Milk amyloid a and selected serum proteins in cows suffering from mastitis

Abstract

The aim of this work was to evaluate the influence of clinical and sub-clinical mastitis on the concentrations of mammary associated isotype of serum amyloid A (M-SAA) in milk samples, as well as on the concentrations of haptoglobin (Hp) and serum amyloid A (SAA), and some other biochemical variables in blood serum of dairy cows (n = 41). The concentrations of aforementioned variables were measured in 4 groups of cows divided according to the results of the clinical examination of the udder and to the results of California Mastitis Test (CMT): group 1 - cows without clinical changes on the mammary gland and with negative CMT, group 2 - cows without clinical changes on the mammary gland and with weakly positive CMT, group 3 - cows without clinical changes on the mammary gland and with strongly positive CMT and group 4 - cows with clinical changes on the mammary gland and changes in milk appearance. The concentrations of M-SAA were analyzed also in 145 quarter's milk samples which were categorized according to the same criteria as cows used in the study. By the evaluation of M-SAA concentrations in composite milk samples we found significantly the highest mean value in cows with clinical signs of mastitis. Similar findings were recorded in the M-SAA concentrations in quarter's milk samples. Moreover, higher concentrations of M-SAA were found also in samples from mammary quarters without clinical changes and positive CMT. The analyses of Hp and SAA concentrations showed a trend of higher values in cows with clinical mastitis. The lowest mean concentration of albumin we found in cows with clinical signs of mastitis. Our results indicate elevated production of M-SAA in cows with clinical changes on mammary gland, and suggest the usefulness of this indicator also in the diagnosing of sub-clinical mastitis.