Effect of xylazine, detomidine, medetomidine and dexmedetomidine during laparoscopic SCNT embryo transfer on pregnancy rate and some physiological variables in goats

Abstract

BackgroundThe present study was conducted to determine if using α2-adrenergic agonists results in decreased stress levels (lower cortisol levels) in goats used for laparoscopic embryo [somatic cell nuclear transfer (SCNT)] transfer; and there is an effect on pregnancy rate when stress levels are lessened. Sixty healthy does aged 24 ± 4 months and weighing 30 ± 3 kg were used in experimental, prospective, randomized and blinded study. In this study, embryos were obtained by the Somatic Cell Nuclear Transfer (SCNT) method. Animals were randomly assigned to five groups: control (normal saline); xylazine (100 μg kg− 1); detomidine (50 μg kg− 1); medetomidine (20 μg kg− 1); and dexmedetomidine (5 μg kg− 1). Embryo transfer (through laparoscopic technique) began at 15 min and continued till 45 min post-treatment. Heart rate (HR), respiratory rate (RR), rectal temperature (RT), and ruminal motility were performed before (baseline) and after drug administration. Pregnancy detection was performed 38 days after embryo transfer.ResultsCompared to control, HR, RR and ruminal motility were significantly lower in α2-adrenergic agonists groups at 5–90, 15–60, and 5–120 min, respectively. Serum cortisol values significantly increased from baseline in the control group 45 min after drug administration (p = 0.001). At time points 45 and 60 min, serum cortisol concentration was significantly lower in α2-adrenergic agonists groups compared with the control. The pregnancy rate in control group (n = 4/12, 33.3%) was significantly lower than xylazine (n = 9/12, 75%; p = 0.041), detomidine (n = 10/12, 83.3%; p = 0.013), medetomidine (n = 9/12, 75%; p = 0.041) and dexmedetomidine (n = 10/12, 83.3%; p = 0.013); but no significant differences were observed among different α2-adrenergic agonists groups.ConclusionAlph2-adrenergic agonists were effective on increasing the pregnancy rate of recipient goats receiving cloned embryos. No significant differences were detected among different α2-adrenergic agonists.