| Titles |
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English :
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Genetic and phenotypic parameters for milk yield, days open and number of services per conception of Holstein cows of a commercial herd in Egypt
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Arabic :
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المقاييس الوراثية و المظهرية لصفة انتاج اللبن في 305 يوم و الفترة المفتوحة و عدد التلقيحات اللازمة للحمل للابقار الهولشتين في مزرعة تجارية بمصر
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| Abstract |
A total of 1391 lactating records were obtained from 726 Holstein cows raised at a commercial farm. Records were analyzed to obtain (co) variance estimates for actual 305 day milk yield, days open and number of services per conception. Variance components were estimated by the DF- REML procedure with a multiple trait repeatability animal model. The model included year- season of calving (16 groups) and parity (first three lactations) as fixed effects and additive genetic and permanent environmental as random effects.
Averages of 305 day milk yield, days open and number of services per conception were 7504 kg. 229 days and 2.8 services, respectively. Estimates of heritabiliey for the three traits were 0.090, 0.045 and 0.003 respectively. The corresponding repeatability estimates were 0.386, 0.081 and 0.030 respectively. Genetic correlations between 305 day milk yield with both days open and number of services per conception were high and positive (0.61and 0.97, respectively). The nature of the relationship between milk yield and fertility traits may cause a problem in realizing rapid improvement for both of them simultaneously. The corresponding phenotypic correlations were 0.131 and 0.091, respectively. Genetic and phenotypic correlations between days open and number of services per conception were 0.706 and 0.703 respectively. The results indicate that improvement of fertility traits would be brought about by improving management conditions.
Keywords: Holstein Friesian, genetic parameters, milk yield, fertility, Egypt.
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| Publication year |
2000
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| Pages |
9-17
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| Availability location |
معهد يحوث 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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| serial title |
Egyptian Journal Animal Production
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| Author(s) from ARC |
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| External authors (outside ARC) |
سامى ابو بكر
جامعة القاهرة
محمد عبد العزيز محمد ابراهيم
جامعة القاهرة
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| Agris Categories |
Animal husbandry
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AGROVOC
TERMS |
Cattle.
Cows.
Egypt.
Fertility.
Genetic parameters.
Herds.
Milk yield.
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| Proposed Agrovoc |
phenotypic;
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| Publication Type |
Journal
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