Assessment of acute pain experienced by piglets from ear tagging, ear notching and intraperitoneal injectable transponders

Combined Injection for Control of Iron-Deficiency Anemia and Coccidiosis in Piglets Decreases Stress at Management Time

The aim of the present study was to assess the short-term behavioral and physiological responses of piglets to different treatment protocols for the control of iron-deficiency anemia (IDA) and cystoisosporosis. Piglets were treated with either (1) an injection of iron combined with an oral application of toltrazuril (TLZ) by drenching or (2) a combination injection of TZL + gleptoferron; the behavior of the piglets was then evaluated. For this study, 288 piglets were divided into three experimental groups: 96 piglets were kept untreated (control group); 96 piglets received an oral administration of a generic TZL-based anticoccidial agent (20 mg/kg BW) along with intramuscular administration of iron dextran (200 mg/mL; 1 mL/piglet) at the same handling (oral + parenteral group, O + P); and 96 piglets received an intramuscular application of the combination product (parenteral group, P). For each treated piglet, the total handling time, flight reaction, and the intensity and frequency of vocalizations were determined using the methodology described by Scollo et al. (2020). Piglets in the O + P group were found to emit more screams during treatment administration than animals in the P group (21.05% vs. 8.42% of animals; p < 0.05). Piglets in the O + P group reacted worse to manipulation and oral administration because a higher percentage of animals continued to fidget even after handling (32.63% vs. 12.63%; p < 0.05). Differences in growth performance between the groups were not observed in our study (p > 0.05). In conclusion, the administration of a combination product reduced stress during administration, as indicated by reduced vocalizations and reactions to manipulation.

Pain Assessment in Goat Kids: Focus on Disbudding

Farm animals are routinely subjected to painful husbandry procedures for various purposes. Goat kids are disbudded to improve goat welfare and to ensure safety of other livestock, farm personnel, attending veterinarians and for various other production and managemental procedures. Disbudding is commonly performed on dairy goat farms, in kids under 3 weeks of age. Many scientific studies reported physiological and behavioural changes indicating pain and distress following disbudding, and this can be a significant cause of welfare compromise in goat kids. Recognition and measurement of pain is important to treat and/or manage pain and distress following painful procedures. This review focuses on pain assessment in goat kids following disbudding, using both physiological and behavioural measures. As only a limited information is available on the topic of interest, relevant studies in other young farm animals have also been discussed to compare the status quo in goat kids.

An attentional residual feature fusion mechanism for sheep face recognition

In the era of globalization and digitization of livestock markets, sheep are considered an essential source of food production worldwide. However, sheep behavior monitoring, disease prevention, and precise management pose urgent challenges in the development of smart ranches. To address these problems, individual identification of sheep has become an increasingly viable solution. Despite the benefits of traditional sheep individual identification methods, such as accurate tracking and record-keeping, they are labor-intensive and inefficient. Popular convolutional neural networks (CNNs) are unable to extract features for specific problems, further complicating the issue. To overcome these limitations, an Attention Residual Module (ARM) is proposed to aggregate the feature mapping between different layers of the CNN. This approach enables the general model of the CNN to be more adaptable to task-specific feature extraction. Additionally, a targeted sheep face recognition dataset containing 4490 images of 38 individual sheep has been constructed. Furthermore, the experimental data was expanded using image enhancement techniques such as rotation and panning. The results of the experiments indicate that the accuracy of the VGG16, GoogLeNet, and ResNet50 networks with the ARM improved by 10.2%, 6.65%, and 4.38%, respectively, compared to these recognition networks without the ARM. Therefore, the proposed method for specific sheep face recognition tasks has been proven effective.

