The Concentration of Immunoglobulins A, G, and M in Cow Milk and Blood in Relation with Cow Seasonal Keeping and Pathogens Presence in the Udder

Recent studies show that immunoglobulins A, G, and M contribute significantly to the maintenance of udder health. Unfortunately, the concentration of immunoglobulins in cow milk during the middle period of lactation is low therefore the question of how to stimulate and maintain a sufficient level and spectrum of antibodies in the udder is topical. The aim of the present study was to evaluate the dynamics of the amount of immunoglobulins A, G, and M in cow milk and blood serum in relation with the cow seasonal keeping and presence of pathogens in the udder. The experimental part of the study was carried out on the dairy farm "Pērles", Valmiera region. Cows were kept in a cold loose housing system, grouped and fed differently depending on cow productivity and lactation period. Two times in the housing period and two times in the grazing period milk and blood were sampled from 16 dairy cows and examined for the concentration of immunoglobulins A, G, and M and for the presence of pathogens. Cows for the study were selected with the aim to analyze the milk obtained from clinically healthy udder quarters of cows of similar-age and productivity in the middle stage of lactation. It was determined that seasonal keeping of cows had significantly affected the concentration of immunoglobulins G and A in milk (p<0.001), and of immunoglobulins A, G, and M in blood serum (p<0.001). Some pathogenic bacteria species infecting the udder quarters had considerably influenced the values of immunoglobulins G, A, and M (p<0.05, p<0.001, and p<0.001, respectively) in blood serum. A wide variation amplitude of immunoglobulin G, A, and M concentration in milk and blood serum was observed, which indicates the important role of the individual factor of an animal in the formation of animal defence response.