s40813-025-00428-7

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© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit h t t p : / / c r e a t i v e c o m m o n s . o r g / l i c e n s e s / b y / 4 . 0 / . The Creative Commons Public Domain Dedication waiver ( h t t p : / / c r e a t i v e c o m m o n s . o r g / p u b l i c d o m a i n / z e r o / 1 . 0 / ) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Hokkanen et al. Porcine Health Management (2025) 11:21 https://doi.org/10.1186/s40813-025-00428-7 Porcine Health Management *Correspondence: Ann-Helena Hokkanen ann-helena.hokkanen@helsinki. Full list of author information is available at the end of the article Abstract Background Surgical castration causes severe pain to young piglets. In addition, piglets experience intense stress from handling and restraining during the procedure. Furthermore, piglets must be restrained twice when receiving local anesthesia before castration, and the injections are painful. Unfortunately, strategies to reduce piglets stress

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estrained twice when receiving local anesthesia before castration, and the injections are painful. Unfortunately, strategies to reduce piglets stress during handling, local anesthetic injections, and painful procedures are limited and poorly understood. Thus, we randomized 179 male piglets aged 3 to 4 days to be restrained with either a commonly used commercial tubular bench with a dorsal restraining posture or a custom-made castration rack with a vertical restraining posture. Piglets received local anesthetic or sham injections (mimicking local anesthesia but without skin penetration) 10 min before castration. We then compared the e ect of these devices on the piglets behavioral reactions, vocalizations, and body temperatures at the following four times: when restrained for the rst time, when given local anesthetic injections or receiving sham injections, during the second time restrained, and during castration. Results Piglets were given higher mean reaction scores when restrained in the tubular bench than the castration rack. Piglets showed di ering vocalization patterns in the two devices, with more grunts and screams in the castration rack and more squeals in the tubular bench. Moreover, local anesthetic injections resulted in higher mean reaction scores and longer vocalizations than sham injections during the injections/sham injections but reduced these measures during castration. After castration, the skin temperature was higher in sham-injected piglets than in piglets castrated with local anesthesia, irrespective of the restraining device used. Conclusions Local anesthesia reduced piglets reaction scores and vocalizations during castration. However, receiving local anesthesia was painful. Based on piglet behavior, restraining in a tubular bench was more

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nd vocalizations during castration. However, receiving local anesthesia was painful. Based on piglet behavior, restraining in a tubular bench was more aversive than in the castration rack. However, the devices a ected the proportions of the di erent vocalization types during local anesthetic injections and castration in a manner we cannot fully explain. As the restraining method a ects piglets behavior, it may in uence pain assessment during local anesthetic injections and evaluation of local anesthesia e cacy during castration. Thus, less stressful methods to handle piglets are needed. Two restraining devices in connection to surgical castration with or without local anesthesia: e ects on piglet stress Ann-Helena Hokkanen 1,2* , Mathilde Coutant 3 , Mari Heinonen 1,2 , Marianna Norring 1,2 , Magdy Adam 1,2 , Claudio Oliviero 1,2 , Tiina Bergqvist 1,2 and Anna Valros 1,2

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Page 2 of 14 Background During surgical castration, piglets < 7 days of age are con - ned by holding or attaching them to a bench. Two paral - lel incisions to the skin over the testicles are performed with a scalpel, both testicles are extracted from the scro - tum, and the spermatic cords are severed [ 1 ]. Despite the brevity of the procedure, it causes considerable stress [ 2 4 ], extensive tissue damage [ 5 , 6 ], and severe pain both during [ 7 , 8 ] and after the surgery [ 9 , 10 ]. When pig - lets are castrated without any pain alleviation, they will scream, try to escape the procedure, and swing their legs vigorously [ 11 ]. Pain experienced early in life may have many long-lasting adverse e ects on pig welfare [ 12 , 13 ] and should, therefore, be reduced to minimum. Although the need for alternatives to surgical castra - tion is widely acknowledged, implementing these meth - ods takes time. Accordingly, e ective pain alleviation during castration is needed [ 14 , 15 ]. Currently, in Fin - land, quali ed persons are allowed to castrate male pig - lets < 7 days of age with an open surgical method without tearing the tissues. Before castration, piglets must receive a non-steroidal anti-in ammatory drug (NSAID). Since January 2024, people who have completed training and passed the quali cation test are allowed to apply local anesthesia to the piglets before castration. By 2027, the use of local anesthesia before castration will be manda - tory [ 16 ]. However, while using pain alleviation with an NSAID and a local anesthetic will reduce piglets reac - tions to castration, they seldom eliminate pain entirely during or after castration [ 3 , 4 , 10 , 17 , 18 ]. In addition to castration pain, piglets experience intense stress from handling and restraining

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y during or after castration [ 3 , 4 , 10 , 17 , 18 ]. In addition to castration pain, piglets experience intense stress from handling and restraining during the procedure [ 19 ]. Furthermore, piglets must be restrained twice when they receive local anesthesia before castra - tion. First, the piglets are handled for NSAID administra - tion and injecting local anesthesia. en, a waiting period of 5 to 30 min is needed for the local anesthetic agent to take e ect [ 20 ]. e piglets are then handled again for castration. Piglet behavioral reactions and vocalizations have been previously studied in connection to stress and pain caused by local anesthetic injections and castration [ 2 , 3 , 11 , 19 , 21 , 22 ]. Moreover, skin temperature changes can indicate stress and pain [ 11 , 23 25 ]. However, to our knowledge, there are no studies on how piglets should be held during the administration of local anesthesia to minimize stress. Only one study has explored how piglets perceive di erent restraining devices during castration itself [ 22 ]. One person can perform castration without a restraining device. However, the piglet needs to be restrained by an additional person or a restraining device when local anesthesia is administered to allow the use of both hands for the procedure itself. According to the authors observations, piglets are calmer when restrained in the lap than when using a restraining device, but this, of course, increases labor costs. A tubular restraining device is commonly used, where the piglets are restrained in a dorsal position. Based on the authors experience, this method causes a very strong reaction in piglets. In addition to this being a sign of potentially intense stress in the piglets, behavioral reactions due to handling stress may

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ng reaction in piglets. In addition to this being a sign of potentially intense stress in the piglets, behavioral reactions due to handling stress may compromise the evaluation of pain needed to assess the e cacy of local anesthesia and other pain-mitigating strategies applied at castration. Moreover, the tubular restraining device is di cult to clean between litters and time-consuming to use. ere is thus a need to develop and evaluate alternative restraining methods for pig - lets. One possible alternative to the tubular restraining device is a custom-made castration rack, where the pig - lets are restrained in a vertical position and hung from their groins with their heads down while held in place by the handler s body. e practical bene t of this device is that it poses fewer hygiene challenges and is perceived as easier and faster to use than a tubular restraining device. However, in both devices, the piglets are restrained in unnatural postures. e primary objective of this study was to compare the e ect of two di erent restraining devices, a com - mercially available tubular castration bench (TUBE) and a custom-made castration rack (HANGING), on piglets stress during handling, administration of local anesthe - sia, and surgical castration. e secondary aim was to assess whether the restraining device a ects the clarity of behavioral di erences between piglets during the admin - istration of local anesthesia versus sham injections and between piglets castrated with or without local anesthe - sia. To that extent, we evaluated the animals behavioral reactions, vocalizations, and skin temperature. More - over, we studied the time required to restrain piglets, to administer local anesthesia, and to castrate the piglets in these devices. Methods e University of

