Relationship between THI level and dairy cows’ behaviour during summer period

Abstract

The presented study determining the relationship between the Temperature Humidity Index (THI) value during the summer months (June–August) and daily behaviour of 40 Holstein–Friesian dairy cows, including the length of standing, laying bouts and locomotor activity. Behaviour observations were conducted on a preferences test concerning their choice to time and place of rest with respect to time duration of THI: neutral (maximum 3 h with THI = 68), warm (time of THI > 68 occurrence lasted less than 12 h) and hot (time of THI > 68 occurrence lasted longer than 12 h). Obtained results was processed using analysis of the Spearman’s correlation coefficient with significant at p