Interaction of dietary high-oleic-acid sunflower hulls and different fat sources in broiler chickens

The effect of dietary fat sources (high-oleic-acid sunflower seeds, HOASS; palm oil, PO; and high-oleic-acid sunflower oil, HOASO) and high-oleic-acid sunflower hulls (HOAS hulls; 40 g/kg of diet) on performance, digestive organ size, fat digestibility, and fatty acid profile in abdominal fat and blood serum parameters was evaluated in chickens (from 1 to 21 d of age). Bird performance and digestive organ size were not affected by either dietary fat source or sunflower hull supplementation. Fat digestibility in birds fed diets enriched (HOASS and HOASO) in monounsaturated fatty acids (MUFA) was increased compared with those fed the PO diet. The addition of sunflower hulls did not modify fat digestibility. The fatty acids pattern of abdominal fat reflected the dietary fat profile. The greatest concentrations of C16:0 and C18:0 were found in birds fed PO diets. The C18:1n-9 content was increased in birds that received HOASS and HOASO diets compared with those fed PO diets. The greatest content of C18:2n-6 was observed in birds fed HOASS diets. The ratio of polyunsaturated fatty acid (PUFA) to MUFA was significantly increased in birds fed PO diets compared with those fed HOASS or HOASO diets. The addition of sunflower hulls to the diets resulted in a decrease of C18:2n-6 and PUFA concentrations and PUFA:MUFA ratio in abdominal fat. Dietary fat sources and sunflower hulls modify blood triglycerides and serum lipoproteins. A decrease in triglyceride concentrations was observed in birds fed HOASS diets compared with those fed PO and HOASO diets. The greatest concentrations of serum high density, very low density (VLDL), and low density lipoproteins were found in birds receiving HOASO, PO, and HOASS diets, respectively. The addition of sunflower hulls to the diets caused an increase of serum triglycerides and VLDL concentrations. The MUFA-enriched diets had lower triglyceride and VLDL concentrations than did diets rich in saturated fatty acids. However, the sunflower hull addition had the opposite effect.