Oestrous synchronisation and pregnancy rate following artificial insemination (AI) in South African indigenous goats

Abstract

The study evaluated the effect of duration of progestagen treatment and breed on response to oestrous synchronisation and pregnancy rate following AI in 47 Boer and 27 unimproved indigenous goats. Each breed was subdivided into two groups, based on the duration of progestagen treatment. In the long-term progestagen treatment, controlled internal drug release dispensers (CIDRs) were inserted for 16 days, while in the short-term progestagen treatment, CIDRs were inserted for 9 days. Oestrous detection was performed for a period of 72 h, starting at CIDRs withdrawal. AI was performed 48 h following CIDRs removal with raw or frozen/thawed semen. Pregnancy diagnosis was performed at day 35 following AI. Boer goat exhibited a significantly (p B 0.05) higher oestrous response (100%) than unimproved indigenous goats (88.9%). Breed had no effect on the onset of oestrus. Boer goat does recorded a longer duration of the induced oestrous period, compared to the unimproved indigenous goats. No significant difference was observed between short or long-term progestagen, with respect to the oestrous response, onset and duration of the induced oestrous period. The pregnancy rate was not affected by breed and semen cryopreservation. However, long-term progestagen treatment drastically reduced pregnancy rate. In conclusion, breed had an effect on oestrous response and the duration of induced oestrous period. The interaction of breed and duration of progestagen treatment had no effect on response to oestrus and onset of oestrus. The pregnancy rates of the current study were generally low and were affected by the duration of progestagen treatment.

Manipulation of reproductive seasonality using melatonin implantation in Anglo-Nubian does treated with controlled internal drug release and equine chorionic gonadotropin during the nonbreeding season

“…findings reported by Blaszczyk et al (2004) in Anglo-Nubian goats treated with P 4 -eCG, which resulted in 100% does being in estrus, as well as those of Ramukhithi et al (2012) and Contreras-Villarreal et al (2016), who were able to induce estrus in goats outside the breeding season. This indicates that the incidence of estrus behavior in the present study was not attributable to the melatonin effect, which could be explained by the present observations that Anglo-Nubian does are long-day breeders.…”

Reproductive performance of seasonally anovular mixed-bred dairy goats induced to ovulate with a combination of progesterone and eCG or estradiol

“…() in Anglo‐Nubian goats treated with FGA (fluorogestone acetate)/eCG, obtaining 100% does in estrus; as well, our findings also agree with Ramukhithi et al . () getting goats in estrus outside the breeding season.…”

A Comparative Study on the Reproductive Performance of South African Indigenous Sheep Breeds Following Oestrus Synchronization

“…A short-term oestrus synchronization protocol as described by Ramukhithi et al, (2012) was used with few amendments. In brief, Controlled Intravaginal Drug Release dispensers (CIDR) (Zoetis, CIDR ® ), containing 0.3 g progesterone was inserted according to the manufacturer's instructions, using disinfected applicator.…”

“…Enormous synchronization methods such as progestagengonadrotrophin (Boscos et al, 2002), melatonin and norgestomet implants (Uslu et al, 2012), Control Intravaginal Drug Release (CIDR's) based protocol (Martinez-Ros and Gonzalez-Bulnes, 2019) among many more are being used in small stock production. These oestrus synchronization methods are administered at a short-term (6 -11 days) and or long-term techniques (12 -19 days) (Ramukhithi et al, 2012).…”