Fatty acid profiles and oxidative stability in tissue from chicks fed diets varying in oil and glucosinolate type and content
Four experiments were carried out to investigate the effects of glucosinolates, the level and type of dietary fat and -tocopherol acetate (ATA) supplementation on broiler performance, fatty acid composition, oxidative stability of tissues and immunological changes in the caecal crypts and bone marrow cells. In Experiment 1, 270 chicks were fed diets containing either whole full-fat rape seed (FFR) with a glucosinolate content of 14.4 mmol/kg or marine oil (MO) calculated to provide 40 and 120 g fat/kg diet. At each level of fat in the diet ATA was supplied at 20 and 300 mg/kg diet. Data presented in this study indicate that whole FFR (low glucosinolate) and MS(high glucosinolate) at the level of 300 and 50 g/kg respectively can be consumed by broiler chicks without any detrimental effects. Birds fed diets containing low glucosinolate MuO, RO, and RSM showed similar performance to those of birds fed the soya based control diets. The data showed that fatty acid composition of tissue lipid can be manipulated to varying degrees of changing the fatty acid composition of dietary lipid. Tissue monounsaturated fatty acid (MUFA) and n3 fatty acid proportions were increased and n6:n3 ratio was decreased by feeding diets containing FFR, MS, MuO, RO and RSM, Supplemental ATA increased the -tocopherol content of blood serum and improved the stability of tissue lipid to oxidation when used at the level of 300 mg/kg diet. Inclusion of enzyme treated FFR and RSM in broiler diets improved weight gains and reduced the caecal irritation caused by contents of the diet. Cells identified in the caecal crypts and bone marrow tissue showed a potential for determining the immunological responses of birds to various diets.