Assessing and Mediating Pain in Dairy Cows with Experimentally-Induced Clinical Mastitis

This thesis is an investigation of the objective assessment of pain through the use of pressure algometers and rumination tags and the effects of pain management therapy for experimentally-induced mastitis on behaviour and physiological measures in dairy cattle. Twenty-four lactating Holstein cows were enrolled in a lipopolysaccharide (LPS) endotoxin challenge study, where one mammary quarter was infused with 25 µg of Escherichia coli (E. coli) LPS endotoxin. Subsequently, a subcutaneous injection of either a non-steroidal anti-inflammatory drug (NSAID) (meloxicam; n=12) or placebo (n=12) was randomly allocated and administered using double-blind methods. Several behavioural, physiological and performance parameters were monitored throughout the study period. Beneficial effects of meloxicam administration on pain sensitivity, edema scores and dry matter intake were shown. For a subset of animals receiving placebo treatment, the algometer and rumination tags accurately detected changes in both pain sensitivity and rumination time after endotoxin challenge.