Histological and histomorphometric study of the cranial digestive tract of ostriches (Struthio camelus) with advancing age.

The present study was conducted to determine the histological and histomorphometric variations in the tongue, oesophagus, proventriculus, and gizzard of ostriches (Struthio camelus) with regards to the sex and advancing age. A total of 40 healthy ostriches of both sexes and five age groups; young (up to 1 year, 1 to 2 years and 2 to 3 years) and adult (3 to 4 years and above 4 years) in equal numbers (n = 8) were used in this study. The organs under study were collected immediately after slaughtering the birds. Overall, the colour, shape, weight and various dimensions (length, width, and diameter) of the collected organs were recorded. The mean values of the gross anatomical variables of the studied organs increased (P < 0.05) among all the young groups (i.e., from 1 to 2 years, 2 to 3 years). Similarly, the organs under study in the adult groups (birds aged 3 to 4 years and above 4 years) grew (P < 0.05) as well. However, the differences between the adults were not significant. The histological analysis and histometric measurements were conducted on paraffin embedded tissue sections with Image J® analysis software. The statistical analysis revealed a significant increase in the thickness of the different tunics of the digestive organs in all the groups except those the adult groups. These findings may be of importance for the strategic manipulation of feed and nutrition to enhance the growth rate and also to diagnose pathological processes.