Management factors associated with impaired locomotion in dairy cows in England and Wales.

Forty-nine farms in England and Wales were visited on 4 occasions between February 2003 and March 2004. A total of 21,693 scores of locomotion were assigned to 7,722 cattle. Locomotion was assessed on a 3-point scale by observing the posture of a cow's back while standing and walking (1 = sound, 2 = not sound, 3 = lame). Data on measurable factors potentially associated with locomotion were collected from all farms using direct observations of the farm environment and a comprehensive farmer interview. The mean herd locomotion score was 1.77 +/- 0.02. There was no significant difference in mean herd locomotion scores between 5 herds housed in straw yards (1.72 +/- 0.02) and 44 herds housed in free stalls (1.78 +/- 0.02), possibly because of lack of power. A GLM was produced using data from the 44 herds housed in free stalls, with the mean farm locomotion score of all cows examined on all 4 visits as the outcome variable. Factors associated with an elevated locomotion score were dry cows kept in straw yards compared with free stalls (increase in locomotion score = 0.06 +/- 0.03), pregnant heifers kept with milking cows in winter compared with being kept with dry cows (increase in locomotion score = 0.09 +/- 0.03), aisle widths of < 3 m compared with widths of > or = 3 m (increase in locomotion score = 0.06 +/- 0.02), a curb height of < or = 15 cm compared with a height of > 15 cm (increase in locomotion score = 0.07 +/- 0.03), routine trimming of hooves of all cows by a hoof trimmer or by the farmer compared with no routine hoof trimming (increase in locomotion score = 0.18 +/- 0.04 and 0.13 +/- 0.03 respectively), feeding corn silage to milking cows compared with feeding other forage types (increase in locomotion score = 0.10 +/- 0.03), and the use of automatic scrapers in the free-stall barn compared with tractor scrapers (increase in locomotion score = 0.10 +/- 0.03). These variables were correlated with many other management variables. The use of automatic scrapers was correlated with the use of sawdust on rubber mats in free stalls. Curb height was negatively correlated with increasing distance of the neck rail from the front (head end) of the free stall. These putative risk factors support the hypothesis that locomotion score is linked to management factors; in particular, the combination of sawdust on rubber mats with automatic scrapers was associated with elevated locomotion scores.