Leighton E A, Murrell K D, Gasbarre L C
Maryland Agricultural Experiment Station, Wye Research and Education Center, Queenstown 21658.
J Parasitol. 1989 Aug;75(4):498-504.
Differences in nematode fecal egg counts from 167 purebred Angus calves born in 1986 and 133 born in 1987 that had been naturally exposed to infection on pasture were analyzed for sire effects. The calves were sired by 26 different bulls, all of which were related. Differences among fecal egg counts were attributable to sires (P less than 0.0002), to age of the calf (P less than 0.0007), to age of dam (P less than 0.05), and to collection year (P less than 0.0001). No variation in fecal egg count was attributable to calf sex (P greater than 0.23). After accounting for the effects of year, age of calf, and age of dam, heritability was estimated to be 29% (SE = 18%). It was concluded that a paternal contribution to the genome of each calf played an important role in determining average fecal egg output of the sire group. With heritability at 29%, selection against higher fecal egg counts or selection for lower fecal egg counts would be expected to produce measurable genetic change in a population.
对1986年出生的167头纯种安格斯犊牛和1987年出生的133头纯种安格斯犊牛的线虫粪便虫卵计数差异进行了分析，这些犊牛在牧场自然暴露于感染环境中，分析了父系效应。这些犊牛由26头不同的公牛所生，所有公牛都有亲缘关系。粪便虫卵计数的差异可归因于公牛（P<0.0002）、犊牛年龄（P<0.0007）、母牛年龄（P<0.05）和采集年份（P<0.0001）。粪便虫卵计数没有因犊牛性别而产生差异（P>0.23）。在考虑年份、犊牛年龄和母牛年龄的影响后，遗传力估计为29%（标准误=18%）。得出的结论是，父系对每头犊牛基因组的贡献在决定公牛组的平均粪便虫卵产量方面起着重要作用。遗传力为29%，预计针对较高粪便虫卵计数进行选择或针对较低粪便虫卵计数进行选择将在种群中产生可测量的遗传变化。
