本研究旨在根据妊娠率研究低繁殖性能和高繁殖性能公牛精子的特征和亚群。根据四个农场怀孕率的历史记录,选择了24头公牛。成立两组,低妊娠率(n=12;低),包括妊娠率<52.27%(33.33%至51.81%)的公牛;和一组妊娠率高(n=12;高),妊娠率>52.27%(52.27%至69.64%),固定时间人工授精(FTAI)后。对解冻的精子吸管进行精子动力学分析,形态学,质膜完整性和精子亚群。LOW组表现出更高比例的静态细胞(p<.05)。相比之下,HIGH组显示出膜完整性和总运动性和进行性运动性的百分比更高,和细胞具有快速和中等速度(p<0.05)。在集群过程中,建立了四个精子亚群。低生育率公牛在第2亚群中比例最高(41.46%),以缓慢和进行性精子为特征。高生育率公牛在第3亚群中的比例最高(37.17%),以快速和非线性精子为特征。这项研究的结果表明,快速和非线性精子比例较高的公牛似乎具有更大的受精能力,并且亚群分析可以被认为是鉴定高生育力射精的工具。
This study aimed to study the characteristics and subpopulations of spermatozoa from bulls with low and high reproductive performance based on pregnancy rates. Based on historical records of pregnancy rate from four farms, 24 bulls were selected. Two groups were established, with low pregnancy rates (n = 12; LOW), including bulls that presented pregnancy rates <52.27% (33.33% to 51.81%); and a group with high pregnancy rates (n = 12; HIGH), with pregnancy rates >52.27% (52.27% to 69.64%), after fixed-time artificial insemination (FTAI). The thawed sperm straws were analysed to sperm kinetics, morphology, plasma membrane integrity and sperm subpopulations. The LOW group exhibited a higher proportion of static cells (p < .05). In contrast, the HIGH group showed greater percentages for membrane integrity and total and progressive motility, and cells with fast and medium velocity (p < .05). In the cluster procedures, four sperm subpopulations were established. The low-fertility bulls presented the highest percentage of subpopulation 2 (41.46%), characterized by slow and progressive spermatozoa. The high-fertility bulls exhibited the highest percentage of subpopulation 3 (37.17%), characterized by fast and nonlinear spermatozoa. Results from this study indicated that bulls with greater percentages of fast and nonlinear spermatozoa seem to have greater fertilization capacity and the subpopulations analysis can be considered a tool to identify ejaculates with high fertility.