Two studies have been carried out in pigs to determine the relation between escape behaviour and production parameters and between escape behaviour and other factors. In the first, 823 piglets were tested with the backtest at 10 and 17 days of age. Production parameters, such as average daily weight gain and lean meat percentage, were recorded. In the second, the backtest was performed on 566 piglets at 3, 10 and 17 days of age. Escape behaviour in the backtest (backtest score) of the mother was known for 364 piglets. Parameters concerning the health of sow and piglets were recorded, as well as the sow's reaction on piglet removal for testing. Relations between production parameters and backtest scores of the animals were calculated, as well as the influence of birth weight, gender (all males were castrated), parents and health parameters on backtest scores. Backtest scores were fairly consistent over successive tests. Males had higher backtest scores than females, and piglets from sows with low backtest scores had low scores themselves. Finally, a higher backtest score gave a higher lean meat percentage and a better carcass grading at slaughter. No relation with daily weight gain was found. It is concluded that there are individual differences between the ways in which pigs cope with a stressful situation, as is measured with the backtest, and that this coping behaviour is consistent. A positive relation exists between backtest scores and lean meat percentage, and a heritability of backtest scores is assumed.
van Erp -, E., Kuijpers, A. H., Schrama, J. W., Ekkel, E. D., & Tielen, M. J. M. (2000). Individual behavioural characteristics in pigs and their impact on production. Applied Animal Behaviour Science, 66(3), 171-185. https://doi.org/10.1016/S0168-1591(99)00094-5