Short communication: The effects of cabergoline administration at dry-off of lactating cows on udder engorgement, milk leakages, and lying behavior

Abstract

Cabergoline is an ergot derivative with high affinity for the D2 dopamine receptors whose dopaminergic effects cause inhibition of prolactin (PRL) secretion; thus, it could be considered a molecule that acts as a potential dry-off facilitator. One hundred ninety-nine Holstein cows (102 primiparous; 97 multiparous) producing ≥18kg/d at dry-off were split in 2 treatments to evaluate the effects of diminishing PRL secretion at dry-off (between 70 and 50 d from the expecting calving date) on udder engorgement, milk leakage, and cow well-being after dry-off. Treatments consisted of a single i.m. injection of 5mL of a solution containing 5.6mg of cabergoline (CAB; Velactis, Ceva Santé Animal, Libourne, France) or 5mL of saline solution as a placebo (CTRL). Each animal was evaluated for presence or absence of milk leakages during the 4 d following dry-off and udder engorgement was determined using a digital algometer. Lying behavior was recorded during 10 d after dry-off. Twenty-five cows from each treatment were randomly chosen and blood sampled at 3 and 15 d after dry-off, and again at 5 and 3 d before the expected calving date to determine serum PRL concentrations. Cows on CAB had lower serum PRL concentrations than cows on CTRL at 3 and 15 d after dry-off. Average udder engorgement was lower for cows on CAB than for cows on CTRL following dry-off, and it decreased as days after dry-off increased. The overall incidence of milk leakage in cows on CAB (3.1±0.88%) was 73.5% of that obtained in cows on CTRL (11.7±1.64%); cows on CAB had 0.2 lower odds of incurring milk leakage than cows on CTRL. The day following dry-off, CAB cows lied about 1.5h/d more than cows on CTRL. We conclude that i.m. administration of 5.6mg of cabergoline at dry-off effectively reduces PRL secretion, udder engorgement, and milk leakages, and improves lying time the day following dry-off.