Ageing effect on the structure and functional activities of the pigeon (Columba livia var. domestica) digestive system

Abstract The current investigation was conducted to evaluate the ageing effect on the tongue, duodenum, and the pancreas of male Columba livia var. domestica. Three age groups (n = 5) were collected at three weeks, six months, and five years old. For tongue and duodenum, alcian blue, PAS, and silver nitrate stains were performed alongside haematoxylin and eosin. Transmission and scanning electron microscopes were considered for tongue and duodenum specimens. Insulin expression in the pancreatic islets was estimated using the immunohistochemical technique. Biochemical assessment of super oxide dismutase (SOD), amylase, lipase, and malondialdehyde (MDA) was determined. Morphometrically, crypts of Lieberkühn number and villus height: crypt depth ratio were recorded. Old tongue exhibited smooth keratinised epithelium. Image analysis showed intense alcian blue, and PAS stains in adult tongue. During old age, villus height: crypt depth decrease correlated with dense distribution of reticular fibres in between degenerated crypts. Langerhans islets showed atrophy, degenerated cells, and decreased insulin expression associated with decreased SOD activities and increased MDA. Thus, ageing altered the structure of tongue, duodenum, and pancreas that reflected the impairment of their functional activities that may result in malnutrition and thereby weight loss. Such cases will be reflected in economic loss. Accordingly, the utilisation of birds during adult life should be recommended.