The first aim of this study was to calculate the prevalence of painful lesions of the digits (“alarm” lesions; ALs) in Swiss dairy herds and cow–calf operations over a three-year study period. The following ALs were included in the calculation: the M2 stage of digital dermatitis (DD M2), ulcers (U), white line fissures (WLF) of moderate and high severity, white line abscesses (WLA), interdigital phlegmon (IP) and swelling of the coronet and/or bulb (SW). Between February 2020 and February 2023, digit disorders were electronically recorded during routine trimmings by 40 specially trained hoof trimmers on Swiss cattle farms participating in the national claw health programme. The data set used consisted of over 35,000 observations from almost 25,000 cows from 702 herds. While at the herd-level, the predominant AL documented in 2022 was U with 50.3% followed by WLF with 38.1%, at the cow-level, in 2022, it was DD M2 with 5.4% followed by U with 3.7%. During the study period, within-herd prevalences of ALs ranged from 0.0% to a maximum of 66.1% in 2020. The second aim of this study was to determine herd- and cow-level risk factors associated with digital dermatitis (DD), U and white line disease (WL) in dairy cows using data from 2022. While for DD, analysed herd-level factors appeared to have a greater effect on the probability of its occurrence, the presence of U and WL was mainly associated with the analysed cow-level factors. The risk for DD increased with a higher herd trimming frequency. Herds kept in tie stalls had a lower risk for DD and WL and a higher risk for U compared to herds kept in loose housing systems. Herds with predominantly Holstein Friesian cows as well as Holstein Friesian cows had a higher risk for the occurrence of DD compared to herds and cows of other breeds. With increasing parity, cows had a higher risk of developing U and WL, whereas for DD, parity was negatively associated with prevalence. Cows trimmed during the grazing period had a higher risk of U and WL than cows trimmed during the housing period. These findings may contribute to improve management measures affecting the health of the digits in farms with structures similar to those evaluated in the current study, such as small herds with frequent access to pasture. Further research is warranted to demonstrate how measures addressing the current results combined with those of individual herd risk assessments might contribute to an improvement in the health of the digits in the respective dairy herds.

The purpose of this study was to investigate the evolution of digit health (DH) on Swiss dairy farms participating in a nationwide DH program and to identify risk factors associated with poor DH. Specially trained claw trimmers recorded disorders of the digits (DOD) electronically during routine trimmings between January 2020 and June 2023. The first part of the study was a non-randomized controlled implementation study, comparing the evolution of DH in 75 herds that received professional on-farm risk assessments as well as veterinary advice with 49 herds that did not. Overall DH improved over time in both groups, with no difference between the groups. Differences emerged when implementation rates of measures after on-farm risk assessment were considered: DH of farms implementing >50% of recommended measures improved significantly more compared with farms implementing £ 50%. Also, farms where cows predominantly suffered from infectious-related lesions improved significantly compared with farms where cows suffered predominantly from mechanical-metabolic-related lesions. The second part of the study consisted of a retrospective observational risk factor analysis with a larger population (498 farms). Here, greater improvement of DH on a farm over the study period was associated with a higher Farm-Claw-Score (FCS; index for decreased DH) at the beginning of the study and longer duration of participation in the DH program. Moreover, less improvement of DH was associated with freestalls, with "valley area" farm sites and with herds with Holstein Friesian cows as predominant breed. Our results suggest that, if implemented appropriately, measures issued by DH experts may improve DH. Furthermore, voluntary participation in a DH program in combination with routine electronic recording of DH data by claw trimmers seem to raise farmers' motivation to improve DH. Our results are useful for farmers and veterinarians as well as for establishing DH programs in other countries.