Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends
The Kenya Livestock Recording Centre progeny testing data base covering the period 1968 through 1987 was used to estimate genetic and phenotypic trends in Friesian cattle for milk yield of all lactations, first lactation milk yield, age at first calving, and calving interval. Annual genetic and phen...
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| Format: | Journal Article |
| Language: | Inglés |
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Wiley
1991
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| Online Access: | https://hdl.handle.net/10568/28852 |
| _version_ | 1855521181283647488 |
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| author | Rege, J.E.O. |
| author_browse | Rege, J.E.O. |
| author_facet | Rege, J.E.O. |
| author_sort | Rege, J.E.O. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | The Kenya Livestock Recording Centre progeny testing data base covering the period 1968 through 1987 was used to estimate genetic and phenotypic trends in Friesian cattle for milk yield of all lactations, first lactation milk yield, age at first calving, and calving interval. Annual genetic and phenotypic trends were estimated at 2.5 and 1.2 kg, -5.2 and -5.5 kg, -14.4 and 3.1d, and -.1 and .7d, respectively for these traits. None of these trends was significantly different from zero, except the genetic trend for age at first calving. There were differences in ranking of bulls. This was a possible cause of extensive use of genetically poor bulls at the expense of superior ones. However, high semen demand was the main cause of low genetic progress. |
| format | Journal Article |
| id | CGSpace28852 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 1991 |
| publishDateRange | 1991 |
| publishDateSort | 1991 |
| publisher | Wiley |
| publisherStr | Wiley |
| record_format | dspace |
| spelling | CGSpace288522023-09-09T00:36:35Z Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends Rege, J.E.O. friesian cattle reproductivity productivity genetic characters genotypes phenotypes milk yield calving interval lactation age at first calving The Kenya Livestock Recording Centre progeny testing data base covering the period 1968 through 1987 was used to estimate genetic and phenotypic trends in Friesian cattle for milk yield of all lactations, first lactation milk yield, age at first calving, and calving interval. Annual genetic and phenotypic trends were estimated at 2.5 and 1.2 kg, -5.2 and -5.5 kg, -14.4 and 3.1d, and -.1 and .7d, respectively for these traits. None of these trends was significantly different from zero, except the genetic trend for age at first calving. There were differences in ranking of bulls. This was a possible cause of extensive use of genetically poor bulls at the expense of superior ones. However, high semen demand was the main cause of low genetic progress. 1991-01-12 2013-05-06T07:01:34Z 2013-05-06T07:01:34Z Journal Article https://hdl.handle.net/10568/28852 en Limited Access Wiley Journal of Animal Breeding and Genetics;108(6):424-433 |
| spellingShingle | friesian cattle reproductivity productivity genetic characters genotypes phenotypes milk yield calving interval lactation age at first calving Rege, J.E.O. Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends |
| title | Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends |
| title_full | Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends |
| title_fullStr | Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends |
| title_full_unstemmed | Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends |
| title_short | Genetic analysis of reproductive and productive performance of Friesian cattle in Kenya. II. Genetic and phenotypic trends |
| title_sort | genetic analysis of reproductive and productive performance of friesian cattle in kenya ii genetic and phenotypic trends |
| topic | friesian cattle reproductivity productivity genetic characters genotypes phenotypes milk yield calving interval lactation age at first calving |
| url | https://hdl.handle.net/10568/28852 |
| work_keys_str_mv | AT regejeo geneticanalysisofreproductiveandproductiveperformanceoffriesiancattleinkenyaiigeneticandphenotypictrends |