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studied the time required to restrain piglets, to administer local anesthesia, and to castrate the piglets in these devices. Methods e University of Helsinki Viikki Campus Research Eth - ics Committee (17/2023) approved the study protocol. Written consent from the animal owners was obtained. Animals and housing We conducted the study in the farrowing unit of a com - mercial piglet-producing farm in Southern Finland. e Keywords Piglets, Handling, Castration bench, Procaine with epinephrine, Castration, Pain, Behavioral reactions, Animal welfare, Sus scrofa , Management

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Page 3 of 14 experiment day was a farm s routine castration day in October 2023. In total, we included 179 male crossbred piglets (Yorkshire & Finnish Landrace x Tempo) from 23 litters. e average parity of the sows was 3.4 (range 1 5), including one litter from a primiparous sow. e sows were fed daily 4 kg of a mixed ration (a farm-made feed mixture with energy 8.8 MJ, crude protein 150.7 g/ kg, and crude ber 57.9 g/kg). Water was available ad libitum . All piglets were born during the same week and housed in similar conditions in two di erent farrowing rooms, each housing 45 sows in pens (3 m x 2.5 m) with partly slatted ooring. Sows were loose housed but con ned in crates during the rst days after farrowing. e crates were opened after piglet castration. e room tempera - ture in the farrowing unit was 21.5 °C. e piglet nest had a solid concrete oor bedded with sawdust and a oor temperature of 38 °C. On the day of the study, the age of the piglets was 3 days in 22 litters and 4 days in one litter. Piglets were not ear tagged or marked, not tail docked, and their teeth were left intact. As the study was performed in connection with the normal farm routines, we were unable to weigh the piglets. However, we divided the piglets into two size groups (normal and small) after visually estimating their size, thus simulating how it would be done in practice on a pig farm. We included and randomly allocated to the di erent groups only piglets in sound general condition with completely descended tes - ticles and free of overt anatomical malformations. Study design Timeline e study timeline is presented in Fig. 1 . An experienced farm employee (later referred to as the handler) per - formed piglet handling and castration. Initially, the han - dler carefully

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1 . An experienced farm employee (later referred to as the handler) per - formed piglet handling and castration. Initially, the han - dler carefully collected all the piglets and placed them in the piglet nest. Subsequently, she lifted one piglet at a time from the nest and injected a suspension of 45 mg toltrazuril (coccidiostat) and 200 mg gleptoferron (iron) (Forceris , 1.5 mL, Ceva Animal Health A/S, Libourne, France) intramuscularly and returned the female pig - lets to the sow. She turned male piglets towards one of the researchers, who measured skin temperature and marked the piglet in numerical order with a text marker. en, the handler put the male piglets back in the nest. From the nest, the handler picked piglets one by one unaware of the predetermined treatment order used to ensure all treatments were performed within each litter and to achieve a similar number of piglets within each treatment. When all male piglets from the given litter were in the nest, the handler lifted the rst male piglet (in numeri - cal order) and xed it into the restraining device (either TUBE or HANGING according to the predetermined order, described in more detail below under the heading procedures ). en, the handler xed the piglet in place while a veterinarian approached the piglet and secured it in place in the device using his hands (TUBE) or his body (HANGING). At this stage, the two observers scored the reaction of the piglet (timepoint RESTRAIN 1). en, the Fig. 1 Timeline of the study investigating restraining devices and the use of local anesthesia in piglet castration. An injection containing iron and coc - cidiostat and an injection of meloxicam were administered to all study piglets. The piglets were restrained at two time points (RESTRAIN 1 and RESTRAIN 2) using

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and an injection of meloxicam were administered to all study piglets. The piglets were restrained at two time points (RESTRAIN 1 and RESTRAIN 2) using either a tubular castration bench (TUBE) or a castration rack (HANGING). The piglets received either local anesthesia (LA) or sham injections (NO LA) at the timepoint LOCAL. Finally, surgical castration was performed at the timepoint CASTRATION. Between all procedures, the piglets stayed in their nests

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Page 4 of 14 veterinarian administered either local anesthesia (LA) or sham injections (NO LA), and the observers scored the reaction to LA or NO LA (timepoint LOCAL). Sub - sequently, the handler took the piglet out of the device, injected the NSAID meloxicam (Metacam® 5 mg/mL, injection solution for cattle and swine, Boehringer Ingel - heim Pharma GmbH & Co. KG, Ingelheim am Rhein, Germany; target dose approximately 0.4 mg/kg body weight intramuscularly according to farm routine prac - tice), turned the piglets towards the researcher for skin temperature measurement, and then returned the piglet to the nest. We handled all male piglets in the litter the same way, and video and audio recorded all procedures using an iPhone 11 pro, video HD (1080 pixels) 30 frames per second. After all male piglets in the litter had been handled, there was a 10-minute interval between LA administra - tion for the rst piglet and starting castration, during which time we performed the same procedures described above for the next litter. After the 10-minute waiting period, the handler took the rst piglet (in numerical order starting at number one, i.e., the piglet that received LA rst) from the nest, turned it to the researcher for skin temperature measure - ment, and then put the piglet in the restraining device according to its assigned treatment (TUBE or HANG - ING). e observers scored the reaction of the piglet (timepoint RESTRAIN 2). en, the handler surgically castrated the piglet, and the observers scored the reac - tion of the piglet to castration (timepoint CASTRA - TION). en, the handler took the piglet from the device, turned it towards the researcher for skin temperature measurement, and carefully put it back in the pen with the sow. At this point, the study ended for

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rned it towards the researcher for skin temperature measurement, and carefully put it back in the pen with the sow. At this point, the study ended for this individual piglet. We then performed the same procedures for the other piglets of the litter in numerical order. Procedures Handling and restraining devices: We randomized the piglets to be handled with either a commercially available tubular castration bench (TUBE, Fig. 2 a) or a custom- made castration rack (HANGING, Fig. 2 b). In TUBE, piglets were restrained in a dorsal position in a narrow tubular part, with their hind legs pushed cranially by a metal bar. In HANGING, the piglets were restrained in a vertical position as they were hung from their groins with their heads down while held in place by the handler s body. Local anesthesia (LA) We randomized half of the TUBE- handled piglets and half of the HANGING-handled piglets to receive either LA or NO LA. We used a solution con - taining 40 mg/mL procaine hydrochloride and 0.036 mg/ mL epinephrine tartrate (Procamidor Comp® Vet., 40 mg/ mL, Richter Pharma AG, Wels, Austria), administered the product using an automatic self- lling syringe (HSW ECO-MATIC®, Henke-Sass, Wolf GmbH, Tuttlingen, Germany) with a 27 G needle (0.4 × 13 mm) and replaced needles between each litter. For normal-sized piglets, a total of 1.5 mL of the anesthetic solution (equivalent to 60 mg of procaine) was administered across three sepa - rate injection sites, with each site receiving 0.5 mL. For small piglets, the dosage was reduced to 0.9 mL in total (equivalent to 36 mg of procaine), divided into three injec - tions of 0.3 mL each. e same veterinarian performed all local anesthetic injections. First, he xed the testicles caudally between the thumb and middle nger, applying a

