Two successful embryo transfers of mini-donkey embryos in Brazilian Northeastern jennies using an alternative method: Case report.

Pregnancy rates after embryo transfer (ET) are disappointing in donkey species. This study aims to report two successful ET of mini-donkey embryos using Brazilian Northeastern jennies as recipients. Eighteen embryo flushes were performed 9 days post-ovulation in two non-pregnant mini-donkeys jennies (11 and 7 cycles per jenny). Eleven embryos (61%, 11/18) were collected and transferred to Brazilian Northeastern jennies 4-6 days post-ovulation by conventional (n = 6) or an alternative (n = 5) technique. The alternative method consisted of inserting a Polansky equine vaginal speculum smeared with lubricant in the vagina of the recipient jenny. The arms of the speculum were extended to allow the visualization of the cervix. Then, using an adapted crafted, elongated, toothed tissue grasping forceps, the external cervical os was held, and the cervix was gently pulled backward, aiming to straight the cervical canal. The ET gun was inserted through the vagina and cervix by visual inspection, and the embryo was released into the uterine lumen. All embryos collected were Grade 1 and classified as Expanded Blastocysts. No jennies become pregnant after conventional ET (0/6), whereas two recipient jennies (40%, 2/5) become pregnant and delivered offspring in the following year after ET using the alternative technique. In conclusion, Brazilian Northeastern jennies can be used as embryo recipients using the alternative method proposed in the present study. However, further investigations are needed to improve the knowledge and results of ET in donkey species.

Comparative Efficacy of Histrelin Acetate and hCG for Inducing Ovulation in Brazilian Northeastern Jennies (Equus africanus asinus).

The goal of this study was to compare the efficiency of histrelin acetate (GnRH analog) and human chorionic gonadotropin (hCG) to hasten ovulation in Brazilian Northeastern jennies (Equus africanus asinus). Thirty cycles of ten jennies were randomly assigned in one of the three groups: G0 (control group), saline; G1, 250 µg of histrelin acetate; G2, 2500 IU of hCG. Jennies were evaluated by transrectal palpation and ultrasonography, and had the administration of an ovulation-inducing agent when a follicle measuring between 29 and 32 mm of diameter was diagnosed. Jennies were monitored every 6 hours by transrectal ultrasonography until ovulation. The interval between prostaglandin administration and ovulation was lower (P < .05) in jennies from the G1 (145.2 ± 34.6 hours) and G2 (147.4 ± 27.3 hours) groups compared with the control cycle (220.0 ± 41.8 hours). Both treatments (G1, 41.15 ± 3.5 hours; G2, 37.8 ± 2.5 hours) also reduced (P < .05) the interval that jennies took to ovulate after the administration of the ovulation-inducing agent compared with the control (81.8 ± 28.8 hours). All jennies from G1 and G2 ovulated up to 48 hours after ovulation induction, whereas 100% of jennies in the control cycle ovulated later (>48 hours from the administration of saline). In conclusion, both histrelin acetate and hCG at the used dose are efficient ovulation-inducing agents in jennies promoting ovulation up to 48 hours after administration.

Fractionated semen collection as a tool to rescue fertility in stallions with seminal vesiculitis.

Treatments for seminal vesiculitis have poor outcomes in stallions; thus, the development of alternative strategies is warranted. This study aimed to evaluate fractionated semen collection as a method to restore the fertility of stallions diagnosed with seminal vesiculitis. Eighteen ejaculates from six stallions (three ejaculates/stallion) diagnosed with seminal vesiculitis were harvested in fractions, as follows: Fraction A (FA), the first two jets; Fraction B (FB), the third and fourth jets; and Fraction C (FC), the fifth and remaining jets of the ejaculate. All fractions were subject to standard semen evaluations that were performed in addition to cytology and bacterial aerobic cultures. Fractions were extended and cooled to 5 °C. As a proof of concept, 20 mares (48 estrous cycles, ∼8 cycles/stallion) were bred with 1 billion sperm from FA (cooled at 5 °C for 24 h). In our study, FA had negative bacterial cultures, absent macroscopic or microscopic abnormalities; FB had positive bacterial cultures in two stallions and presence of polymorphonuclear neutrophils (PMNs) in all samples, but with no macroscopic abnormalities; and FC had positive bacterial cultures, purulent appearance, and the presence of degenerated PMNs, just as noted in the whole semen. Overall, post-cooling sperm motility results were superior (P < 0.05) for FA in comparison with FB and FC. First cycle pregnancy rates using FA varied from 66% to 86%. None of the non-pregnant mares developed endometritis. In conclusion, fractionated semen collection can be used to obtain semen free of contamination and to achieve satisfactory pregnancy rates from stallions with seminal vesiculitis.

An approach to rescue the fertility of stallions with a high level of hemospermia.

A high amount of blood and not the mere presence of blood in equine semen impacts fertility. The aim of this study was to develop an approach to rescue the fertility of stallions with high hemospermia levels. Semen from 15 stallions was divided into four experimental groups: (a) Control-pure raw semen, (b) WB50-50% (v/v) whole blood added into semen, (c) E1-WB50 extended in a 1:1 (v/v) ratio with milk-based extender and (d) E2-WB50 extended in a 2:1 ratio with milk-based extender. Sperm kinetics, plasma membrane integrity (PMI), lipid peroxidation (PER) and intracellular superoxide (O2 ) production were immediately evaluated. Four cycles of 20 mares were randomly assigned to the experimental groups. Mares were bred with an insemination dose of 1 billion total sperm and pregnancy was diagnosed 14 days after ovulation. Sperm kinetics could not be evaluated in the WB50 samples. Total motility was lower (p < .05) in E1 than in CT and E2 samples. Progressive motility decreased (p < .05) with an increase in the percentage of blood in the samples. The PMI and PER did not differ between groups (p > .05); however, O2 production was higher (p < .05) in WB50 than in E2 samples, while the values were intermediate (p > .05) for CT and E1 samples. The control (90%) and E2 (90%) groups had superior (p < .05) fertility than the others (WB50-0% and E1-25%). It was concluded that sperm motility and fertility of semen with a large amount of blood can be rescued by dilution with a 2:1 extender:semen ratio using a milk-based extender.