INFLUENCE OF THE TEMPERATURE FACTOR IN DIFFERENT VENTILATION SYSTEMS ON THE PHYSIOLOGICAL PARAMETERS OF BOARS

Abstract

Extreme climatic conditions are a challenge for the adaptation of animals, including pigs. Heat stress causes damage to the pig industry and pig welfare, as it reduces productive traits of pigs, slows down or stops sexual cycles, reflexes, reduces quality fertilization, etc. In order for farmers to control the microclimate of livestock premises, a number of air ventilation systems are used. The article presents the results of measurements and analysis of temperature oscillations depending on the type of ventilation system in the boar housing during the month of August and the impact on their physiological parameters. Experimental studies were conducted during 2021, with a total of 18 boars of the Large White, Landrace and Duroc breeds used at PJSC Stepnoy Stud Farm in Zaporizhzhya region. The rules for handling boars in the experiment were in line with the legislation on the protection of animals and their comfort kept on farms. The results of the experiment show that with geothermal ventilation in the housing there was a «basement effect», which caused a decrease in air temperature by 5.9 °C (p<0.05) in the area where boars lay at a distance of 25–30 cm from the floor, and in the area where animals stood (60–70 cm from the floor) – by 7.3 °C (p<0.05), relative to the transverse ventilation system. Boars kept in housing with a transverse ventilation system had significantly (p<0.05) higher respiratory rate – by 50.9 beats/min and heart rate – by 45.7 beats/min compared to similar boars with a cooled air supply. The effect of air temperature under different ventilation systems for keeping boars on their metabolism shows that at higher temperatures of the comfort zone, boars reduce their activity with the possibility of increased heat transfer directly through the skin and surface evaporation of water. At indoor temperatures above 30 °C, thermoregulation mechanisms fail and body temperature rises. At an indoor air temperature of 35 °C, the body temperature rises to 42 °C or more, breathing becomes more frequent, refusal to eat is observed, and coma and death quickly follow. Adult pigs are more tolerant of low temperatures.