Study of prenatal and postnatal development of spleen of Gallus Domesticus (deshi chicken).

Spleen is one of the secondary or peripheral lymphoid organs along with cecal tonsils in birds. The growth of the spleen of Gallus Domesticus (deshi chicken) from prenatal embryonic day fifteen (ED15) to postnatal day ninety (D90) were studied. In macroscopic study it was found that the shape of the spleen was rounded with slightly flattened from side to side at its middle part at prenatal period (ED15, ED18) and becomes rounded at postnatal stages of the deshi chicken (D90). Regarding position it lies close to the right side of the junction between proventriculus and gizzard and was similar in prenatal and postnatal stages. The result of the present study revealed that the mean diameter and weight of the spleen in deshi chicken gradually increases with increase of age, which were 2.00+/-0.136mm and 0.007+/-0.00gm respectively at ED15 stage and it reaches upto 10.40+/-0.331mm and .303+/-0.004gm respectively at day 90 (D90). It was observed that the differences of diameter & weight of the spleen between different ages were statistically significant (p<0.01). Histologically the spleen was surrounded by thin capsule in prenatal life, which gradually becomes thicker in postnatal life. The splenic pulps were not differentiated into white and red pulp on 15th day of embryonic life (ED15) but they were gradually differentiated into white and red pulp in the late prenatal (ED18) and postnatal period. The growth and development of spleen at each stage of the study period were found to be significantly high. Present study indicates that chicken splenic cell population, structure and function were similar to human spleen histologically. It was also found that the chicken embryo allows easy experimental access to all the stages of the splenic development, so the present study will be helpful for experimentation on lymphoid organs and to understand pathophysiology of immunological diseases of human.