Chandler J E, Steinholt-Chenevert H C, Adkinson R W, Moser E B
Department of Dairy Science, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803, USA.
J Dairy Sci. 1998 Jul;81(7):1855-67. doi: 10.3168/jds.S0022-0302(98)75756-X.
Ejaculates from sires were examined by polymerase chain reaction to determine percentage of sperm bearing the Y chromosome. Results were verified by examining the percentage of male calves per ejaculate used in artificial insemination (AI) and the percentage of male piglets per litter from a controlled mating program. Spermatozoal DNA was amplified by polymerase chain reaction with specific primers for the Y chromosome. Image analysis measured the fluorescent intensity of the 194-bp band. Ejaculates were compared with a pooled standard of spermatozoal DNA equated to a 50% Y-bearing sperm ejaculate. Calving data were obtained from information collected for the National Association of Animal Breeders for dystocia evaluation of cows bred to AI bulls. Breeding data were obtained from AI technician receipts. Calving and breeding data were merged on cow, sire, calving date, and breeding date. The percentage of males were calculated per sire, ejaculate, and herd combination. Farrowing data were evaluated for the percentage of male piglets per litter. Ejaculates within bulls contributed to variation (24 +/- 9.8% to 84 +/- 9.8%) in the percentage of sperm bearing the Y chromosome. Ejaculates from the same bull contributed to variation in the percentage of male calves (16.1 to 72.3%). Ejaculates from the same boar contributed to variation in the percentage of male piglets that ranged from 7.8 to 94.7%. These percentages and the results obtained by polymerase chain reaction analysis of ejaculates suggested that spermatozoa bearing X and Y chromosomes were unequally represented in ejaculates. The use of ejaculates screened by polymerase chain reaction could enhance production of the desired sex of calf.
通过聚合酶链反应检测种公牛的射精样本，以确定携带Y染色体精子的百分比。通过检查人工授精（AI）中每次射精所产雄性犊牛的百分比以及来自受控配种计划的每窝雄性仔猪的百分比来验证结果。用针对Y染色体的特异性引物通过聚合酶链反应扩增精子DNA。图像分析测量194碱基对条带的荧光强度。将射精样本与等同于50%携带Y染色体精子射精量的精子DNA混合标准品进行比较。产犊数据来自为全国动物育种者协会收集的用于评估与AI公牛配种的母牛难产情况的信息。配种数据来自AI技术员的记录。产犊和配种数据根据母牛、种公牛、产犊日期和配种日期进行合并。计算每个种公牛、每次射精和每个牛群组合的雄性百分比。评估产仔数据中每窝雄性仔猪的百分比。公牛体内的射精样本导致携带Y染色体精子百分比存在差异（24±9.8%至84±9.8%）。同一头公牛的射精样本导致雄性犊牛百分比存在差异（16.1%至72.3%）。同一头公猪的射精样本导致雄性仔猪百分比存在差异，范围为7.8%至94.7%。这些百分比以及对射精样本进行聚合酶链反应分析得到的结果表明，携带X和Y染色体的精子在射精样本中的比例并不相等。使用经聚合酶链反应筛选的射精样本可以提高所需性别的犊牛产量。
