POSTNATAL GROWTH AND DEVELOPMENT OF LYMPHOID ORGANS AND TISSUES IN DESHI CHICKEN (GALLUS DOMESTICUS) OF BANGLADESH

Abstract

The gross and histomorphometrical studies were conducted in scavenging and captive deshi chickens of Bangladesh to know the comparative postnatal growth and development of lymphoid organs and tissues during the period of March to December, 2017. Total 40 non-descriptive deshi chickens were reared in scavenging and intensive system (20 chickens for each) from day 1 to 180 according to standard rearing system. Gross examinations of different lymphoid organs were performed for different ages (day 1, day 30, day 90 and day 180) of both types of rearing chickens. For histomorphometrical study the tissue samples were fixed, processed and stained with H & E stain according to the standard histological procedure and AmScope image measurement software were used for histomorphometry. The gross weight, length and width of thymus, spleen and cecal tonsils were gradually increased significantly (P≤0.05) with the advancement of ages in both scavenging deshi chickens (SDC) and captive deshi chickens (CDC) but the weight, height and width of bursa were decreased at D180 in both types of reared chickens. In both SDC and CDC, the highest weight (1.88 ± 0.13 and 2.04 ± 0.11 gm, respectively), height (1.26 ± 0.11 and 1.48 ± 0.08 cm, respectively) and width (0.76 ± 0.09 and 1.04 ± 0.11 cm, respectively) of bursa was found at D90 but the highest number of thymic lobe (6.40 ± 0.54 and 6.40 ± 0.54, respectively), weight (0.98 ± 0.08 and 1.26 ± 0.11 gm, respectively) and length (3.68 ± 0.08 and 3.78 ± 0.08 cm, respectively) of thymus; the highest weight (2.78 ± 0.16 and 3.06 ± 0.18 gm, respectively), length (1.98 ± 0.08 and 2.26 ± 0.16 cm, respectively) and width (1.42 ± 0.08 and 1.62 ± 0.08 cm, respectively) of spleen and the highest weight (2.60 ± 0.10 and 2.72 ± 0.08 gm, respectively), length (1.70 ± 0.10 and 1.82 ± 0.08 cm, respectively) and width (1.18 ± 0.08 and 1.30 ± 0.10 cm, respectively) of cecal tonsil was found at D180. All the gross parameters were found significantly (P≤0.05) higher in CDC as compared with SDC. Similarly, the histomorphometrical parameters such as length and width of thymic lobules, white pulps of spleen and lymphatic nodules of cecal tonsils were also increased significantly (P≤0.05) with the advancement of ages in both SDC and CDC but height of epithelium, number and height of mucosal folds, number of follicles per mucosal fold of bursa were decreased at D180 in both SDC and CDC. All those histomorphometrical parameters were found significantly (P≤0.05) higher in CDC as compared with SDC. So, it is concluded that the higher gross and histomorphometrical parameters of lymphoid organs of captive deshi chickens than that of scavenging deshi chickens were due to their different rearing system.