The postpartum period in dromedary camels: Uterine involution, ovarian activity, hormonal changes, and response to GnRH treatment

The aim of the present study was to investigate the time for complete uterine involution and resumption of ovarian activity in postpartum dromedary camels, relative to hormonal changes. A total of six females were examined by ultrasonography twice weekly starting 3 d after parturition. GnRH was administered when the follicles reached >= 0.9 cm diameter. Blood samples were collected for hormonal analysis. Results revealed that the mean intervals for complete involution of the previously gravid horn, non-gravid horn, and cervix were 34.33 +/- 13.9, 29.01 +/- 0.81, and 28.71 +/- 1.51 d, respectively. After GnRH treatment (Days 17-34), five of the six camels had ovulated. The corpus luteum was detected by Day 4.1 +/- 1.6 after GnRH treatment and lasted for 6 +/- 11.1 d. Serum progesterone (P4) was basal and increased only after GnRH treatment. Serum estradiol 17-beta (E2) peaked twice: when a large follicle was detected and 8.5 +/- 12.8 d post-GnRH treatment. The serum FSH pattern was biphasic, with two peaks just before the recruitment of small follicles and 4.67 +/- 4.1 d after GnRH treatment. The five ovulating females were mated; two conceived after the first service and three after the second service. The interval from calving to conception was 78.16 +/- 13.71 d. It was concluded that in dromedary camels, involution of the uterus is completed by the 5th week postpartum, these camels are highly responsive to early GnRH treatment, and they can be mated between the 5th and 6th week after parturition with encouraging conception rates. (C) 2014 Elsevier B.V. All rights reserved.