Zhang B R, Larsson B, Lundeheim N, Håård M G, Rodriguez-Martinez H
Department of Obstetrics and Gynaecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
Int J Androl. 1999 Aug;22(4):253-60. doi: 10.1046/j.1365-2605.1999.00178.x.
In the present study, we assessed the degree to which various bull sperm traits, including the ability to bind to homologous zona pellucidae (ZP) and to fertilize in vitro, were related to field fertility after AI as 56d-non-return rates (56d-NRR based upon 8620 AIs) with frozen-thawed semen from 12 Swedish Red and White young (11-13 months) bulls (3 freezing batches/bull, 1-2 consecutive ejaculates/batch), entering a national breeding program and housed at two AI-bull stations. Significant (p < 0.01) correlations among in vitro tests were found for swim-up separated spermatozoa (concentration and concentration of motile spermatozoa) with the ZP-binding assay (ZBA, r = 0.72 and r = 0.73, respectively) and blastocyst rates (r = 0.79 and r = 0.79, respectively). A strong correlation was found between cleavage and blastocyst rates (r = 0.81, p < 0.01). Whereas bull station influenced (p < 0.05-0.001) all these variables, bull only affected (p < 0.05) ZBA and cleavage. There was no significant difference in 56d-NRRs (p > 0.05, range 62-67.2%) among bulls, once the absolute NRRs had been corrected for season, area and parity. Neither bull, batch nor station had a significant effect on field fertility (p < 0.05). None of the single sperm traits/tests in vitro correlated significantly with in vivo fertility. A correlation with bull fertility was, however, found when measures of sperm traits were combined and predicted NRRs, calculated by regression analyses, were tested against observed 56d-NRRs. The predictive bull fertility, based on the tested three frozen batches, varied from 61.8 to 67.5% (p < 0.05) and was highly correlated with the observed fertility NRRs (r = 0.92, p < 0.001). Although the results suggest that the combined analyses of swim-up separated sperm traits, ZBA and IVF can be used to predict bull fertility, it might not be possible to determine the life-time fertility of a breeding sire owing to the limited number of observations made.
在本研究中，我们评估了各种公牛精子特性（包括与同源透明带（ZP）结合的能力以及体外受精能力）与人工授精后56天未返情率（基于8620次人工授精的56d-NRR）所反映的田间生育力之间的关联程度。这些精子来自12头瑞典红白相间的年轻（11 - 13个月）公牛，它们进入了一个国家育种计划，并饲养在两个人工授精公牛站，每头公牛有3个冷冻批次（每个批次1 - 2次连续射精），精液经过冷冻解冻处理。对于上浮分离的精子（浓度和活动精子浓度）与透明带结合试验（ZBA，r分别为0.72和0.73）以及囊胚率（r分别为0.79和0.79），在体外试验中发现了显著（p < 0.01）的相关性。卵裂率和囊胚率之间存在很强的相关性（r = 0.81，p < 0.01）。虽然公牛站对所有这些变量都有影响（p < 0.05 - 0.001），但公牛仅对ZBA和卵裂有影响（p < 0.05）。一旦对绝对未返情率进行季节、地区和胎次校正，公牛之间的56d-NRRs没有显著差异（p > 0.05，范围为62 - 67.2%）。公牛、批次或站对田间生育力均无显著影响（p < 0.05）。体外的单一精子特性/试验与体内生育力均无显著相关性。然而，当将精子特性的测量值进行合并，并通过回归分析计算预测的未返情率，然后与观察到的56d-NRRs进行比较时，发现了与公牛生育力的相关性。基于测试的三个冷冻批次，预测的公牛生育力在61.8%至67.5%之间变化（p < 0.05），并且与观察到的生育力未返情率高度相关（r = 0.92，p < 0.001）。尽管结果表明，对上浮分离的精子特性、ZBA和体外受精进行综合分析可用于预测公牛生育力，但由于观察次数有限，可能无法确定种公牛的终生生育力。
