An experiment to determine the feasibility of automatically detecting hyperketonaemia in dairy cows

Seven cows were monitored for 10 days during which hyperketonaemia was experimentally induced in five cows. Concentrations of acetone in breath, ketones in milk and volume of milk yield were recorded at intervals throughout the period. The concentrations of acetone exhaled by the cows whose feed was reduced rose above 5 μg/l within 7 h of feed being reduced. Five repeated samples each from a ketotic and healthy cow had means of 46 and 21 μg/l with 6.5 μg/l standard error of difference (P = 0.005). Ketone bodies (acetoacetate and acetone) in milk did not rise above 1 mmol/l until 48 h after reducing feed. The milk secretion rate dropped by 10% approximately 36 h after the feed was cut. The onset of ketosis could be detected automatically before clinical signs appeared. Further work is required to determine the statistical validity of different techniques of automatic monitoring, to improve and automate the collection of representative breath samples, to develop sensor systems and to develop a better disease model.