Effect of Antibacterial Agents on the Motility of Stallion Spermatozoa at Various Storage Times, Temperatures and Dilution Ratios1, 2

Abstract

Two experiments were conducted to study the effect of eight antibacterial agents on equine spermatozoan motility. The treatments included seven levels (0, 250, 500, 1,000, 1,500, 2,000 and 2,500 units of µg) of each antibacterial agent at two dilutions (1:5 and 1:10) in an egg yolk-Tris extender. Motility was estimated after storage at 38 and 5 C. Levels up to 2,500 units or µg/ml of gentamicin sulfate, lincomycin, nalidixic acid, polymyxin B sulfate, or sodium penicillin G had no detrimental effect on spermatozoan motility, although occasionally stallion interactions, usually of small magnitude, were observed. Streptomycin sulfate, even at the lower levels, was detrimental at 38 C but not at 5 C. At both 5 C and 38 C, kanamycin sulfate resulted in lower spermatozoan motility which became significant after storage at the longer time intervals. Erthyromycin was detrimental to motility at both temperatures, especially at higher levels and after longer exposure times. Motilities were higher (P<.05) at the dilution ratio of 1:10 when averaged over other factors. Motility declined significantly (P<.01) over time at both storage temperatures.