عنوان مقاله [English]
نویسندگان [English]چکیده [English]
This experiment was conducted to determine the effects of either twice or thrice a day feeding regimens on performance and as well on plasma hormone and metabolite levels of broiler breeder hens during 24 to 38 wk of their productive age. Breeder pullets were provided form a commercial flock, and distributed in experimental units, in a compeletly randomized design with three feeding regimens (treatments) included 1, 2 or 3 feeding times per day with 4 replicates. Birds fed once a day, received all their total feed at 06:15 h, whereas birds fed twice a day, received 50% of their total feed allowance at 06:15 h and the other 50% at 12:15 h, and while birds fed thrice a day, received 33% of their total feed at 06:15 h, 33% at 12:15 h and the last portion at 18:15 h. Total daily feed did not differ among treatments. Blood samples were taken at the peak of production (32 wk of age) and at the end of trial (38 wk of age). For the 13 wk production period, total hen-day egg production through 38 wk of age in the hens that were provided feed twice and thrice a day was greater (67.1 and 67.2 vs 62.2 eggs/hen, P<0.01) than in hens fed once a day. Also, broiler breeder hens fed 2 or 3 times per day laid heavier eggs (P<0.01) compared with once a day fed birds. Twice and thrice a day fed birds carried significantly lower plasma T3, glucose and cholesterol concentration and higher 17 ?-estradiol level than did once a day fed birds (P<0.05). In conclusion, the twice and thrice a day feeding regimens improve the reproductive performance of broiler breeder hens during the early egg-laying cycle.