Department of Livestock and One Health, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Liverpool, CH64 7TE, United Kingdom.
Scotland's Rural College (SRUC), The Roslin Institute Building, Easter Bush, Midlothian, EH25 9RG, United Kingdom.
J Dairy Sci. 2023 Mar;106(3):1874-1888. doi: 10.3168/jds.2022-22064. Epub 2023 Jan 27.
Sole hemorrhage and sole ulcers, referred to as sole lesions, are important causes of lameness in dairy cattle. The objective of this study was to estimate the genetic parameters of a novel trait reflecting how well cows recovered from sole lesions and the genetic correlation of this trait with overall susceptibility to sole lesions. A cohort of Holstein dairy cows was prospectively enrolled on 4 farms and assessed at 4 timepoints: before calving, immediately after calving, in early lactation, and in late lactation. At each timepoint, sole lesions were recorded at the claw level by veterinary surgeons and used to define 2 binary traits: (1) susceptibility to sole lesions-whether animals were affected with sole lesions at least once during the study or were unaffected at every assessment, and (2) sole lesion recovery-whether sole lesions healed between early and late lactation. Animals were genotyped and pedigree details extracted from the national database. Analyses were conducted with BLUPF90 software in a single-step framework; genetic parameters were estimated from animal threshold models using Gibbs sampling. The genetic correlation between both traits was approximated as the correlation between genomic estimated breeding values, adjusting for their reliabilities. A total of 2,025 animals were used to estimate the genetic parameters of sole lesion susceptibility; 44% of animals recorded a sole lesion at least once during the study period. The heritability of sole lesion susceptibility, on the liability scale, was 0.25 (95% highest density interval = 0.16-0.34). A total of 498 animals were used to estimate the genetic parameters of sole lesion recovery; 71% of animals had recovered between the early and late lactation assessments. The heritability of sole lesion recovery, on the liability scale, was 0.27 (95% highest density interval = 0.02-0.52). The approximate genetic correlation between each trait was -0.11 (95% confidence interval = -0.20 to -0.02). Our results indicate that recovery from sole lesions is heritable. If this finding is corroborated in further studies, it may be possible to use selective breeding to reduce the frequency of chronically lame cows. As sole lesion recovery appears to be weakly genetically related to sole lesion susceptibility, successful genetic improvement of sole lesion recovery would benefit from selection on this trait directly.
蹄底出血和蹄底溃疡，简称蹄底病变，是奶牛跛行的重要原因。本研究的目的是估计一个反映奶牛从蹄底病变中恢复情况的新性状的遗传参数，以及该性状与整体对蹄底病变易感性的遗传相关性。一组荷斯坦奶牛前瞻性地在 4 个农场登记，并在 4 个时间点进行评估：分娩前、分娩后立即、泌乳早期和泌乳晚期。在每个时间点，兽医在蹄部水平记录蹄底病变，并用于定义 2 个二进制性状：（1）对蹄底病变的易感性——动物在研究期间是否至少有一次受到蹄底病变的影响，或在每次评估中均未受到影响；（2）蹄底病变恢复——早期和晚期泌乳之间蹄底病变是否愈合。对动物进行基因分型，并从国家数据库中提取系谱细节。采用 BLUPF90 软件在单步框架中进行分析；使用 Gibbs 抽样从动物阈值模型中估计遗传参数。通过调整可靠性，将两个性状的遗传相关性近似为基因组估计育种值之间的相关性。共有 2025 头动物用于估计蹄底病变易感性的遗传参数；44%的动物在研究期间至少记录了一次蹄底病变。在隶属度尺度上，蹄底病变易感性的遗传力为 0.25（95%最高密度区间=0.16-0.34）。共有 498 头动物用于估计蹄底病变恢复的遗传参数；71%的动物在早期和晚期泌乳评估之间已恢复。在隶属度尺度上，蹄底病变恢复的遗传力为 0.27（95%最高密度区间=0.02-0.52）。两个性状之间的近似遗传相关性为-0.11（95%置信区间=-0.20 至-0.02）。我们的结果表明，蹄底病变的恢复是可遗传的。如果这一发现在进一步的研究中得到证实，那么通过选择性繁殖减少慢性跛行奶牛的频率可能成为可能。由于蹄底病变恢复与蹄底病变易感性在遗传上似乎相关性较弱，因此成功的蹄底病变恢复遗传改良将受益于直接对该性状进行选择。
