Blockey M A, Taylor E G
Aust Vet J. 1984 May;61(5):141-5. doi: 10.1111/j.1751-0813.1984.tb07217.x.
Premature spiral deviation of the penis was investigated in 1083 British breed beef bulls in 42 herds in Victoria (35) and Western Australia (7) by means of the serving capacity test. The herd prevalence was 60%. The prevalence of the defect at the initial test for all bulls was 10%. The prevalence in 635 polled bulls was 16% compared to a prevalence of 1% in 448 horned bulls. The breed prevalence and the number of bulls tested per breed was Red Poll 27% (15), Murray Grey 25% (4), Poll Shorthorn 21% (34), Angus 17% (415), Poll Hereford 10% (167) and Hereford 1% (448). The difference between the last 2 breed types was highly significant (P less than 0.001). The prevalence of the defect increased from 0 to 30% over 9 years in one Victorian herd. The age of affected bulls varied from 2 to 11 years with most affected bulls aged from 3 to 6 years. Common ancestry was found between affected bulls in Western Australia, providing circumstantial evidence that it may be an inherited defect. None of the 103 affected bulls examined in this study had suffered obvious injury to the penis or prepuce. Eighty per cent of 56 affected bulls from Victoria had low serving capacity. Four bulls (2 from each state) with moderate to severe spiral deviation of the penis attained pregnancy rates of 43%, 33%, 3% and 3% respectively, in single sire mating trials. Recommendations for culling defective bulls are presented, based on the herd prevalence and severity of the defect in individual bulls.(ABSTRACT TRUNCATED AT 250 WORDS)
通过授精能力测试，对维多利亚州（35个牛群）和西澳大利亚州（7个牛群）的42个牛群中的1083头英国品种肉用公牛进行了阴茎过早螺旋状偏斜情况的调查。牛群患病率为60%。所有公牛初次检测时该缺陷的患病率为10%。635头无角公牛的患病率为16%，相比之下，448头有角公牛的患病率为1%。各品种的患病率以及每个品种检测的公牛数量分别为：红白花牛27%（15头）、墨累灰牛25%（4头）、无角短角牛21%（34头）、安格斯牛17%（415头）、无角海福特牛10%（167头）、海福特牛1%（448头）。最后两种品种类型之间的差异极为显著（P小于0.001）。在一个维多利亚州的牛群中，该缺陷的患病率在9年里从0上升到了30%。受影响公牛的年龄在2至11岁之间，大多数受影响公牛年龄在3至6岁。在西澳大利亚州受影响的公牛之间发现了共同祖先，这提供了间接证据表明它可能是一种遗传性缺陷。在本研究中检查的103头受影响公牛中，没有一头阴茎或包皮受到明显损伤。来自维多利亚州的56头受影响公牛中有80%授精能力低。在单配种公牛试验中，4头阴茎有中度至重度螺旋状偏斜的公牛（每个州2头），其受胎率分别为43%、33%、3%和3%。基于牛群患病率和个体公牛缺陷的严重程度，提出了淘汰有缺陷公牛的建议。（摘要截选至250字）
