Electron microscopy and pedigree study in an Ayrshire bull with tail-stump sperm defects
Foote, R.H.; Hough, S.R.; Johnson, L.A.; Kaproth, M.
Veterinary Record 130(26): 578-579
1992
ISSN/ISBN: 0042-4900 PMID: 1496771 Document Number: 391319
Severe oligoteratozoospermia in a 20-month-old Ayrshire bull is reported. Semen ejaculates were collected during a 2 month period from this bull (A) and compared with those from another bull (B) with a similar pedigree. Bull A consistently ejaculated few sperm whereas bull B produced almost 9 times as many sperm per ejaculate. Sperm from A were nearly devoid of normal tails and were not motile. Percentages of unstained, partially stained and fully stained sperm following staining with aniline blue-eosin were 48, 5 and 47% from A and 77, 11 and 12% from B. Classification of spermatozoa for A was no tail, 7%; very short stump, 43%; rounded body and coiled tails, 38%; rudimentary tail, 12%; developed tail, <1% and sperm with intact acrosomes, 83%. For B, 96% had intact acrosomes, 90% normal heads and tails, 5% abnormal heads, 4% abnormal tails and 1% no tails. Scanning electron microscopy showed that all sperm from A were abnormal; most sperm from B were normal. Five cows were inseminated with sperm from bull A; none conceived. Semen from bull B was used for first service inseminations with a 56 day non-return rate of 69.2% (breed average 73.2%). Bull A had the same sire and paternal grandsire (with the paternal grandsire appearing on the maternal side of the pedigree) as another Ayrshire bull with same defect, suggesting that the oligoteratozoospermia is inherited. It is suggested that male relatives of affected bulls should be tested and suspected carriers eliminated from service.