Dairy cattle

Genomic reliabilities for a prospective hoof health trait in US dairy cattle genetic evaluations

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Abstract

After mastitis, lameness is the most prevalent and costly health-related issue in dairy cattle operations worldwide. Given the economic impact, there is strong interest from US dairy producers to genetically select for animals with ability to resist lameness. Hoof lesions are the primary cause of lameness in dairy cattle, and records collected during routine and remedial hoof trims provide a readily available source of data on lameness incidence.The Council on Dairy Cattle Breeding (CDCB) received data from Dairy Records Management Systems (Raleigh, NC) for development of a hoof health trait. The data included 450,000 hoof trimmer records from 260,000 parities with lactation information available in the National Cooperator Database (NCD). Available data was collected between 2009 and 2024. The data included records of incidence on 13 lesion types, with the most prevalent lesions (incidence rate per parity) being Digital Dermatitis (6.4%), Abscess (2.8%), Ulcer (2.2%), and White Line (1.9%). The majority of lesions have incidence too low to effectively evaluate, and so, to make full use of available data, Infectious and Non-Infectious lesion groups were defined and modeled as binary traits (1 = occurrence of any lesion within the group; 0 = none). Following inclusion of herdmates from the NCD lacking a hoof trimmer record but assumed to be healthy, data was available for 667,000 and 484,000 lactations for Infectious and Non-Infectious lesions, respectively. Incidence rates per lactation in these groups were 7.67 and 3.88% for Infectious and Non-Infectious, respectively. Genotypes (69.2k SNPs) were available for 39,228 cows with a hoof health record and 11,622 sires of cows with a hoof health record.A model similar to that used for traditional health traits already evaluated by CDCB was used; this included year-season and age-parity as fixed effects, inbreeding and heterosis as covariates, and herd-year, herd-sire, additive genetic, and permanent environment as random effects. Heritabilities were estimated under traditional BLUP and threshold models. Additive genetic values and reliabilities were estimated under traditional BLUP, multi-step GBLUP, and single-step GBLUP models. Single-step GBLUP solutions were estimated using the BLUPF90 suite of programs.Estimated heritabilities for Infectious lesions were 5.1 (linear) and 5.7% (threshold) and for Non-Infectious lesions were 3.1 (linear) and 4.4% (threshold). Mean (SD) reliabilities of genotyped sires for Infectious and Non-Infectious lesions, respectively, were 0.44 (0.16) and 0.28 (0.12) under traditional BLUP, 0.67 (0.081) and 0.50 (0.069) under multi-step GBLUP, and 0.63 (0.063) and 0.51 (0.062) under single-step GBLUP. Despite low heritabilities for both Infectious and Non-Infectious lesions, genomic information increased reliabilities relative to only pedigree information, and it is expected that continued expansion of the reference data will yield further gains in genomic reliabilities.

Keywords: 2026

How to Cite:

Ling, A., Xu, C., Fourdraine, R., Cole, J. & Gaddis, K., (2026) “Genomic reliabilities for a prospective hoof health trait in US dairy cattle genetic evaluations”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2285845. doi: https://doi.org/10.31274/wcgalp.23806

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