Identifying areas of animal welfare concern in different production stages in Danish pig herds using the Danish Animal Welfare Index (DAWIN)

Animal welfare is of increasing public interest, and the pig industry in particular is subject to much attention. The aim of this study was to identify and compare areas of animal welfare concern for commercial pigs in four different production stages: (1) gestating sows and gilts; (2) lactating sows; (3) piglets; and (4) weaner-to-finisher pigs. One welfare assessment protocol was developed for each stage, comprising of between 20 and 29 animal welfare measures including resource-, management- and animal-based ones. Twenty-one Danish farms were visited once between January 2015 and February 2016 in a cross-sectional design. Experts (n = 26; advisors, scientists and animal welfare controllers) assessed the severity of the outcome measures. This was combined with the on-farm prevalence of each measure and the outcome was used to calculate areas of concern, defined as measures where the median of all farms fell below the value defined as 'acceptable welfare.' Between five and seven areas of concern were identified for each production stage. With the exception of carpal lesions in piglets, all areas of concern were resource- and management-based and mainly related to housing, with inadequate available space and the floor type in the resting area being overall concerns across all production stages. This means that animal-based measures were largely unaffected by perceived deficits in resource-based measures. Great variation existed for the majority of measures identified as areas of concern, demonstrating that achieving a high welfare score is possible in the Danish system.

SheepFaceNet: A Speed-Accuracy Balanced Model for Sheep Face Recognition

The recognition of sheep faces based on computer vision has improved the efficiency and effectiveness of individual sheep identification, providing technical support for the development of smart farming. However, current recognition models have problems such as large parameter sizes, slow recognition speed, and difficult deployment. Therefore, this paper proposes an efficient and fast basic module called Eblock and uses it to build a lightweight sheep face recognition model called SheepFaceNet, which achieves the best balance between speed and accuracy. SheepFaceNet includes two modules: SheepFaceNetDet for detection and SheepFaceNetRec for recognition. SheepFaceNetDet uses Eblock to construct the backbone network to enhance feature extraction capability and efficiency, designs a bidirectional FPN layer (BiFPN) to enhance geometric location ability, and optimizes the network structure, which affects inference speed, to achieve fast and accurate sheep face detection. SheepFaceNetRec uses Eblock to construct the feature extraction network, uses ECA channel attention to improve the effectiveness of feature extraction, and uses multi-scale feature fusion to achieve fast and accurate sheep face recognition. On our self-built sheep face dataset, SheepFaceNet recognized 387 sheep face images per second with an accuracy rate of 97.75%, achieving an advanced balance between speed and accuracy. This research is expected to further promote the application of deep-learning-based sheep face recognition methods in production.

Using Pruning-Based YOLO v3 Deep Learning Algorithm for Accurate Detection of Sheep Face

Simple Summary

The identification of individual animals is an important step in the history of precision breeding. It has a great role in both breeding and genetic management. The continuous development of computer vision and deep learning technologies provides new possibilities for the establishment of accurate breeding models. This helps to achieve high productivity and precise management in precision agriculture. Here, we demonstrate that sheep faces can be recognized based on the YOLOv3 target detection network. A model compression method based on K-means clustering algorithm and combined with channel pruning and layer pruning is applied to individual sheep identification. In addition, the results show that the proposed non-contact sheep face recognition method can identify sheep quickly and accurately.

Abstract

Accurate identification of sheep is important for achieving precise animal management and welfare farming in large farms. In this study, a sheep face detection method based on YOLOv3 model pruning is proposed, abbreviated as YOLOv3-P in the text. The method is used to identify sheep in pastures, reduce stress and achieve welfare farming. Specifically, in this study, we chose to collect Sunit sheep face images from a certain pasture in Xilin Gol League Sunit Right Banner, Inner Mongolia, and used YOLOv3, YOLOv4, Faster R-CNN, SSD and other classical target recognition algorithms to train and compare the recognition results, respectively. Ultimately, the choice was made to optimize YOLOv3. The mAP was increased from 95.3% to 96.4% by clustering the anchor frames in YOLOv3 using the sheep face dataset. The mAP of the compressed model was also increased from 96.4% to 97.2%. The model size was also reduced to 1/4 times the size of the original model. In addition, we restructured the original dataset and performed a 10-fold cross-validation experiment with a value of 96.84% for mAP. The results show that clustering the anchor boxes and compressing the model using this dataset is an effective method for identifying sheep. The method is characterized by low memory requirement, high-recognition accuracy and fast recognition speed, which can accurately identify sheep and has important applications in precision animal management and welfare farming.

