Scheepens, C.J.M., M.J.C. Hessing, E. Laarakker, W.G.P. Schouten, M.J.M. Tielen. 1991. Influences of intermittent daily draught on the behaviour of weaned pigs. Applied Animal Behaviour Science 31: 69-82.
The influence of time-unpredictable and uncontrollable draught (forced cold air) on the behaviour of pigs was observed in a climate-controlled pig house with two identical rooms each with five pens. Two days after farrowing, pigs were matched pairwise to correct for genetic, weight and sex differences, and weaned at an average age of 35 days. From then on, the pigs in the experimental room were submitted to draught in a time-unpredictable way. Days with time-unpredictable draught were followed by days without draught.
Behavioural studies started on Day 35 and ended on Day 75 of the experiment. The total activity of the pigs was higher during draught (P<0.005). Explorative behaviour was four times higher during draught periods than during non-draught periods. Redirected explorative behaviour on penmates, including earbiting, occurred more during draught periods (P<0.05). Agonistic behaviour increased strongly during draught periods (P<0.005); headknocks with biting as an excessive form of aggression occurred only during these periods.
Even in periods without draught, pigs in the experimental room had a sternum: recumbent lying ratio which was higher that that of pigs in the control room and lay in contact with penmates more than did pigs in the control room. Unpredictable and uncontrollable draught as a climatic stressor had enormous effects on the behaviour of pigs; redirected explorative behaviour on penmates and excessive aggression could be detrimental for health and the performance of pigs.
Scheepens CJ, Hessing MJ, Hensen EJ, Henricks PA., 1994. Effect of climatic stress on the immunological reactivity of weaned pigs. Vet Q. 16 :137-43.