Acute phase protein responses to uterine bacterial contamination in cattleafter calving

Repeated ultrasonographic examinations and collections of blood samples and uterine lumenal swabs between seven and 28 days after calving were used to examine the relative effects of bacterial contamination and involution of the uterus on the concentrations of acute phase proteins in the blood of 26 dairy cows. The severity of bacterial contamination, as determined by the total bacterial growth score, was a significant variable for the concentrat ions of the acute phase proteins alpha (1)-acid glycoprotein (P<0.0001), ha ptoglobin (P<0.05) and ceruloplasmin (P<0.0001). In addition, the concentra tions of <alpha>(1)-acid glycoprotein and ceruloplasmin were increased in t he cows from which Escherichia coli (P<0.0001) and Arcanobacterium pyogenes (P<0.05), respectively, were isolated from the uterine lumen. Uterine invo lution, as determined by the decreasing diameter of the previously gravid u terine horn, was associated with a decrease in the concentrations of alpha (1)-acid glycoprotein (P<0.005), haptoglobin (P<0.05) and ceruloplasmin (P< 0.01). However, the response of the acute phase proteins to bacterial conta mination was independent of the day on which the samples were collected, in dicating that their concentrations were increased by bacterial contaminatio n in addition to the changes associated with uterine involution.