Mitigating hunger in pregnant sows

Pregnant (dry) sows are fed a restricted food ration to ensure good health, production and longevity, but this results in behavioural signs of hunger: Oral behaviours increase and may be re-directed ‘unnaturally’ towards non-food, prompting welfare concerns. ‘Dietary fibre’ encompasses a variety of chemical classes, with a variety of physio-chemical properties. It reduces abnormal oral behaviours, and fibres which are soluble and fermentable in the hind gut appear to prolong satiety, reduce activity and improve welfare. EU rules require fibre in dry sow diets and access to foraging materials, but implementation differs across member states. Diet, feeding system, number of meals and social structure combine to affect welfare of the sow and developing piglets e.g., through pre-natal stress. Current breeding trends to increasing litter size and associated practices like the use of ‘nurse sows’ may require a rethink of sow nutrition to safeguard longevity and welfare.