Effects of dietary soybean and sunflower oils with and without L-carnitine supplementation on growth performance and blood biochemical parameters of broiler chicks

Abstract. An experiment was designed to investigate the effects of soybean, sunflower oil and dietary L-carnitine supplementation on growth performance, some blood biochemical parameters and antibody titer against Newcastle disease of broiler chicks. A 5-week feeding trial, 240 1-day old male broiler chicks (Ross 308) were randomly allocated to six dietary treatments as a 3 × 2 factorial experimental design where three sources of dietary oil contained soybean, sunflower and soybean plus sunflower oil with and without 120 mg kg⁻¹ of L-carnitine supplementation in the diet. Results showed that soybean oil with L-carnitine significantly improved body weight gain and feed conversion ratio of broiler chicks in the grower and total period of rearing (p < 0.05). L-carnitine supplementation significantly increased total protein, globulin, cholesterol, HDL and LDL (high- and low-density lipoprotein) of blood serum in broiler chicks (p < 0.05). L-carnitine supplementation increased antibody titer against Newcastle disease of chicks and the highest levels were observed in those with the supplement of L-carnitine in the soybean oil dietary treatment. Results of this experiment showed that the growth performance and blood biochemical responses of broiler chicks to dietary supplementation with L-carnitine in dietary oil source and soybean oil, in comparison to sunflower oil, is the better plant oil for growth and immunological performance of broiler chicks.