Reproductive development of dairy heifers in an integrated livestock-forest system during the summer.
This study aimed to assess the cortisol, body and reproductive development of prepubertal Holstein and Holstein-Gir ¾ heifers at 27 months of age maintained in an integrated livestock-forest (ILF) system for 60 summer days compared to the monoculture system in full sun (FS). The ILF system promoted...
| Autores: | , , , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | Brasil |
| Recursos: | Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
| Repositorio: | Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
| Idioma: | inglés |
| OAI Identifier: | oai:www.alice.cnptia.embrapa.br:doc/1157603 |
| Acesso em linha: | http://www.alice.cnptia.embrapa.br/alice/handle/doc/1157603 https://doi.org/10.1590/1984-3143-AR2023-0100 |
| Access Level: | acceso abierto |
| Palavra-chave: | Estresse térmico Desenvolvimento reprodutivo Sistema integrado Integração pecuaria-floresta Bovino Bem-Estar Gado Leiteiro Reprodução Animal |
| Resumo: | This study aimed to assess the cortisol, body and reproductive development of prepubertal Holstein and Holstein-Gir ¾ heifers at 27 months of age maintained in an integrated livestock-forest (ILF) system for 60 summer days compared to the monoculture system in full sun (FS). The ILF system promoted changes (P=0.02) in the cortisol levels of Holstein-Gir ¾ heifers and did not affect weight gain in any of the breed groups studied. Animals in ILF system presented a lower (P=0.006) vulvar development for the rima height parameter and similar for the vulva width parameter. The ovarian follicular population of Holstein-Gir ¾ heifers in the ILF system was lower (P=0.004); however, for the Holstein heifers, no statistical difference was found, and numbers were higher (P=0.08) in the ILF system. None of the other ovarian parameters studied had any changes, and we also found important racial differences. Weight gain (P=0.003), vulvar development (P<0.001), and mean follicular size (P=0.008) were higher in the Holstein-Gir ¾ animals. Based on such results, the effect of the ILF system at 27 months of age on stress and reproductive parameters in the Holstein breed is considered positive, although negative effects have been detected on reproductive parameters in the Holstein-Gir ¾ breed. |
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