Feeding behaviour in turkeys with a change-over from crumbs to pellets

Poultry receive different diets during their rearing but these changes can result in a major reduction in feed intake and subsequently in growth. This problem is widespread in turkeys, especially with feed changes from crumbs to pellets. This experiment aimed to analyse behaviour during this change-over and identify the respective cues involved. Moreover, because pellet colour and hardness have been shown to influence feeding behaviour, differences in these cues were used to investigate their impact on behaviour during the change-over.Ninety-six caged turkeys were fed with crumbs until 28 days of age. They were divided into five groups: a control group that received crumbs throughout the experiment and four experimental groups each receiving one of four pellet types contrasting in colour and hardness. Feeds were distributed at the beginning of the light period and feed intake was measured every 20 min for 2 h on three different days: before feed transition (D − 1), during change-over from crumbs to pellets (D0) and 24 h after transition (D + 1). Animals were filmed two minutes each day at the beginning of the light period.Feed intake significantly decreased within the first 20 min of change-over (D0) in experimental birds and was lower than for controls. This drop disappeared after 24 h. Feed ingestion behaviours (open-beak pecking and swallowing) were lower on D0 than on D − 1 and D + 1, whereas exploration of the feed was higher. The delay between accessing the feed for the first time and the first peck was two times higher on D0 than D − 1 indicating that visual cues induced neophobia in touching feed. Birds reduced swallowing behaviour and dropped feed more often on D0 than on D − 1 supporting the idea that touch appears to reduce ingestion behaviour. However, pellets with different hardness and colour induced similar behavioural changes. The birds that used a closed beak on their first contact with the pellets had a lower feed intake during the first 20 min and a longer delay before swallowing than those that pecked with their beak open.This study demonstrates significant short-term reactions during feed transition related to distal and proximal cues of the food particles. It also highlights different feeding behaviours according to birds, and demonstrates individual sensitivity to feed change.