An important tool for improving the productive characteristics of pigs, including boars, is a thorough study of their behavioural patterns and reactions to compliance with housing conditions, which serves as an indicator of the protocol for assessing the welfare of this sex group in commercial pig farms. The purpose of the experiment was to identify the influence of age, season of the year, and type of ventilation on the duration of behavioural acts of boars by breeds to establish their behavioural patterns in industrial technology. The experiment involved 18 boars of the Large White, Landrace, and Duroc breeds. The boars selected for the experiments were clinically healthy and divided into two groups of 9 animals each. The control group of boars was kept in a room with a transverse ventilation system, and the animals of the experimental group were kept in geothermal air supply conditions for a year. In the process of visualising the behaviour parameters of boars of different breeds, it was found that: the duration of rest was significant (P < 0.001) affected by 49.1-67.6% – age, 10.9-23.2% – season of the year, 0.1-3.0% – type of ventilation; the duration of movement during the day was significant (P < 0.001) affected by 44.7-68.0% – age, 9.1-28.5% – season of the year, 0.5-3.2% – type of ventilation; the duration of admission feed and water were significant affected (P< 0.001) by 49.7-71.9% – age, 7.9-25.9% – season of the year, 0.1-2.4% – type of ventilation. A behavioural act that prevailed in duration and frequency (P < 0.001), especially in the summer-autumn period, was rest, which increased in time with age from 72.3% to 76.4%, regardless of the breed, season of the year, and type of ventilation. In summer and autumn, the transverse air supply system visualised abnormal apathetic behaviour during rest in animals (lying on their sides, stomach, eyes closed, without any reactions to indifferent stimuli, and the time that boars spent on stereotypical behaviour (head banging, jumping and licking the bars of the cage) increased by 3% (P< 0.95) and in the “position of sitting dog” by 2% (P< 0.95). The results obtained allow introducing the use of ethological factors in industrial pig production to increase boar sperm production, and identify individuals with behavioural deviations to develop ways to assess welfare and integrate them into production