Feed particles : what chickens see and touch !

Abstract

Day-old chicks learn to associate nutritional effects with the sensorial characteristics of feed particles, thanks to a precise visual observation of details and specific tactile capabilities of their beak. Selection of feed particles is fast and accurate. However this selection may vary according to the sensorial experience of the animal concerning the feed. Eating rate depends on the size and hardness of the pecked particles. The consequences on production are dependent on environmental conditions. Under fluctuating environmental conditions, chickens adapt faster to a dietary change than when they are kept under a homogenous and constant environment in the shed. The production system may therefore change the perception of the structure of feed particles by chickens and its consequences on productivity. Optimal characteristics are difficult to standardise. New methods result from the collaboration between nutritionists and feed technologists. They evaluate how the bird actually perceives the shape and texture of the feed particles. Studies of food intake behaviour of chickens are useful, at both the farm and laboratory levels, to measure the consequences of feed technology and adapt new modes of feed distribution. Nutrition and sensorial detection interact at the three critical phases of food intake behaviour : identification, prehension and intake of the feed. Modern feed technology that is integrated into the production system should take these three phases into account.