Impact of Routine Management Procedures on the Welfare of Suckling Piglets

Piglets often undergo several painful treatments during the initial days of their lives. In this review, we investigate the acute (i.e., immediate), short-, and long-term implications of piglet processing on behavioral, physiological, clinical, and performance parameters, and how welfare impairments depend on performance instead of sham procedure, alternative techniques, or the age of the piglets. Welfare indicators that have been used to determine the least distressing procedures and knowledge gaps with regard to the procedures are identified and discussed. Tail docking and especially piglet castration have been the most researched topics, whereas marking for identification has been rarely addressed. Few or no studies have investigated the effects of teeth resection and tail docking on piglets of different age groups. Additionally, results are often found to be inconsistent, highlighting the need for additional research to determine the optimal age for processing. Studies comparing different processing techniques have produced contradictory results, but ear notching, teeth clipping, hot cautery tail docking, and tearing during castration have been determined to result in increased pain. Generally, a shorter procedure duration can reduce stress, with operator training having a distinct impact on piglet welfare during processing. As such, these topics should be further investigated.

Influence of the application methods of iron/anticoccidial products on the behaviour and associated stress factors of suckling piglets

The aim of the present study was to evaluate the effect of different treatment protocols for the control of iron-deficiency anaemia and coccidiosis, one combination injection versus injection of iron and oral application of toltrazuril, on the general behaviour of piglets. Piglets were divided into three experimental treatment groups: 24 piglets were left untreated; (control group, C); 24 piglets received an oral administration of generic anticoccidial agent (20 mg/kg BW) plus intramuscular administration of iron dextran (200 mg/ml; 1 ml/piglet) in the same handling (oral + parenteral group, O+P) and 24 piglets received an intramuscular application of the combination product (parenteral group, P). As expected, the handling time was higher in the oral + parenteral group than in the parenteral group. Regarding the behaviour of piglets, the time spent suckling after treatment was variable in the control and oral + parenteral groups, while piglets from the parenteral group spent more time suckling, and hence, their time spent resting was decreased. A statistical trend of lower concentration of cortisol was observed in P compared to O+P after processing. Regarding productivity indices, the average daily gain of piglets during lactation and, subsequently, their weaning weight were higher in P compared to O+P, and similar to the control. In conclusion, administering a combination product injection decreases the time of administration compared to individual treatments.

Early Life Painful Procedures: Long-Term Consequences and Implications for Farm Animal Welfare

Farm animals routinely undergo painful husbandry procedures early in life, including disbudding and castration in calves and goat kids, tail docking and castration in piglets and lambs, and beak trimming in chicks. In rodents, inflammatory events soon after birth, when physiological systems are developing and sensitive to perturbation, can profoundly alter phenotypic outcomes later in life. This review summarizes the current state of research on long-term phenotypic consequences of neonatal painful procedures in rodents and farm animals, and discusses the implications for farm animal welfare. Rodents exposed to early life inflammation show a hypo-/hyper-responsive profile to pain-, fear-, and anxiety-inducing stimuli, manifesting as an initial attenuation in responses that transitions into hyperresponsivity with increasing age or cumulative stress. Neonatal inflammation also predisposes rodents to cognitive, social, and reproductive deficits, and there is some evidence that adverse effects may be passed to offspring. The outcomes of neonatal inflammation are modulated by injury etiology, age at the time of injury and time of testing, sex, pain management, and rearing environment. Equivalent research examining long-term phenotypic consequences of early life painful procedures in farm animals is greatly lacking, despite obvious implications for welfare and performance. Improved understanding of how these procedures shape phenotypes will inform efforts to mitigate negative outcomes through reduction, replacement, and refinement of current practices.

