Ear tagging in piglets: the cortisol response with and without analgesia in comparison with castration and tail docking

Abstract

The objectives of the present study were to compare the cortisol response caused by ear tagging piglets with the distress caused by other known painful husbandry procedures (e.g. castration and tail docking) and to evaluate the effectiveness of analgesia with meloxicam to reduce the cortisol response caused by these procedures. In total, 210 male piglets were randomised to equal numbers (n = 30) into one of seven groups: a control group which was only handled (H), an ear tagged group that received no analgesia (ET), an ear tagged group with analgesia (ETM), a castration group with no analgesia (C), a castration group with analgesia (CM), a tail-docked group with no analgesia (TD) and a tail-docked group with analgesia (TDM). The procedures were carried out on day 3 or 4 after farrowing. Five blood samples were taken from each piglet: 30 min before the respective procedure (baseline value), and 30, 60 min, 4 and 7 h after processing, to assess cortisol concentrations. Means as well as the area under the curve (AUC) value were analysed and the effective sizes of the procedures were established. At 7 h after the experimental treatment, cortisol concentrations had returned to base values in all groups. ET evoked a greater cortisol response than H piglets at 30 min (P < 0.001) and 60 min (P = 0.001). The cortisol response to ET was lower than C at 30 min (P = 0.001) but did not differ significantly at the other sample times. The mean cortisol response was similar between ET and TD piglets over all sample times. Taking both intensity and duration of the cortisol response into account (AUC), ET evoked a greater response than TD. Analgesia (ETM) resulted in significantly lower cortisol levels than ET at 30 and 60 min post-procedure. Castration (C) provoked the highest cortisol response of all procedures; a significant analgesic effect (CM) was shown only at 4 h post-procedure. TD resulted in significantly higher cortisol levels than H piglets only at 30 min; analgesia (TDM) significantly reduced the cortisol response at 30 min. We conclude that ear tagging causes a dramatic increase in cortisol levels compared with handling alone in piglets, which suggests that this procedure causes substantial distress. However, further research is needed to confirm these results.

Assessing Pain Control Efficacy of Meloxicam and Ketoprofen When Compounded with Iron Dextran in Nursing Piglets Using A Navigation Chute

“…The doses of meloxicam and ketoprofen were based on the label doses for meloxicam and ketoprofen. These doses have been documented to be effective at reducing post-surgical pain in nursing piglets in similar studies evaluating castration pain [ 2 , 4 , 5 , 6 , 7 , 8 , 9 ].…”

“…Drugs licensed for use in Canada for the control of pain in swine are currently limited to non-steroidal anti-inflammatory drugs (NSAIDs) such as meloxicam, ketoprofen, and flunixin meglumine. Given as a single injection prior to castration, meloxicam [2,[4][5][6][7] and ketoprofen [8,9] have been shown to provide post-castration pain relief to piglets. The labelled doses of meloxicam and ketoprofen (0.4 mg/kg and 3 mg/kg, respectively) are for older pigs.…”

“…The labelled doses of meloxicam and ketoprofen (0.4 mg/kg and 3 mg/kg, respectively) are for older pigs. However, studies have evaluated and documented the efficacy of these label doses in smaller (nursing) piglets [2,[4][5][6][7][8][9].…”

4. Husbandry interventions in suckling piglets, painful consequences and mitigation

“…Plasma cortisol concentrations 4 hours after notching or ear tagging did not differ when compared to sham-processed piglets (Marchant-Forde et al, 2009), but it was probably too late to measure the cortisol response to pain. Indeed, an increase in plasma cortisol was seen 30 and 60 minutes after performing ear notching (Numberger et al, 2016). Yet, no comparison was done at this time between the two techniques.…”

The Use of Vocalization Signals to Estimate the Level of Pain in Piglets

“…Pain Numberger et al (2016) evaluated the cortisol level in piglet subject to painful procedures and found that the cortisol response increased as the degree of pain imposed by the process (handling of the pig, marking tail trimming, and castration. Marchant et al (2009) compared tail trimming using two methods cold and hot and found that hot caudectomy presented vocalization with higher frequency and duration than in the cold procedure.…”