Invited review: Genetics and claw health: Opportunities to enhance claw health by genetic selection

Authors: HERINGSTAD, BJORG - Norwegian University Of Life Sciences; EGGER-DANNER, CHRISTA - Central Association Of Austrian Cattle Breeders(ZAR); CHARFEDDINE, NOUREDINNE - Collaborator; PRYCE, JENNIE - La Trobe University; STOCK, KATHARINA - Collaborator; KOFLER, JOHANN - University Of Veterinary Medicine; SOGSTAD, ASE - Collaborator; HOLZHAUER, MENNO - Gd Animal Health Service; FIEDLER, A - Collaborator; MUELLER, KERSTIN - Freie University; NIELSEN, PETER - Collaborator; THOMAS, G - Collaborator; GENGLER, NICOLAS - University Of Liege; DE JONG, G - Collaborator; ODEGARD, C - Collaborator; MALCHIODI, FRANCESCA M - University Of Guelph; MIGLIOR, FILIPPO - University Of Guelph; ALSAAOD, MAHER - University Of Bern; Cole, John

Submitted to: Journal of Dairy Science
Publication Type: Review Article
Publication Acceptance Date: 1/8/2018
Publication Date: 6/1/2018
Citation: Heringstad, B., Egger-Danner, C., Charfeddine, N., Pryce, J., Stock, K., Kofler, J., Sogstad, A.M., Holzhauer, M., Fiedler, A., Mueller, K., Nielsen, P., Thomas, G., Gengler, N., De Jong, G., Odegard, C., Malchiodi, F., Miglior, F., Alsaaod, M., Cole, J.B. 2018. Invited review: Genetics and claw health: Opportunities to enhance claw health by genetic selection. Journal of Dairy Science. 101(6):4801–4821. https://doi.org/10.3168/jds.2017-13531.
DOI: https://doi.org/10.3168/jds.2017-13531

Interpretive Summary: Foot and claw disorders are important for economic milk production and animal welfare, and are among the most common reasons for involuntary culling in dairy cattle. Some countries now routinely use information collected at claw trimming to compute genetic evaliations for improved claw health, and other countries are planning to implement evaluations of their own once sufficient data are available. This review describes opportunities for the improvement of claw health by genetic selection. Data sources, phenotypes, and models are discussed, and a review of genetic parameters for claw disorders and possible indicator traits is presented.

Technical Abstract: Routine recording of claw health status at claw trimming of dairy cattle have been established in several countries, providing valuable data for genetic evaluation. In this review, issues related to genetic evaluation of claw health are examined, data sources, trait definitions and data validation procedures are discussed, and a review of genetic parameters, possible indicator traits, and status of genetic and genomic evaluations for claw disorders are presented. Different sources of data and traits can be used to describe claw health. Severe cases of claw disorders can be identified by veterinary diagnoses. Data from lameness and locomotion scoring, activity information from sensors, and feet and leg conformation traits are used as auxiliary traits. The most reliable and comprehensive information is data from claw trimming. In genetic evaluation, claw disorders are usually defined as binary traits, based on whether or not the claw disorder was present (recorded) at least once during a defined time period. The traits can be specific disorders, composite traits, or overall claw health. Data validation and editing criteria are needed to ensure reliable data at trimmer, herd-, animal- and record level. Different strategies have been chosen, reflecting differences in herd sizes, data structures, management practices, and recording systems among countries. Heritability of the most commonly analyzed claw disorders based on data from routine claw trimming were in general low, with ranges of linear model estimates from 0.01 to 0.14, and threshold model estimates from 0.06 to 0.39. Estimated genetic correlations among claw disorders varied from -0.40 to 0.98. The strongest genetic correlations were found among sole hemorrhage (SH), sole ulcer (SU), and white line disease (WL), and between digital/interdigital dermatitis (DD/ID) and heel horn erosion (HHE). Genetic correlations between DD/ID and HHE on the one hand and SH, SU, or WL on the other hand were in most cases low. Although some of the studies were based on relatively few records and the estimated genetic parameters had large standard errors, there was, with some exceptions, consistency among studies. Various studies evaluate the potential of various data soureces for use in breeding. Hoof trimming data are recommended to be used for maximization of genetic gain, although auxiliary traits are very valuable to increase reliability of genetic evaluation. Routine genetic evaluation of direct claw health has been implemented in The Netherlands (2010), Denmark, Finland and Sweden (joint Nordic evaluation; 2011), and Norway (2014), and others countries plan to implement this in the near future.