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. e same veterinarian performed all local anesthetic injections. First, he xed the testicles caudally between the thumb and middle nger, applying a steady but low pressure during the xation (see Fig. 3 ). Fig. 2 Piglet restraining devices used in the study. Piglets were restrained either with a tubular castration bench (Fig. 2 a) or with a castration rack (Fig. 2 b). In Fig. 2 a, the piglet is being given a sham injection, while in Fig. 2 b, the piglet receives subcutaneous local anesthesia

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Page 5 of 14 en, he inserted the needle just beneath the skin of the scrotum ( Cutis scroti ) of the right testicle and injected the anesthetic agent subcutaneously by continuously dis - pensing the drug while withdrawing the needle and then releasing the testicle. e veterinarian repeated the same procedure under the scrotal skin of the left testis. He then inserted the needle to its full length (13 mm) between the two testicles, targeting the area around the spermatic cords, and injected the third dose of the local anesthetic agent (Fig. 3 ). Subsequently, the handler removed the pig - let from the restraining device and placed it into the nest. Sham injections (NO LA) e handler secured the pig - lets in the restraining devices as described above. e veterinarian then xed the testicles with his ngers and touched the testicles with an automatic syringe (with a capped needle on) at the same three locations as described in Fig. 3 to simulate LA administration but without any tissue damage. e handler then removed the piglet from the restraining device and placed it into the nest. Castration After securing the piglet in the restraining device, the handler used a scalpel blade to cut an incision (approximately 1 cm) through the scrotal skin and sper - matic fasciae. She then gently pressed the right testicle between her index nger and thumb until it was entirely outside the scrotum. She carefully lifted the testicle verti - cally and cut the spermatic cord a few millimeters below the testicle using the scalpel. She then made the second incision and repeated the procedure on the left testicle. Between each piglet, she disinfected the blade in a povi - done-iodine solution and a new blade was used after each litter. Data collection Behavioral reactions ree observers

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disinfected the blade in a povi - done-iodine solution and a new blade was used after each litter. Data collection Behavioral reactions ree observers independently scored piglets behavioral reactions (including piglet movements, such as kicking and struggling, and vocalizations) on a scale from 0 (no reaction) to 10 (the worst reaction imaginable) at the following four time points: when the piglet was restrained for the rst time (RESTRAIN 1), during local anesthetic injections or sham injections (LOCAL), during the sec - ond time the piglet was con ned (RESTRAIN 2), and during castration (CASTRATION). ree observers are recommended for such subjective scorings [ 26 ]. How - ever, due to space restrictions at the farm, two observ - ers were present during piglet handling and performed direct observations. e third observer assessed the piglets reactions from videos recorded with an iPhone placed approximately 20 30 cm from the piglets heads. All observers could see with which device the piglet was handled and, for many of the animals, also whether the piglet was receiving LA or NO LA. However, the three observers were blinded regarding whether the piglet was castrated with or without local anesthesia. Vocalizations We recorded vocalizations from the video recordings described above and analyzed the vocalizations during the administration of LA and NO LA (LOCAL) and dur - ing castration (CASTRATION). In the tubular restrain - ing device, both periods started when the handler locked the hind bar that xed the piglet to the device and ended when she touched the same bar to open it and take the piglet out of the device after injections or castration. In the HANGING restraining device, the periods started when the handler put the piglet s hind limbs on the device

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vice after injections or castration. In the HANGING restraining device, the periods started when the handler put the piglet s hind limbs on the device and let go of the legs (i.e., when the piglet was held in place with the handler s body) and ended when she touched the pig to take it out of the device. We analyzed the vocalizations with Raven Pro 1.6 bio - acoustics analysis software (Cornell Lab of Ornithology, Ithaca, New York, USA). We manually selected each vocalization in the audio les to obtain its duration and categorized it as a grunt, scream, or squeal according to previously reported method [ 19 ]. A grunt was character - ized as a vocalization with a low tone, a scream as a vocal - ization with high, long and loud tone (often as long as an expiration of the piglet), and a squeal was a vocalization Fig. 3 The three-step method of injecting the local anesthetic agent for castration. After securing the testicles with his ngers, the veterinarian inserted the needle subcutaneously on the right testicle, injected the anesthetic agent continuously while withdrawing the needle, released the testicle, and repeated the procedure for the left testis. Lastly, he inserted the needle to its full length (13 mm) between the two testicles, aiming at the area around the spermatic cords, and injected the third dose of the local anesthetic

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Page 6 of 14 with high tone (could be with di erent notes) [ 19 ]. We then calculated the mean call durations of all calls and separately for each call type during LOCAL and CAS - TRATION in seconds. As the durations of di erent pro - cedures (administering local anesthesia, administering sham injections, and castration) were di erent, we calcu - lated the duration (seconds) of vocalizations per second of the procedure during LOCAL and CASTRATION by dividing the sum of call durations by the duration of the procedure (obtained from the video recordings). Skin temperature We used a hand-held infrared thermometer (model PCE- IR 100; PCE Produktions und Entwicklungsgesellschaft mbH, Meschede, Germany) to measure changes in skin temperature [ 25 ]. We measured skin temperature near the internal organs, ventrally at the base of the ster - num near the xiphoid process (Fig. 4 ) after RESTRAIN 1 + LOCAL and RESTRAIN 2 + CASTRATION. Skin temperature was also measured before these procedures to allow us to control individual di erences (see also timeline, Fig. 1 ). Time needed to restrain piglets and duration of procedures We analyzed video recordings to determine the time required for restraining the piglets (restraining duration) and performing the procedures (administration of local anesthesia, sham injections, and castration) (procedural duration) in the TUBE or HANGING device. For the TUBE, the restraining duration started from the moment the handler turned the piglet onto its back (still in the hands of the handler) and ended when the handler locked the hind bar of the device in the nal position. For the HANGING device, the restraining duration started from the moment the handler turned the piglet s head down in her hands and ended when the piglet s legs were posi -

