a comparison of different levels of vitamin premix in finisher diet on performance and meat lipid oxidation of raising broilers in floor and battery cage systems

two trials were carried out to compare the effect of different levels of vitamin premix, in two raising systems of floor and cage, on performance and meat quality of broiler chicks. the chicks were fed with adjusted diets as based on wheat and barley for duration of 29 to 42 days. trial 1 was carried out through an employment of 288 male broiler chicks (ross 308) in 4 treatments and 4 replicates in a completely randomized design in floor system. trial 2 was carried out simultaneously with the trial 1 by using 64 male broiler chicks (ross 308) with 4 treatments and 4 replicates in a system of raising cages. the treatments were comprised of 0, 33.33, 66.66 and 100 percent of vitamin premix. feed intake and body weight gain in each replicate were calculated within 35 and 42 days, while carcass weight, abdominal fat percentage, the level of aspartate amino transferase (ast) and alkaline phosphatase (alp) enzymes being assessed. also, after the birds being slaughtered, in order to assess the level of lipid oxidation, thighs of birds were frozen at -20?c for 6 months. according to the results of trial 1 the level of lipid oxidation and ast enzyme were affected by the no vitamin premix containing diet at 36-42 days of age, (p< 0.05). in trial 2, according to the recorded performances, carcass weight and the level of ast enzyme, in birds which were fed with no vitamin premix containing diet (zero level) in comparison with the other treatments and at 36-42 days of age were of significant differences (p < 0.05). also according to the lipid oxidation and alp enzyme the birds which were fed with the diet of treatments 1 and 2 in comparison with the other treatments and at 42 days of age were of significant differences (p < 0.05). considering the results in this study, it seems that there is the possibility of decreasing the level of vitamin premix in finisher diet of broiler chickens in floor raising system up to 33% and up to 66% in cage system common now, without any negative effect on performance and on their frozen meat quality.