| Titles |
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English :
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Effect of decreased variation of body weight at 20 weeks of age on subsequent production of Gimmizah breeder
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Arabic :
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تأثير انخفاض التباين في وزن الجسم عند عمر 20 أسبوع على الإنتاج لأمهات دجاج الجميزة
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| Abstract |
This study was conducted to investigate the effect of decreased variation of body weight at 20 weeks of age on production performance. Day – old chicks of Gimmizah strain were feed a starter ration ad- libitum to 10 weeks of age. 525 birds from pedigree closed flock, individually weight at 10 weeks of age and sorted into 3 groups. Small birds ( 577.7 g ), middle birds ( 785.9 g ) and heavy birds
( 957.1 g ). All groups divided into 5 treatments ( each 105 birds ). Treatment 1, from the smallest weight group, was ad- libitum fed from 10 to 20 weeks of age. Treatment 3 from the middleweight birds was ad- libitum fed initially then restricted as necessary to maintain the average weight of flock. Treatment 4, from the heaviest weight birds, was fed restricted to attain the average weight of flock at 20 weeks of age. Treatments 2 and 5 represented random samples of equal numbers birds from each group .pullets in treatments 2 and 5 were ad-libitum and restricted – fed, respectively. At 20 weeks of age pullets per treatment were transferred to layer cages.
The results showed that, differences, which existed among the mean weights of treatments 1, 3, and 4 at 10 weeks of age, decreased to
23.1g at 20 weeks. At 20 weeks of age the pullets in these treatments, averaged 78.8% to 91.4% ± 10% of the average weight.
Pullets in treatment 4 ( heaviest third, restricted- fed ) were significantly ( p< 0.01) older when reaching 10 and 50% production than those of pullets in treatments 1, 2, and 3. The mean hen-day percentage, egg mass/ hen/ day, feed intake /hen /day and feed conversion of pullets in treatments 3 and 4 were increased significantly ( p < 0.01 ) than those from the other treatments. The mean egg weights of pullets in treatments 4, and 5 were larger ( p< 0.01 ) than the other treatments. Differences among treatments in Haugh unit score and shell thickness were not significant.
In conclusion, separation of pullets based on weight at 10 weeks of age, and restriction of feed in groups, which were heavier than the recommended weight, increased uniformity of pullets at sexual maturity age and subsequent layer performance for various traits improvement.
Keywords: Gimmizah, body weight , egg production .
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| Publication year |
2002
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| Pages |
219-233
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| Availability location |
معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
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| Availability number |
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| Organization Name |
Animal Production Research Institute (APRI)
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| City |
الاسكندرية
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| serial title |
Egyptian Poultry Science
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| ISSN |
1110-5623
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| Author(s) from ARC |
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| Agris Categories |
Animal husbandry
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AGROVOC
TERMS |
Body weight.
Egg production.
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| Proposed Agrovoc |
Gimmizah;variation of body weight;
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| Publication Type |
Journal
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