Objective Measures for the Assessment of Post-Operative Pain in Bos indicus Bull Calves Following Castration

Abstract

Simple SummarySurgical castration of cattle is a common husbandry procedure, and although this procedure is known to cause pain in cattle and other species, in some countries it is often performed without anaesthesia or analgesia. Society is increasingly aware of this animal welfare issue and it is creating pressure to drive research into animal welfare science with the aim of identifying practical and economical approaches to pain management in livestock. To effectively manage pain, a pain assessment must be performed. Pain assessment methods are often subjective and therefore influenced by the observer. Ideally, objective assessments that generate consistent and repeatable results between observers should be identified. Bos indicus bull calves were divided into four groups: no castration (NC, n = 6); castration with pre-operative local anaesthetic (CL n = 12); castration with pre-operative anti-inflammatory medication (CM, n = 12); and, castration without pain relief (C, n = 12). A range of objective assessments was performed: bodyweight measurements, activity, and rest levels, and four different compounds in the blood. The results of this study suggest that animals rest for longer periods after the pre-operative administration of anti-inflammatory medication. The other objective assessments measured in this study were not able to consistently differentiate between treatment groups. These findings emphasise the need for alternative quantifiable and objective indicators of pain in Bos indicus bull calves.AbstractThe aim of the study was to assess pain in Bos indicus bull calves following surgical castration. Forty-two animals were randomised to four groups: no castration (NC, n = 6); castration with pre-operative lidocaine (CL, n = 12); castration with pre-operative meloxicam (CM, n = 12); and, castration alone (C, n = 12). Bodyweight was measured regularly and pedometers provided data on activity and rest from day −7 (7 days prior to surgery) to 13. Blood was collected for the measurement of serum amyloid A (SAA), haptoglobin, fibrinogen, and iron on days 0, 3 and 6. Bodyweight and pedometry data were analysed with a mixed effect model. The blood results were analysed with repeated measure one-way analysis of variance (ANOVA). There was no treatment effect on bodyweight or activity. The duration of rest was greatest in the CM group and lowest in the C group. There was a significant increase in the concentrations of SAA, haptoglobin, and fibrinogen in all of the groups from day 0 to 3. Iron concentrations were not different at the time points it was measured. The results of this study suggest that animals rest for longer periods after the pre-operative administration of meloxicam. The other objective assessments measured in this study were not able to consistently differentiate between treatment groups.

Effects of Topical Anaesthetic and Buccal Meloxicam Treatments on Concurrent Castration and Dehorning of Beef Calves

“…Topical anaesthetic allows delivery of lignocaine and bupivacaine via absorption at the wound site and MEL is absorbed through the mucosa of the buccal cavity. There are few previous studies investigating the effects of surgical husbandry procedures and pain relief on welfare of Bos indicus cattle [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. In our study, results of experiments 1 and 2 have not been directly compared due to differences in animal numbers, dehorning and castration technicians and experimental environments and timeframes.…”

“…The importance of conducting studies that closely represent current industry practice and the possible changes to it has previously been acknowledged [ 22 ] and is emphasised in the current study. The difficulty in obtaining consistent results across all measures of pain and for all treatments is a common issue in studies on animal pain and may be especially apparent in studies on Bos indicus cattle which are usually unaccustomed to humans and handling [ 22 , 23 ].…”

Analgesic effects of intravenous flunixin and intrafunicular lidocaine or their combination for castration of lambs

“… 22 In addition to the previous drugs, meloxicam has been widely investigated, with promising results. 23 24 …”

Effect of oral meloxicam administration on growth performance and behavior of pre-weaning age calves following band castration

“…Neither fibrinogen nor haptoglobin concentrations in response to castration were altered by M administration in the current study. Musk et al (2017) also failed to observe any effect of M administration on circulating concentrations of haptoglobin or fibrinogen following surgical castration of 6- to 8-month-old Bos indicus calves. Additionally, circulating concentrations of haptoglobin and fibrinogen were not affected by the subcutaneous administration of M at the time of band or surgical castration in 7- to 8-day-old calves ( Marti et al, 2018 ).…”

“…Similarly, subcutaneous M administration immediately prior to band or surgical castration did not affect ADG to 56 days post-castration in 7- to 8-day-old calves ( Marti et al, 2018 ). Subcutaneous M administration 30 min prior to surgical castration of 6- to 8-month-old Bos indicus calves under general anesthesia had no effect on ADG to 13 days post-castration ( Musk et al, 2017 ). Additionally, subcutaneous M administration 30 min prior to surgical or band castration had no effect on ADG to 28 days post-castration in 7- to 8-month-old calves ( Meléndez et al, 2018b ).…”