Motility of Bovine Spermatozoa and Control of Bacteria at 5 and 25° C. in Extenders Containing Sulfanilamide, Penicillin, Streptomycin and Polymyxin

In artificial breeding the general practice is to preserve bovine spermatozoa in a buffered yolk medium by cooling to approximately 5 C. and holding the extended semen at that temperature until used. This procedure is based on considerable experimental evidence which has been reviewed by Anderson (1) showing that spermatozoa survive longer at 5 C. than at higher temperatures. Considerable expense is involved in packaging and storing semen so as to maintain a temperature of 5 C. until the semen is used for insemination. Therefore, any method of preserving the spermatozoa which is cheaper than refrigeration is of practical importance. Foote and Salisbury (5, 6) have shown that the motility of spermatozoa stored at 20 C. in a citrate-phosphate buffer is prolonged by the addition of a number of antibacterial agents. Since egg yolk is an excellent medium for bacterial growth, one of the problems of preserving spermatozoa in egg yolk at "room" temperature appears to be that of controlling bacterial growth at this temperature. Dimitropoulos et al. (2) and Hennaux et al.