An update on oestrus synchronisation of goats in Nigeria

Comparative evaluation of estrus synchronization protocols on reproductive performance and estrus behavior in Barbados Black Belly sheep

Background and Aim

Estrus synchronization of ewes has been accomplished using several protocols with various degrees of success in improving reproductive efficiency and obtaining the most effective protocol used in sheep farming. This study aimed to compare the effectiveness of three treatment protocols and to record the intensity and duration of estrus signs and pregnancy rate in Barbados Black Belly (BBB) sheep.

Materials and Methods

Thirty-two primipara BBB ewes aged 18-24 months were equally divided into three treatment groups. T1: the ewes were injected intramuscularly with 2 mL Lutalyse (PGF2α) (10 mg) on days 0 and 10. T2: 1 mL Fertiline (50 μg; Gonadorelin acetate) on day 0 and 2 mL lutalyse (10 mg) on day 7. T3: 1 mL fertiline (50 μg) on day 0, 2 mL lutalyse (10 mg) on day 7, and 1 mL Fertiline (50 μg) on day 9. Estrus response was assessed using naturally mating rams and ewes. Pregnancy was determined using ultrasonography between 55 and 80 days after the last hormonal injection. The following estrus signs were noted: Swollen vulva, mucus discharge, sniffing, excitement, loss of appetite, mounting, and rapid tail movement.

Results

Of the expressed signs, swollen vulva was most frequent, whereas loss of appetite and mucus discharge were the least overt signs recorded. The estrus response (%), onset (%), and duration (h) in ewe synchronization of the three treatment protocols were 100%, 58.3 ± 23.4%, and 48.0 ± 18.2 h (T1), 100%, 61.7 ± 41.2%, and 45.0 ± 27.0 h (T2), and 37.5%, 32.1 ± 1.7%, and 29.2 ± 1.25 h (T3), respectively. The pregnancy rates were 87.5%, 87.5%, 37.5%, and 50.0% in T1, T2, T3, and T4, respectively.

Conclusion

Prostaglandin F2α+PGF2α and GnRH+PGF2α synchronization protocols were more effective in the fertilization of BBB ewes with better expression of estrus signs compared with the GnRH+PGF2α+GnRH (OVS) protocol.

Ovarian Dynamics and Changes in Estradiol-17β and Progesterone Relationship with Standing Estrus, Preovulatory Follicles, and Ovulation Using Single Prostaglandin F2α Injection in Barbari Goats

The purpose of the present research was to define ovarian follicular dynamics and plasma endocrine profiles in response to a single PGF2α injection, administered indiscriminately during the breeding season of Barbari goats. Ovarian dynamics were observed at every 12 h interval by using B mode ultrasonography, blood samples for hormonal analysis such as estradiol 17β and progesterone were collected at every 12 h interval, and bucks with aprons were used to identify standing estrus at every 6 h interval. Relative to PGF2α, the start of standing estrus and ovulation differ (p < 0.05) between early- (n = 7), intermediate- (n = 6), and late-responding (n = 6) goats. The highest plasma level of estradiol 17β was detected 12 h prior to ovulation. The average diameter of the ovulatory follicle and length of standing estrus were comparable (p > 0.05) between the goats. The corpus luteum degenerated more quickly (p < 0.05) in early- than intermediate- and late-responding goats. Dominant follicle diameter and estradiol 17β concentration also differ (p < 0.05) among groups. Although the plasma level of progesterone did not vary (p = 0.065), the variation in progesterone concentration with time differed (p < 0.05) amongst the goats. As a result, this research indirectly reveals that the beginning of standing estrus, end of estrus, and ovulation after PGF2α might fluctuate in Barbari goats because of follicular and hormonal dynamics during the luteal phase.

Effect of Simmental bull seminal plasma protein in egg yolk-citrate extender on Kacang buck semen fertility

