Effect of ivermectin (Mectizan) on semen and testicular characteristics in Yankasa rams Effect of Ivermectin (Mectizan) on semen and testicular characteristics in Yankasa rams

Abstract

Ivermectin (Mectizan) is a well-tolerated acaricide and anthelmintic produced by Streptomyces avermitilis cultures, with no side-effects at pharmacological doses. the aim of the study was to examine the effect of Mectizan on semen parameters and testicular characteristics of Yankasa rams. Twenty, apparently, healthy rams aged 1.5-2 years and weighing 25-30 kg were used for this study. The rams were housed in standard pen with access to feed and water provided ad libitum. Mectizan was administered orally eight times at 14 days intervals for 16 weeks at 200 mg/kg to all the rams. Semen was collected using electro-ejaculator once weekly for three weeks before the treatment and throughout the treatment period. Semen parameters before and after treatment were evaluated for volume, density, colour, motility, pH, live spermatozoa and sperm morphology. Five pairs of testes were removed through surgical castration from five rams randomly selected five days after the last treatment for histological examination using haematoxylin and eosin stain. There was no significant (P > 0.05) difference in the semen parameters of all the rams before and after the treatment. The volume of ejaculates was higher (P < 0.05) from weeks 4 to 16 compared to pre-treatment values. The seminal pH were not significantly different. No lesions were observed on the histological section of the testes. It was concluded that repeated use of Mectizan at the recommended dosage of 200 mg/kg did not alter semen parameters and testicular characteristics, and may not impair reproduction in Yankasa rams.