The effects of continuous stray voltage were evaluated on growing-finishing pigs between the ages of 10 and 12 wk. Seventy-two pigs were assigned to six blocks of 12 animals each. The following treatments were randomly distributed in each block according to a 2 × 3 factorial design: feeding level (A) (restricted or ad libitum) and voltage level (0, 5 or 8 volts) as a continuous difference of potential between feeder or drinker and the metallic floor). The total drinking time (P < 0.10) and the number of drinking bouts (P < 0.05) were lower in the 8-V group than in the 0-V group for restricted-fed pigs during the hour after feed distribution. The percentage of observation time spent drinking during light hours was reduced in the 5-V and 8-V groups at 18 (P < 0.01) and 20 wk (P < 0.05). However, it was only between 14 and 16 wk of age that water intake was lower in the voltage groups (P < 0.05). There was no effect of voltage on mean daily feed intake and average daily gain over the whole fattening period (P > 0.3). Nonetheless, the mean eating frequency during light hours from 10 to 20 wk of age was higher in the 8-V than in the 0-V and 5-V groups of restricted-fed pigs, while it was similar in the three groups fed ad libitum (A × V lin; P < 0.05). Stray voltage at 8 V increased sitting time and decreased resting time in restricted-fed groups during light hours (A × V lin; P < 0.05) but the occurrence of aggressive encounters was very low in the three treatment groups throughout the study. Finally, the metabolic profile, the frequency and the severity of gastric ulcerative lesions and the meat color were similar among the treatments (P > 0.10). Key words: Stray voltage, growing-finishing pigs, behavior, growth performance, health
Stray voltage threshold is better determined under choice test conditions in sheep
