Characterisation of pigs into different personalities using the behavioural tests backtest and human approach test

The knowledge of the reaction of pigs in challenging situations is important for breeding and husbandry. The aim of the study was to investigate whether the backtest and the human approach test, as simple and practical behavioural tests, can be used to characterise pigs according to different behaviour in stressful situations i.e. - so-called “coping styles”. The conditions for coping are the consistency of behaviour over time and across situations. The backtest was performed twice with 1382 suckling piglets. The human approach test was performed at different ages: twice with suckling pigs (n=1318), four times with weaned pigs (n=1317) and once with gilts (n=230). Significant effects on the traits of the number of escape attempts (NEA), duration of escape attempts (DEA) and latency to the first escape attempt (LEA) in the backtest were batch, test number and birth weight. The results of the latency (LC) trait in the human approach tests were significantly influenced by batch, test number, and gender (additionally the distance of the pen with weaned pigs to the door; additionally the body weight with gilts). The correlations between the backtest traits were high (NEA-DEA rp=0.73-0.79, NEA-LEA rp=−0.43 to −0.53, DEA-LEA rp=−0.43 to -0.54). Therefore, it is sufficient to record only the NEA traits in further studies. The correlations between the two backtests (rp=0.31-0.43) and the Kappa-coefficients (ĸ=0.14-0.21), as a measurement of agreement of the classes of behaviour, showed that the behaviour of the piglets in the first backtest was different to the second one. The first backtest might thus be more the convincing test. The relations between the human approach tests at different ages showed that the smaller the time difference between was the tests, the higher was the correlation (rp=0.20-0.52). A good distinction between pigs was observed in weaned pigs and gilts. The human approach test with gilts might be the more satisfying test with regard to breeding issues. The relation between the backtests and the human approach tests was poor. Therefore, both tests seem to measure different behaviour and the variation in behaviour is only random.