Serum Progesterone Concentration One Day before Embryo Retrieval, Transfer and its Effect on Embryo Quality and Pregnancy Rate in Dromedary Camels

The present study aimed to evaluate the association between serum progesterone (P4) concentration one day before embryos recovery and transfer (ET) on embryos quality and post - ET conception rate (CR) in dromedary camels. Based on serum P4 concentration one day before recovery, donors (D) were categorized into four groups; P4 D G1 (P4 was <1 ng/ml), P4 D G2 (P4 averaged ≥ 1 - < 3 ng/ml), P4 D G3 (P4 averaged ≥ 3 - < 5 ng/ml) and P4 D G4 (P4 was ≥ 5ng/ml). The recipients (R) were categorized, based on serum P4 concentration one day before ET, into three groups; P4 R G1(P4 was <1 ng/ml), P4 R G2 (P4 averaged ≥1 - < 2 ng/ml) and P4 R G3 (P4 was ≥ 2 ng/ml). Grade 1 (G1) - embryos were the highest in P4 D G4 compared with P4 D G3 (p < 0.01) and P4 D G2 (P < 0.001). The CR was the highest in P4 RG3 compared with P4 RG2 (P > 0.05) and P4 RG1 (P <0.001). It is concluded that the increase in the serum P4 concentration one – day before recovery in donors is associated with an increase in the proportion of G1-embryos, which is, at the same time, associated with an increase in the post–ET CR. In addition, an optimal CR could be obtained by selecting recipients having serum P4 concentration >1 - 2 ng/ml one – day before ET and it increases as serum P4 concentrations increase beyond 2 ng/ml.