A new antibiotic combination for frozen bovine semen. 2. Evaluation of seminal quality.

Amikacin, clindamycin, gentamicin, Linco-Spectin, minocin and tylosin were added individually and in combinations at various concentrations to bovine neat semen and to egg-yolk citrate, egg yolk-tris or heated whole milk extenders (nonglycerol fractions) prior to final processing for freezing to -196 degrees C. After thawing samples, seminal quality was measured by progressive motility and acrosomal integrity evaluations. Studies were performed in parallel with microbiological efficacy studies of Shin et al. (7). The antibiotic combination including gentamicin, tylosin and Linco-Spectin at 500 ug/ml, 100 ug/ml and 300/600 ug/ml, respectively, was not detrimental to seminal quality and, in the parallel studies, was most efficacious in controlling microorganisms potentially present in bovine semen.