Amen, M. H., & Al-Daraji, H. J. (2011). Effect of Dietary Supplementation with Different Level of Zinc on Sperm Egg Penetration and Fertility Traits of Broiler Breeder Chicken. Pakistan Journal of Nutrition, 10(11), 1083–1088. https://doi.org/10.3923/pjn.2011.1083.1088