Histological and Histochemical Studies on the Paraorbital Gland in Broilers

The objective of this investigation was to study histological and histochemical structure of the paraorbital gland in broilers. Samples were obtained from 10 male and 10 female adult healthy Ross broilers. Tissue sections were stained with hematoxylin eosin, Verhoeff’s, Masson’s trichrome, alcian blue (pH 2.5), periodic acid-Schiff and Gomori’s method for reticulum. Results revealed the paraorbital gland of Ross broilers was covered by a thin capsule, which contributed trabeculae that divide the organ into lobes and lobules. The capsule consisted of parasympathetic ganglia, nerve bundles, adipose tissue, elastic, collagen and reticular fibers. The glandular epithelium was multilobular and compound tubuloalveolar. Plasma cells were present in interlobular connective tissues. The paraorbital duct was lined by columnar epithelial cells of varying height. The goblet cells were not found in paraorbital duct. Histochemical stainings revealed that the secretion of paraorbital gland was mucous and all epithelial cells of both corpus glandulae and ducts contained both neutral and acidic mucins. The histological and histochemical properties of the gland showed no gender differences. It is concluded that the general histological and histochemical structure of the paraorbital gland in broilers was similar to that of native chickens and domestic geese, but there were also some differences.