Resynchronization of synchronized follicular wave in dromedary camels of unknown pregnancy status (Camelus dromedarius)

Abstract

This study was designed to evaluate the use of resynchronization (Resynch) protocol in dromedary camels. In experiment 1, the effect of initiation of Resynch protocol with GnRH treatment on Day 14 ± 2 after timed breeding (TB) in camels of unknown pregnancy status on pre-established pregnancy and resynchronized fertility, was examined. The camels (n = 201) were divided into two groups after synchronized TB. Control (n = 98) group camels were examined for early pregnancy on Day 21 ± 2 after TB and second mating in nonpregnant camels was done when a dominant follicle of 11–17 mm in diameter was present. Resynch (n = 103) group camels received GnRH treatment on Day 14 ± 2 after TB and PGF2α treatment upon nonpregnancy diagnosis (7 days later) and second mating (resynchronized TB) was done (12 days after GnRH). The pregnancy diagnosis and losses were monitored using ultrasonography. The pregnancy rate on Day 90 (61.2 vs. 59.2%) after TB and pregnancy loss (14.3 vs 11.6%) were similar between control and Resynch groups (P >0.05). There was also no difference in the pregnancy rate (57.1 vs 52.9%) after second mating between the groups (P >0.05). In experiment 2, the reproductive performance following synchronized and resynchronized timed natural services was evaluated in camels under farm (n = 120) and field conditions (n = 214) conditions. Acceptable pregnancy rates were recorded after synchronized TB-1, resynchronized TB-2 and TB-3 under farm and field conditions. After 3 timed services, a cumulative pregnancy rate of 82.5 and 79.7% was recorded under farm and field conditions respectively. In conclusion, the Resynch protocol initiated with GnRH treatment on Day 14 ± 2 after breeding, with unknown pregnancy status, was effective in resynchronizing the follicular wave for subsequent TB, without having any effect on the pre-established pregnancy in dromedary camels.