EFECTO DE LA MELATONINA EXÓGENA SOBRE LA VIABILIDAD EMBRIONARIA EN OVEJAS CON DIFERENTE CONDICIÓN CORPORAL DURANTE EL ANESTRO ESTACIONAL

SARRACINI, D.; FRANCO, C.A.; MARTINEZ, D.; VAZQUEZ, M.I.*

Congreso; 44° Congreso Argentino de Producción Animal-Certamen de Tesis de Grado; 2021

Asociación Argentina de Producción Animal (AAPA)

The work was carried out at the facilities of the Animal Reproduction Department (UNRC), in Río Cuarto, Argentina (30º07´S, 64º14´W). In seasonal anestrus (October to December), thirty one (31) crossbred sheep were used, separated into 2 groups according to their initial CC: fat (G, CC≥3.5) or thin (F, CC≤3, 0) (scale 1-5). In turn, each of them was separated into 2 groups, considering the treatment (+ MEL) or not (-MEL) with a melatonin implant. Thus, the design included 4 groups: G-MEL, G + MEL, F-MEL and F + MEL. All animals received a diet based on alfalfa hay and corn grain in order to cover maintenance requirements (NRC, 2007) and Ad-libitum water. After 40 days from insertion of melatonin implants, all females received a treatment to induce ovulation and were inseminated via cervical, with fresh semen, at 48 h after the removal of the intravaginal sponges (IATF). Fourteen days after the IATF, estrus were detected, once per day, using a vasectomized ram, during a period of 21 d. The females that returned to estrus were mated with an adult male. Ovarian ultrasound was performed at 7 days post-IATF to determine the presence and area of the corpora lutea (CL). The pregnancy diagnosis was made by ultrasound at 30 days and 50 days post-IATF. The CC presented differences between groups G and F, during the entire experimental period (p