Superovulation in waptiti (Cervus elaphus) during the anovulatory season

Abstract

The objective was to evaluate the efficacy of three previously unreported ovarian superovulatory treatment protocols in wapiti. Protocols were initiated specifically at the time of ovarian follicular wave emergence, and intended to enable determination of the effects of frequency of treatment (i.e., animal handling) and LH supplementation on ovarian response. Thirteen parous wapiti hinds, 2 to 4 y of age, were used late in the anovulatory season (July). The ovaries were examined daily by transrectal ultrasonography. Hinds were given 5 mg estradiol 17-β im (day of treatment designated as Day 0) to induce a new wave of ovarian follicular development. On the expected day of wave emergence (Day 3), hinds were assigned randomly to three treatment groups and given: (1) 100 mg FSH im once a day for 4 days (N = 5); (2) 200 mg FSH sc on Day 3 and Day 5 (N = 4); or (3) 200 mg FSH plus 2.5 mg LH sc on Day 3 and Day 5 (N = 4). All hinds were given 10 mg LH im on Day 6 to induce ovulation. The mean (± SEM) number of ovulations per animal in the respective groups was 6.2 ± 2.0, 15.5 ± 5.9, and 14.8 ± 2.7. In conclusion, the technique of inducing follicular wave emergence to initiate superovulatory treatment at the time of wave emergence was effective in wapiti during the anovulatory season. The most efficient and effective method of ovarian superovulation in this study involved administration of estradiol 17-β on Day 0, followed by 200 mg FSH sc on Days 3 and 5, and induction of ovulation (10 mg of LH) on the evening of Day 6. Compared with conventional methods that require 14 days and handling the hinds six times, the protocol used herein reduced the treatment period to 8 days and the number of animal handlings to four.