COMPARISON OF DIFFERENT HOUSING SYSTEMS FOR COWS DURING HEAT STRESS

Abstract

The work aimed to study the effect of high temperatures on the comfort of keeping Holstein cows with different options for loose housing. The study of the effect of high temperatures on the comfort of keeping cows was carried out in the period from 02.07–12.07 2018 in the Kyiv region. Three farms were selected with loose cow housing systems and various options for the level of animal comfort. The first option is loose housing in an easy-to-collect room. The second option is loose keeping in an easily collectible room with fans and a water irrigation system. The third option is for walking and feeding grounds with sheds. During the daily observation period, the main indicators of the microclimate in the recreation area (air temperature, relative humidity, wind speed), respiration rate, assessment of the severity of respiration and heat load indices were determined. The best performance among the studied housing technologies was recorded on a farm using irrigation and ventilation systems. During the period of the highest heat stress (12.00–16.00 h), the air temperature (Т) did not exceed 29.05±0.50 °С, the respiratory rate – 77.0±1.33 times/mins, the environmental stress index (ESI) – 39.07±0.14 °С, the heat load index (HLI) – 73.56±2.48. The lowest indices of the comfort of keeping were in an easily assembled room: T – 31.1±2.24 °C, respiratory rate – 82.0±1.80 times/min, ESI – 41.62±0.17 °C, HLI – 77.88±0.64. Intermediate indicators were for the content on the stern area: T – 30.3±2.31 °C, respiratory rate – 76.0±1.82 times/mins, ESI – 41.62±0.17 °C, HLI – 77.42±0.51. In all options for keeping cows, an increase in temperature to an average daily +27.7 °C became a significant stress factor that significantly influenced the dynamics of the respiration rate, the assessment of the severity of respiration, the value of ESI and HLI. It was found that for keeping cows in buildings using irrigation and ventilation systems, as well as on walking grounds, the indicators of the temperature-humidity index (THI), frequency and severity of respiration during the period of maximum temperature load (12.00–16.00 h) were lower than those for keeping in an easily assembled room.