CIDR-hCG treated dromedary camels Effect of time of eCG administration on serum progesterone level, times to estrus and ovulation of CIDR-hCG treated dromedary camels Ahmed Ali12 and Fahd Al-Sobayil1 48th Annual Conference Physiology and Pathology of Reproduction Februartagung 2015“ 11th – 13th February 2015 in Zurich 1Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, Qassim University, 51452 Buraydah, Qassim, Saudi Arabia 2Department of Theriogenology, Faculty of Veterinary Medicine, Assiut University, 71526 Assiut, Egypt Introduction Embryo transfer offers many advantages to commercial animal breeding (Skidmore 2004; Nagy et al., 2013); however, in camels it is still far behind what had been accomplished in other farm animals. One reason is that the estrous cycle (follicular waves) of female camels has certain peculiarities; namely the ovarian activity is strictly follicular, it does not have a luteal phase and the ovulation is induced (Musa and Abusineina, 1978; Al Eknah, 2000, Skidmore, 2011). Moreover, superovulation treatments facing some difficulties including high incidence of non-responsive females, follicle luteinization before breeding, high incidence of over stimulated ovaries, and the refractory response to superovulation with FSH and eCG (Skidmore, 2004). Furthermore, in these programs, females must be examined frequently for the presence of dominant follicle, and insemination or mating should be performed when follicles attained diameter between 1.5 and 2.0 cm (Skidmore et al., 1995). This method is actually labor intensive. This study was conducted to characterize the ovarian dynamics and serum P4 profiles during CIDR-eCG-hCG superovulatory program in dromedary camels and to investigate the effect of time of eCG administration on the superovulatory response. Materials and Methods Superovulation programs: All females received a single dose of 25 mg Dinoprost 3 days before starting the program to ensure the absence of any luteal structure on the ovary. Controlled internal drug release (CIDR) containing 1.9 g P4 were inserted into the vagina for 14 days. Two days before CIDR-withdrawal, six females (group 1) received 3000 iu eCG im, the other five females (group 2) received the same dose at CIDR withdrawal. All females received 1500 iu hCG im two days after CIDR withdrawal. Animals were observed for estrus and hand mated with a fertile male. Estimation of serum P4 level: Blood samples (10 mL) were taken for estimation of the serum P4 level. Samples were collected just before CIDR insertion (0h), then on the following times: 20min, 40min, 60min, 2h, 3h, 4h, 5h, 6h, 12h, 18h, 24h, after that daily up to the day of CIDR withdrawal. P4 was analyzed using the electrochemiluminescence immunoassay (ECLIA) and cobas e 411 immunoassay analyzers. Estimation of numbers of corpora lutea: The ovaries were examined via transrectal ultrasonography, The ultrasound examination was performed on d+14 after CIDR withdrawal to estimate the number of corpora lutea. Group 2, n=5 Group 1, n=6 hCG 1500 hCG 1500 eCG 3000 iu eCG 3000 iu PG PG 2d 2d Estrus + Mating 2d Estrus + Mating 2d 2d CIDR (1.9 P4) for 14d CIDR (1.9 P4) for 14d Results and Discussion Serum P4 level: All animals showed similar P4 profiles from d0 through d12 of CIDR treatment (Fig 1). P4 increased within 20min of CIDR insertion, reached the highest level by 4h, remained approximately constant between 4h and 6h, and then decreased slowly. Afterwards, the mean level decreased steadily up to the d12 (P< 0.0001). After CIDR withdrawal, the P4 returned to basal levels until d+4, where it increased steadily until d+14 (P<0.0001). There was a positive correlation between number of corpora lutea by d+14 and the serum P4 levels (r=0.78, n=8, P<0.05). There were no differences in the mean serum P4 levels between group 1 and 2 from d12 through d+14 (Fig 2). Estrus and ovulation: Estrus symptoms occurred in all females. Times from CIDR withdrawal to estrus beginning are shown in (Fig 3). Estrus occurred non-significantly earlier in group 1 (4.8±0.9d) than in group 2 (6±0.7d). The duration of estrus did not differ significantly between group 1 (3.6±0.3d) and group 2 (3±0.5d). Ovulation (serum P4 >1.0 ng/mL) occurred in all females but one in group 1. Times from CIDR withdrawal to ovulation are shown in (Fig 3). The mean interval from CIDR withdrawal to ovulation occurred non-significantly earlier in group 1 (8.2±1d) than in group 2 (9±1d). Number of corpora lutea: The mean number of the corpora lutea by d+14 did not differ between group 1 (4.6±0.7) and group 2 (5.2±1.5). Follicle luteinization (thickening in follicular wall) was observed in one case in group 1 that failed to ovulate. Conclusion: data described in this study might help in designing fixed-time superovulation programs in dromedary camels. eCG hCG Group 1, n=6 a b c bd ae eCG hCG Group 2, n=5 Fig 2: Serum progesterone levels (mean+SEM) in female camels treated with eCG before (group1) or at (group 2) CIDR withdrawal. Fig 1: Serum progesterone levels (mean+SEM) from just before CIDR insertion (d0) to d12 of CIDR treatment, n=11. Fig 3: Number of female camels showed estrus and ovulated after CIDR – withdrawal in CIDR-eCG-hCG superovulation programs. Group 1: eCG administrated 2d before CIDR withdrawal, n=6; Group 2: eCG administrated at CIDR withdrawal, n=5. CIDR remained intravaginal for 14d. References Skidmore (2004) Embryo Transfer, J.A. Skidmore (Ed.), Publisher: International Veterinary Information Service (www.ivis.org), Ithaca, New York, USA.; Nagy et al. (2013) Use of assisted reproduction for the improvement of milk production in dairy camels (Camelus dromedarius). Anim Reprod Sci. 136, 205-210; Musa and Abusineina (1978) The oestrous cycle of the camel (Camelus dromedarius). Vet. Rec. 103, 556-557; Al Eknah (2000) Reproduction in Old World camels. Anim. Reprod. Sci. 60-61, 583-592. Review, Skidmore (2011) Reproductive physiology in female Old World Camelids. Anim. Reprod. Sci. 124, 148-154. Review; Skidmore et al. (1995) The ovarian follicular wave pattern in the mated and non-mated dromedary camel (Camelus dromedarius).J. Reprod. Ferti. Suppl. 49, 545-548.