L-carnitine as a water soluble derivative of lysine has a crucial biological role in lipid metabolism. Present experiment was conducted to study the effect of L-carnitine supplementation into broiler and/or breeder diets on broilers' performance, blood related factors, carcass characteristics and immune system. L-carnitine was added to the broiler breeder's diets at levels of 0, and 60 PPM from 25th weeks of age and their progenies diets at levels of 0, 100, and 200 PPM. The broilers performance was investigated in starter, grower and finisher periods. Feeding of L-carnitine reduced feed intake and body weight gain of broilers (p<0.01), while feed conversion ratio was not affected (p>0.05). Serum cholesterol and triglyceride, carcass characteristics and anti-SRBC titers were not influenced by L-carnitine supplementation to broilers' diets (p>0.05). Breeders' diet supplementation with L-carnitine resulted in significant differences in broilers' anti-SRBC titers at 48 day of age and spleen weights at 21 day age (p<0.05). Significant interaction was evidenced for breeders and broilers' diets supplementation with L-carnitine for anti-NDV titers in broilers sera (p<0.05) .
Key words: broiler, broiler breeder, L-carnitine, blood related factors, carcass characteristics.