Serum concentrations of brain-derived neurotrophic factor as a potential biomarker of swine welfare.

Objective: Describe concentrations of brain-derived neurotrophic factor (BDNF) detectable in piglet sera before and after road transport, and evaluate the correlation of serum BDNF with other physiological parameters used to assess swine welfare. Animals: Commercial crosses of piglets that underwent weaning and transport at approximately 3 wk of age. Procedure: Sixteen piglets were randomly selected from a larger study for complete blood counts, serum biochemistry testing, cortisol assays, and BDNF assays. Samples were collected 1 d before transport and immediately after transport (> 30 h) under commercial conditions. We assessed the change in serum BDNF concentration; and the correlations between serum BDNF and serum cortisol, neutrophil to lymphocyte ratios (N:L), glucose, and hematological indicators of muscle fatigue. Results: Serum BDNF concentrations increased after transport (P < 0.05) and changed inversely compared to cortisol and N:L. Consistent correlations between BDNF and other physiological parameters were not observed. High inter-pig variation in serum BDNF was present at both sample times. Conclusions: Serum BDNF may be used as an additional indicator of swine welfare. Further research characterizing piglet BDNF concentrations in response to conditions promoting positive or negative affective states would be valuable. Clinical relevance: This communication discusses common hematological parameters used to quantify changes in pig welfare and introduces BDNF, which is a parameter of interest in human cognitive functioning research that may be useful for evaluating the effect of exposure to beneficial or aversive stimuli in animals. The implications of variation in sample collection, handling, and storage procedures for BDNF detection are highlighted.

Concentrations sériques du facteur neurotrophique dérivé du cerveau en tant que biomarqueur potentiel du bien-être des porcs. Objectif: Décrire les concentrations de facteur neurotrophique dérivé du cerveau (BDNF) détectables dans les sérums de porcelets avant et après le transport routier, et évaluer la corrélation du BDNF sérique avec d'autres paramètres physiologiques utilisés pour évaluer le bien-être des porcs. Animaux: Croisements commerciaux de porcelets qui ont été sevrés et transportés à l'âge d'environ 3 semaines. Procédure: Seize porcelets ont été sélectionnés au hasard dans une étude plus vaste pour une numération globulaire complète, des tests de biochimie sérique, des dosages de cortisol et des dosages de BDNF. Les échantillons ont été prélevés 1 jour avant le transport et immédiatement après le transport (> 30 h) dans des conditions commerciales. Nous avons évalué la variation de la concentration sérique de BDNF; et les corrélations entre le BDNF sérique et le cortisol sérique, les rapports neutrophiles/lymphocytes (N:L), le glucose et les indicateurs hématologiques de la fatigue musculaire. Résultats: Les concentrations sériques de BDNF ont augmenté après le transport (P < 0,05) et ont changé inversement par rapport au cortisol et à N:L. Des corrélations cohérentes entre le BDNF et d'autres paramètres physiologiques n'ont pas été observées. Une forte variation inter-porcs du BDNF sérique était présente aux deux moments d'échantillonnage. Conclusions: Le BDNF sérique peut être utilisé comme indicateur supplémentaire du bien-être des porcs. Des recherches supplémentaires caractérisant les concentrations de BDNF chez les porcelets en réponse à des conditions favorisant des états affectifs positifs ou négatifs seraient utiles. Pertinence clinique: Cette communication traite des paramètres hématologiques courants utilisés pour quantifier les changements dans le bien-être des porcs et présente le BDNF, qui est un paramètre d'intérêt dans la recherche sur le fonctionnement cognitif humain qui peut être utile pour évaluer l'effet de l'exposition à des stimuli bénéfiques ou aversifs chez les animaux. Les implications pour la détection par le BDNF des variations dans les procédures de collecte, de manipulation et de stockage des échantillons sont mises en évidence.(Traduit par Dr Serge Messier).

The perception of humans by piglets: recognition of familiar handlers and generalisation to unfamiliar humans.

