Random regression test day models to estimate genetic parameters for milk yield and milk components in Philippine dairy buffaloes

Title
Random regression test day models to estimate genetic parameters for milk yield and milk components in Philippine dairy buffaloes
Publication Date
2015
Author(s)
Flores, Ester Battad
Van Der Werf, Julius H
( author )
OrcID: https://orcid.org/0000-0003-2512-1696
Email: jvanderw@une.edu.au
UNE Id une-id:jvanderw
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Wiley-Blackwell Verlag GmbH
Place of publication
Germany
DOI
10.1111/jbg.12133
UNE publication id
une:19651
Abstract
Heritabilities and genetic correlations for milk production traits were estimated from first-parity test day records on 1022 Philippine dairy buffalo cows. Traits analysed included milk (MY), fat (FY) and protein (PY) yields, and fat (Fat%) and protein (Prot%) concentrations. Varying orders of Legendre polynomials (Legm) as well as the Wilmink function (Wil) were used in random regression models. These various models were compared based on log likelihood, Akaike's information criterion, Bayesian information criterion and genetic variance estimates. Six residual variance classes were sufficient for MY, FY, PY and Fat%, while seven residual classes for Prot%. Multivariate analysis gave higher estimates of genetic variance and heritability compared with univariate analysis for all traits. Heritability estimates ranged from 0.25 to 0.44, 0.13 to 0.31 and 0.21 to 0.36 for MY, FY and PY, respectively. Wilmink's function was the better fitting function for additive genetic effects for all traits. It was also the preferred function for permanent environment effects for Fat% and Prot%, but for MY, FY and PY, the Legm was the appropriate function. Genetic correlations of MY with FY and PY were high and they were moderately negative with Fat% and Prot%. To prevent deterioration in Fat% and Prot% and improve milk quality, more weight should be applied to milk component traits.
Link
Citation
Journal of Animal Breeding and Genetics, 132(4), p. 289-300
ISSN
1439-0388
0931-2668
Start page
289
End page
300

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