A systematic review of porcine models in translational pain research

Translating basic pain research from rodents to humans has proven to be a challenging task. Efforts have been made to develop preclinical large animal models of pain, such as the pig. However, no consistent overview and comparison of pig models of pain are currently available. Therefore, in this review, our primary aim was to identify the available pig models in pain research and compare these models in terms of intensity and duration. First, we systematically searched Proquest, Scopus and Web of Science and compared the duration for which the pigs were significantly sensitized as well as the intensity of mechanical sensitization. We searched models within the specific field of pain and adjacent fields in which pain induction or assessment is relevant, such as pig production. Second, we compared assessment methodologies in surrogate pain models in humans and pigs to identify areas of overlap and possible improvement. Based on the literature search, 23 types of porcine pain models were identified; 13 of which could be compared quantitatively. The induced sensitization lasted from hours to months and intensities ranged from insignificant to the maximum attainable. We also found a near to complete overlap of assessment methodologies between human and pig models within the area of peripheral neurophysiology, which allows for direct comparison of results obtained in the two species. In spite of this overlap, further development of pain assessment methodologies is still needed. We suggest that central nervous system electrophysiology, such as electroencephalography, electrocorticography or intracortical recordings, may pave the way for future objective pain assessment.

Pain Management in Farm Animals: Focus on Cattle, Sheep and Pigs

Pain causes behavioral, autonomic, and neuroendocrine changes and is a common cause of animal welfare compromise in farm animals. Current societal and ethical concerns demand better agricultural practices and improved welfare for food animals. These guidelines focus on cattle, sheep, and pigs, and present the implications of pain in terms of animal welfare and ethical perspectives, and its challenges and misconceptions. We provide an overview of pain management including assessment and treatment applied to the most common husbandry procedures, and recommendations to improve animal welfare in these species. A cost-benefit analysis of pain mitigation is discussed for food animals as well as the use of pain scoring systems for pain assessment in these species. Several recommendations are provided related to husbandry practices that could mitigate pain and improve farm animal welfare. This includes pain assessment as one of the indicators of animal welfare, the use of artificial intelligence for automated methods and research, and the need for better/appropriate legislation, regulations, and recommendations for pain relief during routine and husbandry procedures.

Analgesia for Sheep in Commercial Production: Where to Next?

Simple Summary

Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on industry to alleviate pain associated with husbandry practices, injury and illness. Although a number of analgesic solutions are now available for sheep, providing some amelioration of the acute pain responses, this review has highlighted a number of potential areas for further research.

Abstract

Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on livestock production industries to alleviate pain associated with husbandry practices, injury and illness. Over the past 15–20 years, there has been considerable research effort to understand and develop mitigation strategies for painful husbandry procedures in sheep, leading to the successful launch of analgesic approaches specific to sheep in a number of countries. However, even with multi-modal approaches to analgesia, using both local anaesthetic and non-steroidal anti-inflammatory drugs (NSAID), pain is not obliterated, and the challenge of pain mitigation and phasing out of painful husbandry practices remains. It is timely to review and reflect on progress to date in order to strategically focus on the most important challenges, and the avenues which offer the greatest potential to be incorporated into industry practice in a process of continuous improvement. A structured, systematic literature search was carried out, incorporating peer-reviewed scientific literature in the period 2000–2019. An enormous volume of research is underway, testament to the fact that we have not solved the pain and analgesia challenge for any species, including our own. This review has highlighted a number of potential areas for further research.

Suitability of Different Thermometers for Measuring Body Core and Skin Temperatures in Suckling Piglets

Simple Summary

After birth, piglets’ temperatures usually drop some degrees because of low ambient temperatures in the stable. Piglets have no ability to increase their body temperatures during their first days of life, which can cause health issues if piglets are not appropriately cared for. Monitoring temperatures can, therefore, contribute to reducing impaired wellbeing and unnecessary losses. The most common method for assessing core temperatures is measuring rectally with a digital thermometer. This, however, takes time and requires securing of the animal, which is stressful. Therefore, the aim of this study was to determine whether other thermometers or thermometric devices, such as an infrared camera, can deliver results similar to the digital thermometer. For the measurements in newborn piglets, infrared ear thermometers, infrared forehead thermometers, and infrared laser thermometers were used, as it was assumed that these would deliver results fast and cause little distress in piglets. The results were compared to rectally measured temperatures and it was found that the temperatures measured in-ear correspond to a great extent to rectal temperatures and show little variation between measurements, while the other used devices can only give a rough estimate of the actual core temperatures.