Humans are part of the environment of domestic animals and interact with them daily, providing a good basis for the study of interspecific relationships. Abilities to discriminate and recognise individuals form the basis of these relationships, and they are crucial skills for domestic animals, since individual humans can differ in their behaviour towards them. At the same time, with experience, animals may develop a general memory of humans and generalise their behaviour towards strangers. This study aimed to determine the extent to which weaned piglets can discriminate familiar humans and generalise their past experience when faced with unfamiliar humans. Forty-eight groups of three piglets were submitted to two consecutive 5-day conditioning periods of the same or opposite valence (positive and/or negative) given by one (A) or two (A then B) handlers. The reactivity of piglets to a motionless human and to an approaching human was measured before and after conditioning periods with unfamiliar and familiar handlers. Thereafter, piglets which received treatments with the two handlers A and B were subjected to a choice test between both handlers. The reactivity to an approaching human appeared to better reflect the past experience with familiar handlers since piglets clearly recognised them and adapted their behaviour accordingly. In contrast, reaction of piglets to a motionless human reflected their natural propensity to seek interaction, even after a negative experience. Although piglets were able to extend their memory of humans to an unfamiliar human through generalisation, many factors seemed to interact in this process, especially the complexity of the previous experience (inconsistent vs consistent) and the context in which piglets met the unfamiliar human (motionless vs approaching). We conclude that discrimination and generalisation processes of reactivity to humans do not simply rely on past interactions, but also depend on the context according to the degree of similitude with their past experience.

A computer vision image differential approach for automatic detection of aggressive behavior in pigs using deep learning.

Pig aggression is a major problem facing the industry as it negatively affects both the welfare and the productivity of group-housed pigs. This study aimed to use a supervised deep learning (DL) approach based on a convolutional neural network (CNN) and image differential to automatically detect aggressive behaviors in pairs of pigs. Different pairs of unfamiliar piglets (N = 32) were placed into one of the two observation pens for 3 d, where they were video recorded each day for 1 h following mixing, resulting in 16 h of video recordings of which 1.25 h were selected for modeling. Four different approaches based on the number of frames skipped (1, 5, or 10 for Diff1, Diff5, and Diff10, respectively) and the amalgamation of multiple image differences into one (blended) were used to create four different datasets. Two CNN models were tested, with architectures based on the Visual Geometry Group (VGG) VGG-16 model architecture, consisting of convolutional layers, max-pooling layers, dense layers, and dropout layers. While both models had similar architectures, the second CNN model included stacked convolutional layers. Nine different sigmoid activation function thresholds between 0.1 and 1.0 were evaluated and a 0.5 threshold was selected to be used for testing. The stacked CNN model correctly predicted aggressive behaviors with the highest testing accuracy (0.79), precision (0.81), recall (0.77), and area under the curve (0.86) values. When analyzing the model recall for behavior subtypes prediction, mounting and mobile non-aggressive behaviors were the hardest to classify (recall = 0.63 and 0.75), while head biting, immobile, and parallel pressing were easy to classify (recall = 0.95, 0.94, and 0.91). Runtimes were also analyzed with the blended dataset, taking four times less time to train and validate than the Diff1, Diff5, and Diff10 datasets. Preprocessing time was reduced by up to 2.3 times in the blended dataset compared to the other datasets and, when combined with testing runtimes, it satisfied the requirements for real-time systems capable of detecting aggressive behavior in pairs of pigs. Overall, these results show that using a CNN and image differential-based deep learning approach can be an effective and computationally efficient technique to automatically detect aggressive behaviors in pigs.

Aggressive behavior in pigs is a major concern for the swine industry that negatively affects animal welfare. This study aims to provide an efficient automatic solution based on computer vision and supervised deep learning models able to distinguish between aggressive and non-aggressive behavior of pigs using video recordings.

The protective role of wallowing against heat stress in gestating and lactating sows housed outdoors.

