The Ph.D. Thesis submitted by Mr. Ayman Hassan Mahmoud Omr , Animal, poultry production. Department, entitled: "Effect of microbial phytase supplementation on productive and reproductive performance of nile tilapia, oreochomis niloticus" Under supervision of: 1. Prof. Samir Yousef Hussein 2. Prof. Mahmoud Ali Abd-Elnabi 3. Prof. Nadi Mohamed Essay Would be discussed at Monday 16/1/2012 on 2.00 o’clock in Department Hall