Preference for pasture versus freestall housing by dairy cattle when stall availability indoors is reduced.

Providing cattle with access to pasture has been shown to yield benefits, including access to more space, fewer agonistic interactions, better air quality, and the ability to perform a greater range of normal behaviors. Preference for pasture appears to depend on several parameters, including weather conditions and availability of shade. The primary aim of this study was to evaluate the preference for pasture versus inside a freestall barn with variable stocking densities at the stalls. We also investigated the effect of temperature-humidity index (THI) and precipitation on this preference. Overall, cows spent on average 13.7±2.6 h/d (mean ± SD) on pasture (ranging from 7.2 to 18.0 h/d across days); at night (between 2000 and 0600 h) cows spent the majority of their time (78.5±27.8%) on pasture. Stall availability had no effect on time spent outside, but time spent on pasture decreased with increasing THI during the day and declined during nights with more rainfall. Stall usage changed depending on stall availability; standing with 2 and 4 feet in the stall and lying time indoors decreased with decreasing stall availability. Indoor lying time also increased with higher THI and more precipitation. In conclusion, cows preferred to be outside at night; they were much more likely to remain indoors during the day, even when overstocked.