The effect of neck strap positioning relative to dairy cow body size on rising, lying down, and defecation behaviour in lying cubicles

In cubicle housing systems for dairy cows, neck rails/straps/chains are used to limit bedding soiling by faeces and urine. Flexible neck straps are an alternative to rigid neck rails, which are associated with animal welfare issues such as painful collisions, injuries, and atypical behaviours. However, no literature exists on the positioning of flexible neck straps in relation to their effectiveness in limiting soiling of the bedding material and their effect on cow behaviour. In a research barn with 40 cows, we experimentally investigated how neck strap positioning relative to cow body size affects rising and lying down behaviours, general lying behaviour, and defecation behaviour in lying cubicles. To expand the range of body-relative positioning beyond that resulting from the herd's variation in body size, we varied the neck strap height (105, 120, and 135 cm) and its distance from the curb (155 and 170 cm) in two experiments. The resulting ratios of neck strap height to withers height (NSH ratio) ranged from 0.65 to 0.96, and the ratios of neck strap distance from the curb to diagonal body length (NSD ratio) ranged from 0.85 to 1.11. With the exception of sideways head lunging, atypical rising and lying down behaviours were rare throughout the study. A higher (less restrictive) NSH ratio was associated with a reduced probability of crawling backwards on the carpal joints during rising. We found no statistical support for an effect of neck strap positioning relative to cow body size on the probabilities of other atypical rising and lying down behaviours, or daily lying time and frequency. For defecations within a 120 s time window around rising events while in the lying cubicle, a higher (less restrictive) NSH ratio was associated with a higher probability of faeces landing in the cubicle. This probability also increased with a higher (less restrictive) NSD ratio. Overall, our results indicate that the positioning of flexible neck straps relative to cow body size, as tested in this study, does not considerably affect dairy cow behaviour, suggesting that flexible straps can accommodate cows of different sizes. The effectiveness of positioning cows in the lying cubicle in such a way that limits soiling of the bedding around rising events increased with a lower (more restrictive) NSH ratio. Thus, flexible neck straps can be a viable alternative to rigid neck rails by limiting soiling of lying cubicles around rising events without considerably impeding dairy cow movements during rising and lying down.