Comparison of Behavioural Response of Crossbred Dairy Cows in Distinct Type Barns Across Four Different Seasons in the Tropical Humid Climate of Kerala

Abstract

The study was conducted across four different seasons during March, 2023 to February, 2024 at Cattle Farm, University Livestock Farm and Fodder Research and Development Scheme, Mannuthy, Kerala, India to analyse the effect of housing modification on thermal stress response in crossbred dairy cows based on the behavioural changes in tropical humid climate of Kerala. Treatments included T₁ (North-south oriented barn), T₂ (East-west oriented barn) and T₃ (East-west oriented barn with roof modification). Eighteen crossbred dairy cows were allotted randomly into three treatments with six animals each. The results highlighted significantly higher Equivalent Temperature Index in T₁ and T₂ compared to T₃ barn at the different diurnal time points across all seasons. Standing time was significantly higher in T₁ animals (893.00±10.65, 742.00±1.53 and 826.50±1.29 min day^-1) compared to T₂ (861.33±2.26, 690.67±1.69 and 630.17±0.65 min day^-1) and T₃ (782.67±2.22, 732.5±1.34 and 725.50±1.38 min day^-1)  in pre-monsoon, south-west monsoon and post monsoon season respectively. Significantly higher feeding bouts were observed in T₁ animals compared to T₂ and T₃ in all seasons, whereas seasonal comparison showed higher feeding bouts during southwest monsoon (51.50±3.31, 46.00±1.37 and 47.67±2.97 bouts day^-1 in T₁, T₂ and T₃ respectively) and post monsoon (56.00±1.46, 52.33±2.26 and 44.17±2.24 bouts day^-1 in T₁, T₂ and T₃ respectively) and lowest in pre-monsoon season. Drinking bouts were significantly higher in T₁ animals compared to T₂ and T₃. Climatic stress was observed inside all three treatments barns throughout study period, but T₃ barn performed comparatively better in reducing heat load due to roof modification employed.