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, the restraining duration started from the moment the handler turned the piglet s head down in her hands and ended when the piglet s legs were posi - tioned correctly in the device, and she could let go. e procedural duration (LOCAL or CASTRATION) started when the handler locked the hind bar to its nal position (TUBE) or let go of the piglet s legs (HANGING) and ended when she touched the piglet for the rst time to take it out of the device. Statistical analysis We used IBM SPSS Statistics version 29.0 (IBM Inc. Chi - cago, IL) to analyze the data. We used an interclass correlation analysis with a two- way mixed e ect model assuming consistency to assess the consistency of reaction scoring between the observ - ers. e overall inter-observer reliability was excellent during all four observation periods (Interclass correla - tion [df = 343 357]: 0.92 0.95, 95% con dence interval: 0.90 94 [lower bound] − 0.93 0.96 [upper bound]). us, we used the mean score of the observations in the sta - tistical analysis (mean reaction score). Continuous vari - ables were assessed for normality visually and using the Shapiro-Wilk test. Mean reaction scores and duration of vocalizations during the four di erent time points (RESTRAIN 1, LOCAL, RESTRAIN 2, CASTRATION), and skin tem - perature after the procedures (LOCAL and CASTRA - TION) were all normally distributed. Accordingly, we studied the e ects of the restraining device and local anesthesia on piglets mean reaction scores and vocaliza - tions during each of the di erent time points, and skin temperature after the procedures, using separate mixed models. e models included restraining device (TUBE or HANGING), treatment (local anesthesia [LA] or sham injections [NO LA]), piglet size (small or normal, based on visual

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uded restraining device (TUBE or HANGING), treatment (local anesthesia [LA] or sham injections [NO LA]), piglet size (small or normal, based on visual estimation), and the interaction between Fig. 4 Location of the skin temperature measurement. Skin temperature was measured ventrally at the base of the sternum near the xiphoid process with a hand-held infrared thermometer

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Page 7 of 14 restraining device and treatment as xed factors, with sow included as a random factor. However, sow as a random factor was redundant in the model for grunts during castration. For temperature after LOCAL and CASTRATION, skin temperature before the procedure was included as a covariate. e results are presented as estimated means (EM) and standard errors (SE). In lin - ear mixed-e ects models, deviations from assumption of normality and variance homogeneity were assessed with Kolmogorov-Smirnov test and visually by examining the residual plots. We studied the time needed to restrain piglets and the duration of di erent procedures (administration of local anesthesia/sham injections and castration) in the di er - ent treatment groups with pairwise comparisons per - formed with t-tests. e results are presented as mean and standard deviations (SD). We estimated the sample size based on previous research [ 3 ]. Due to technical and human errors, some data were missing ( n = 172 179 for behavioral reactions and vocalizations, and n = 162 176 for skin temperature measurements), resulting in di erent sample sizes in dif - ferent comparisons. P -values < 0.05 were considered sta - tistically signi cant and p -values < 0.1 as tendencies. Results e 179 piglets were randomized into di erent treatment groups (LA in TUBE, NO LA in TUBE, LA in HANG - ING, and NO LA in HANGING), as shown in Table 1 . Table 1 also shows the number of piglets per treatment according to their size (normal or small). Behavioral reaction scores Both the restraining device and the LA vs. NO LA treat - ment in uenced the mean reaction scores of the pig - lets. As expected, only the device a ected the mean reactions during the time points, including handling only (RESTRAIN 1 and RESTRAIN 2,

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of the pig - lets. As expected, only the device a ected the mean reactions during the time points, including handling only (RESTRAIN 1 and RESTRAIN 2, see Fig. 5 a and c). e reaction of the piglets was scored to be higher in the TUBE than in the HANGING treatment at both time points. During LOCAL, the reaction of the piglets was scored to be higher both in the TUBE as compared to the HANGING device and in the piglets given LA as Table 1 Number of study piglets ( n = 179) according to their size and treatment group Treatment group Piglet size Total normal small Local anesthesia in tubular device 30 19 49 Sham injections in tubular device 24 20 44 Local anesthesia in castration rack 28 15 43 Sham injections in castration rack 31 12 43 Fig. 5 Estimated marginal mean and standard error for mean reaction scores for piglets restrained with di erent devices and treated with or without local anesthesia. The piglets were restrained either with a tubular device (TUBE) or a castration rack (HANGING). The piglets received either local anesthesia (LA) or sham injections (NO LA) before castration. Three observers scored piglets reaction at four time points: ( a ) RESTRAIN 1 (only restraining, n = 172); ( b ) LOCAL (restraining and administration of local anesthesia/sham injections, n = 177); ( c ) RESTRAIN 2 (only restraining, n = 178) and ( d ) CASTRATION (restraining and surgical castration, n = 179)

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Page 8 of 14 compared to NO LA (Fig. 5 b). During CASTRATION, the restraining device did not in uence the reaction score, but piglets in the NO LA group were scored to react stronger than those in the LA group (Fig. 5 d). e interaction between restraining devices and LA vs. NO LA was not signi cant in any of the models. Small pig - lets got lower mean reaction scores during all time points compared to normal size piglets (for full model results, see Supplementary Tables 1 a-e). Vocalizations Di erences in piglets vocalizations between the two devices studied and between LA and NO LA are shown in Fig. 6 a-d during LOCAL and in Fig. 7 a-d during CAS - TRATION. Overall, piglets that received LA vocalized longer during the administration of local anesthesia (Fig. 6 a) and less during castration than piglets in NO LA (Fig. 7 a). Moreover, the vocal responses of the pig - lets during the administration of the local anesthetic (Fig. 6 b and d) and castration (Fig. 7 b-d) were a ected by the restraining device used. e interaction between restraining devices and LA vs. NO LA was not signi - cant in any of the models. ere was no di erence in the total duration of vocalizations during either LOCAL or CASTRATION between small and normal-sized piglets. However, small piglets grunted longer and screamed less than normal-sized piglets (for full model results, see Sup - plementary Tables 2 a-e and 3 a-e). e proportions of di erent types of vocalizations (mean durations per second) of piglets in the di erent treatment groups during LOCAL and CASTRATION are shown in Fig. 8 a and b, respectively. A relatively higher proportion of vocalizations were screams during CAS - TRATION in the piglets that had not received local anes - thesia (Fig. 8 b). Proportions of grunts and

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ion of vocalizations were screams during CAS - TRATION in the piglets that had not received local anes - thesia (Fig. 8 b). Proportions of grunts and screams were higher in the group restrained in the HANGING device as compared to the TUBE device, while squeals occurred at a higher proportion in the TUBE than in the HANG - ING handled piglets. Skin temperature Overall, the skin temperature of the piglets was, on aver - age, 38.9 °C (SD 0.42 °C) before LOCAL and 38.6 °C (0.48 °C) before CASTRATION, and 38.9 °C (0.36 °C) vs. 38.6 °C (0.49 °C) after LOCAL and after CASTRATION respectively. e skin temperature did not di er between the treatment groups after LOCAL, even though it was numerically higher in the TUBE and LA groups than in other treatment groups (Fig. 9 a). After CASTRATION, the skin temperature tended to be higher in NO LA piglets than in LA piglets ( p = 0.05), irrespective of the restraining device used (Fig. 9 b). e interaction between Fig. 6 Estimated marginal mean and standard error for the duration (seconds) of piglets vocalizations per second during the administration of local anesthesia (LA) or sham injections (NO LA). Di erent vocalizations of piglets are presented as total vocalizations ( a , n = 178), grunts ( b , n = 178), screams ( c , n = 178), and squeals ( d , n = 178). Piglets had been treated with local anesthesia (LA) or sham injections (NO LA), and they were restrained either with a tubular bench (TUBE) or a castration rack (HANGING)

