The use of BoviPure[superscript TM] for the separation of X and Y chromosome-bearing bovine sperm cells

Abstract

Altering the sex ratio of offspring could be beneficial to livestock producers, particularly those raising beef and dairy cattle. Scientists have been investigating techniques to potentially control sex ratio. Density gradients have been used for separation of X and Y chromosome-bearing sperm by some researchers. To further investigate this idea, a study was conducted in which sperm were separated through a multi-layer density gradient prepared with BoviPure[Superscript TM], a product formulated specifically for separation and purification of bovine sperm. Oocytes were fertilized with sperm washed with BoviPure[Superscript TM] or with Brackett-Oliphant medium (control sperm). Embryos were sexed using polymerase chain reaction (PCR) after 2 and 8 days of culture. Cleavage rate of BoviPure[Superscript TM] and control oocytes was different (P<.01), but no difference (P>.05) was found in blastocyst development between the two groups. There was no difference (P>.05) in embryonic sex ratios between oocytes fertilized with control sperm or sperm separated through a BoviPure[Superscript TM] density gradient. Under conditions of this study, X and Y chromosome-bearing sperm could not be segregated by use of a BoviPure[Superscript TM] density gradient. Further research is needed in this area so that sex ratios can be altered at fertilization, before pregnancy is established.