Effects of percutaneous needle liver biopsy on dairy cow behaviour.

In cattle, percutaneous needle liver biopsy is used for scientific examination of liver metabolism. The impact of the biopsy procedure is, however, poorly investigated. Our aim was to examine the behaviour of dairy cows during and after liver biopsy. Data were collected from 18 dry cows. Percutaneous needle liver biopsies (after administration of local anaesthesia (2% Procaine)) and blood samples were taken during restraining. During the control treatment, animals were restrained and blood sampled. During the biopsy procedure, cows showed increased restlessness (P=0.008), frequency of head shaking (P=0.016), and decreased rumination (P=0.064). After biopsies, tail pressing (P=0.016) and time spent perching (P=0.058) increased. Time spent upright (P=0.10) and number of leg movements (P=0.033) increased during the night as compared to controls. Thus, liver biopsy induced behavioural changes for up to 19 h--and particularly for behaviour previously associated with pain. Even though the exact welfare impact of percutaneous needle liver biopsies in cows is not known, and the magnitude of the behavioural changes was limited, pain always has negative effects on animal welfare. Therefore, if the present biopsy procedure--involving several biopsy passes--is to be used, improvement of the anaesthetic protocol as well as the inclusion of analgesics should be considered.