Hashim, M.; El-Safty, S.; El-Eraqi, K.; El-Sherif, H.; Azza, T.; Marwa, K.; Ibrahim, H.; Abdelhady, A. Effect of β-Mannanase Enzymes Supplementation to Energy Deficient Diets on Productive Performance, Physiological and Carcass Traits of Broilers. Int. J. Poult. Sci. 2020, 19 (10), 455–466. https://doi.org/10.3923/ijps.2020.455.466.