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Page 9 of 14 the restraining device and LA vs. NO LA was not signi - cant in either of the models. e piglet size category did not in uence skin temperature, but temperature before correlated positively with the temperature after both LOCAL and CASTRATION (for full model results, see Supplementary Tables 4 a and b). Durations required for each procedure e restraining duration was shorter with HANG - ING than TUBE (3.5 ± 2.0 versus 6.3 ± 3.2 s, p = 0.001). Moreover, administering LA took 14.9 ± 6.1 s, NO LA 9.3 ± 1.6 s, and castration 14.2 ± 4.7 s. Administering LA lasted 11.7 ± 5 s in TUBE and 12.6 ± 5.4 s in HANGING ( p = 0.928). Castration required 14.3 ± 4.5 s in TUBE and 14.1 ± 4.9 s in HANGING ( p = 0.843). Castration after Fig. 8 Proportions of di erent piglet vocalizations of all vocalizations recorded during the procedures. Results are shown for each treatment group sepa - rately: the piglets were either restrained in a tubular device (TUBE) or a hanging castration rack (HANGING), and treated with local anesthesia (LA) or with sham injections (NO LA) during administration of local anesthesia or sham injections (LOCAL) ( a ) and during castration (CASTRATION) ( b ) Fig. 7 Estimated marginal mean and standard error for duration (seconds) of piglets vocalizations per second during castration. Di erent vocalizations of piglets are presented as total vocalizations ( a , n = 179), grunts ( b , n = 179), screams ( c , n = 179), and squeals ( d , n = 179). Piglets had been treated with local anesthesia (LA) or sham injections (NO LA) and they were restrained either with a tubular bench (TUBE) or a castration rack (HANGING)

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Page 10 of 14 LA took less time (13.3 ± 3.1 s) compared to after NO LA (15.2 ± 5.8 s) ( p < 0.001). Discussion We found that the restraining device a ected the piglets behavioral reaction scores during handling and piglets vocalizations both during local anesthetic administration and castration. Piglets received higher reaction scores when restrained with TUBE than with HANGING. us, they possibly perceived TUBE as more aversive than HANGING. e validity of our reaction scoring method is supported by the piglets stronger behavioral reaction scores during local anesthetic administration (LA) than the sham injections (NO LA). Moreover, NO LA piglets had higher reaction scores during castration than LA piglets. Our ndings are consistent with the literature, as several authors concluded that local anesthesia induces stress, discomfort, and pain [ 3 , 4 , 27 ], and piglets treated with local anesthesia prior to castration resisted less dur - ing the procedure than their counterparts castrated with - out local anesthesia [ 2 , 11 , 28 ]. Interpreting the results becomes more complex when vocalizations are considered; piglets tended to vocalize longer when castrated in HANGING than in TUBE. is contradicts our nding that piglets had higher behavioral scores when restrained in TUBE. Indeed, piglets also Fig. 9 Estimated marginal mean and standard error for skin temperature of piglets measured with an infra-red thermometer near the xiphoid process. Results are shown after the rst restraining and administration of local anesthesia (LA) or sham injections (NO LA) ( a , n = 162) and after the second restrain - ing and castration with local anesthesia (LA) or sham injections (NO LA) ( b , n = 176). The piglets were restrained with either a tubular bench (TUBE) or a

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d castration with local anesthesia (LA) or sham injections (NO LA) ( b , n = 176). The piglets were restrained with either a tubular bench (TUBE) or a castration rack (HANGING)

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Page 11 of 14 vocalized longer when receiving LA than NO LA and when castrated after NO LA than LA. ese ndings are consistent with other studies [ 3 , 4 , 29 , 30 ]. For example, Coutant et al. [ 3 ] found that the local anesthetic injec - tions resulted in higher values of vocal parameters than those of sham-handled piglets, indicating a signi cant stress response [ 31 ]. Moreover, Lou et al. [ 30 ] observed that piglets castrated under 24 h of age produced more vocalizations of a higher frequency than sham-castrated piglets, and these high-frequency vocalizations tended to be longer in duration during castration than during sham castration. In contrast to our ndings, Weary and col - leagues [ 21 ] found no e ect of the handling method on the rate of high calls produced by the piglets in connec - tion to castration. Piglets suspended by their rear legs in the handler s hands had low calls at a slower rate than pig - lets restrained in a bench in a dorsal position. Moreover, piglets restrained dorsally on the bench produced low calls at a lower rate than those restrained in a V-trough [ 21 ]. us, evaluating di erent restraining methods by their aversiveness needs further research. It is possible that longer vocalizations produced while castrated with HANGING when compared with TUBE may result from di erent body postures during restraining; piglets could probably vocalize longer while hanging upside down than when restrained in the dorsal position with the hind legs pushed cranially. Additionally, it is also possible that the two di erent restraining postures were perceived as dif - ferentially aversive. Being restrained dorsally in a narrow TUBE and having legs xated on the bench may provoke more resistance behavior as an attempt to escape and adjust body

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restrained dorsally in a narrow TUBE and having legs xated on the bench may provoke more resistance behavior as an attempt to escape and adjust body postures. However, being hung upside down could induce more fear of falling, thus resulting in fewer resistance movements but more and longer high-tone vocalizations, such as screams, which are often associ - ated with fear, panic, and pain [ 22 ]. e restraining device, administration of local anes - thetic, and castration all a ected the durations and proportions of di erent vocalizations in piglets. Dur - ing LOCAL, the total duration of all vocalizations was signi cantly longer in LA than in NO LA. Furthermore, although the restraining device did not in uence the duration of all vocalizations during LOCAL, the pig - lets grunted longer when restrained with HANGING and squealed longer in TUBE. During castration, the total duration of all vocalizations was longer among NO LA piglets than those castrated with LA. Moreover, the restraining device in uenced the duration of all vocaliza - tions during castration, as piglets tended to vocalize for a longer time in HANGING than in TUBE. Speci cally, the piglets grunts and screams were longer in HANG - ING than in TUBE, and piglets squealed longer in TUBE. Interestingly, the restraining device and the severity or type of pain experienced by piglets appear to a ect the di erent proportions of vocalizations during painful pro - cedures. During LOCAL, the proportion of screams was greater among LA piglets than among NO LA piglets in TUBE but not in HANGING. In contrast, the propor - tion of grunts remained similar in both devices, while the proportion of squeals was slightly greater among NO LA than among LA piglets in TUBE but again not in HANGING. In contrast, the

