Vol. 3, Issue 4, Part A (2018)

The evolution of spleen average weight peeked development at 7^th week of age and inter in a stationary phase characterized by keeping its weight to 3, 7g until 8^th weeks of post-hatching age. This histological variations are not in close relationship to the sexual maturity lake the thymus and the bursa of Fabricius. The weight pulp and red pulp are intermingled and there is no limit between two pulp. These results can be used in the diagnosis of different diseases such as Gumboro disease, Marek disease.