Welfare Status in Dairy Cows during Confined and Grazing Periods in the North American Pacific Northwest using Blood Parameters and Visual Assessments.

Abstract

Grazing is usually associated with higher well-being in dairy cows. However, current research on the welfare of grazing cows lacks validation via blood profiling. We monitored four dairy farms that seasonally graze in the temperate North American Pacific Northwest, USA, to address this gap. We collected blood and hair samples and scored the animals for welfare-related visual evaluations during the dry period and early and late lactation stages during the confined and grazing periods. Over 20 blood parameters were analyzed, plus cortisol in the tail hair as a stress indicator. Blood profiling indicated that cows during the grazing period had a more stable metabolism across the stages of lactation, a more robust immune system, and slightly greater inflammation than during the confined period. The amount of cortisol in the hair was lower in cows during the grazing vs. confined period. Only a few direct animal measurements were affected, including a better body condition and cleanliness score compared to the confined period. Overall, our data indicate better welfare conditions in cows during the grazing period compared to the confined period.