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oth devices, while the proportion of squeals was slightly greater among NO LA than among LA piglets in TUBE but again not in HANGING. In contrast, the vocalization pattern shifted noticeably during castration; the proportion of grunts was much lower, and the proportions of screams and squeals were much greater among NO LA than LA. e proportion of screams was especially high when piglets were restrained in the vertical position during castra - tion. us, grunting could be more a sign of overall dis - comfort (and maybe also a piglet s e ort to contact the mother sow) and is replaced by squealing and screaming, calls previously found to be used by piglets experiencing severe pain and distress [ 11 , 21 , 22 , 32 ], during castration. We wanted to study piglets reactions and vocalizations in a real-life setting in a commercial piggery with as few deviations from normal procedures as possible. Natu - rally, this approach limited our ability to record more advanced vocal parameters. ere are limitations in using durations and categories of vocalizations to measure pain and stress in young piglets. Indeed, previous studies have shown that more advanced vocal parameters, such as frequency, energy, or amplitude, seem to be more sensi - tive and accurate in reporting pain and stress than other general measures, such as average call duration or pro - portion of call time used in the current study [ 19 ]. us, future work could focus on these more complex indica - tors of pain and distress. Moreover, future studies are needed to understand how the physical situation restricts piglets ability to express their emotions and experiences with di erent types of vocalizations. Finally, our results indicate that the size of the piglet a ects their vocaliza - tions and should be

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xperiences with di erent types of vocalizations. Finally, our results indicate that the size of the piglet a ects their vocaliza - tions and should be considered with more care in future studies. We chose to use vocalization variables standardized for time (i.e., duration per second), as the di erent time points during the experiment di ered in duration within and between treatments. us, the outcome re ects the intensity of the negative e ect of the procedures on the piglets. However, from a welfare perspective, it may be even more relevant to assess the magnitude of the impact, i.e., the combination of intensity and duration [ 33 ]. For this, we could have used the total duration of vocaliza - tions (without standardizing for timepoint duration) as the outcome variables. To test for this, we analyzed the results with both types of variables, while we decided only to report the intensity results here for simplicity. e results were very similar when using intensity and when using magnitude variables. As we believe the intensity

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Page 12 of 14 results are easier to compare with other studies using the same approach [e.g., 19], we opted only to report these. We expected the skin temperature would increase while resisting procedures by trying to escape, kicking, and vocalizing. Moreover, as our measuring point is near the internal organs and the activation of the sympathetic nervous system causes vasoconstriction and redirection of blood ow to the internal organs [ 23 ], an increase in temperature is expected. Indeed, the mean skin tempera - tures were higher after castration with NO LA than with LA. is aligns with our ndings that the mean behav - ioral reaction scores were greater among piglets in the NO LA compared with the LA treatment group during CASTRATION. We chose this method for measuring skin temperature to add a non-invasive, rapid, and objec - tive measurement indicative of piglets stress and resis - tance movements to our study design. We acknowledge that our approach of using changes in skin temperature as an indicator of stress and pain di ers from the approach in previous research. Speci cally, prior research consid - ered a decrease in skin surface temperature, measured in the groin area following castration, as an indicator of sympathetic nervous system activation and, thus, dis - tress and pain [ 25 ]. Future research should be conducted to explore how the skin temperature measured near the xiphoid process and other sites of the body correlates with the actual body temperature among young piglets experiencing stress and pain while restrained in di er - ent postures. is would build on suggestions of previ - ous studies examining castration-related pain in piglets [ 11 ] and reviews on the use of infra-red skin temperature measurement for monitoring porcine health and assess

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ng castration-related pain in piglets [ 11 ] and reviews on the use of infra-red skin temperature measurement for monitoring porcine health and assess - ing pain [ 1 , 24 ]. In addition to evaluating piglets behavioral reactions, vocalizations, and skin temperature, our results revealed that these restraining devices also di ered in handling duration. More time was needed to restrain the piglets in TUBE than HANGING. However, the time needed to administer LA was similar between the devices. ere were also no di erences between the two handling methods in the duration of the castration procedure. It is worth noting that our operator has long experience in castrating, but both devices were new to her as she usu - ally performs the procedure by holding piglets between her thighs. However, our results show that castrating pig - lets with LA took less time than performing the proce - dure after NO LA, consistent with ndings from previous research [ 2 ]. Considering the time needed to handle and restrain piglets is essential, as shorter handling times are preferred for reasons of animal welfare and time manage - ment. Moreover, as using local anesthesia approximately doubles the overall time needed to castrate individual piglets, the handling method should allow quick injec - tions. erefore, our results emphasize the need to develop easy-to-use methods that minimize stress for the piglets while also facilitating procedures and ensur - ing safety for the operator. Moreover, as strong reactions to handling could potentially hinder caregivers ability to accurately assess the methods used to provide local anes - thesia before castration and the e cacy of local anesthe - sia during castration, less stressful handling methods are needed both in scienti c research and in

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efore castration and the e cacy of local anesthe - sia during castration, less stressful handling methods are needed both in scienti c research and in practice. us, future studies are warranted on how piglets react to han - dling, restraining, administration of local anesthesia, and castration while being held in the assistant s lap. e optimal technique to administer local anesthesia in young piglets for castration remains unknown [ 1 , 3 , 34 ]. In particular, intratesticular injections, while com - mon, cause pain and possible tissue damage [ 3 , 4 ]. To address this, we employed a modi ed technique designed to deliver the local anesthetic as close as possible to the incision sites but under the skin and deeper to the area where the spermatic cords will be cut. However, consis - tent with previous ndings, LA still resulted in signi cant behavioral reactions compared with NO LA [ 3 , 4 ]. us, the e cacy of local anesthesia before piglet castration in improving welfare remains a subject of ongoing debate. e bene ts of pain reduction during castration must be weighed against the stress and pain associated with its administration. Further research is needed to optimize anesthetic protocols, re ne handling techniques, and develop alternative methods that minimize both the pro - cedural and post-procedural pain experienced by piglets. One of our aims was to assess whether the restrain - ing device hinders the e ective evaluation of the local anesthesia protocol during castration, as it is essential that the operator can make a reliable assessment of the e cacy of the local anesthesia used. Our results suggest that the type of restraining device used may indeed hin - der this assessment. For instance, piglets restrained in the tubular device received almost similar

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e type of restraining device used may indeed hin - der this assessment. For instance, piglets restrained in the tubular device received almost similar mean behav - ioral scores both when rst restrained and during castra - tion under local anesthesia. Notably, the mean di erence in behavioral scores between piglets castrated with or without local anesthesia was 3 points on a 0 to 10 scale, which is just one point more than the di erence in scores observed between the two restraining devices during the initial restraint. is indicates that strong reaction to handling can make it challenging, if not impossible, to reliably assess the e cacy of local anesthesia. Conclusion e choice of restraining method signi cantly a ects pig - lets reactions and vocalizations, potentially preventing an accurate assessment of local anesthesia e cacy. How - ever, neither device was optimal as both induced strong reactions among the piglets. It is di cult to compare the devices based on our results, especially as they seem to

