Abstract

Facial eczema (FE) is a disease caused by the fungal toxin sporidesmin, which upon ingestion by dairy cows can cause liver damage in susceptible animals. Skatole is formed in the rumen by the breakdown of dietary protein, absorbed into blood and is cleared by metabolism in the liver to 3-methyloxindole (MOI) and 3-hydroxy-3-methyloxindole (HMOI) and products of further oxidation and conjugation. In this study we have determined the concentrations of skatole, MOI and HMOI in the blood of dairy cows selected for their "high" gamma-glutamyltransferase (GGT) and "low" GGT in autumn and spring. Significant differences in skatole and MOI median concentrations were found in the autumn blood between the high and low GGT groups (skatole: 11.9 and 1.1 ng/mL respectively, P <0.001; MOI: 23.9 and 11.9 ng/mL respectively, P <0.05) although there was no difference in blood HMOI levels. Similar trends were observed for animals with high GGT in both autumn and spring when compared to low autumn and spring GGT. Animals with high autumn GGT and low spring GGT also contained increased median concentrations of skatole and MOI in the spring blood compared to the low autumn and spring GGT group, suggesting a lingering effect of FE damage on liver detoxification efficiency not detected by measuring spring GGT levels.

K, Fraser, GA Lane, M Yu, CA Morris, and NG Cullen

Proceedings of the New Zealand Society of Animal Production, Volume 68, Brisbane, Australia, 134-137, 2008