Abstract
This 2 × 2 factorial study evaluated different progesterone treatment durations and porcine follicle-stimulating hormone (pFSH) presentations for superovulation in acyclic Toggenburg goats. Goats (n = 56) received short (six days, G6) and long-term (17 days, G17) progesterone intravaginal devices combined with 133 mg (G6(133mg) and G17(133mg)) or 250 IU of pFSH (G6(250IU) and G17(250IU)) administered in six decreasing doses from 48 h before to 12 h after device removal. Does were naturally mated while in estrus. To monitor ovulation and the number of corpora lutea, ovarian transrectal ultrasound evaluations were performed on the days of the first pFSH administration, device removal, and six days later. Non-surgical embryo recovery (NSER) was performed 6–7 days after the first breeding. The G6(250IU) group had a shorter estrus duration and required fewer matings than the other groups (P < 0.05). Overall, the interval between the last dose of pFSH and the first sign of estrus detected (46.2 ± 2.3 vs. 35.3 ± 2.5 h) and the duration of estrus (38.2 ± 1.9 vs. 31.3 ± 3 h) differed (P < 0.05) between FSH(133mg) and FSH(250IU), respectively, regardless of progesterone treatment duration. Shorter duration of NSER proceeding and higher embryo viability rate (P < 0.05) were observed in G17 groups. However, the percentage of viable structures was higher (P < 0.05) in G6(133mg) (52.5%; 21/40) and G17(250IU) (54.5%; 30/55) groups than in the G6(250IU) (10.6%; 5/47) and G17(133mg) (23.3%; 7/30) groups. In conclusion, short-term treatment with 133 mg of pFSH is effective in achieving satisfactory embryo viability rate while minimizing the animal’s exposure to progesterone.