Growth performance, behavior, gene expression, carcass characteristics, stress indicators, and economical parameters of avian 48 broiler chickens raised under three different stocking density / Shimaa A. Sakr, Ahmed F. Abouelnaga, Ahmed I. Ateya, Nada M. A. Hashem, Noha M. Wahed, Ibrahim F. Rehan, Asmaa Elnagar, František Zigo, Illia Siedoi, Walied A. Kamel, Huda, A. El-Emam KE304