SEXUAL PRECOCITY ASSOCIATED WITH THE CONCENTRATION OF PLASMA PROGESTERONE IN NELORE HEIFERS RAISED IN NORTHERN BRAZIL
The objective of this study was to identify sexually precocious heifers by observing ovulation (presence of corpus luteum - CL) and correlating it with the plasma progesterone concentration, as well as to verify the accuracy of the ultrasound examination (US) in this class of animals. The animals we...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Brasil |
| Institución: | Universidade Federal de Alagoas (UFAL) |
| Repositorio: | Ciência Agrícola (Online) |
| Idioma: | inglés |
| OAI Identifier: | oai:www.seer.ufal.br:article/8694 |
| Acceso en línea: | https://www.seer.ufal.br/index.php/revistacienciaagricola/article/view/8694 |
| Access Level: | acceso abierto |
| Palabra clave: | Bos indicus Corpus luteum Ovulation Puberty Ultrasonography |
| Sumario: | The objective of this study was to identify sexually precocious heifers by observing ovulation (presence of corpus luteum - CL) and correlating it with the plasma progesterone concentration, as well as to verify the accuracy of the ultrasound examination (US) in this class of animals. The animals were kept in Brachiaria brizantha pastures in an extensive system with water and mineralized salt ad libitum. Nelore heifers (n=50) with initial age and weight of 10 months old and 210 kg, respectively, were used. Only 14% (7/50; p <0.05) of the heifers entered puberty at up to 12 months of age. Regarding the accuracy of the US in relation to the plasmatic concentration of P4 we verified that both the animals with and without CL presented concentrations of P4 inconsistent with the expected. The means of the plasmatic concentrations of P4 in pubertal heifers were superior (p<0.05) in both second and third ultrasonographic exams (1.30 ± 0.14 and 1.74 ± 0.22 ng/mL, respectively), when compared to the non-pubertal heifers (0.53 ± 0.08, 0.89 ± 0.04 ng/mL, respectively). In conclusion, the herd presented low sexual precocity and the accuracy of the ultrasound examination in this class of animals was relatively low. |
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