بررسی طول دوره تغذیه با جیره ‌های پیش دان و پس دان بر عملکرد رشد، خصوصیات لاشه و بستر جوجه‌های گوشتی ماده

This study was carried out to evaluate the duration of time of feeding starter and finisher diets on live performance and carcass characteristics of female broilers. Starter diet was fed to 14 or 21 days of age. Finisher diet was fed beginning at 35 or 42 days up to 49 days of age. The results indicated that reduction of duration of feeding starter diet reduced weight gain (P<0.0071) and impaired feed conversion ratio (P<0.0002) up to 21d. Reduction of time of feeding starter diet caused a decrease in body weight at 21d (P<0.0071) whereas it had no effect on body weights at 42 and 49 days. Increasing time of feeding finisher diet caused a drop of the weight gain (P<0.0076) and impaired feed conversion ratio (P<0.0001) up to 42d but these differences were not significant up to 49d, suggesting a catch-up growth during 42 to 49d. There was no significant effect of dietary treatments on carcass characteristics at 49 days of age. Lowering time of feeding starter diet and increasing time of feeding finisher diet caused a significant decrease in pH, moisture and nitrogen contents of the litter.