Postpartum reproductive stimulation of jennies under controlled grazing in dry tropical region

Abstract:

This work was developed to investigate the Criollo donkey’s reproductive behavior in postpartum anoestrus at the dry tropic. For this investigation, twenty four females handled under controlled grazing, were subjected to three synchronization treatments: T1: day 0, ear implant of 3 mg norgestomet (Crestar ®, Intervet Inc.) + 50 mg P4/IM (Progesterona ®, Erma), day 12th, implant removal and administration of 0.25 mg/IM sodium cloprostenol (Lutaprost ®, Agrovetmarket S.A.); T2: day 0, was applied 250 μg of gonadorelin, GnRH/IM (Fertagyl ®, Intervet Inc.) and, day 12th, IM administration of 0.25 mg sodium cloprostenol (Lutaprost ®); T3: day 0, placement of vaginal device, 0.5 g P4 (DIB®, Sintex), day 12th, device removal + administration of 0.25 mg/IM of sodium cloprostenol (Lutaprost ®). The three protocols analyzed, resulted in an increase in the level of P4 of 16.6 ± 8.8 ng/mL, without any difference between protocols; the female donkeys exposed to the protocols with ear implants and vaginal devices, manifested an estrus that began at 3.3 ± 0.4 days. On the other hand, with the protocol using GnRH, the estrus was manifested at 3.9 ± 0.5 days (p<0.05). When the presence of all or part of the typical symptoms of this species was measured, the estrous was not uniform; of 46% of animals, showed an optimal behavior, in 37% of animals a very good pattern was registered and in the remaining 17% oestrus was just good, excelling in this variable the ear implant protocol. The duration of estrus was associated with the estrus pattern, so, optimal and very good estrus, lasted four days and good estrus lasted five days. The conception rate was 100% in the jennies with ear implants, 75% in the protocol of GnRH and 37.5% in the vaginal device (p<0.05). In this treatment the presence of vaginal catarrh was detected, when the devices were removed in all jennies, this problem apparently affects the process of conception by natural mating.

Año de publicación:

2015

Keywords:

• Oestrus
• Equus asinus
• Gestation
• Synchronization protocols

Fuente:

scopus