The influence of a magnesium-rich marine extract on behaviour, salivary cortisol levels and skin lesions in growing pigs.

摘要: Growing pigs can display undesirable behaviours, reflecting or causing poor welfare. Addition of magnesium (Mg) to the diet could reduce these, as Mg supplementation has been associated with improved coping ability in response stress. This study examined effect a Mg-rich marine extract-based product (Supplement) on behaviour, skin and tail lesion scores salivary cortisol concentrations growing pigs. At weaning (28 days), 448 piglets were assigned either Control Supplement (0.05%) diets single-sex groups 14. Four weeks later (c. 17 kg), blocked according weight back test scores. Seven from each pen mixed seven another same sex dietary treatment yield following groups: control male, female (n = 4 each). marked start 9-week experimental period. Instances behaviours recorded for 8 × 2 min periods 1 day/week: aggression (fight, head-knock bite); harmful (tail-in-mouth, ear-chewing belly-nosing); sexual/mounting behaviour. focal selected pen, their behaviour was continuously 5 day. Saliva collected once per week at 1000 h by allowing chew cotton bud c. min. Salivary analysed duplicate an enzyme immunoassay. Skin lesions scored severity day/week. There fewer aggressive incidents pens (P < 0.01), mounting (performed only males) almost three times lower than 0.01). However, there no incidence behaviours. Behaviour showed duration spent less time performing compared 0.001). had occurrence tail-biting outbreaks females scores, particular ears shoulders Finally, Mounting is major welfare concern uncastrated pigs, therefore this represents important benefit Supplement. Reduced cortisol, conjunction reduced supplemented females, suggests that addition extract pig system.