Estimation of direct and maternal breed effects for prediction of expected progeny differences for birth and weaning weights in three multibreed populations.
J Anim Sci
; 75(5): 1203-12, 1997 May.
Article
en En
| MEDLINE
| ID: mdl-9159266
Direct and maternal breed effects on birth and 200-d weights were estimated for nine parental breeds (Hereford [H], Angus [A], Braunvieh [B], Limousin [L], Charolais [C], Simmental [S], Gelbvieh [G], Red Poll [R], and Pinzgauer [P]) that contributed to three composite populations (MARC I = 1/4B, 1/4C, 1/4L, 1/8H, 1/8A; MARC II = 1/4G, 1/4S, 1/4H, 1/4A; and MARC III = 1/4R, 1/4P, 1/4H, 1/4A). Records from each population, the composite plus pure breeds and crosses used to create each composite, were analyzed separately. The animal model included fixed effects of contemporary group (birth year-sex-dam age), proportions of individual and maternal heterosis and breed inheritance as covariates, and random effects of additive direct genetic (a) and additive maternal genetic (m) with covariance (a,m), permanent environment, and residual. Sampling correlations among estimates of genetic fixed effects were large, especially between direct and maternal heterosis and between direct and maternal breed genetic effects for the same breed, which were close to -1. This resulted in some large estimates with opposite sign and large standard errors for direct and maternal breed genetic effects. Data from a diallel experiment with H, A, B, and R breeds, from grading up and from a top cross experiment were required to separate breed effects satisfactorily into direct and maternal genetic effects. Results indicate that estimation of direct and maternal breed effects needed to predict hybrid EPD for multibreed populations from field data may not be possible. Information from designed crossbreeding experiments will need to be incorporated in some way.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Destete
/
Peso al Nacer
/
Peso Corporal
/
Cruzamiento
/
Envejecimiento
/
Bovinos
Tipo de estudio:
Prognostic_studies
/
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
J Anim Sci
Año:
1997
Tipo del documento:
Article
País de afiliación:
México
Pais de publicación:
Estados Unidos