Nutrient and fatty acid deposition in broilers fed different dietary fatty acid profiles

The aim of this study was to determine the effect of different dietary fatty acid profiles on efficiency of energy, fat, nitrogen, and fatty acid deposition in broiler chickens. Sixty female broiler chickens were fed a basal diet without additional fat or with 4 other diets with different fats (tallow, olive, sunflower, and linseed oils) at 10% from 28 to 48 d of age. Among broilers fed diets with added fat, those fed linseed oil had less abdominal fat (in grams and percentage) than those fed tallow (P < 0.05). Absorbed fat losses were slightly higher for birds fed linseed oil, and nitrogen efficiency was lower in those fed tallow (P < 0.05). However, there were not significant differences in energy deposition among broilers fed diets with added fat. Fatty acid balance showed the highest values of fatty acid oxidation during the experimental period in broilers fed linseed oil (48.2 g), followed by those fed sunflower oil (23.2 g). Contribution of endogenous fat synthesis to total body fat deposition was minimal in birds fed diets with added fat accounting for 3, 1.2, 8.5, and 7.3 g for broilers fed tallow, olive, sunflower, and linseed oils, respectively. This reflects lipogenesis inhibition by dietary fat addition. Interestingly, between broilers fed diets with added fat, higher values of fatty acids from endogenous synthesis were found in broilers fed diets rich in polyunsaturated fatty acids (PUFA). Results suggest that reduction of abdominal fat in broilers fed linseed oil seems to be a consequence of higher lipid oxidation despite the higher synthesis of endogenous fatty acids.