Idowu O, Ajuwon R, Oso A, Akinloye O. Effects of Zinc Supplementation on Laying Performance, Serum Chemistry and Zn Residue in Tibia Bone, Liver, Excreta and Egg Shell of Laying Hens. Int. J. Poult. Sci. 2011;10(3):225–230. doi:10.3923/ijps.2011.225.230