Contact voltages < 0.5 V in feeders and drinkers influence the behaviour and oxidative status of piglets

Stray currents of low voltage in drinkers and feeders in post-weaning units affect piglets’ behaviour and oxidative status, suggesting that stray currents might induce a physiological stress for piglets.

The aim of this study was to evaluate the impact of stray voltages < 0.5V in pig housing on the behaviour of piglets and health and welfare biomarkers after weaning. For this study, two consecutive batches of 860 pigs weaned at 28 days were divided between two rooms of 12 pens, each with 33-36 piglets. In each pen, the difference in electrical potential between the floor and each drinker and feeder was measured every two weeks. Piglets were divided into four groups as a function of the voltage in drinkers and feeders. Behaviour was observed by scan sampling twice a week for seven weeks. It showed that piglets exposed to high-voltage drinkers (> 125 mV) spent less time standing inactive (P = 0.05) and more time orally manipulating pen mates (P = 0.003). Piglets exposed to high-voltage feeders (> 50 mV) spent less time sleeping (P = 0.02). They also spent more time nosing and being aggressive to pen mates but these effects were influenced by the voltages in drinkers (P = 0.03 and 0.02, respectively). Hydroperoxides concentration tended to be higher in piglets exposed to high voltages in both drinkers and feeders (P = 0.06). Our results suggest that the presence of stray currents in housing might influence the behaviour and oxidative status of piglets in post-weaning facilities