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Genetic and phenotypic parameters of number of services per conception as a threshold trait and 305 milk yield as continuous trait using gibbs sampling and mtdfreml
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Abstract: Gibbs Sampling (GS) and Mulltiple-trait Derivative-Free Restricted Maximum Likelihood (MTDFREML) were utilized to estimate and compare the variance components and genetic parameters of number of services per conception (NSC) measured as a binary trait and 305-day milk yield (305-MY) as a continuous trait.
A total of 2572 records obtained from 1491 Friesian cows raised at two experimental farms of Ministry of Agriculture, Egypt over 15 years were used.
Heritability estimates were 0.04 and 0.22 by MTDREML and 0.11 ± 0.03 and 0.28 ± 0.05 using GS for the two studied traits, respectively. Repeatability estimates were 0.11 and 0.33 by MTDREML and 0.17±0.02 and 0.45±0.06 by GS, respectively.
Genetic and phenotypic correlations between the two traits were 0.34 and .06 using MTDFREML and 0.25 and 0.10 using GS, respectively.
The obtained results revealed that GS estimates for heritability and repeatability were 2.75 and 1.27 times those by MTDFREMLfor NSC and 1.55 and 1.36 time for 305-MY, respectively. Although, heritability estimates for the threshold trait were not similar from using the two procedures, they were all low indicating that the direct genetic selection to improve this trait would be ineffective.
Keywords: Friesian, genetic parameters, REML, Gibbs sampling, genetic and phenotypic correlations.
Abbreviation key: NSC = Number of services per conception, 305-MY= 305 day milk yield MTDFREML = Multiple Trait Derivative Free-REML, GS = Gibbs Sampling.
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| Publication year |
2002
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| Pages |
95-103
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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 |
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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) |
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| Agris Categories |
Animal husbandry
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AGROVOC
TERMS |
Cows.
Genetic correlation.
Genetic parameters.
Phenotypes.
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| Proposed Agrovoc |
phenotypic parameters;threshold trait;gibbs sampling;
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| Publication Type |
Journal
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