Abstract

Monitoring the temperature of piglets after birth is critical to ensure their well-being. Rectal temperature measurement is time-consuming, requires fixation of the animal and is stressful for piglets. This study aims to evaluate the effectiveness of infrared thermometry and thermography as compared to rectal temperatures. We investigated digital thermometers for rectal measurements, infrared ear thermometers, infrared forehead thermometers, infrared laser thermometers and an infrared camera during field trials with piglets aged 1–13 days. Temperatures differed between the left and right ear and ear base (p < 0.01), but not between temples. Three forehead and laser devices yielded different temperatures (p < 0.01). Temperatures assessed with a laser thermometer decreased with distance from the target (p < 0.01). The highest correlation observed was between the rectal and tympanic temperatures (r = 0.89; p < 0.01). For temperatures assessed with the camera, inner thigh and abdomen correlated most closely to core temperature (0.60 ≤ r ≤ 0.62; p < 0.01). Results indicate that infrared ear thermometry commonly used in humans is also suited for assessing temperature in piglets. The inner thigh and abdomen seem promising locations for estimating core temperature with an infrared camera, but this approach needs to be adapted to reduce time exposure and stress for the piglets to be used under practical conditions.

Welfare Benefits of Intradermal Vaccination of Piglets

Vaccination is reported as a stressful and painful event for animals. This study investigated whether needle-free intradermal vaccination improves the welfare of weaned pigs through the reduction of stress and pain biomarkers and improvement of behavioural parameters compared to traditional intramuscular injection with a needle. A total of 339 weaned piglets were allocated to 3 treatment groups: Intradermal Application of Liquids (IDAL) pigs, vaccinated against Porcine Circovirus type 2 (PCV2) by means of intradermal vaccination using a needle-free device Porcilis^® PCV ID; Intramuscular (IM) pigs vaccinated against PCV2 with Porcilis^® PCV intramuscularly with a needle; CONTROL pigs were managed identically but did not receive any vaccine injection. At the time of the injection, the reaction of IDAL piglets was similar to control piglets, whereas a greater percentage of piglets vaccinated intramuscularly displayed high-pitch vocalizations (7% CONTROL, 7% IDAL, 32% IM) and retreat attempts (3% CONTROL, 7% IDAL, 39% IM). The day after vaccination, IDAL piglets did not differ from the control piglets for any of the behavioural variables studied through scan samplings. IM piglets showed a lower frequency of social negative interactions (p = 0.001) and rope manipulation (p = 0.04) compared to the CONTROL group. Resting postures did not differ between treatments. At 28 h post-vaccination, IDAL piglets presented lower blood C-reactive protein levels (CONTROL = 20 μg/mL; IDAL = 39 μg/mL; IM = 83 μg/mL, p < 0.0001) and blood Haptoglobin (CONTROL = 1.8 mg/mL; IDAL = 1.9 mg/mL vs. IM = 3.1 mg/mL, p < 0.0001) compared to IM piglets. Salivary chromogranin A and alpha-amylase did not differ between treatment groups when measured 25 min post-vaccination. The method of vaccination did not affect the growth of the piglets or their rectal temperature. These results support that needle-free intradermal vaccination reduces vaccination-related pain in growing pigs.

Possibilities of establishing a smallholder pig identification and traceability system in Kenya

Consumers have a right to safer foods, and traceability is one approach to meeting their expectations. Kenya does not have an operational animal traceability system, and while a few initiatives have been piloted, these have only focused on the beef value chain. In this paper, we begin a discussion on traceability in the pig value chain, with an initial focus on smallholder systems of Western Kenya. First, a background to local pig production is given, and a description of animal identification and traceability options applicable to these systems is explained. Based on this, a “butcher-to-farm” traceability system, with health, production and food safety as objectives, is discussed. Requirements for establishing such a system (including actor incentives) are additionally discussed. The proposed approach can be piloted in the field and findings used to inform the design of a larger pilot and possibly pave way for implementation of a national traceability system, in line with the guidelines provided by the World Organization for Animal Health (OIE). Organized systems in the area (including commercial producer and trader groups) would offer a useful starting point.

