| Titles |
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English :
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Lifetime performance traits for Holstein Friesian cattle raised in Egypt
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| Abstract |
A total of 5662 lactation records for 1029 Holstein cows raised in three commercial herds was used in the present study to determine the strength of the phenotypic relationship between productive, reproductive and lifespan traits. The study took into account lifespan traits (lifetime, productive life, lifetime days in milk and lifetime score), lifetime milk yield and reproductive traits (age at first calving and calving interval). Milk yield was calculated per day of lifetime, productive life and lifetime days in milk. Partial lifespan traits were considered for the first three parities.
The statistical model included herd, year of birth and season of birth of the cow as fixed effects. Year of birth contributed significantly to variation in all traits. Herd showed significant effect on all the traits except for milk per-day of productive life and milk per-day of lifetime days in milk. Season of birth showed a significant effect on all lifespan traits. Milk/d of lifetime days in milk was added to the model as a fixed effect with four levels according to mean and SD of milk/d of lifetime days in milk when analyzing lifespan traits only. it significantly contributed to explaining the variation in all lifespan traits with high percentage of variance explained averaging 41.27%. Lifetime (LT) averaged 3200 d, productive life (PL) accounted for 75% of LT while lifetime days in milk represented 64% and 85% of LT and PL, respectively. During lifetime, cows gave an average of 5.5 parities. Milk per-day of lifetime, per productive life and lifetime days in milk averaged 10.76 kg, 14.60 kg and 17.13 kg, respectively. High correlations were recorded between lifespan traits and lifetime milk yield (0.92-0.97). Partial lifetime (2 & 3 parities) per-day of milk yield had high correlation (0.71-0.92) with total lifetime per-day of milk yield. Therefore, good use of these traits would be helpful in determining best individuals early in life.
Keywords: Phenotypic parameters, lifetime, Holstein Friesian
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| Publication year |
2008
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| Pages |
11-20
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| Availability location |
معهد بحوث الانتاج الحيوانى- شار ع 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) |
حارث عمر الحماد
جامعة القاهرة
محمد عبد العزيز محمد ابراهيم
جامعة القاهرة
على عطية نجم
جامعة القاهرة
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| Agris Categories |
Animal husbandry
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AGROVOC
TERMS |
Cattle.
Egypt.
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| Proposed Agrovoc |
Phenotypic parameters;lifetime;Holstein Friesian;
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| Publication Type |
Journal
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