Graduate Student Literature Review: The effect of chain length and stall width on common outcome measures of dairy cow welfare in stall-based housing systems

Given increased societal concern for the welfare of dairy cattle and the heightened concern of consumers about the ability of cows to fulfill their needs for rest and for movement, an understanding of the effect of stall-based housing systems on such needs becomes of prime scientific importance. In tie-stall systems, the ability of the cow to express her need for movement is largely affected by tethering; increasing chain length increased the cow's ease of movement in the space allowed to her. Regarding the ability of the cow to rest, the size of the stall bed (including its width) has been linked with measures of lying time. For the most part, current industry recommendations are not being followed on commercial farms, although improvements in terms of compliance seem to have been made in the last decade. Following the recommendations for chain length appears to aid in reducing the prevalence of injuries and may even aid in maintaining the cleanliness of the cows, although the few studies available are inconsistent. Wider stalls were associated with increased lying time and reduced prevalence of injuries, although in the latter case, data from different studies show inconsistent results. The link between stall width and common welfare outcome measures appears more clearly in tiestall systems, although improving the lateral space allowance for cows reduces collisions with equipment in freestall systems as well. Overall, the width of the stall and the length of the chain play roles in modulating the cows' ability to rest and to move comfortably in the confines of the stall, and should be carefully considered when designing stall-based housing systems that enhance the welfare of dairy cows.