ABSTRACT
This study tested various combinations of ketamine and xylazine with the objective to improve on the efficiency of the preliminary electroejaculation technique developed for semen collection from the agouti (Dasyprocta leporina). There were two experiments, which were each replicated. Experiment 1 had six treatments: treatment 1 (30 mg/kg ketamine and 10 mg/kg xylazine), treatment 2 (20 mg/kg ketamine and 10 mg/kg xylazine), treatment 3 (30 mg/kg ketamine and 5 mg/kg xylazine), treatment 4 (20 mg/kg xylazine), treatment 5 (30 mg/kg xylazine), and treatment 6 (40 mg/kg xylazine). Experiment 2 included five treatments: treatment 7 (40 mg/kg xylazine), treatment 8 (20 mg/kg ketamine and 40 mg/kg xylazine), treatment 9 (15 mg/kg ketamine and 40 mg/kg xylazine), treatment 10 (10 mg/kg ketamine and 40 mg/kg xylazine), and treatment 11 (5 mg/kg ketamine and 40 mg/ kg xylazine). Mean induction times were 3:27 +/- 0:31 and 4:59 +/- 0.49; mean immobilization times were 1:55 +/- 0.11 and 1:19:06 +/- 0:11.7 hr, respectively, for experiments 1 and 2. Treatment 4 produced the best ejaculation time and semen volume, 4.53 +/- 0.52 min and 0.41 +/- 0.07 ml, respectively. Spermatozoa were observed in 75% of ejaculate samples collected when treatments 6 and 7 were applied. The best treatments were 6 and 7 (P < 0.05); spermatozoa concentration (431 +/- 180 x 106/ml), motile cell % (47.17 +/- 8.78%) and forward progressive motility % (47.1 +/- 10.5%). Success rates for samples containing spermatozoa increased from 30% in previous experiments to 41.33%. It was concluded that weaker dosages of xylazine may require being administered in combination with ketamine to completely anaesthetize the male agouti for electroejaculation.
