Comparative histology and histochemistry of the nasolabial glands of the young and adult water buffalo (Bubalus bubalis L.) and cattle (Bos taurus L.)

The skin of the muzzle was composed of epidermis, dermis and hypodermis. The dermis was thicker in cattle than in the Philippine water buffalo. It was divided into the outer papillary layer and the inner reticular layer. The reticular layer of the dermis was thicker in cattle. The glands in the Philippine water buffalo were observed in the reticular layer and in the hypodermis. In the cattle, the glands were found in the hypodermis. In both species, the capsule was moderately developed and detached connective tissue septae dividing the glands into lobes and lobules. The division of glands into lobules was more developed in the Philippine water buffalo. The connective tissue framework in both animals was predominantly made up of collagen fibers. Elastic fibers were not observed. The interlobar connective tissue septae were developed in both animals, dividing the gland into distinct lobes. The interlobular septae on the other hand, was more developed in the Philippine water buffalo. The nasolabial glands in both animals were predominantly mucous in the Philippine water buffalo and predominantly serous in cattle. There were fewer interlobular and intralobular ducts in cattle. The larger excretory ducks appeared relatively straight to slightly coiled in both animals. Each acinus was made up of several secretory cells, radially-arranged around a lumen of variable sizes. There were no differences in the morphology of the nasolabial glands between the young and adult Philippine water buffalo and cattle. The mucous acini reacted positively to PAS, and AB pH 1.0 and 2.5 in both sexes and ages. However, the reaction was more intense in the young animals. The reaction to PAS, AB pH 1.0 and 2.5 suggest the presence of neutral mucopolysaccharides, weakly-sulfated mucopolysaccharides and acidic mucopolysaccharides, respectively. No significant differences observed regarding various measurements of the acini and its duck systems in both animals except in the epithelial height of the intralobular duct. The epithelial height was tallest in female Philippine water buffalo (7.3 plus or minus 0.41 micron) and shortest in female cattle (4.05 plus or minus 0.84 micron). In adult animals, it was tallest in the male Philippine water buffalo (8.62 plus or minus 0.47 micron) and shortest in the male Philippine water buffalo (4.9 plus or minus 0.37 micron).