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

摘要

The variation of head areas of normal spermatozoa attributable to breed, individual bull and ejaculate, and the effectiveness of the separation of X and Y chromosome-bearing spermatozoa were determined. Spermatozoa were evaluated using video enhanced contrast microscopy combined with video intensified fluorescent microscopy and PCR. In experiment 1, spermatozoal head areas were measured from 2 ejaculates collected from 10 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 individual bulls across breeds. In experiment 2, spermatozoa from 5 ejaculates were separated on individual SEPDEVICEs a patented process using glass microspheresin straws. Head area, fluorescent intensity and PCR of spermatozoa retained in the SEPDEVICE suggested a separation based on size in 1 of 5 samples. Ejaculate variation in head areas affected separation efficiency.