Effects of dietary inclusion of Radix Bupleuri extract on the growth performance, and ultrastructural changes and apoptosis of lung epithelial cells in broilers exposed to atmospheric ammonia

Abstract To explore whether Radix Bupleuri extract (RBE) could protect lung injury of broilers under ammonia (NH3) exposure, 360 one-d-old male broilers were randomly allocated to four groups of six replicates each in a 2 × 2 factorial design with two diets (the basal diet [control; CON] and the basal diet supplemented with RBE [RB]) and two air conditions (normal condition [