Investigation of the use of meloxicam for reducing pain associated with castration and tail docking and improving performance in piglets

Abstract

Objectives: To determine the effect of meloxicam, administered to suckling piglets prior to castration and tail docking, on growth and mortality, and to determine evidence of pain reduction. Materials and methods: Piglets (n = 2888) were alternately assigned either to meloxicam (extra-label use) or a placebo injected intramuscularly 30 minutes prior to processing, which included tail docking for females, and tail docking and castration for males. All piglets were weighed on the day of processing (5 to 7 days of age) and at weaning (19 to 21 days of age). Vocalization scoring during castration, behavioral observations, and analysis of plasma cortisol concentrations were performed on a subset of animals. Results: Growth was not associated with treatment, but was positively correlated with weight at processing and negatively correlated with litter size. Mortality did not differ between treatment groups, but there was an interaction between treatment and parity, with piglets nursing older sows (parity > 5) and treated with placebo being 4.4 times more likely to die than piglets nursing older sows and treated with meloxicam (95% CI, 1.31-14.3) (P = .01). Behavior scores for isolation (isolating themselves from the other pigs) and plasma cortisol concentrations were higher for placebo-treated piglets than for meloxicam-treated piglets (P < .05). Implications: Routine treatment of piglets with meloxicam prior to castration and tail docking (extra-label use) does not improve growth, but may reduce mortality in litters nursing older sows. Observations of behavior and analysis of cortisol concentrations indicate meloxicam treatment does reduce pain.