Comparison of Vocalization Patterns in Piglets Which Were Crushed to Those Which Underwent Human Restraint

Though many studies focused on piglet crushing utilizing piglet vocalizations to test sow response, none have verified the properties of test vocalizations against actual crushing events. Ten sows were observed 48 h after parturition, and crushing events were recorded from all sows. When a crushing event occurred, a second piglet within the same litter was used to solicit a vocalization through manual restraint to compare restrained piglets' call properties to those of crushed piglets'. A total of 659 Restrained calls and 631 Crushed calls were collected. Variables were gathered at the loudest point in a call, and as an average across the entire call. Crushed piglets had a lower fundamental frequency (p < 0.01; Crushed: 523.57 ± 210.6 Hz; Restrained: 1214.86 ± 203.2 Hz) and narrower bandwidth (p < 0.01; Crushed: 4897.01 ± 587.3 Hz; Restrained: 6674.99 ± 574.0 Hz) when analyzed at the loudest portion of a call. Overall, piglets which were crushed had a lower mean peak frequency than those which were restrained (p = 0.01; 1497.08 ± 239.4 Hz and 2566.12 ± 235.0 Hz, respectively). Future research should focus on measuring sow reactivity to Crushed and Restrained piglets to continue to improve research practices.

Topical vapocoolant spray reduces nociceptive response to ear notching in neonatal piglets

OBJECTIVE

To evaluate the efficacy of a vapocoolant spray (VS) to provide local anaesthesia for piglets during ear notching.

STUDY DESIGN

Randomized study.

ANIMALS

Eleven 10 day old and forty 3-5 day old Large White piglets.

METHODS

Temperature validation studies using thermocouples and a temperature data logger were conducted on dead and live tissue to determine optimal spray distance and duration to reduce tissue temperature to below 10 °C. A behavioural trial was conducted to assess efficacy for ear notching. Piglets were randomly assigned to one of four treatment groups: positive control (POS; n = 10), VS (n = 10), lignocaine (LIG; n = 10) and negative control (NEG; n = 10). Spray was administered to the margin of each ear, from a distance of 10 cm, and for a duration of 2 seconds immediately prior to ear notching. Behavioural observation was used to assess movement and vocal response, with responses categorized as no response (0) and response (1).

RESULTS

Temperature and tissue validation studies indicated that a 2 second spray from 10 cm reduced tissue temperature to below 10 °C, and reduced response to stimulation of the skin with an 18 gauge needle (p < 0.001). There was a significant effect of treatment on response to ear notching (p < 0.001). The probability of a piglet to respond to ear notching was 98.7% for NEG piglets, compared with those treated with VS (5.3%), LIG (1.1%) and sham-notched piglets (0.9%).

CONCLUSIONS AND CLINICAL RELEVANCE

This study contributes new data on the pain of ear notching in piglets. The application of a topical VS prior to ear notching reduced the antinociceptive response of piglets to the procedure, similar to that of a local anaesthetic. Cryoanaesthesia presents a simple and effective option for reducing the pain response to this simple husbandry procedure.

The use of infrared thermography for welfare assessment during the application of ear tags to lambs

Abstract. The aim of this study was to determine the effect of metal-tipped, plastic-tipped, and electronic ear tags on the likelihood of infection using infrared thermography and to evaluate the effect on welfare by examining the behavioral responses of the lambs. Ninety lambs with an average age of 6 months were used in this study. Before the application of the ear tags, infrared images of the right and left ears of the lambs were taken with the thermal camera and the infrared temperatures were recorded. Measurements were repeated on days 1, 4, 10, and 30 after the ear tag application. The mean of infrared ear temperatures on days 0, 1, 4, 10, and 30 were found to be 14.60, 23.20, 23.77, 20.36, and 17.61 °C for the metal-tipped ear tag group; 15.69, 21.50, 20.42, 18.00, and 16.39 °C for the plastic-tipped ear tag group; and 15.17, 29.47, 27.49, 25.93, and 20.61 °C for the electronic ear tag group. The infrared temperatures on days 1, 4, and 10 in the control and experimental groups were significantly different from each other (P < 0.001). The plastic-tipped ear tags caused fewer problems and are preferred to the traditional ear tags with metal tips. The electronic ear tags caused more inflammatory reactions compared to metal- or plastic-tipped ear tags. The infrared thermography method may be used as a useful tool in the early detection of the inflammatory reactions and infections caused by the application of ear tags.

