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| DALTRO, D. dos S.; SILVA, M. V. G. B.; GAMA, L. T. da; MACHADO, J. D.; KERN, E. L.; CAMPOS, G. S.; PANETTO, J. C. do C.; COBUCI, J. A.. |
| The objective of this work was to evaluate the effects of breed and heterosis on the estimates of genetic parameters of 305-day milk yield (305MY), by fitting milk yield data to the Wood, Mixed Log, Morgan, and Wilmink non-linear models. A total of 258,891 test-day milk yield records of 37,965 Holstein (H), Gyr (G), and Girolando (1/2 H, 1/4 H, 3/4 H, 3/8 H, 5/8H and 7/8H genetic groups) cows from 1840 herds were collected in the state of Minas Gerais, Brazil, in the period of 1998 to 2014. The pedigree file included 36,640 animals, 3677 bulls and 24,472 cows. The genetic parameters were obtained by one-character analysis using the AIREMLF90 software. The heritability estimates of 305MY, and of 305MY fitted to the different nonlinear models ranged from... |
| Tipo: Artigo de periódico |
Palavras-chave: Heterose; Vaca Leiteira; Gado Leiteiro; Modelo Matemático; Bovino; Dairy cows; Heritability; Heterosis; Mathematical models. |
| Ano: 2020 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1133496 |
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| CAMPOS, R. V.; COBUCI, J. A.; KERN, E. L.; COSTA, C. N.; McMANUS, C. M.. |
| The objective of this study was to estimate genetic and phenotypic parameters for linear type traits, as well as milk yield (MY), fat yield (FY) and protein yield (PY) in 18,831 Holstein cows reared in 495 herds in Brazil. Restricted maximum likelihood with a bivariate model was used for estimation genetic parameters, including fixed effects of herd-year of classification, period of classification, classifier and stage of lactation for linear type traits and herd-year of calving, season of calving and lactation order effects for production traits. The age of cow at calving was fitted as a covariate (with linear and quadratic terms), common to both models. Heritability estimates varied from 0.09 to 0.38 for linear type traits and from 0.17 to 0.24 for... |
| Tipo: Separatas |
Palavras-chave: Functional Trait; Selection.; Dairy cattle; Genetic correlation; Heritability.. |
| Ano: 2015 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1033399 |
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| KERN, E. L.; COBUCI, J. A.; COSTA, C. N.; DUCROCQ, V.. |
| ABSTRACT: Longevity is an important trait due to its relationship with profitability. Type traits have been used as indirect predictors for productive life. The objective of this study was to evaluate the relationship of 20 type traits on length of productive life in Brazilian Holsteins, using a piecewise Weibull proportional hazard model. Three analyses were performed i) productive life was corrected for within herd level of production as a proxy for functional longevity, which included the time-dependent effects of region within year, class of milk production within herdyear, milk production class within lactation number, fat class and protein contents within herd and (variation in) herd size as well as the time-independent fixed effect of age at first... |
| Tipo: Separatas |
Palavras-chave: Conformation traits; Culling risk; Survival analysis; Dairy cattle; Longevity. |
| Ano: 2018 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1103810 |
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