Abstract

Facial eczema (FE) negatively influences production and welfare. One consequence of FE is reduced feed intake, which could possibly be a consequence of cows experiencing nausea or pain or both. The aim of this study was to evaluate the association of cortisol and acute phase protein (APP) concentrations (indirect measures of pain) with gamma glutamyl transferase (GGT) and bile acid concentrations (indirect measures of liver damage) in dairy cattle. Blood samples were collected from 2,080 lactating dairy cattle from seven farms that were affected by FE and located in the North Island of New Zealand. Blood samples were analysed for GGT, bile acid, cortisol and APP (serum ferroxidase (SF), serum amyloid A and haptoglobin) concentrations. Data were analysed using best subsets linear regression including farm as a factor and various other prediction variables. There was a significant positive relationship between GGT and bile acid (P<0.001, Adjusted R2=37.3%), SF (P<0.001, Adjusted R2=27.4%), and haptoglobin (P<0.001, Adjusted R2=1.9%) concentrations, but not with cortisol. The positive association between GGT concentrations and APP (SF, haptoglobin) may partly reflect the degree of liver damage caused by sporidesmin intoxication, however, it could also suggest that animals with higher GGT levels are experiencing systemic inflammation and potentially pain. Keywords: acute phase proteins; facial eczema; gamma-glutamyl transferase; inflammation; pain

M, Sutherland, F Huddart, NR Cox, E Cuttance, and K Schütz

New Zealand Journal of Animal Science and Production, Volume 81, Online, 122-128, 2021