Behavioural, growth and immune consequences of early weaning in one-week-old Large-White piglets

Genetic improvement in sows' prolificity is limited by their milk capacities, which do not allow all piglets to survive or grow normally. This experiment compared the behaviour, growth and immune responses of piglets that were weaned early at 6 days of age (EW) vs. control Large White piglets' (C) suckled by their mothers. Behaviour of 9 litters of 5 to 8 piglets in each group were observed from d5 to d20. All piglets were weighed from birth to d74. Three piglets from each group were slaughtered on d36 for immunological analysis. Until they began to eat dry food, EW piglets walked and vocalised more than C piglets. After that time, when resting, they were less often lying down and more frequently in contact with littermates under the heater. Aggressive behaviour and bellynosing were more frequent. They displayed a more marked growth check after weaning than did C piglets until 28 days of age. In EW piglets, at 36 days of age, there was a higher density of T-and B-lymphocytes in the gut epithelium and lamina propria, respectively, in relation to the size of lymphoid follicles of Peyer's patches. The results indicate great behavioural adaptation capacities of very early-weaned piglets, together with earlier maturation of their gut immune system. pig / weaning / behaviour / immunology / welfare Rsum -Consquences sur le comportement, la croissance et le systme immunitaire, d'un sevrage l'ge d'une semaine, chez des porcelets Large-White. Les capacits laitires limites des truies hyperprolifiques ne permettent pas tous les porcelets de survivre ou de crotre normalement. L'objectif de cette tude est de mesurer les paramtres comportementaux, zootechniques et immunologiques, exprims par des porcelets Large-White sevrs ultra-prcocement (EW) 6 jours et des porcelets tmoins (C) allaits par leur mre. Les comportements de 9 portes de 5 8 porcelets EW