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Page 13 of 14 a ect the types of vocalizations in a manner we cannot fully explain. Moreover, while the administration of pro - caine with epinephrine e ectively alleviates pain in pig - lets aged 3 to 4 days, it also requires additional handling and needle injections, inducing stress and pain, which is evident through stronger reactions and longer and more intense vocalizations. Besides increasing the welfare bur - den of the procedure for the piglets, the strong reactions to handling can complicate or even prevent the assess - ment of pain and distress caused by the local anesthetic injections and the e ect of local anesthesia during castra - tion. erefore, our research underscores the importance of identifying the best methods for restraining young pig - lets for local anesthesia administration and castration. Supplementary Information The online version contains supplementary material available at h t t p s : / / d o i . o r g / 1 0 . 1 1 8 6 / s 4 0 8 1 3 - 0 2 5 - 0 0 4 2 8 - 7 . Supplementary Material 1 Acknowledgements We thank the owners and the farm personnel for participating in the study. We especially thank Nea Kettunen for her assistance and expertise throughout the long study day. We also thank Vilja Hukkinen for her assistance with video recordings. Author contributions A-H.H., M.C., M.H., M.A., C.O., T.B., and A.V. designed the study. A-H.H., M.H., M.A., C.O., and A.V. collected the data. M.N. and T.B. assisted in preparing the data for statistical analysis. M.C. was responsible for the analysis of vocalizations and was involved in interpretation of the results. A-H.H. and A.V. performed the statistical processing of the data, interpreted the results, and prepared the rst version of the manuscript. All the authors participated in writing and editing

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processing of the data, interpreted the results, and prepared the rst version of the manuscript. All the authors participated in writing and editing the nal manuscript and accepted it. Funding The Juliana von Wendt Foundation and Suomen Sianjalostuksen Säätiö funded this research. A-H.H. thanks the Finnish Foundation of Veterinary Research for a personal grant. Data availability The datasets generated and/or analyzed during the current study are not publicly available due to being under further analysis but are available from the corresponding author upon reasonable request. Declarations Ethics approval and consent to participate The study protocol was considered ethically acceptable by the University of Helsinki Viikki Campus Research Ethics Committee (17/2023) and the written owner consent was obtained. Consent for publication Not applicable. Competing interests The authors declare no competing interests. Author details 1 Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland 2 Research Centre for Animal Welfare, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland 3 Department of Animal and Veterinary Sciences, Aarhus University, Tjele, Denmark Received: 31 October 2024 / Accepted: 19 February 2025 References 1. Sheil M, Polkinghorne A. Optimal methods of documenting analgesic e - cacy in neonatal piglets undergoing castration. Animals. 2020. h t t p s : / / d o i . o r g / 1 0 . 3 3 9 0 / a n i 1 0 0 9 1 4 5 0 . 2. Skade L, Kristensen CS, Friis Nielsen MB, et al. E ect of two methods and two anaesthetics for local anaesthesia of piglets during castration. Acta Vet Scand. 2021. h t t p s : / / d o i . o r g / 1 0 . 1 1 8 6 / s 1 3 0 2 8 - 0 2 0 - 0 0 5 6 6 - 8 . 3. Coutant M,

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f piglets during castration. Acta Vet Scand. 2021. h t t p s : / / d o i . o r g / 1 0 . 1 1 8 6 / s 1 3 0 2 8 - 0 2 0 - 0 0 5 6 6 - 8 . 3. Coutant M, Malmkvist J, Kaiser M, et al. Piglets acute responses to local anes - thetic injection and surgical castration: e ects of the injection method and interval between injection and castration. Front Vet Sci. 2022. h t t p s : / / d o i . o r g / 1 0 . 3 3 8 9 / f v e t s . 2 0 2 2 . 1 0 0 9 8 5 8 . 4. Coutant M, Malmkvist J, Kaiser M, et al. Piglets acute responses to procaine- based local anesthetic injection and surgical castration: e ects of two volumes of anesthetic. Front Pain Res. 2022. h t t p s : / / d o i . o r g / 1 0 . 3 3 8 9 / f p a i n . 2 0 2 2 . 9 4 3 1 3 8 . 5. Morales J, Dereu A, Manso A, et al. Surgical castration with pain relief a ects the health and productive performance of pigs in the suckling period. Porcine Health Manag. 2017. h t t p s : / / d o i . o r g / 1 0 . 1 1 8 6 / s 4 0 8 1 3 - 0 1 7 - 0 0 6 6 - 1 . 6. Viscardi AV, Turner PV. Use of meloxicam or ketoprofen for piglet pain control following surgical castration. Front Vet Sci. 2018. h t t p s : / / d o i . o r g / 1 0 . 3 3 8 9 / f v e t s . 2 0 1 8 . 0 0 2 9 9 . 7. Yun J, Ollila A, Valros A, et al. Behavioural alterations in piglets after surgical castration: e ects of analgesia and anaesthesia. Res Vet Sci. 2019. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . r v s c . 2 0 1 9 . 0 5 . 0 0 9 . 8. Robles I, Luna SPL, Trindade PHE, et al. Validation of the Unesp-Botucatu pig composite acute pain scale (UPAPS) in piglets undergoing castration. PLoS ONE. 2023. h t t p s : / / d o i . o r g / 1 0 . 1 3 7 1 / j o u r n a l . p o n e . 0 2 8 4 2 1 8 . 9. Hay M, Vulin A, Génin S, et al. Assessment of pain induced by castration in

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o i . o r g / 1 0 . 1 3 7 1 / j o u r n a l . p o n e . 0 2 8 4 2 1 8 . 9. Hay M, Vulin A, Génin S, et al. Assessment of pain induced by castration in piglets: behavioral and physiological responses over the subsequent 5 days. Appl Anim Behav Sci. 2003. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / S 0 1 6 8 - 1 5 9 1 ( 0 3 ) 0 0 0 5 9 - 5 . 10. Coutant M, Malmkvist J, Tallet C, et al. Administration of procaine-based local anaesthetic prior to surgical castration in uences post-operative behaviours of piglets. Appl Anim Behav Sci. 2022. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . a p p l a n i m . 2 0 2 2 . 1 0 5 8 1 3 . 11. Hansson M, Lundeheim N, Nyman G, et al. E ect of local anaesthesia and/ or analgesia on pain responses induced by piglet castration. Acta Vet Scand. 2011. h t t p s : / / d o i . o r g / 1 0 . 1 1 8 6 / 1 7 5 1 - 0 1 4 7 - 5 3 - 3 4 . 12. Williams MD, Lascelles BDX. Early neonatal Pain A review of clinical and experimental implications on painful conditions later in life. Front Pediatr. 2020. h t t p s : / / d o i . o r g / 1 0 . 3 3 8 9 / f p e d . 2 0 2 0 . 0 0 0 3 0 . 13. Adcock SJ. Early life painful procedures: Long-Term consequences and impli - cations for farm animal welfare. Front Anim Sci. 2021. h t t p s : / / d o i . o r g / 1 0 . 3 3 8 9 / f a n i m . 2 0 2 1 . 7 5 9 5 2 2 . 14. Briyne ND, Berg C, Blaha T, et al. Pig castration: will the EU manage to ban pig castration by 2018? Porcine Health Manag. 2016. h t t p s : / / d o i . o r g / 1 0 . 1 1 8 6 / s 4 0 8 1 3 - 0 1 6 - 0 0 4 6 - x . 15. Heinonen M, Kastraatioselvitys. 2021. h t t p s : / / v a l t i o n e u v o s t o . / d o c u m e n t s / 1 4 1 0 8 3 7 / 1 8 5 8 0 2 7 / S e l v i t y s _ S i k o j e n _ k a s t r a a t i o _ 2 0 2 1 . p d f % 2 0 / f a d e c 6 f 1

