Spermatozoa were initially separated from fresh boar ejaculates using a 1.0 M sucrose density gradient. Spermatozoa (1 x 10(8) cells/ml) were subjected to gas cavitation (650 psi, 10 minutes), followed by a 4-step centrifugation technique to yield the final plasma membrane preparation. Purity of the plasma membrane isolate was determined using microscopic techniques (i.e. differential interference contrast and transmission electron microscopy) and marker enzymes for biochemical characterization. Plasma membranes were found to be removed primarily from the periacrosomal region of the sperm. Acrosomes appeared to remain intact on the cavitated spermatozoa. Transmission electron microscopy yielded a homogenous population of 100-200 microns unilamellar vesicles. Enzyme markers specific for plasma, acrosome and mitochondrial membranes substantial the purity observed under visual examination.
Two experiments were conducted to determine whether contact with latex or vinyl examination gloves affects canine spermatozoal motility. In experiment 1, semen was collected by digital manipulation from each of 5 dogs, and initial spermatozoal motility was assessed. The ejaculate was divided into 5 equal subsamples of 2 ml each, then randomly assigned to a control group, or treated with a 0.5-cm2 piece of latex or vinyl glove with or without talcum powder. After such exposure, spermatozoal motility was assessed at 1 and 5 minutes. Talcum powder within latex or vinyl glove treatments had no significant effect on spermatozoal motility at either period. Spermatozoal motility in samples did not differ between the control and vinyl glove groups; however, latex glove-treated samples were found to have a significant (P less than 0.05) decrease in spermatozoal motility at 1 and 5 minutes. In experiment 2, the effects of latex and vinyl gloves on canine spermatozoal motility during a sham laboratory manipulation was performed. Three ejaculates of approximately 10 ml were collected from each of 5 dogs and randomly assigned, within each dog, to be either a control (no glove exposure) or allowed to briefly contact either a latex or vinyl glove during sample manipulation. Spermatozoal motility was assessed for each sample immediately prior to and at 1 minute after manipulation. Exposure of semen to latex gloves significantly (P less than 0.05) decreased sample spermatozoal motility, whereas vinyl glove exposure had a minimal (P greater than 0.05) effect.(ABSTRACT TRUNCATED AT 250 WORDS)
Carcass and reproductive data including scan weight, ribeye area, rump fat, 12-13th rib fat and percentage intramuscular fat and reproductive tract scores (RTS) at 344 days were collected on 180 1998-born and 70 1999-born Angus heifers to determine the relationship between these traits. 1998-born heifers with higher RTS tended to be heavier and have more rump fat at 405 days (P < .05). Heavier heifers and heifers with more rump fat had higher RTS when adjusted to 395 days (P < .05). 1999-born heifers showed a similar pattern, with heavier heifers having higher RTS (P < .05). Rump fat was not as significant for 1999-born heifers compared with 1998-born heifers. Heavier heifers with more rump fat are more likely to have more mature reproductive tracts at breeding.