The genetic resources of Indonesia's indigenous Kacang goat require preservation. Artificial insemination is expected to accelerate population increases and preserve genetic resources simultaneously. The present study was the maiden attempt for cryopreservation of Kacang buck sperm. The objectives of this study were to determine whether the supplementation of superior Simmental bull seminal plasma protein in egg yolk-citrate extender could improve the quality of post-thawed Kacang buck sperm, increase conceptions rates, and improve kidding rates. Buck semen was diluted without supplementation (T0) and with supplementation of 2.5 mg (T1) and 5 mg (T2) of Simmental bull seminal plasma protein per mL egg yolk-citrate extender. Extended semen was packed in 0.25 mL straw as cryopreserved frozen semen. Post-thawed semen samples were evaluated for viability, motility, intact plasma membranes, malondialdehyde level, and DNA fragmentation. Estrus was synchronized for sixty Kacang does, which were divided randomly into three groups and inseminated using post-thawed semen. The progesterone serum concentration of the does was measured 7 and 22 days post-insemination to detect ovulation and conception. Pregnancy was confirmed using abdominal palpation at 43 days post-insemination and by observing birth. The T1 group showed the highest (P < 0.05) post-thawed viability, motility, and intact plasma membrane. Conception, pregnancy and kidding rates were also higher in T1 than other treatment groups. In conclusion, the 2.5 mg Simmental bull seminal plasma protein supplementation per mL egg yolk-citrate extender provided the best seminal quality and fertility of post-thawed Kacang buck semen.

New simplified protocols for timed artificial insemination (TAI) in milk-producing donkeys

This study compared the outcome of two new timed artificial insemination (TAI) protocols in a milk-producing donkey farm. Ninety Amiata jennies were inseminated at the moment of ovulation induction with hCG, with fresh-transported semen that had been stored at room temperature from 3 up to 6 h, with an approximate average storage time of 4 h and a half. In both protocols, on Day 0 jennies were treated with alfaprostol (PGF2α), and on Day 7 they were checked by ultrasound (US) and, if in estrus, they were treated in order to induce ovulation and were then artificially inseminated. In the slow-short TAI protocol, jennies not already inseminated were treated again with PGF2α at Day 14. On day 21 US was repeated and estrus jennies were induced to ovulate and inseminated. In the fast-long TAI protocol, US was performed once a week in jennies not already inseminated and if found in estrus, they were induced to ovulate and inseminated, while those not in estrus were treated again with PGF2α. This protocol was repeated for up to nine weeks. The rates of inseminated/treated, pregnant/inseminated and pregnant/treated jennies were 76%, 56% and 43% for the slow-short TAI protocol and 94%, 47% and 44% for the fast-long TAI protocol. The age class and the lactation status of the jennies had no significant effect on synchronization success or final pregnancy rate. This study demonstrates that it is possible to achieve reasonable pregnancy rates through simplified TAI protocols in jennies, reducing animal handling to a minimum.

Bio-economic and operational feasibility of introducing oestrus synchronization and artificial insemination in simulated smallholder sheep breeding programmes

Low selection intensity due to few selection candidates available at any one time due to thinly spread year-round lambings in villages and prohibitively large nucleus requirements to provide sufficient improved rams to the production tier are the major challenges for designing effective village-based and central nucleus-based breeding programmes, respectively, for smallholder sheep farmers. To tackle these challenges, we used deterministic simulation to design three schemes in village-based programmes introducing hormonal oestrus synchronization (natural oestrus (VNE), single oestrus synchronization (VSE1) and double oestrus synchronization (VSE2)) and three schemes in central nucleus programme introducing artificial insemination (AI) (natural mating with nucleus sizes of 5% (CNM1) and 1% (CNM2) of the total ewe population and natural mating in breeding tier and AI in production tier (CAI)). The schemes were evaluated for their bio-economic and operational feasibility, taking Bonga sheep of Ethiopia as a case study. The selection intensities achieved in VNE, VSE1 and VSE2 were 2.0, 2.3 and 2.4, respectively, for selecting rams for the breeding tier and 0.0, 0.8 and 1.0, respectively, for the production tier. The profits per ewe per year from VNE, VSE1 and VSE2 were Birr 12.2, 21.7 and 24.5, but the profit from VNE for the production tier was zero. CAI generated more genetic gains in the breeding objective (Birr 4.8) than CNM1 (Birr 2.5) and CNM2 (Birr 0.0) in the production tier. However, CAI was less profitable than CNM1 and CNM2. In conclusion, hormonal oestrus synchronization was found to be a feasible technological aide to accelerate genetic progress in village-based programmes. CNM1 and CNM2 could not be recommended as CNM1 requires large nucleus of 10 325 ewes and CNM2 results in zero genetic gain in the production tier. CAI could overcome the challenge in central nucleus programmes, namely unaffordable large nucleus, but the scheme needs to be subsidized by the public sector to be economically feasible for farmers.