Reproductive characteristics of foal heat in female donkeys

Abstract

In this study, the first postpartum heat, termed the foal heat, characteristics and performance in female donkey (jenny) of Martina Franca are described. To this end, the follicular development of 42 jennies during foal heat was compared with that of 31 jennies at the third estrus after foaling. Estrus length (7.1 ± 0.9 and 6.8 ± 0.7 days), follicular development and preovulatory follicle size (43.7 ± 3.5 and 45.1 ± 2.5 mm) were similar between jennies during the foal heat and during the third estrus after foaling. The pregnancy rate at day 14 was significantly lower in the foal heat jennies (57.1%) than the third estrus jennies (82.3%). However, the pregnancy rate at day 14 in foal heat jennies increased significantly when the onset of foal heat was ⩾8 days after foaling (93.8%) or when the ovulation happened ⩾12 days after foaling (85.7%). The data provided in the present study suggest that the foal heat in the endangered jennies of Martina Franca could be successfully utilized to reduce the interpartum period if the onset of foal heat occurs >8 days after foaling.

Subdose of human chorionic gonadotropin applied at the Hou Hai acupoint on follicular dynamics and luteal development in donkeys

“…Quaresma and Payan-Carreira (2015) reported a mean follicle diameter of 40.2 mm in single ovulations, 36.7 mm in double ovulations, and 38.6 mm in triple ovulations, when characterizing the estrous cycle of donkeys. This was similar to the results of Carluccio et al (2017), who obtained pre-ovulatory follicle diameter of up to 45.1 mm in postpartum estrous cycles for this species, without using an ovulation inducer. Both studies found higher mean follicle diameter values than the one obtained in the present study.…”

The Potential for New Donkey Farming Systems to Supply the Growing Demand for Hides

“…Gestation lengths have been studied for a number of donkey breeds in recent years [12,34,35,38,[48][49][50] but not for Chinese breeds. The reported average gestation length ranges from 353 days [12] to 371 days [48][49][50]. The shortest and longest gestation are reported by Galisteo and Perez-Marin [35] as 331 and 421 days, respectively.…”

“…Foal heat, the first heat after giving birth, usually occurs in the first two weeks after a jenny has given birth to a foal [51]. In donkeys, foal heat can be used successfully but with slightly lower conception rates than in the following cycles [38,49]. Secondly, the conception rates reported in the literature are mainly based on controlled research studies.…”

“…Most studies on donkey reproduction do not report the number of abortions, with a few notable exceptions [12,34,37,49]. In Carluccio et al [49], one out of 73 pregnancies, i.e., less than two percent, is reported to have ended in abortion. The abortion occurred before day 45 of the pregnancy.…”

“…Often double ovulations do not result in viable twin pregnancies [34]. A widespread practice is that if twin embryos are detected, one of them is crushed [49]. By contrast, in the study carried out by Galisteo and Perez-Marin [35], 3 out of the 58 pregnancies were twin pregnancies that were carried to term and resulted in viable foals.…”