Sıcaklık ve nisbi nemi otomatik olarak kontrol edilebilen kapalı bir ahırda 11 baş Esmer sığır önce 14 gün süre ile 13 °C sıcaklık ve % 65 nisbi nemde (optimum ahır koşullan), sonra 14 gün süre ile 21 °C sıcaklık ve % 85 nisbi nemde (geleneksel ahır koşullan) tutularak bazı fizyolojik özellikleri ve verim performansları incelenmiştir. Gruplar arasında ortalama rektal sıcaklık ve solunura sayısı bakımından gözlenen farklar çok önemli (P

Eleven Brown Swiss cattle were housed in a stall barn, humidity and temperature of which could be controlled automatically for 14 days at 13 °C and 65 % humidity (optimum barn condition), then they were housed for 14 days at 21°C and 85 % humidity (traditional barn condition) and some physiological traits and performance of the cows were determined. The differences between barn conditions for average rectal temperature and respiration rate were highly significant (P<0.01) and the values in the traditional barn condition were higher than those in the optimum barn condition. The difference obtained between two groups for pulse rate was not significant. Although average daily milk and milk fat yield of Brown Swiss cattle were 0.602 and 0.026 kg higher, the differences were not statistically significant. Similarly, average percentages of the milk fat and dry matter were not significantly influenced by the different barn conditions. In conclusion, it could be stated that Brown Swiss cattle were not statistically influenced in a significant level concerning milk and milk fat characteristics by the traditional barn conditions.