A Review of Pain Assessment in Pigs

There is a moral obligation to minimize pain in pigs used for human benefit. In livestock production, pigs experience pain caused by management procedures, e.g., castration and tail docking, injuries from fighting or poor housing conditions, “management diseases” like mastitis or streptococcal meningitis, and at parturition. Pigs used in biomedical research undergo procedures that are regarded as painful in humans, but do not receive similar levels of analgesia, and pet pigs also experience potentially painful conditions. In all contexts, accurate pain assessment is a prerequisite in (a) the estimation of the welfare consequences of noxious interventions and (b) the development of more effective pain mitigation strategies. This narrative review identifies the sources of pain in pigs, discusses the various assessment measures currently available, and proposes directions for future investigation.

Comparison of Intramuscular or Subcutaneous Injections vs. Castration in Pigs-Impacts on Behavior and Welfare

Simple Summary

Physical castration (PC) of piglets is a painful and stressful procedure and alternatives are being sought to improve animal well-being, such as immunological castration (IC). However, IC requires injections which may also cause pain and stress during handling. In this study, piglets and finishing pigs were placed in the following treatment groups: no handling or treatment (NO), sham-handling (SHAM), intramuscular injection (IM), subcutaneous injection (SQ), or PC on piglets only. Behavior was monitored for 1 h prior and 1 h post treatment in each age group. Social behavior and feeding behavior, and signs of pain were recorded. Physical castration caused measurable pain-like behaviors and general behavioral dysregulation at a much higher level than changes associated with handling associated with IM or SQ injections. Overall, injections did not cause a change in weaning pig behaviors. Finishing pigs given SQ injections showed a lower number of feeding behaviors post treatment but other changes were not observed in the other treatment groups.

Abstract

Physical castration (PC) is painful and stressful for nursing piglets. One alternative to PC is immunological castration (IC), but the pain and stress of handling associated with injections have not been assessed. The objectives of this study were to measure the pain and distress of subcutaneous (SQ) and intramuscular (IM) injections compared to PC in piglets, and to compare SQ or IM injections in finishing pigs. After farrowing, 3 to 5 d old male piglets were randomly assigned to (control) no handling treatment (NO), sham-handling (SHAM), IM, SQ, or PC. Finishing pigs were assigned to NO, SHAM, IM, or SQ. Behavior was monitored for 1 h prior and 1 h post treatment in each age group. Social, feeding behaviors, and signs of pain were recorded. Finishing pigs treated with SQ injections had higher feeding behaviors pre-treatment than they did post-treatment. Overall, physical castrations caused measurable pain-like behaviors and general behavioral dysregulation at a much higher level than the other treatment groups. SQ and IM injections did not cause either significant behavioral or physiological alterations in piglets. SQ injections caused a decrease in finishing pig feed behaviors post treatment (p = 0.02) and SHAM treated finishing pigs spent significantly more time lying than the other treatment groups. In general IM and SQ injections did not cause any other significant changes in behavior or physiology.

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

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.

[Impact of the simultaneous implementation of husbandry procedures on suckling piglets]

OBJECTIVE

In addition to castration, further husbandry procedures are performed in piglets during the first week of life without anaesthesia. The aim of the present study was to investigate the pain-induced stress of the husbandry procedures castration, tail docking and ear tagging performed in piglets in combination in comparison with castration or handling alone. Furthermore, the effect of the presurgical administration of the nonsteroidal anti-inflammatory drug meloxicam alone or in combination with iron was investigated.

MATERIAL AND METHODS

The levels of pain and stress were evaluated based on cortisol and catecholamine concentrations, as well as from behavioural observations. The compatibility and the effect of combined drug administration were assessed, and the daily weight gain and blood iron level were determined.

RESULTS

When comparing the application procedures, the slight changes observed at the iron injection site were reduced by 40% when using the mixture. After performing all three husbandry procedures without administration of meloxicam (KSO group), higher cortisol concentrations were induced for up to 4 hours compared to the handling (H) and castration (K) groups. In piglets receiving meloxicam or the mixture of iron and meloxicam presurgically, the cortisol concentration was significantly reduced for 0.5 hours after castration and up to 4 hours following all three husbandry procedures when compared to piglets without medication (groups K and KSO, respectively).

