Comparison of Two Superovulation Protocols in the Dromedary Camel (Camelus dromedarius)

Multiple ovulation and embryo transfer (MOET) has increased in practice, particularly in racing camels. Ovarian superstimulation methods remain poorly studied. Response the superovulation remains variable. We hypothesized that initiation of treatment at a specific day after ovulation would result in improved results than the traditional treatment. The objectives of this study were to compare ovarian response and embryo yield in donor camels superstimulated with follicle stimulating hormone ( pFSH) following either progesterone treatment or at a specific time after ovulation.
Twenty multiparous healthy females were assigned to two treatment groups. Females in both groups received the same pFSH (Folltropin®, 20 mg/mL, IM, NIH-FSH-P, Bioniche, Pullman, WA) protocol: twice daily (am/pm) in decreasing doses (60/60 mg, 50/50 mg, 40/40 mg, 30/30 mg, 20/20 mg). Group 1 (n=10) received pFSH treatment starting 3 days after induction of ovulation with 100 µg gonadotropin releasing hormone (GnRH). Gonadotropin releasing hormone was administered when a mature follicle (12 to 18 mm in diameter) was present and there was increased uterine tone and edema. Group 2 (n=10) received pFSH after a 14-day course of progesterone in oil (100 mg/day, IM). Additionally, females in Group 2 received two doses of 500 mcg cloprostenol at 12 hour intervals on day 7 after induction of ovulation to ensure luteolysis. Ovarian follicular activity was monitored every other day by transrectal ultrasonography with a 7.5 MHz linear-array transducer during treatment and females were mated once to one of three proven fertility bulls when the diameter of the follicles reached 12 to 14 mm. All females received GnRH (100 µg, IM) and human chorionic gonadotropin (1500 IU, IV) immediately after mating. Presence of corpora lutea was detected by transrectal ultrasonography on day 8 after mating (day 0 = day of mating) and the uterus was flushed for embryo recovery using a non-surgical technique.
There was no significant difference between the two treatments in the interval from the last pFSH treatment to mating (7.5±0.5 days for Group 1 vs. 7.5±1.2 days for Group 2) and number of follicles at the time of mating (15.7±6.2 vs. 10.4±5.9). The number of corpora lutea at the time of embryo collection (12.8±4.3 vs. 8.2±4.3) and the number of transferrable hatched blastocysts (6.9± 3.0 vs. 3.8± 2.7) were significantly higher (P<0.05) in Group 1.
This study demonstrated that initiation of pFSH treatment three days after induction of ovulation may be more efficient for MOET in camels than initiation of treatment after 14 days of progesterone administration. However, embryo yield for both treatments remains highly variable. Further research is needed to develop a more predictable control of the follicular wave and superstimulation response in camels.