Dietary administration of chestnut extract in chicken broiler

Same breeders refer that dietary use of chestnut extract could improve broiler chicken performances. However it is commonly accepted that dietary tannins reduce digestibility of crude protein and consequently the growth rate. A chestnut extract (obtained by chestnut wood, Castanea sativa) was fed to broiler chickens (Cobb 508) to test the effects on in vivo performances. The same basal diet was supplemented with 0% (CE 0), 0.15% (CE 15), 0.20% (CE 20) and 0.25% (CE 25) of chestnut extract. All the diets were added with 1% celite (external marker) in order to study the digestibility in vivo by means of acid insoluble ash (AIA). During the trial the digestibility test was performed twice: at the age of 44-46 days and 58-60 days. Each experimental diet was fed to 8 birds individually caged. The animals were fed the experimental diets from the age of 37 days to 61 days, previous one week pre-adaptation. Nor feed conversion ratio neither final body weight were affected by dietary treatments. Crude protein digestibility was affect by age but not by dietary treatment.