CONCLUSION AND CLINICAL RELEVANCE

The results indicate that the blood cortisol concentration significantly rose due to multiple pain and distress when combining castration, ear tagging and tail docking. Application of meloxicam before performing these husbandry procedures reduced pain equally to its application before castration alone. The application of a mixed preparation of iron and meloxicam did not affect the efficacy of either drug and improved the local tolerance of the iron injection.

Using the mouse grimace scale to assess pain associated with routine ear notching and the effect of analgesia in laboratory mice

Social housing is recommended where possible for laboratory mice. In order to achieve this, mice must be individually identifiable. Although, various methods are available, permanent identification is often required, such as ear notching. This method is likely to be painful and to date there is limited literature on pain assessment and alleviation for this routine husbandry practice. Here we aimed to determine if the mouse grimace scale (MGS) could be used to assess pain in C57BL/6 mice following routine ear notching. Langford et al. found that very acute noxious stimuli (i.e. < 10 min in duration) did not produce a change in MGS score in comparison to baseline. Here, no significant difference was found between MGS scores at baseline and immediately post ear notching, potentially indicating that the pain associated with ear notching is either too acute to assess using the MGS tool or the practice is not painful. Studies in other species indicate that ear notching is painful, therefore, unless we can confidently conclude that the process of ear notching is not painful, we should err on the side of caution and assume it is painful due to the large number of mice ear-notched and potential welfare consequences. Alternative methods of assessing pain following this routine practice should be used in order to assess both the potential pain in mice, and the effectiveness of analgesics or local anaesthetics to relieve any associated pain.

Postnatal piglet husbandry practices and well-being: the effects of alternative techniques delivered in combination

After birth, piglets undergo procedures likely to cause stress. The aim of this study was to evaluate stress responses evoked by 2 combinations (More Stressful [all a] or Less Stressful [all a] or More Stressful [all b]) of alternative methods for performing the following processing procedures: 1) teeth resection (TR) – [a] clip vs. [b] grind; 2) identification (ID) – [a] ear tag vs. [b] ear notch; 3)iron administration (FE) – [a] inject vs. [b] oral; 4) castration (CA) – [a] cords cut vs. [b] cords torn; 5) taildocking (TD) – [a] cold clip vs. [b] hot clip [corrected]. Ten litters of eight 2- and 3-d-old piglets were assigned to each procedure. Within each litter 1 male and 1 female piglet was assigned to 1 of 4 possible procedures: the 2 combinations, sham procedures, and sham procedures plus blood sampling. Blood was collected before processing and at 45 min, 4 h, 48 h, 1 wk, and 2 wk afterward and assayed for cortisol and β-endorphin concentrations. Procedures were videotaped and analyzed to evaluate the time taken to perform the procedure and the number of squeals, grunts, and escape attempts. Vocalizations were analyzed to determine mean and peak frequencies and duration. Piglets were weighed before the procedure and at 24 h, 48 h, 1 wk, and 2 wk afterward. Identification, tail docking, and castration lesions were scored on a 0 to 5 scale at 24 h, 1 wk, and 2 wk postprocedure. Both combinations of methods took longer to carry out than sham procedures and resulted in more squeals, grunts, and escape attempts during the procedures and higher peak frequencies of vocalizations compared with the control treatments (P < 0.05). Cortisol concentrations 45 min after processing were also higher in the 2 combination treatments than in the sham treatments (P < 0.05). Comparing between procedure treatments, the More Stressful combination of methods took longer to carry out, resulted in higher β-endorphin concentrations at 1 wk, had higher peak frequency of vocalizations, and increased ear (P < 0.05) and tail wound (P < 0.1) lesion scores at 1 wk than the Less Stressful combination. Growth during d 2 to 7 postprocedure was lower in More Stressful piglets than control piglets (P < 0.05) but by 2 wk, growth was unaffected. Using measures of behavior, physiology, and productivity, the More Stressful combination of procedures decreased welfare relative to the Less Stressful combination; however, both combinations decreased welfare relative to controls. The time taken to carry out the procedure would appear to be an important factor in the strength of the stress response.