Abstract
Background

The Japanese quail (Coturinx coturnix japonica) has a crucial role in the lives of humanity since the 12th
century and continues to play main roles in our industry and scientific research. The advantages that the Japanese
quail has, such as heavy egg production and high-quality meat with low cholesterol and fat contents, Moreover,
the Japanese quail is easily managed, with high feeding conversion, low cost of investment, and high rate of returns.
Salivary glands are a part of the lingual apparatus that secretes serios and mucous saliva. Whereas, the saliva secretions have different roles in the food variation, apprehension, and moisture of food bolus. The morphological
and cytochemical analysis are done on 20 healthy Japanese quail embryos of 6th, 10th, 11th, and 13th days of incubation and 25 healthy quail chicks at hatching day old, 7th, 14th, 30th, and 60th days old. These samples are investigated histologically, histochemically, and scanned by electron microscopy serially. Our purpose of the study is to highlight the area of the oropharyngeal salivary glands and their role in food variation, as few studies spoke about that in Japanese quail.
Results

The primordia of the sublingual and mandibular salivary glands were noticed at the 6th and 10th days
of the prehatching respectively as an epithelial bud. After hatching, both primordia were elongated and differentiated
into secretory units. These glands were mucous polystomatic tubulo-alveolar paired glands, which were situated
in the submucosa of the oropharyngeal floor (sublingual floor and paralingual grooves). The sublingual glands
consisted of 3–5 lobes extended from the two Os ceratobranchial by their wide ends caudally, to beyond the median
sulcus of the prefrenular part of the sublingual space rostrally. The taste buds were variable in size and position. The
mandibular glands lay on the paralingual groove, which arose at the 10-day old embryo. The mandibular glands were
located dorsomedial to the sublingual glands and extended longitudinally from the rostral border of the frenulum
linguae to the caudal tips of the sublingual glands. The taste buds decreased in volume and number with advancing
age.
Conclusion

Overall, salivary glands increase in their alcianophilic activity of the secretions with advancing age, which
indicates low PH within the secretory end pieces.