Effect of fat and antioxidants on broilers performances under heat stress condition and oxidative stability of chicken meat during storage

This experiment was carried out in order to investigate the effect of heat stress and antioxidant (100 IU vitamin E and 50 mg/kg zinc) on birds receiving diet containing fish oil (unsaturated fatty acid) on performance and oxidative stability of thigh chicken meat. One hundred and sixty arbor acres female broilers were randomly assigned into 2x2 factorial treatment groups، temperature in 2 levels 300C and 200C and diet content %5 USFA with and without antioxidant (100ppm vitamin E and 50 mg/Kg. Zn) There were 4 replicates of 10 birds each. Meat samples stored at 40C and MDA produced at 0، 3، 6 days were measured by TBA method. The results showed that high environment decreases weight gain and increased feed efficiency (p<0. 05) but antioxidant addition to diet had no significant effect on these parameters. Results also demonstrated that heat stress increase USFA، mono unsaturated fatty acid (MUFA)، proportion unsaturated fatty acid to saturate fatty acid (USFA/SFA) and increased MDA produce in 0، 3 and 6 days (p<0. 05). Heat stress increased percentage fatty acid، gross energy and serum MDA Diet supplemented with antioxidant decreased USFA، omega-6 (n-6)، omega-3 (n-3)، polyunsaturated fatty acid (PUFA)، USFA/SFA and MDA produced at 0، 3 and 6 days. Also، USFA and gross energy of meat were higher in diet supplemented with antioxidant.