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Self-Administration of Meloxicam via Medicated Molasses Lick Blocks May Improve Welfare of Castrated Calves
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Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia
2
School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia
*
Author to whom correspondence should be addressed.
Animals 2025, 15(3), 442; https://doi.org/10.3390/ani15030442 (registering DOI)
Submission received: 1 November 2024
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Revised: 16 December 2024
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Accepted: 18 December 2024
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Published: 5 February 2025
(This article belongs to the Special Issue Developments in Therapeutic Drugs for Pain Management in Animals)
Simple Summary
Livestock husbandry procedures inflict long-term pain and inflammation, with implications for animal welfare and production. Current formulations of pain relief available to livestock producers, including topical anaesthetics and non-steroidal anti-inflammatory drugs, are limited in their duration of action, only lasting 24–72 h. The ad libitum administration of the non-steroidal anti-inflammatory drug, meloxicam, orally via a medicated lick block is a novel concept that may enable pre-emptive and long-term analgesia to be established and maintained in a manner that is practical for livestock producers. This novel delivery system was evaluated against conventional subcutaneous meloxicam in surgically castrated calves. Results showed that therapeutic concentrations of meloxicam were established in calves fed medicated lick blocks; however, concentrations were highly variable between individuals. The administration of meloxicam by this method improved wound healing scores. Meloxicam, regardless of administration method, improved some behavioural outcomes following surgical castration. The results of this study highlight the complexities of assessing and addressing pain in cattle. If shown to be safe, medicated lick blocks could be a feasible option for providing improved pain relief to cattle, leading to advancements in animal welfare.
Abstract
The self-administration of meloxicam via medicated feed is a novel concept that could enable non-invasive, pre-emptive and long-term analgesia. Forty Bos taurus male calves were randomly allocated to four treatment groups: no castration (PC), surgical castration (NC), surgical castration with subcutaneous meloxicam (M), and surgical castration with medicated lick blocks (ML). Data collection occurred at various timepoints over 13 days following treatment. Plasma concentration of meloxicam was greater in ML compared to M calves at all timepoints except day 1 (p < 0.001); however, variation between ML individuals was high (standard deviation = 1.68). There was no effect of treatment on scrotal diameter or scrotal temperature. Wound morphology scores were improved in ML compared to NC calves. Eating observations were greater in ML calves immediately post-castration, followed by M calves at 3 h post-castration (p < 0.001). ML calves were observed locomoting more (p = 0.0032) and lying less (p < 0.001) than PC calves. These findings indicate that meloxicam-medicated lick blocks may provide a practical option for a longer duration of pain mitigation for surgically castrated calves. Conclusions are limited by the complexities of assessing pain in cattle, and further research into the toxicity effects of continued administration of meloxicam is recommended.