The objective of this study was to describe the physiological response of gestating and lactating sows to naturally-occurring environmental conditions, and to identify factors that may contribute to or prevent heat stress, while being kept outdoors in Québec, Canada during the summer. Six groups of 4 Yorkshire-Landrace sows lived in outdoor pens equipped with a wallow, shade structure, farrowing huts and access to a pasture from July to September 2018. Between week 15 of gestation and week 3 of lactation (inclusive), we recorded the location of each sow 5 days/week during 5 daily 15-min observation periods, and additionally measured the sow's respiratory rate and mud cover at the end of each observation period. Simultaneously, we collected sow body temperature data with vaginal temperature loggers 24 h/d on week 15 of gestation and week 2 of lactation, and monitored environmental conditions with temperature and humidity loggers to calculate the temperature humidity index (THI). Sows had significantly higher and more variable body temperatures during lactation compared to gestation (P ≤ 0.0001), and when THI was analysed as a continuous variable, it was positively associated with sow body temperature during the night in lactation. During gestation, neither respiratory rate nor body temperature were associated with high or low levels of THI (P = 0.15 and 0.79, respectively) or mud cover (P = 0.29 and 0.94, respectively). However, in lactation, respiratory rate was higher when, simultaneously, THI exceeded 74 and mud cover was low (P = 0.006), while a THI higher than 74 and a low mud cover had independent effects on body temperature (P = 0.012 and 0.004, respectively). In lactation, sows that spent an entire observation period in the farrowing hut also had a higher respiratory rate than sows that left the hut at least once (P = 0.009). In summary, lactating sows were more likely to show increases in respiratory rate and body temperature in warmer conditions than gestating sows, and our findings also suggest that time in the farrowing hut may be a risk factor for heat stress. However, mud cover may limit these physiological consequences when sows have access to a wallow.

Impact of a Dietary Citrus Extract on the Behavior and Production of Lactating Dairy Cows Following Regrouping: A Preliminary Study.

Exposure of lab animals, humans, and pigs to olfactory sensory feed additives may reduce response to stress and anxiety. The objective of this preliminary study was to determine if feeding a citrus-based olfactory sensory functional feed extract (derived from Citrus sinensis) reduces the negative impact of regrouping of lactating dairy cows. Thirty-two (parity = 2.0 ± 1.2; mean ± SD), mid-lactation Holstein dairy cows (169.8 ± 16.8 DIM) were enrolled as focal cows in this study and housed individually in a tie-stall facility where they were randomly assigned to 1 of 2 treatment diets: (1) control total mixed ration (TMR) (control; n = 16; primiparous = 7; multiparous = 9), or (2) control TMR with 4 g/d of citrus extract (CE) (Phodé, Terssac, France) (CE; n = 16; primiparous = 7; multiparous = 9). Cows were fed their experimental diets for 7 d in the tie-stall facility (baseline), then moved to 1 of 2 experimental free-stall pens (containing 29 other cows) for a period of 7 d, where they remained on the same treatment diet as before. Compared with their baseline, primiparous control cows had decreased rumination time on d 1 and 2, had decreased lying time on d 1, and tended to have decreased lying time on d 2 and 3 following regrouping. In contrast, primiparous cows fed the CE diet did not experience a change in rumination and lying time. Primiparous CE cows had greater feeding time on d 1 and tended to have greater feeding time on d 2 after regrouping compared to primiparous control cows. Primiparous control cows had greater idle standing time, as compared to the CE cows, across the 7 d after regrouping. Primiparous CE cows initiated less total competitive behavior after regrouping, but were also displaced more frequently from the feed bunk and from the free stalls on d 1 after regrouping, as compared to the primiparous control cows. For multiparous cows, CE supplementation was not consistently associated with any benefits to behavior or production after regrouping, possibly because these cows were more experienced with social stressors. Results indicate that feeding CE to mid-lactation naïve primiparous dairy cows may reduce the initiation of competitive interactions and lessen the reduction in rumination and lying time after regrouping. These results need to be verified in further studies where potential confounding effects (e.g., pen social dynamics, pen location) are minimized.

Physiological response of weaned piglets to two transport durations observed in a Canadian commercial setting.

