Efeito do uso de sistema de resfriamento adiabático evaporativo sobre a produ??o de leite no estado do Paraná

摘要

The aim of this study was evaluate the use of adiabatic evaporative cooling system (AECS) of air as an alternative to improve the thermal environment, aiming the milk production (MP) of cows with production levels of 15 and 35 kg day -1 . The climatological data of air temperature and relative humidity used to estimate Temperature and Humidity Index (THI) and MP were collected in the IAPAR (Instituto Agron?mico do Paraná) meteorological field stations from Paraná State. The use of AECS of air provides a significant reduction in the THI values, in all locations and periods of the years, which resulted in improvements in MP. For the East, North and West Regions, from December to February, were observed loss of MP to high producing animals (35 kg day -1 ) however, after simulation using AECS of air, there was an increase in estimated production milk of 6.3%, 9.5% and 9.4%, respectively. The lower efficiency of using AECS for the East Regions can be related to the high values of relative humidity observed, which reduce the efficiency of air AECS. Thus, the most suitable environment conditions provided by AECS justify its use, since observed each local condition, month and animal category.