تاثیر روش های مختلف اعمال محدودیت غذایی بر عملکرد، ترکیب لاشه و فراسنجه های خونی جوجه های گوشتی

This experiment was conducted to evaluate the effect of different methods of feed restriction on the performance, carcass traits and blood parameters of broiler chickens. birds fed a standard diet as ad libitum for the first week after post hatch. one hundred and forty four ross male broiler chicks were distributed in 24 experimental unite and subjected to one of the four experimental groups from 7 to 14 days of age following quantitative feed restriction, qualitative feed restriction, feed removal daily for 8 hours and ad-libitum schedules. six replicates of 6 birds were allocated to each group. all birds had free excess to feed after feed restriction period. data analyzed in a completely randomized design. results showed that birds were subjected to feed restriction had significantly lower body weight than ad libitum group at 14d (p < 0.05). final body weight gain and feed intake were significantly lower in quantitative feed restriction and qualitative feed restriction groups than feed removal and ad libitum groups (p < 0.05). birds were subjected to quantitative feed restriction and qualitative feed restriction had lower carcass traits than ad libitum group (p < 0.05). the lowest abdominal fat percent was found in quantitative feed restriction group which was significantly lower than ad libitum group (p < 0.05). the hemoglobin and thyroid hormone (t3 and t4) concentrations did not differ between the experimental groups. birds were subjected to qualitative feed restriction had significantly lower hematocrit value and lactate dehydrogenized enzyme activity than birds feed ad libitum. based on the results of this experiment, feed removal daily for 8 hours from 7 to 14 days of age is the better method than quantitative and qualitative feed restriction for improving broilers performance.