The use of oxytocin to cause cervical dilation for transcervical insemination in nulliparous goats: Improving pregnancy and kidding rates

Abstract

To evaluate the effect of oxytocin as a cervical dilator, a study was carried out on nulliparous goats inseminated transcervically at the beginning of the breeding season. One hundred sixteen nulliparous goats with a mean live weight of 33.4 ± 0.68 kg and an age of 13.7 ± 0.37 months were used. The goats were exposed to active bucks of proven fertility for a period of 14 d in order to induce oestrus. One week later, the Ovsynch protocol was applied, which consisted of the application of 20 mg of gonadorelin (Day Zero), 0.075 mg of cloprostenol (Day 7) and of a second dose of 20 mg of gonadorelin applied on Day 9. Artificial insemination (AI) was performed 16 hr later. Three treatments were evaluated: T1 = 50 IU saline, T2 = 25 IU oxytocin; T3 = 50 IU of oxytocin, intravenously applied 10–15 min before AI. The time required to inseminate each treated goat from groups T2 and T3 was 49.56 and 56.25 s, respectively, versus 85.78 s needed for the goats from group T1 (p < .0001). In the T1 group of goats, the insemination catheter was inserted 2.1 cm into the cervical canal and in goats from groups T2 and T3 it reached 3.41 and 3.77 cm into the cervical canal, respectively (p = .02). Pregnancy rates and prolificacy (kids/doe) were higher (p = .02) for groups T2 (82.93%; 1.16) and T3 (76.92%; 1.21) respectively than for control goats (61.11%; 0.69). In conclusion, the intravenous administration of oxytocin led to greater dilation and depth of cervical penetration, obtaining higher pregnancy rates and prolificacy.

Reproductive Management in Goat Breeding

“…The intravenous aplication of oxytocin (25-50i.u.) leads to a greater dilation and depth of cervical penetration, obtaining higher pregnancy rates and prolificacy [11]. Cervix at the time of insemination is pink in colour, volcano or bud like, 3-4 cm long with 3-4 circular folds.…”

Effect of oxytocin added into sperm on artificial insemination in sheep

“…Successful pregnancies cannot be measured solely by the success of forward motility of spermatozoa; the effects originating from the female are equally important. Several studies report the positive effect of insemination depth on success (Eppleston et al, 1994;Falchi et al, 2021;Gutierrez et al, 2022) -insomuch that being able to leave semen 1 cm forward affects the rate of a successful pregnancy by 7 %-12 % (Eppleston et al, 1994). The initial position of the semen released (pushing the se-Ç.…”