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/ d o c u m e n t s / 1 4 1 0 8 3 7 / 1 8 5 8 0 2 7 / S e l v i t y s _ S i k o j e n _ k a s t r a a t i o _ 2 0 2 1 . p d f % 2 0 / f a d e c 6 f 1 - c 4 a 2 - 5 8 6 b - 1 4 4 9 - 8 f b 5 7 8 c 6 2 4 7 b / S e l v i t y s _ S i k o j e n _ k a s t r a a t i o _ 2 0 2 1 . p d f ? t = 1 6 4 3 8 8 6 5 7 8 6 1 3 . Accessed 6 2024. 16. Finlex 693. /2023. Laki eläinten hyvinvoinnista (Legislation in Finnish). 2023. h t t p s : / / n l e x . / / l a k i / a l k u p / 2 0 2 3 / 2 0 2 3 0 6 9 3 . Accessed 6 2024. 17. Abendschön N, Senf S, De ner P, et al. Local anesthesia in piglets undergo - ing Castration A comparative study to investigate the analgesic e ects of four local anesthetics based on defensive behavior and side e ects. Animals. 2020. h t t p s : / / d o i . o r g / 1 0 . 3 3 9 0 / a n i 1 0 1 0 1 7 5 2 . 18. Söbbeler FJ, Wendt S, Briese A, et al. Comparative study of Pain-Related responses of male piglets up to seven days of age to the application of di er - ent local anaesthetics and subsequent castration. Animals. 2022. h t t p s : / / d o i . o r g / 1 0 . 3 3 9 0 / a n i 1 2 2 0 2 8 3 3 . 19. Coutant M, Malmkvist J, Foldager L, et al. Relationship among indicators of pain and stress in response to piglet surgical castration: an exploratory analysis. J Vet Behav. 2023. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . j v e b . 2 0 2 3 . 0 7 . 0 0 1 .

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Page 14 of 14 20. Courboulay V, Hemonic A, Prunier A. Evaluation des di érentes méthodes de prise en charge de la douleur lors de la castration. 2018. h t t p s : / / w w w . j o u r n e e s - r e c h e r c h e - p o r c i n e . c o m / t e x t e / 2 0 1 8 / b i e n e t r e / b 0 5 . p d f . Accessed 10 2024. 21. Weary DM, Braithwaite LA, Fraser D. Vocal response to pain in piglets. Appl Anim Behav Sci. 1998. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / S 0 1 6 8 - 1 5 9 1 ( 9 7 ) 0 0 0 9 2 - 0 . 22. Taylor AA, Weary DM. Vocal responses of piglets to castration: identifying procedural sources of pain. Appl Anim Behav Sci. 2000. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / S 0 1 6 8 - 1 5 9 1 ( 0 0 ) 0 0 1 4 3 - X . 23. McCa erty DJ. The value of infrared thermography for research on mammals: previous applications and future directions. Mamm Rev. 2007. h t t p s : / / d o i . o r g / 1 0 . 1 1 1 1 / j . 1 3 6 5 - 2 9 0 7 . 2 0 0 7 . 0 0 1 1 1 . x . 24. Soerensen DD, Pedersen LJ. Infrared skin temperature measurements for monitoring health in pigs: A review. Acta Vet Scand. 2015. h t t p s : / / d o i . o r g / 1 0 . 1 1 8 6 / s 1 3 0 2 8 - 0 1 5 - 0 0 9 4 - 2 . 25. Bonastre C, Mitjana O, Tejedor MT, et al. Acute physiological responses to castration-related pain in piglets: the e ect of two local anesthetics with or without meloxicam. Animal. 2016. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 7 / S 1 7 5 1 7 3 1 1 1 6 0 0 0 5 8 6 . 26. Koo TK, Li MY. A guideline of selecting and reporting intraclass correlation coe cients for reliability research. J Chiropr Med. 2016. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . j c m . 2 0 1 6 . 0 2 . 0 1 2 . 27. Saller AM, Werner J, Reiser J, et al. Local anesthesia in piglets undergoing castration A comparative study to

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j . j c m . 2 0 1 6 . 0 2 . 0 1 2 . 27. Saller AM, Werner J, Reiser J, et al. Local anesthesia in piglets undergoing castration A comparative study to investigate the analgesic e ects of four local anesthetics on the basis of acute physiological responses and limb movements. PLoS ONE. 2020. h t t p s : / / d o i . o r g / 1 0 . 1 3 7 1 / j o u r n a l . p o n e . 0 2 3 6 7 4 2 . 28. Miller R, Grott A, Patzkéwitsch D, et al. Behavior of piglets in an observation arena before and after surgical castration with local anesthesia. Animals. 2023. h t t p s : / / d o i . o r g / 1 0 . 3 3 9 0 / a n i 1 3 0 3 0 5 2 9 . 29. Leidig MS, Hertrampf B, Failing K, et al. Pain and discomfort in male piglets during surgical castration with and without local anaesthesia as determined by vocalisation and defence behaviour. Appl Anim Behav Sci. 2009. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . a p p l a n i m . 2 0 0 8 . 1 0 . 0 0 4 . 30. Lou M, Ventura B, Deen J, et al. Surgical castration changes struggle behavior and vocalizations in male piglets. J Appl Anim Welf Sci. 2022. h t t p s : / / d o i . o r g / 1 0 . 1 0 8 0 / 1 0 8 8 8 7 0 5 . 2 0 2 1 . 1 9 1 6 9 3 8 . 31. Puppe B, Schön PC, Tuchscherer A, et al. Castration-induced vocalisation in domestic piglets, Sus scrofa: complex and speci c alterations of the vocal quality. Appl Anim Behav Sci. 2005. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . a p p l a n i m . 2 0 0 5 . 0 5 . 0 0 1 . 32. Marx G, Horn T, Thielebein J, et al. Analysis of pain-related vocalization in young pigs. J Sound Vib. 2003. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / S 0 0 2 2 - 4 6 0 X ( 0 3 ) 0 0 5 9 4 - 7 . 33. Guidance on Risk Assessment for Animal Welfare. EFSA Journal. 2021. h t t p s : / / d o i . o r g / 1 0 . 2 9 0 3 / j . e f s a

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) 0 0 5 9 4 - 7 . 33. Guidance on Risk Assessment for Animal Welfare. EFSA Journal. 2021. h t t p s : / / d o i . o r g / 1 0 . 2 9 0 3 / j . e f s a . 2 0 1 2 . 2 5 1 3 . Accessed 10 2024. 34. Werner J, Saller AM, Reiser J, et al. Evaluation of two injection techniques in combination with the local anesthetics Lidocaine and mepivacaine for piglets undergoing surgical castration. Animals. 2022. h t t p s : / / d o i . o r g / 1 0 . 3 3 9 0 / a n i 1 2 0 8 1 0 2 8 . Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional a liations.