Blom E
Nord Vet Med. 1976 Jun;28(6):295-8.
A case of sterility in an 18-month-old bull of the Holstein-Friesian breed was investigated. A semen sample sent to the laboratory showed a very low sperm concentration and abnormal sperm morphology. On the preliminary examination, the major sperm defect (60-70%) seemed to be tailless heads. When higher manification was used it was found that most of the defective heads had a short tail rudiment, a tail stump 2-3 mu long. Loose sperm tails were seldom seen in the smears. The defect has been described previously from Canada where it has occurred in different breeds, including Holstein-Friesians. The dam of the Danish bull in question was inseminated with imported American semen, and the sire is one of the most demanded Holstein-Friesian bulls at present. The possible heredity of the defect is discussed.
对一头18个月大的荷斯坦-弗里生公牛不育病例进行了调查。送往实验室的一份精液样本显示精子浓度极低且精子形态异常。初步检查时，主要的精子缺陷（60 - 70%）似乎是无头精子。当使用更高放大倍数观察时，发现大多数有缺陷的头部都有一个短的尾芽，即2 - 3微米长的尾残端。涂片上很少见到松散的精子尾部。此前在加拿大也曾描述过这种缺陷，在包括荷斯坦-弗里生牛在内的不同品种中都有发生。所讨论的这头丹麦公牛的母亲用进口的美国精液进行了人工授精，而其父是目前最受欢迎的荷斯坦-弗里生公牛之一。文中讨论了该缺陷可能的遗传性。
