Survival and fertility of antibiotic-treated bovine spermatozoa.

Motility of spermatozoa stored at 5 C with up to 1000 units or mug of chloramphenicol, polymyxin, kanamycin, tylosin, ampicillin, lincomycin, spectinomycin, erythromycin, novabiocin, or terramycin per ml of extender was compared to that with penicillin plus dihydrostreptomycin. Novabiocin and terramycin were toxic, but other antibiotic treatments had no effect. However, erythromycin and tylosin, as well as colymycin, depressed motility of frozen thawed spermatozoa. Spermatozoal motility was equivalent, following freezing in ampules or straws. All of the antibiotics which were non-toxic when added singly to frozen semen were also not harmful to frozen spermatozoa when as much as 2000 units or mug were added per ml of extender containing penicillin and dihydrostreptomycin. The addition of 1000 units or mug of ampicillin, chloramphenicol, kanamycin, lincomycin, polymyxin, or spectinomycin per ml of extender containing 750 units penicillin and 750 mug dihydrostreptomycin per ml did not influence the fertility of frozen spermatozoa in a field test involving 19,663 first inseminations.