Observational studies describing the impact of transport duration on weaned piglet welfare are limited. Current Canadian transport regulations are heavily informed by studies involving market hogs. Due to physiological differences between weaned piglets and market hogs, additional data on their response to transport are needed for age-specific evidence-based recommendations. A cohort study was conducted to describe and compare mortality, injury, weight change, hematological or biochemical changes in hydration, muscle injury and stress response observed in weaned piglets undergoing short duration (SD, <3 h), or long duration (LD, >30 h) commercial summertime transport events. Data collection on 440 of 11,434 transported piglets occurred the morning of the day before transport (T0), at arrival (T1) and approximately 3 to 4 d (78 to 93 h) after arrival at the nursery barn (T2). Low mortality occurred over all transport events (0.06%) with no association observed between transport duration and odds of death during transport (P = 0.62). The incidence of lameness between T0 and T1 was low (1.84% of the 435 focal piglets scored) with all lameness cases identified as mild in severity. Lesions on ears and skin were more prevalent than other injury types after transport (T1) and may have been related to mixing aggression associated with weaning rather than transport alone. LD piglets weighed 0.39 kg less than SD piglets at T1 (P < 0.01), but no difference in group weight was observed at T2 (P = 0.17). Hematological and biochemical differences were present between groups at T1. LD piglets had increased hematocrit levels compared with SD piglets (P = 0.01), suggesting increased body water losses. SD piglets showed greater levels of muscle injury compared with LD piglets including elevated aspartate aminotransferase (P < 0.01) and creatine kinase (P < 0.01). However, these parameters were within normal reference ranges for piglets of this age group. Indicators of physiological stress response including cortisol and neutrophil to lymphocyte ratios were elevated in SD piglets compared with LD piglets (P = 0.02 and P < 0.01, respectively). The results of this study demonstrate that both short and long transport durations can result in detectable physiological changes in weaned piglets. The overall impact of these durations on piglet welfare should be further explored by analyzing behavioral time budgets during and after transport.

Growing Pigs' Interest in Enrichment Objects with Different Characteristics and Cleanliness.

Enrichment objects can be a practical way to provide rooting and chewing material to growing pigs, on which they can express species-specific behaviors. The challenge is to provide enrichment objects that will satisfy pigs' behavioral needs, while being practical and low-cost for the producers. Two trials were conducted to evaluate the effects of object characteristics such as design, location, cleanliness or degree of wear, on pigs' interest over time. The first trial compared seven objects, varying in their design and location, presented individually for five consecutive days to groups of 12 ± 3 (average ± SD) pigs, weighing 61 ± 9.2 kg. The pigs' interest in the objects was evaluated based on the frequency, total duration and mean length of manipulation with the objects. All objects were manipulated at different levels depending on their characteristics. On average, the pigs interacted more frequently (p < 0.001) with a chewable object made of three polyurethane balls, spring-mounted and anchored to the floor, and spent more time manipulating a dried wood beam on the floor (p < 0.05), which was destructible and chewable, than suspended ropes, plastics and rubber objects, and a plastic ball on the floor. The second trial used two-choice preference tests to compare objects varying in their degree of cleanliness or wear, presented in pairs to growing pigs weighing 47 ± 7 kg and housed in groups of 14 ± 1. Two identical objects were placed simultaneously in a pen over 5 days, and only one of them was cleaned or replaced daily (treatment) while the duplicate was left untouched (control). The results showed no clear preference between control and treatment objects, indicating that short-term maintenance of the objects might be unnecessary.

Season, Transport Duration and Trailer Compartment Effects on Blood Stress Indicators in Pigs: Relationship to Environmental, Behavioral and Other Physiological Factors, and Pork Quality Traits.

The objective of this study was to assess the effects of the season, travel duration and trailer compartment location on blood creatine-kinase (CK), lactate and cortisol concentrations in 384 pigs and assess their relationships with trailer temperature, heart rate and gastrointestinal tract temperature (GTT), behavior, carcass damage scores and meat quality. Blood CK was greater in pigs transported in summer (p = 0.02), after 18 h transportation (p < 0.001) and in pigs located in C4, C5 and C10 (p = 0.002). In winter, the concentration of blood lactate was higher (p = 0.04) in pigs transported for 6 h in C5. Pigs located in C10 showed higher (p = 0.01) concentration of cortisol than those transported for 18h in C4 in summer. The highest correlations were between blood cortisol and GTT (r = 0.53; p < 0.001), and between blood CK and GTT (r = 0.41; p < 0.001), truck temperature (r = 0.42; p < 0.001), and pHu in the longissimus muscle (r = 0.41; p < 0.001). In conclusion, although increased blood cortisol and CK levels appear to indicate a physical stress condition in transported pigs, the weak to moderate correlations with environmental and other animal welfare indicators suggest that blood stress parameters can only be used as a complementary measurement in the assessment of the pigs' response to transport stress.

Broad cognitive abilities of children with mental retardation: an analysis of group and individual profiles.

