Transient stray voltage: Is it detrimental to growth performance, health status and welfare of market pigs?

Abstract

The effects of transient stray voltage associated with an alternating current were evaluated in growing-finishing pigs from 9 to 22 weeks of age. Seventy-two pigs were assigned to 9 blocks of 8 animals each. In each block, the following treatments were randomly distributed: a constant voltage differential created between the feeder or drinker and the metallic floor (woven wire), at a level of 0 volt plus 2-volt pulses (0 V-2 V), 2 volts plus 3-volt pulses (2 V-5 V), 5 volts plus 3-volt pulses (5 V-8 V), and a control treatment without any voltage differential (0 V-0 V). The constant voltage was applied 24 h per day. The pulses of 3 s duration were in the form of an increase in the amplitude of the constant 60-Hz signal. One pulse appeared every 20, 40 and 100 s during the hour following feed distribution and every 60, 120 and 300 s during the rest of the day. The animals were fed ad libitum and received fresh feed twice per day. Once during the 2-week periods at 9-10, 13-14, 17-18 and 21-22 weeks of age, the behaviour of the pigs was recorded during the hour following the two daily feed distributions. Animal weights and blood samples were taken every 2 weeks, from 9 to 21 weeks of age. No significant effect of transient stray voltage on any of the variables measured for the feeding, drinking, sitting or lying activities was found (p > 0.05). At 9-10 weeks of age, the number of rooting bouts was higher for the 5 V-8 V treatment (p = 0.03) and the number of events of butting the penmate was higher for the 2 V-5 V treatment (p = 0.05). Although the water and feed intake did not differ between treatments (p > or = 0.39), the average daily gain of the control group was lower than that of treated groups (p = 0.04) at 9 and 10 weeks of age, while the pigs submitted to a 2 V-5 V treatment had a higher daily gain than the pigs in the other treatment groups (p = 0.05) at 17 and 18 weeks of age.(ABSTRACT TRUNCATED AT 400 WORDS)

Untitled

“…The effect of continuous stray voltage, with a potential difference up to 8 V (volt) between feeder or drinker and the floor (metallic or wet flooring material), will decrease resting time but shows no effect on health, welfare or growth (Robert et al, 1992(Robert et al, , 1994(Robert et al, , 1996(Robert et al, ,1999Matte et al, 1992). Lower levels, with or without pulses, are insignificant (van der Heyde et al, 1995;Godcharles et al, 1993).…”

Les courants électriques parasites en élevage

“…Ainsi, chez la vache laitière, des courants de 3,6 mA, 6 mA, 10 mA et 12,5 mA, appliqués entre la patte antérieure droite et la patte postérieure droite, durant la traite, entraînent respectivement une augmentation de + 3, + 6, + 17 et + 30 battements/minute (augmentations relatives de + 4%, + 8%, + 23% et + 40%, respectivement) (Lefcourt et al 1985(Lefcourt et al , 1986. Par ailleurs, Gorewit et Scott (1986) ont observé une augmentation de + 25 battements/minute (augmentation relative de + 33%) chez des vaches laitières immédiatement après l'application de 4 mA dans la région lombaire.…”

“…Cependant, la plupart des études sur les performances laitières en milieu expérimental contrôlé ne montrent pas d'effets des tensions parasites. Ainsi, la quantité de lait produite et sa qualité (taux butyreux et protéique) ne sont pas modifiées chez des vaches laitières soumises à des courants de 1 à 8 mA appliqués au niveau de la colonne vertébrale (Gorewit et al 1985, Gorewit et Scott 1986, de la mamelle aux sabots (Henke Drenkard et al 1985), entre le sabot postérieur droit et le genou antérieur droit (Lefcourt et al 1985), ou entre les sabots antérieurs et postérieurs (Reinemann et al 2002). Le temps de traite n'est pas modifié par des courants de 3,6 à 8 mA appliqués de la mamelle aux sabots (Henke Drenkard et al 1985) ou entre le sabot postérieur droit et le genou antérieur droit (Lefcourt et al 1985).…”

Opinion of the Scientific Panel on Animal Health and Welfare (AHAW) on a request from the Commission related to welfare of weaners and rearing pigs: effects of different space allowances and floor

“…The effect of continuous stray voltage, with a potential difference up to 8 V (volt) between feeder or drinker and the floor (metallic or wet flooring material), will decrease resting time but shows no effect on health, welfare or growth (Robert et al, , 1994(Robert et al, , 1996(Robert et al, ,1999Matte et al, 1992). Lower levels, with or without pulses, are insignificant (van der Heyde et al, 1995; Godcharles et al, 1993).…”