Ontogeny of belly nosing in pigs weaned at 14 days of age: A study from weaning to 13 weeks of age

Abstract

As weaning age decreases, belly nosing tends to increase, and can have lasting effects on growth, as well as the frequency of nosing and chewing penmates into the grow-finish phase of development. The objective of this study was to investigate the incidence of belly nosing and sucking in early-weaned pigs as these behaviours relate to other oral-nasal behaviours, such as tail biting. Piglets sired by Duroc (n = 120) and Large White (n = 122) boars were weaned at 14 d of age and observed at 18, 23, 28, 50, 63 and 91 d of age for nosing and sucking behaviours during nursery and grow-finish. Continuous observations at 21 and 35 d of age were used to determine mean belly nosing and sucking bout lengths. Belly nosing commenced within 4 d of weaning, peaked in incidence at 23-28 d of age and gradually decreased thereafter (P < 0.001). Belly sucking gradually increased with age (P < 0.001). Belly nosing and sucking bout durations also increased with age (P < 0.01 and P < 0.001, respectively), with belly nosing bouts lasting an average of 17.5 (21 d) to 27.3 (35 d) s compared with mean belly sucking bouts of 22.6 (21 d) to 58.1 (35 d) ss. The results suggest that vices associated with belly nosing continue to present a welfare concern in latter stages of developmentKey words: Behaviour, ontogeny, pigs, belly nosing, early weaned