Effect of preemptive flunixin meglumine and lidocaine on behavioral and physiological indicators of pain post-band and knife castration in 6-mo-old beef calves.

Citation

Nordi, W.M., Marti, S., Gellatly, D., Meléndez, D.M., González, L.A., McAllister, T.A., Fierheller, E.E., Caulkett, N.A., Janzen, E., Schwartzkopf-Genswein, K.S. (2020). Effect of preemptive flunixin meglumine and lidocaine on behavioral and physiological indicators of pain post-band and knife castration in 6-mo-old beef calves., 230 http://dx.doi.org/10.1016/j.livsci.2019.103838

Plain language summary

Six month old Angus bull calves were used in a 71 d study to assess the effects of analgesic (flunixin meglumine) and an anesthetic (lidocaine) in alleviating pain associated with band and knife castration. Calves were either band or knife or not castrated (controls) and given the drug combination or not. The drug combination was effective at reducing some behavioral and physiological indicators of pain in castrated calves. It also alleviated pain at the time of castration as well as post-operative pain and therefore is a viable strategy for pain control during and after castration.

Abstract

One hundred and seventy-four Angus bull calves (248 ± 27.1 kg of body weight (BW), 6-mo-old) were used in a
71 d study to assess the efficacy of the combination of flunixin meglumine and lidocaine in mitigating pain
associated with band and knife castration. The experiment consisted of a 3 × 2 factorial design that included
castration method -sham (C), band (B) or knife (K); and medication – lidocaine (scrotal ring block 30 mL, 2% HCl
lidocaine) and flunixin meglumine (single s.c. dose of 2.2 mg/kg BW) (M), or saline solution (NM). Animals were
weighed on d 0 and weekly until d 71 (final BW) post-castration to obtain ADG. Physiological indicators included
salivary cortisol collected on d 0 (30, 60, 120 and 240 min), d 2, 8, and weekly until d 48 post-castration; scrotal
and eye temperature assessed on d 1, 2, 6, 8, and weekly until d 36 post-castration; fecal samples for E. coli
collected on d 0, 2, 6, 8, and 22 post-castration. Behavioral measures included stride length on d 0, 8, and weekly
until d 36, visual analog scale (VAS) evaluated during castration, and feeding behavior collected daily from d 0
to d 71 post-castration. Final BW and ADG were greater (P < 0.05) in C than B and K castrated calves. Salivary
cortisol concentrations were greater (P < 0.05) in B and K calves than C calves up to 4-h post-castration, and
remained greater in K calves up to 48-h post-castration, while concentrations were lower (P = 0.01) in M than
NM calves. Fecal E. coli varied daily (P = 0.01) however, there was no obvious pattern over time. Scrotal
temperature was greatest (P < 0.05) in K, intermediate in C and lowest in B calves, except at 30 min, and 22 and
36 d post-castration where they did not differ from C calves. Eye temperature was greater (P < 0.05) in B and K
than C calves on d 2 and 8 post-castration. No differences (P > 0.10) were observed for stride length. The VAS
scores were greater (P = 0.01) in K than C and B calves, while NM had greater scores (P < 0.01) than M calves.
Dry matter intake and meal size were greater (P = 0.05) in M than NM calves. Meal duration was greater
(P = 0.01) in B and C than K calves on d 0, while K calves had greater (P < 0.01) meal duration than C calves 1
and 2-wk post-castration. Overall, the combination of flunixin meglumine and lidocaine reduced physiological
and behavioral indicators of pain, suggesting that their combined use was effective at mitigating pain associated
with band and knife castration.