Diagnostic importance of the concentration of milk amyloid A in quarter milk samples from dairy cows with mastitis

Abstract

Acute phase proteins have been used as biomarkers of inflammation. Their concentrations increase in milk from cows with latent and subclinical mastitis. The aim of our study was to evaluate milk amyloid A (MAA) as indicator of udder inflammation. We used 24 dairy cows from a herd with 120 Slovak Pied cattle. In addition to bacteriological examination, the following indicators were determined in all quarter milk samples. On the basis of results of clinical examination, Californian mastitis test (CMT), and number of Somatic cell count (SCC), four groups of quarter milk samples were formed. The levels of MAA in both subgroups of Group 1 (healthy cows), divided by the number of SCC - IA (n = 10), IB (n = 15), determined at repeated samplings, differed significantly from the initial levels (P < 0.01). Highly significant correlation (R2 = 0.272), was detected between SCC, and MAA in Group 2 (n = 27) at individual collections (P < 0.01), while in the Group 3 (n = 25) the level of both indicators decreased by the end of the experiment despite higher initial concentrations (P < 0.01). No significant differences in MAA were observed between individual collections in Group 4 (n = 6). No positive correlation (R2 = 0.525) was detected between SCC and MAA in this group. The obtained results allowed us to conclude that MAA in milk can act as a marker of inflammation of the udder only in the initial, asymptomatic stages of dairy cow mastitis. The experiment was one of first studies with MAA in Slovak Pied cattle.