Ovulatory Response and Embryo Yield in Jakhrana Goats Following Treatments with PMSG and FSH

Abstract

Superovulatory response and embryo production efficacy were investigated in adult (age 2-4 years, average body weight: 27-43 kg) cycling Jakhrana goats (n = 15) under semi-arid environmental conditions of India by administering different superovulatory regimens. Goats were reared under semi-intensive system of management in established farm conditions. To synchronize oestrus, a luteolytic dose of carboprost tromethamine (Upjohn, UK) was administered intramuscularly to all does at the dose rate of 5 microg per kg body weight in a double dose schedule with an interval of 11 days. For superovulation, 750 IU of PMSG (Folligon, Intervet, Boxmeer, Holland) per goat was administered intramuscularly 24 h before administering a second dose of luteolytic agent in five does (treatment 1). FSH (Sigma, St. Louis, MO, USA) 12.50 IU per goat was administered intramuscularly in a decreasing daily dose schedule (2.50, 2.50; 1.875, 1.875; 1.25, 1.25; 0.625, 0.625) at 12 h intervals over four days, initiated 48 h before administering second dose of carboprost tromethamine in 5 does (treatment 2). FSH (Super-Ov, Ausa Intern, USA) was administered at a uniform dose rate of 8.33 units per goat intramuscularly at 24 h intervals over three consecutive days (total dose was 25 units), initiated 48 h before administering a second dose of carboprost tromethamine in 5 does (treatment 3). To synchronize ovulation in responders, human chorionic gonadotrophin (hCG, Chorulon, Intervet) was injected intramuscularly at a dose rate of 500 IU in each goat on the day of oestrus appearance. Goats were laparotomized 72-82 h following the onset of synchronized oestrus and their genitalia were flushed using a standard collection procedure. Variability (p > 0.05) in superovulatory response (number of established corpora lutea) was observed: FSH (Sigma), 11.8 +/- 2.9; FSH (Super-Ov), 11.6 +/- 4.5; PMSG (Intervet), 8.4 +/- 2.3. A similar pattern was reflected in mean embryo and transferable embryo recovery, respectively (p > 0.05): FSH (Sigma), 8.0 +/- 1.8, 5.2 +/- 1.7; FSH (Super-Ov), 6.6 +/- 2.4, 5.4 +/- 2.4; PMSG, 5.8 +/- 1.9, 3.8 +/- 2.2. In PMSG-treated does, comparatively more unfertilized ova or retarded embryos were recovered than in FSH-treated does. The superiority of FSH preparations over PMSG was reflected in terms of total and transferable embryo production (p > 0.05). On average, five transferable embryos (excellent and good quality) were recovered per doe treated with FSH of either source. The mean ova/embryo recovery was satisfactory (55-68%). Results indicated that Jakhrana goats can be superovulated for embryo production using FSH of either source to augment productivity.

Preliminary results evaluating a simplified superovulation protocol in Boer goats

“…Similar results were obtained in goats superovulated with FSH or eCG (Goel and Agrawal, 2005). However, this observation came as a surprise as goats superovulated with eCG usually exhibit oestradiol-17β peak concentration earlier, which could lead to the early onset of oestrus (Riesenberg et al, 2001a).…”

“…In the current study, the lower number of ovulations measured may be due to ovulations not being visible because of the premature luteal regression or obscured by unovulatory follicles -which are commonly reported following superovulation with eCG (Riesenberg et al, 2001b). However in goats where eCG or FSH are combined with hCG, the ovulation and embryo recovery rate were similar (Goel and Agrawal, 2005). In the present study not only was the superovulation response reduced when the simplified protocol was used, but also the number of embryos recovered while the number of unfertilised ova recovered increased.…”

“…Superovulation in goats can generally be performed utilising FSH or eCG gonadotrophins. The FSH protocol most commonly used involves oestrous synchronisation with the aid of progestagens for 9-17, days followed by the administration of FSH for 6-8 dosages, beginning approximately 48 h before progestagen removal (Gonzalez-Bulnes et al, 2003, Goel and Agrawal, 2005, Lehloenya et al, 2008, Lehloenya et al, 2009and Lehloenya and Greyling, 2010. On the other hand, eCG is usually administered as a single injection, due to its long halflife, approximately 48 h before progestagen removal (Espinosa-Marquez et al, 2004 andHoltz, 2005).…”

“…On the other hand, eCG is usually administered as a single injection, due to its long halflife, approximately 48 h before progestagen removal (Espinosa-Marquez et al, 2004 andHoltz, 2005). When comparing the efficiency of FSH and eCG as superovulation agents in goats, it has been reported that FSH produced higher ovulation and embryo recovery rates, as well as more transferable embryos, although more variable than eCG (Mahmood et al, 1991 andGoel andAgrawal, 2005). Although the utilisation of FSH in the superovulation programme of goats has demonstrated the ability to produce better results, this regime is more labour intensive and imposes more stress to the animals, due to excessive handling -as it must be administered twice daily over a 4 day period.…”

Effect of supplementation of hCG or GnRH on ovulation and subsequent embryo production of eCG superovulated goats

“…Moreover, different goat breeds produced variable results by using eCG for superovulation such as 3 embryos in Jamunapari (Goel and Agrawal, 1990), 3 embryos in Boer goats (Nowshari et al, 1995); 6 embryos in Jakhrana goats (Goel and Agrawal, 2005); 2 embryos in indigenous dairy goats (Pampukidou et al, 2011) and 1 embryo in crossbred does (Xiao et al, 2013) Although, both hCG and GnRH were supplemented for ovulation synchronisation, hCG supplementation produced better results. Human chorionic gonadotrophin supplementation produced a significantly higher number of structures but due to higher number of unfertilised oocyte total recovered and transferable embryos were not increased significantly.…”