Use of hormonal subdoses applied in Bai Hui acupuncture in estrus synchronization protocols for goats

Abstract

The objective of this study was to evaluate the efficacy of delivering reduced doses of hormones via the Bai Hui acupoint in estrus synchronization in goats. A total of 40 goats received intravaginal sponges with medroxyprogesterone acetate for 7 days. The goats were then randomly distributed into 5 treatment: T1 - application of 132.5 μg of cloprostenol and 300 IU of equine chorionic gonadotropin (eCG), both by intramuscular injection (IM); T2 - application of 39.75 μg cloprostenol at the Bai Hui acupoint, and 300 IU of eCG by IM; T3 - application of 132.5 μg of cloprostenol by IM, and 90 IU of eCG at the Bai Hui acupoint; T4 - application of 39.75μg of cloprostenol and 90 UI of eCG, both in Bai Hui and T5 acupuncture: application of 39.75μg of cloprostenol and 90 UI of eCG, both applied in false acupoint. The goats were subjected to an estrus synchronization protocol and monitored for estrus detection, coverage and evaluation of reproductive parameters to detect entry into estrus. The data were subjected to normality tests, followed by appropriate statistical analyses of each variable. There was no significant difference (P > 0.05) in the percentage of animals in estrus (95.00 ± 11.18%), interval between sponge removal and beginning of estrus (49.72 ± 8.93 h), interval between sponge removal and end of estrus (76.84 ± 11.98 h), duration of estrus (27.08 ± 8.68 h), size of the largest follicle (6.82 ± 0.44 mm), interval between sponge removal and ovulation (78.28 ± 10.82 h), time from ovarian onset to estrus (28.52 ± 5.44 h), follicular growth rate (0.86 ± 0.29 mm/day), number of ovulations (1.32 ± 0.23), plasma progesterone concentration at 7 days after ovulation (10.28 ± 1.65 ng.mL-1), and gestation rate at 30 days after the beginning of estrus (75 ± 12.5%). However, the cost of the synchronization protocol per animal was 43.42% lower in treatments 4 and 5 (30% of the doses) than in treatment 1 (100% of the dose). Ovulation and estrus were efficiently synchronized with the use of 39.75 μg of sodium cloprostenol and 90 UI of eCG, applied at the Bai Hui acupoint or at a false acupoint.