Evaluation of bovine spermatozoal morphologic features after staining or fixation
Harasymowycz, J.; Ball, L.; Seidel, G.E.
American Journal of Veterinary Research 37(9): 1053-1057
1976
ISSN/ISBN: 0002-9645 PMID: 60893 Document Number: 106440
The morphological features of acrosomes in fresh and in incubated, extended semen were evaluated after staining with Hancock's, Blom's or Wells-Awa's stains, or after fixation with buffered glutaraldehyde. Evaluations were done of stained smears by bright field microscopy and of fixed, unstained preparations by differential interference contrast microscopy using wet mounts. Raw semen samples from 1st ejaculates of 80 bulls were evaluated. The percentage of spermatozoa with intact acrosomes averaged 83.5% in unstained preparations fixed in glutaraldehyde, compared with 68.1, 74.5, and 67.4% for smears stained with Hancock's, Blom's or Wells-Awa's procedures (P<0.01). With incubated, extended spermatozoa from 57 bulls, glutaraldehyde-fixed, unstained samples had more intact acrosomes (P<0.01) than did samples stained with Hancock's or Blom's procedures (55 v 24.0 and 34.7%), but unstained samples were not significantly different from Wells-Awa-stained smears (49.3% intact acrosomes). In a 2nd experiment, several morphological characteristics of spermatozoa from fifteen 1st ejaculates of 7 bulls were evaluated after staining with Hancock's or Blom's stains, or after fixation in buffered glutaraldehyde or buffered-formol saline fixatives. Higher counts (P<0.01) of head abnormalities were found in wet, unstained fixed preparations (4.83, 4.47, 7.87, and 7.93% resp. for Hancock's, Blom's, glutaraldehyde and formol saline methods). There were more (P<0.05) separated heads on stained, dry smears (1.43, 1.23, 0.47, and 0.47% resp. for Hancock's, Blom's, glutaraldehyde and formol saline procedures). Fixation with buffered glutaraldehyde resulted in higher counts (P<0.01) of proximal protoplasmic droplets (2.47, 1.03, 0.67, and 1.43% resp. for glutaraldehyde, Hancock's, Blom's and formol saline procedures). Although not significant, the same trend was observed for distal protoplasmic droplets. Variation in sperm morphology between different parts of slide preparations was observed.