Influence of freestall building orientation on comfort of lactating dairy cattle during summer heat stress

Abstract

A trial was conducted during the summer of 2000 to evaluate the effect of freestall building orientation—east-west vs. northsouth— on respiration rates of lactating dairy cows, temperature-humidity index (THI) in the barns, barn temperature, and barn humidity. Differences between ambient and barn temperature and THI were higher in east-west vs. north-south orientated barns. Respiration rates were higher in north-south than in east-west orientated structures. The magnitude of differences between barn and ambient temperatures and THI did not fully explain differences in respiration rates between north-south and east-west orientated barns. Other factors such as solar radiation, airflow, and animal stress may have contributed to the differences in respiration rates.