Effects of dietary fat origin on the performance of broiler chickens and on the fatty acid composition of selected tissues

Abstract

Experiments were conducted to evaluate the effects of dietary fat origin on the performance and carcass fatty acid composition of broiler chickens. Sunflower and linseed oils (plant origin), fish oil (marine origin) and beef tallow (animal fat) were fed to broiler chickens at dietary levels of 40 g/kg and compared with a control diet with no added fat. Diets were formulated to be isonitrogenous (195 g/kg CP) and isoenergetic (12.4±0.2 MJ/kg). Live weight, feed intake, weight gain and feed conversion ratio for the chickens were measured. The fatty acid composition of the breast muscle and abdominal adipose tissues was also determined. Weight gain differed between the beef tallow diet and the oil diets (P<0.01). Feed conversion ratio (FCR) was not affected by fat supplementation. The fatty acid profiles for the breast muscle and abdominal fat were altered by the diets. The oil diets (plant seed and fish) increased total polyunsatured fatty acid (PUFA) concentration in both types of tissue, while beef tallow decreased it (P<0.001). Total PUFA was, however, higher in the tissues investigated in the chicks fed plant seed oil diets (sunflower or linseed), compared to fish. Chickens fed fish oil diets showed higher concentration (P<0.001) of long chain n-3 PUFA (C22:6n-3, C22:5n-3, C20:5n-3) in the tissues investigated, compared to the others. Total monounsaturated (MUFA) and saturated (SAT) fatty acid concentrations were higher in the chickens fed the beef tallow diet.