight, spleen and liver weight, full abdomen carcass and abdominal fat weight, as well as serum triglyceride levels. Dietary L-carnitine supplementation improved growth performance of broilers, thus it may be a promising solution to reduce fat storage in broilers and improve the quality of carcasses intended for human consumption.