Prevalence of claw disorders in Dutch dairy cows exposed to several floor systems.

Claw health was examined in an observational study on Dutch dairy farms with either a slatted floor (SL), slatted floor with manure scraper (SL-SCR), solid concrete floor (SCF), a straw yard (SY), or a zero-grazing feeding system (ZG). Hooves of cows' hind legs were examined for the presence and severity of claw disorders during hoof trimming events at the end of the pasture (P-study) and housing period (H-study). The number of cows in each study was 3078 (49 herds) and 3190 (47 herds), respectively. Due to a different hoof trimming strategy, data collected during both observation periods in SY herds (638 cows; 16 herds) were combined. Cows in straw yards (SY) had by far the lowest numbers of claw disorders. Over 80% of cows exposed to concrete flooring had at least one claw disorder at the time of observation, whereas on SY surfaces, this percentage was between 55 and 60. Cows on SL-SCR were less frequently affected by interdigital dermatitis/heel erosion (IDHE) and digital dermatitis (DD) than cows on SL (reference floor system). Little difference in claw health was found between SF and SL. The ZG cows were at higher risk (OR > 2) for most claw disorders in the P-study, whereas in the H-study, ZG cows showed less IDHE, sole hemorrhage, and sole ulcer. All herds on concrete flooring (SL, SL-SCR, SCF, ZG) were infected by DD, resulting in an average cow level prevalence of 30%. This indicates that the level of DD infection has increased considerably over the last 10 yr in The Netherlands.