Effect of the nutritive value of dietary fats in relation to their chemical composition on fatty acid profiles of abdominal and skin fat in finishing chickens

An experiment was designed to study the influence of chemical composition of different fat sources on their nutritive value in broilers chickens of 35 days of age and on the fatty acid profile of the abdominal and skin fats after slaughtering. Palm oil (PO); tallow (T1 and T2); tallow + soybean oil (50:50, TSO); tallow + soybean acid oil (50:50, TSAO); soybean oil (SO) and linseed oil (LO) were selected for the evaluation. Fats, with the exception of T1, contained 50 g/kg of soybean lecithin and all of them were included at 60 g/kg level in a basal diet. Experimental diets and added fats were evaluated for apparent metabolizable energy (AME) and apparent fat availability (AFA). In addition, the apparent availability of fatty acids (AAFA) from experimental diets was determined. At the end of a six week feeding period animals were killed by exsanguination in a commercial processing plant and abdominal fat and breast skin were removed for fatty acid determination. The AFA and AME values obtained for added fats at the studied age ranged between 801.8 g/kg and/or 30.9 MJ/kg (TSAO), and 1047.3 g/kg and/or 40.7 MJ/kg (LO). The fatty acid profile of abdominal fat of a given bird was equivalent to the fatty acid profile of its breast skin, regardless of the diet fed. Feeding the basal diet without fat and diets with PO, T1 and T2 gave the lowest U/S ratio in the studied tissues.