نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری، گروه علوم دامی، پردیس کشاورزی و منابع طبیعی دانشگاه تهران، کرج
2 استاد، گروه علوم دامی، پردیس کشاورزی و منابع طبیعی دانشگاه تهران، کرج
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In this experiment, randomized complete block design with four replications was used for evaluating of the effect of three feeding methods including: without feed restriction (control group), 6 hours feed restriction from 7 to 21 days and 4 hours from 22 to 28 days, 6 hours feed restriction from 7 to 14 days and 4 hours from 15 to 21 days on performance and ascites prevention of Arian male broiler chickens in six weeks. Body weight, feed intake, feed conversion ratio, mortality rate and the index of production efficiency were determined during the experiment. Hematocrit and blood parameters were measured at 35 days of age. Carcass characteristics and the right ventricle weight per total ventricle weight (RV:TV) ratios were determined and compared. Feed conversion ratio and production index was improved by feed restriction from 7-21 days (P<0.05) at 42 days. With applying feed restriction ascites mortality was reduced (P<0.05). Applied feed restriction methods on the amount of hemoglobin, red blood cells and hematocrit had no significant effect, but increased levels of corticosterone (P<0.05). Although T3 hormone was not affected by feed restriction but T4 was increased by feed restriction from 7 to 21 days (P<0.05). In addition, T3 to T4 ratios was reduced by feed restriction (P<0.05).The results of this experiment indicated that, 6 hours feed restriction from 7 to 21 days and 4 hours from 22 to 28 days had the lowest ascites mortality and increased body weight insignificantly.
کلیدواژهها [English]