| Titles |
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English :
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Prediction of 305 day milk yield from single and cumulative records of Holestein cows, using regression procedures
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| Abstract |
Simple multiple linear and stepwise regression procedures were used to predict 305 day milk yield (305 MY) of 833 first lactation records of Holestein Friesian cows from single and cumulative monthly milk records. The milk yield of the seventh month (M7) gave the highest correlation with 305 day milk yield of the first lactation (r = 0.863) which was the highest among all months. Simple linear regression equations, 305MY = 2453.59 + 6.59m7 explained 75.9 percent of variation in 305 day milk yield. The accuracy (R2) for predicting 305 day milk yield on the basis of cumulative monthly milk yield increased from a minimum of 54.7 percent for first 60-day milk yield to a maximum of 97.9 percent for 270-day milk yield. Among the various multiple linear regression equation, the equation included the first seven months. This equation explained 94.2 percent of the variation in 305 MY. The equation of choice for stepwise regression was 305MY = 1199.84 + 4.75M7 + 3.25M3, which explained 87.5 percent of variation in 305MY. The increased in R2 with adding extra months was negligible.
Keywords: cattle, regression producers, 305 day milk.
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| Publication year |
2000
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| Pages |
47-52
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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 |
All Africa / ESAP Conference of Animal Production, Alexandria, Egypt,
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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.
Milk yield.
Statistical methods.
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| Publication Type |
Conference/Workshop
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