Influence of neck-rail placement on free-stall preference, use, and cleanliness.

Three experiments examined how the presence of a neck rail at different heights and locations influenced dairy cattle behavior and stall cleanliness. Experiment 1 compared 4 levels of neck-rail height (102, 114, and 127 cm and no neck rail; presented at 160 or 180 cm from the curb) in a preference test. Cows (n = 10) showed no consistent preference based on neck-rail height, regardless of the horizontal position of the neck rail. When cows were restricted to each treatment in turn, however, time spent standing fully (with all 4 hooves) in the stall was least in the stall with the lowest neck rail (mean, 22 min/24 h) and was greatest in the stall with no neck rail (mean, 83 min/24 h). A second experiment examined the effect of a neck rail placed at 3 distances from the curb (140, 175, and 233 cm) when height was held constant (131 cm; n = 12). Time spent standing fully in the stall was least when the neck rail was close to the curb (140 cm; mean, 11 min/24 h) and was greatest when the neck rail was furthest from the curb (233 cm; mean, 86 min/24 h). When the neck rail was far from the curb, the cows were more likely to soil the stall by defecating while standing fully in the stall. Experiment 3 compared soiling of the stall by 14 cows with and without a neck rail at a height of 124.5 cm. When the neck rail was removed, cows were more than twice as likely to soil the stall by defecating while standing fully in the stall compared with when the neck rail was present (1.3 vs. 0.5 defecations/24 h). Thus, restrictive neck-rail placement prevents cows from standing in stall, but helps keep stalls clean. Access to more comfortable flooring surfaces outside the stall may help mitigate the negative effects of restrictive neck rails.