Two protocols to synchronize the oestrus of lactating ewes using progestogens

• Autores: Espinoza Molina, Saúl, Espinoza Rojas, Gabriela, Ticona Huaroco, Chessyra, CCari Huayta, Mario, Pérez Guerra, Uri Harold, Julio Cruz, Danny
• Formato: artículo
• Fecha de Publicación: 2022
• Institución: Universidad Nacional Mayor de San Marcos
• Repositorio: Revistas - Universidad Nacional Mayor de San Marcos
• Lenguaje: español
• OAI Identifier: oai:ojs.csi.unmsm:article/24095
• Enlace del recurso: https://revistasinvestigacion.unmsm.edu.pe/index.php/veterinaria/article/view/24095
• Nivel de acceso: acceso abierto
• Materia: lactating sheep; temporary weaning; synchronization protocol; short; conventional; ovejas lactantes; destete temporal; protocolo de sincronización; ovejas

The aim of this study was to evaluate two protocols for oestrus synchronization using intravaginal progestogens. In the study, 64 ewes with lambs at foot of 30-40 days old were used. The animals were assigned to two groups: (T1): application of a short synchronization protocol (6 days) with suppression of suckling for 30 hours (n1=32) and (T2): application of a long or conventional protocol (12 days) with suppression of suckling for 54 hours (n2=32). Fixed-time artificial insemination (FTAI) was performed with refrigerated semen through the transcervical route at the end of temporary weaning. The pregnancy rate without heat return at 16-17 days post-FTAI, pregnancy rate at 41 days by ultrasound, pregnancy rate at 90 days by balloting and type of delivery were determined. The rate of non-return to oestrus at 15-17 days post-FTAI was 81.25% for T1 and 87.50% for T2 (p<0.05). Likewise, the pregnancy percentages by ultrasound and by balloting were statistically similar between treatments. The twin birth rate was slightly, but not significantly different in T2 (26.92%) than in T1 (19.2%). The results show that when applying a short synchronization protocol, similar results are achieved as when applying the conventional synchronization protocol and with the advantage that it is carried out in less time.