Group and individual broad ability profiles of children with mental retardation and a matched sample of children with average achievement was investigated through use of the 7 Cattell-Horn-Carroll (CHC) factor clusters from the Woodcock-Johnson III Tests of Cognitive Abilities. Results indicate that, as a group, the ranked performance of the children with mental retardation on the CHC factor clusters was largely consistent with the clusters' g loadings. When compared to average-achieving matches, the children with mental retardation scored lower on all CHC factor clusters, but the groups displayed different patterns of performance. Despite normative deficiencies in IQs, children with mental retardation demonstrated a wide range of performance across measures. Implications for assessment and diagnosis are discussed.

Placebo-controlled double-blind clomipramine trial for the treatment of anxiety or fear in beagles during ground transport.

The purpose of this explorative study was, first, to document changes in physiological parameters and behavior observed in dogs following ground transport and, second, to measure the effects on the above variables of a short-term administration of clomipramine, anecdotally already prescribed in private veterinary practice to reduce fear, anxiety, or both. Twenty-four beagles were randomly allocated to either clomipramine (2 mg/kg, q12h for 7 d) or placebo treatment, and then transported 3 times in a truck for 1 hour. Physiological parameters (cortisol, neutrophil:lymphocyte (N:L) ratio, heart rate) and behavior were recorded and analyzed. Clomipramine significantly reduced plasma cortisol (P < 0.05) following transport and tended (P = 0.07) to reduce N:L ratio. Clomipramine tended to only reduce "moving and panting" and drooling. Short-term administration of clomipramine appears to slightly reduce fear, anxiety, or both during transport. More research is needed to confirm the efficacy of this treatment and the appropriate dosage.

Physiology and behavior of dogs during air transport.

Twenty-four beagles were used to measure physiological and behavioral reactions to air transport. Each of 3 groups of 4 sedated (with 0.5 mg/kg body weight of acepromazine maleate) and 4 non-sedated (control) dogs was flown on a separate flight between Montreal, Quebec, and Toronto, Ontario, after being transported by road from Quebec City to Montreal. Saliva and blood samples were taken before ground and air transport and after air transport. The heart rate was monitored during the whole experiment except during ground transport, and behavior was monitored by video during air transport. Sedation did not affect any of the variables measured. The mean plasma cortisol concentration was significantly higher (P < 0.05) after ground transport than at baseline (225.3 vs 134.5 nmol/L); the mean salivary cortisol concentration was significantly higher (P < 0.05) after both ground and air transport than at baseline (16.2 and 14.8, respectively, vs 12.6 nmol/L). The mean neutrophil count was significantly higher (P < 0.05) after both ground and air transport than at baseline (80.6 and 81.4, respectively, vs 69.5 per 100 white blood cells), whereas the mean lymphocyte count was significantly lower (P < 0.05) (13.2 and 13.7, respectively, vs 22.4 per 100 white blood cells). Loading and unloading procedures caused the largest increase in heart rate. On average, the dogs spent more than 50% of the time lying down, and they remained inactive for approximately 75% of the time, except during take-off. These results suggest that transportation is stressful for dogs and that sedation with acepromazine, at the dosage and timing used, does not affect the physiological and behavioral stress responses of dogs to air transport.

Welfare of Pigs Being Transported over Long Distances Using a Pot-Belly Trailer during Winter and Summer.

A total of 2,145 pigs were transported for 8 h in summer (six trips) and winter (five trips) using a pot-belly trailer accommodating pigs in four locations (upper deck or UD, bottom-nose or BN, middle deck or MD and bottom deck or BD). Heart rate of pigs during loading and transportation and lactate and creatine kinase (CK) concentrations in exsanguination blood were measured. Meat quality was evaluated in the Longissimus thoracis (LT), Semimembranosus (SM) and Adductor (AD) muscles. During summer, pigs loaded in the UD and MD had higher (P < 0.05) heart rate at loading compared to those located in the BD and BN. Blood lactate and CK concentrations were higher (P < 0.001) in winter than in summer. Lactate concentration was higher (P = 0.01) in the blood of pigs transported in the BN. Pigs transported in the BN had higher pHu values in the LT, SM and AD muscles (P = 0.02, P < 0.001 and P = 0.002, respectively) and lower (P = 0.002) drip loss values in the SM muscle. This study confirms that some locations within the PB trailer have a negative impact on the welfare of pigs at loading and during transport with more pronounced effects in the winter due to the additive effect of cold stress.