Bixin as natural antioxidant in broilers diet containing fresh or oxidized soybean oil

Abstract

The addition of oils and fats in the diet of broilers is quite common, since these ingredients are good sources of energy. However, these ingredients easily suffer deterioration through lipid oxidation, and the consumption of oxidized foods or ingredients may impair the performance of broilers. In order to evaluate the antioxidant properties of bixin added to the diet of broilers formulated with fresh or oxidized soybean oil and the effect of the oxidized soybean oil on broiler diets, an experiment was carried out with 1000 one-day-old male chicks, Ross 308. The experimental design was completely randomized, arranged in factorial 3 x 2 + 2 positive controls, totalizing eight treatments with five replicates of 25 birds each. The treatments were 1) Basal diet (BD) + fresh soybean oil (FSO); 2) BD + oxidized soybean oil (OSO); 3) BD + FSO + 0.05% bixin; 4) BD + OSO + 0.05% bixin; 5) BD + FSO + 0.10% bixin; 6) BD + OSO + 0.10% bixin; 7) BD + FSO + BHT (positive control 1); and 8) BD + OSO + BHT (positive control 2). Although antioxidant effects have been observed in breast and thigh meat at some times, bixin can not be recommended as a natural alternative to BHT. The inclusion of bixin in broilers diet improved feed conversion ratio and reduced abdominal fat, however, the use of this additive and other carotenoids in the broilers diet requires caution, since the excess may have a negative effect on the quality of the meat, increasing the lipid oxidation due to the pro-oxidant effect, and reducing the shelf-life. The use of degummed oxidized soybean oil impairs feed conversion ratio and increases the deposition of abdominal fat in broilers.