Effect of Centrifugation and Seminal Plasma on Motility and Fertility of Stallion and Bull Spermatozoa

The effect of centrifuging semen on bovine and equine spermatozoan motility and fertility and the effect of seminal plasma and dilution on equine spermatozoan survival during incubation before and after freezing were studied. Centrifugation at 3708 or 829 g was not detrimental (p more than .05) to prefreeze or postfreeze motility when the final concentration of seminal fluid was 10%. However a reduction of seminal plasma to 2% significantly (p less than .05) reduced motility. Spermatozoan motility was significantly (p less than .05) reduced before and after freezing by removal of seminal plasma. The dilution of 1:4 was superior to all other dilutions for prefreeze and postfreeze motility. Postfreeze motility was highest in the extender containing 20% seminal plasma. Frozen or unfrozen equine spermatozoa was not affected (p more than .05) by centrifugation at 310 g for 3.5 minutes; however the fertility of bovine semen was lowered by centrifugation at 270 g for 3 minutes (p less than .05).