Bovine spermatozoal head size variation and evaluation of a separation technique based on this size

The objectives of this study were to determine the variation of head areas of normal spermatozoa attributable to breed, individual bull and ejaculate and to verify separation of X and Y chromosome-bearing spermatozoa and sepa ration effectiveness. Spermatozoa were evaluated using video enhanced contr ast microscopy combined with video intensified fluorescent microscopy and t he polymerase chain reaction(PCR). In Experiment I, spermatozoal head areas were measured from 2 ejaculates collected from bulls of 3 beef and 2 dairy breeds. No differences in head areas were found between breeds or between bulls within breeds; variation was observed among ejaculates from individua l bulls across breeds. In Experiment 2, spermatozoa from 5 ejaculates were separated on individual SEPDEVICEs (Patented). Head area, fluorescent inten sity and PCR of spermatozoa retained in the SEPDEVICEs suggested a separati on based on size in 1 of 5 samples. Ejaculate variation in head areas affec ted separation efficiency. (C) 1999 by Elsevier Science Inc.