Effect of different thickness of keratin layer of ductus papillaris on state of parenchyma in cow udder

Ductus papillaris presents the frontline of defense of the mammary gland against the penetration of microorganisms into the milk cystern and the mammary gland parenchyma. The specific structure of ductus papillaris is in the stratum corneum which lines the ductus papillaris. It is a fine layer similar to wax of various thickness. The thickness of the stratum corneum depends on the age and breed of the animal, as well as on the number of past lactation periods. The stratum corneum or the keratin layer of the ductus papillaris has a bacteriostatic and bactericidal effect and prevents the ascendent penetration of microorganisms into the mammary gland. Measurements of the thickness of the keratin layer of ductus papillaris of each udder quarter revealed the existence of different thickness of the keratin layer. Histological examinations of parenchyma sections of each udder quarter showed different degrees of leukocytary infiltration. The degree of the leukocytary infiltration indicates the existence of various inflammatory processes in the parenchyma that occurred due to the weak frontline defense of the mammary gland against the penetration of microorganisms.