Serum Amyloid-A and Haptoglobin Concentrations and Liver Fat Percentage in Lactating Dairy Cows with Abomasal Displacement

Abstract

Serum amyloid-A (SAA) and haptoglobin are positive acute phase proteins in cattle that are produced by the liver in response to endogenous release of glucocorticoids and pro-inflammatory cytokines. Recent studies have indicated that SAA provides a more sensitive test of inflammation and bacterial infection in cattle than hematological analysis and clinical examination. Albumin is a negative acute phase protein in cattle. We hypothesized that the serum concentration of SAA and haptoglobin would be increased, and the serum concentration of albumin would be decreased, in cows with left displaced abomasum (LDA), right displaced abomasum (RDA), or abomasal volvulus (AV), relative to healthy dairy cows. The basis for our hypothesis was the presence of nutritional stress in cattle with LDA, RDA, and AV, as well as the presence of peritonitis in some cattle with AV. We confined our investigation to cattle that did not have clinical evidence of inflammation or bacterial infection, such as mastitis, metritis, or pneumonia, in order to minimize the confounding effect of clinical disease on the acute phase response.