Histometerical and Morphological Studies of Digestive Tract and Associated Glands in Domestic Pigeon (Columba livia) with Regard to Age

Wide description of avian species is available however, limited is known about pigeon anatomy. This study has been carried out in 30 male and female pigeons (Columba livia) in equal proportion. The birds were divided into 3 groups, Group A: immature, Group B: adult and Group C: old, each having equal males and females. Birds were slaughtered, digestive tract organs and associated glands were collected and fixed in 10% neutral buffered formalin. For histometerical studies, tissues were processed by the paraffin embedding technique and were stained with Hematoxylin and Eosin. Microscopic studies of the different parts of digestive tract showed the significant differences (P<0.05) among all the three groups. Stratified squamous keratinized epithelium of tongue had mean thickness values 84.53 +/- 6.53, 269.44 +/- 8.62 and 200.23 +/- 13.19 mu m in group A, group B and group C, respectively. The lumen of the esophagus was consisted of longitudinal folds along the length. Height of these folds increased with the age advancement and esophageal growth. The mean thickness values of esophageal epithelium were 226.37 +/- 5.45, 360.87 +/- 31.10 and 312.67 +/- 6.69 mu m in group A, B and C respectively, which were significantly different (P=0.01). Mean epithelial thickness values of duodenum, jejunum and ileum were 19.09 +/- 1.88, 35.28 +/- 4.02 and 37.94 +/- 5.04 mu m, respectively. The results showed that the mucosal layers and other layers were the thickest in group B, moderate in group C and lowest in group A. This study of histological parameters of pigeon's digestive system is an addition in the basic knowledge of avian anatomy.