Natural Resistance Mechanisms of the Udder - Cellular Mechanisms

Question 1

What are the cellular constituents of somatic cells in milk?

Answer 1

macrophages, neutrophils, sloughed alveolar epithelial cells with small fraction of lymphocyte

Question 2

What are the predominant cells in milk of noninflamed glands?

Answer 2

Macrophages

Question 3

What are the predominant cells in milk of inflamed glands?

Answer 3

Neutrophils (90% or more)

Question 4

What are the roles of neutrophils in preventing mastitis?

Answer 4

Following infection, neutrophils migrate toward the distal teat end and may migrate through the parenchyma. They work in conjunction with the keratinized teat canal defense mechanism to trap and kill bacteria before they can infect the glandular tissue. Large numbers of neutrophils are needed in milk as neutrophils have a relative impairment in milk