Evans R D, Grandin T, DeJarnette J M, Deesing M, Garrick D J
Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523-1171, USA.
Anim Reprod Sci. 2005 Jan;85(1-2):95-103. doi: 10.1016/j.anireprosci.2004.03.004.
The objective of this study was to characterize facial whorl characteristics in Holstein stud bulls (n = 485) and to investigate their association with measures of semen quantity and quality. Bulls had 1 (n = 454), 2 (n = 21) or no facial hair whorls (n = 5). Some 39% of bulls had whorls in the middle of their forehead, whereas 43% had whorls very low down on their forehead. Spiral whorls were present on 77% of bulls while 22% had elongated whorls. Abnormally shaped whorls were found more often on bulls with low whorls (27% versus 17%, P = 0.01) than on bulls with high or middle whorls. Semen production data were obtained from the AI center database to provide a representative sample of each sires most recent semen production characteristics. The number of semen collections per bull averaged 38 with a range of 1 (n = 9) to 272 (n = 1). The average number of days between collections was 5 but varied from 1 to 425 days. Average age of bulls at first recorded collection was 679 days and ranged from 307 to 4555 days. There were no significant differences between black and white bulls in semen quality or quantity. Semen quality over the summer months was reduced in comparison to the winter months. Age of the bull at time of collection had no effect on any of the semen quality traits. Older bulls had larger scrotal circumference and produced more semen (P > 0.01). Bulls with whorls located in the center of the forehead were not significantly different in semen quality or quantity for the 10 traits considered when compared to bulls with whorls located outside the center. In contrast to previous research findings with Angus cattle, semen attributes were not significantly different between bulls characterized with round (or spiral) epicenters and those with abnormally shaped whorls. The difference between the two studies may be due to the fact that Angus bulls have a higher percentage of abnormal elongated whorls compared to Holsteins.
本研究的目的是描述荷斯坦种公牛（n = 485）的面部涡旋特征，并研究其与精液数量和质量指标的关联。公牛有1个（n = 454）、2个（n = 21）或没有面部毛发涡旋（n = 5）。约39%的公牛在前额中部有涡旋，而43%的公牛在前额非常低的位置有涡旋。77%的公牛有螺旋形涡旋，22%有拉长的涡旋。低涡旋公牛出现异常形状涡旋的情况（27%对17%，P = 0.01）比高涡旋或中涡旋公牛更常见。从人工授精中心数据库获取精液生产数据，以提供每个种公最新精液生产特征的代表性样本。每头公牛的精液采集次数平均为38次，范围为1次（n = 9）至272次（n = 1）。采集之间的平均天数为5天，但从1天到425天不等。首次记录采集时公牛的平均年龄为679天，范围为307天至4555天。黑白公牛在精液质量或数量上没有显著差异。与冬季相比，夏季的精液质量有所下降。采集时公牛的年龄对任何精液质量性状均无影响。年龄较大的公牛阴囊周长更大，精液产量更高（P > 0.01）。与位于中心以外的涡旋的公牛相比，前额中心有涡旋的公牛在所考虑的10个性状的精液质量或数量上没有显著差异。与之前对安格斯牛的研究结果相反，以圆形（或螺旋形）中心点为特征的公牛和涡旋形状异常的公牛之间的精液属性没有显著差异。两项研究之间的差异可能是由于与荷斯坦牛相比，安格斯公牛异常拉长涡旋的比例更高。
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