Pre-test habituation improves the reliability of a handheld test of mechanical nociceptive threshold in dairy cows

Abstract

Mechanical nociceptive threshold (MNT) testing has been used to investigate aspects of painful states in bovine claws. We investigated a handheld tool, where the applied stimulation force was monitored continuously relative to a pre-encoded based target force. The effect on MNT of two pre-testing habituation procedures was performed in two different experiments comprising a total of 88 sound Holsteins dairy cows kept either inside or outside their home environment. MNT testing was performed using five consecutive mechanical nociceptive stimulations per cow per test at a fixed pre-encoded target rate of 2.1N/s. The habituation procedure performed in dairy cows kept in their home environment led to lowered intra-individual coefficient of variation of MNT (P<0.001), increased MNT (P<0.001) and decreased the discrepancy between applied and target force during stimulations (P<0.001). Pre-test habituation improved the reliability of the handheld tool when used in dairy cows kept in their home environment.