Genetic comparison of breeding schemes based on semen importation and local breeding schemes: framework and application to Costa Rica
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| Autores: | , |
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| Formato: | artículo |
| Fecha de Publicación: | 2004 |
| Descripción: | Local breeding schemes for Holstein cattle of Costa Rica were compared with the current practice based on continuous semen importation (SI) by deterministic simulation. Comparison was made on the basis of ge- netic response and correlation between breeding goals. A local breeding goal was defined on the basis of prevail- ing production circumstances and compared against a typical breeding goal for an exporting country. Differ- ences in genetic response were <3%, and the correlation between breeding goals was 0.99. Therefore, difference between breeding objectives proved negligible. For the evaluation of genetic response, the current scheme based on SI was evaluated against a progeny testing (PT) scheme and a closed nucleus (CN) breeding scheme, both local. Selection intensities and accuracy of selection were defined according to current popula- tion size and reproduction efficiency parameters. When genotype × environment interaction (G × E) was ig- nored, SI was the strategy with the highest genetic response: 5.0% above the CN breeding scheme and 33.2% above PT. A correlation between breeding values in both countries lower than one was assumed to assess the effect of G × E. This resulted in permanent effects on the relative efficiencies of breeding strategies because of the reduction in the rate of genetic response when SI was used. When the genetic correlation was assumed equal to 0.75, the genetic response achieved with SI was reduced at the same level as local PT. When an initial difference in average genetic merit of the popula- tions was assumed, this only had a temporal effect on the relative ranking of strategies, which is reverted after some years of selection because the rate of change in genetic responses remains unchanged. Given that the actual levels of genetic correlation between coun- tries may be around 0.60, it was concluded that a local breeding scheme based on a nucleus herd could provide better results than the current strategy based on SI. |
| País: | Repositorio UNA |
| Institución: | Universidad Nacional de Costa Rica |
| Repositorio: | Repositorio UNA |
| Lenguaje: | Inglés |
| OAI Identifier: | oai:https://repositorio.una.ac.cr:11056/24078 |
| Acceso en línea: | http://hdl.handle.net/11056/24078 https://doi.org/10.3168/jds.S0022-0302(04)73301-9 |
| Access Level: | acceso abierto |
| Palabra clave: | DAIRY CATTLE GANADO DE LECHE GENETICA ANIMAL GENETIC PARAMETERS ANIMAL GENETICS COSTA RICA |