Thermal stress influence on the productive and economic effectiveness of Holstein-Friesian dairy cows in temperate climate

Abstract The aim of this study was to evaluate the heat stress influence on milk production from primiparous and multiparous Holstein-Friesian cows estimate economic losses associated with decrease in farm’s yield. selected for were middle phase 1st, 2nd, 3rd lactation characterized by similar daily production. Additionally, animals kept same conditions fed feeds throughout season. analysis covered two 30-day periods – “cold” (April), which no days THI >70 noted, “hot” (July), above 70 90% (74.4 average). average drop noted hot period 1.25 kg/cow 2.78 cows. financial loss resulting a €0.55/day/cow €0.46/day/cow animals. calculated profit 1 kg €0.27/day/kg €0.24/day/kg Based test results, simulated depending yield size primary cattle herd. For cows, estimated ranged €6.07/day (farm sizes 25 kg) nearly €219/day (900 cows/25 kg). In larger facilities cows) an 55 kg, will be about €481. obtained results confirmed assumptions made that change microclimate barn, changes chemical composition efficiency studied activity decreased.