The horizontal ladder test (HLT) protocol: a novel, optimized, and reliable means of assessing motor coordination in Sus scrofa domesticus.

Pigs can be an important model for preclinical biological research, including neurological diseases such as Alcohol Use Disorder. Such research often involves longitudinal assessment of changes in motor coordination as the disease or disorder progresses. Current motor coordination tests in pigs are derived from behavioral assessments in rodents and lack critical aspects of face and construct validity. While such tests may permit for the comparison of experimental results to rodents, a lack of validation studies of such tests in the pig itself may preclude the drawing of meaningful conclusions. To address this knowledge gap, an apparatus modeled after a horizontally placed ladder and where the height of the rungs could be adjusted was developed. The protocol that was employed within the apparatus mimicked the walk and turn test of the human standardized field sobriety test. Here, five Sinclair miniature pigs were trained to cross the horizontally placed ladder, starting at a rung height of six inches and decreasing to three inches in one-inch increments. It was demonstrated that pigs can reliably learn to cross the ladder, with few errors, under baseline/unimpaired conditions. These animals were then involved in a voluntary consumption of ethanol study where animals were longitudinally evaluated for motor coordination changes at baseline, 2.5, 5, 7.5, and 10% ethanol concentrations subsequently to consuming ethanol. Consistent with our predictions, relative to baseline performance, motor incoordination increased as voluntary consumption of escalating concentrations of ethanol increased. Together these data highlight that the horizontal ladder test (HLT) test protocol is a novel, optimized and reliable test for evaluating motor coordination as well as changes in motor coordination in pigs.

Development of a mini pig model of peanut allergy.

Introduction: The prevalence of peanut allergies is increasing, emphasizing the need for an animal model to enhance our understanding of peanut allergy pathogenesis and to advance diagnostic tools and therapeutic interventions. While mice are frequently used as model organisms, their allergic responses do not fully mirror those observed in humans, warranting the exploration of a higher animal model. The porcine gastrointestinal system closely resembles that of humans, and exhibits allergy symptoms akin to human responses, making pigs a promising model for peanut allergy research. Methods: In this study we compared two allergen sensitization protocols involving either topical allergen application after repeated tape stripping (TS) or intraperitoneal (IP) injections to induce peanut-specific allergy and anaphylaxis reactions in mini pigs. Mini pigs sensitized with a combination of peanut protein extract (PE) and cholera toxin (CT) through either the IP or the TS route. Results: Sensitized pigs via both methods developed systemic PE-specific IgG and IgE responses. Following peanut challenge via the IP route, both TS- and IP-sensitized pigs displayed allergy symptoms, including lethargy, skin rashes, vomiting, and a drop in body temperature. However, respiratory distress was observed exclusively in pigs sensitized through the TS route and not in those sensitized through the IP route. However, it is noteworthy that both groups of sensitized pigs maintained peanut hypersensitivity for up to two months post-sensitization, albeit with a reduction in the severity of allergy symptoms. Importantly, both groups exhibited sustained levels of PE-specific IgG, IgE, and elevated concentrations of mast cell protease in their blood following the IP challenges. Discussion: Overall, this study reports TS and IP as two different modes of sensitization leading to onset of peanut specific allergic reactions in mini pigs, but only the TS-sensitization led to systemic anaphylaxis (simultaneous presence of symptoms: breathing difficulty, intense skin rash, and impaired mobility). A distinctive feature of these sensitization protocols is the 100% success rate (N = 4 pigs per group) in sensitizing the subjects.

The Horizontal Ladder Test (HLT) protocol: A novel, optimized, and reliable means of assessing motor coordination in Sus scrofa domesticus.

Pigs can be an important model for preclinical biological research, including neurological diseases such as Alcohol Use Disorder. Such research often involves longitudinal assessment of changes in motor coordination as the disease or disorder progresses. Current motor coordination tests in pigs are derived from behavioral assessments in rodents and lack critical aspects of face and construct validity. While such tests may permit for the comparison of experimental results to rodents, a lack of validation studies of such tests in the pig itself may preclude the drawing of meaningful conclusions. Here, we present a novel, optimized, and reliable horizontal ladder test (HLT) test protocol for evaluating motor coordination in pigs and an initial validation of its construct validity using voluntary alcohol consumption as an experimental manipulation.

Genome Sequences of Four Cluster P Mycobacteriophages.

Four bacteriophages infecting Mycobacterium smegmatis mc2155 (three belonging to subcluster P1 and one belonging to subcluster P2) were isolated from soil and sequenced. All four phages are similar in the left arm of their genomes, but the P2 phage differs in the right arm. All four genomes contain features of temperate phages.

Relationship between Environmental Enrichment and the Response to Novelty in Laboratory-housed Pigs.

Environmental enrichment is the enhancement of the physical or social environment in which an animal lives with the goal to improve its quality of life. Our objective was to investigate the effect of providing environmental enrichment in the home pen on responsiveness to novelty in laboratory-housed pigs. Pigs were housed (4 pigs per pen) in enriched (n = 32) or barren (control; n = 32) pens for 3 wk total and tested in 2 anxiety behavioral tests, the novel object (NOT) and human interaction (HIT) tests. Pigs were placed in a novel arena for a 5-min familiarization period, after which either a novel object (NOT) or an unfamiliar human (HIT) was introduced for a 5-min interaction period. Behavior in the home pen and during NOT and HIT was monitored through direct observations and videorecording. In the home pen, enriched pigs spent more time active and interacting with the environment, whereas control pigs spent more time inactive and in social interactions. In addition, enriched pigs crossed more squares during the familiarization period, tended to freeze more, and interacted less with the novel object or person than control pigs. In conclusion, enrichment may improve welfare by stimulating activity and decreasing aggressive behaviors in the home pen. However, enriched pigs may experience increased anxiety when exposed to novelty, whereas pigs housed without environmental enrichment-due to lack of stimulation in the home pen-may be more motivated to interact with sources of novelty or enrichment during testing than their enriched counterparts.

Impact of Providing Feed and/or Water on Performance, Physiology, and Behavior of Weaned Pigs during a 32-h Transport.

Transportation at weaning is a complex stressor made up of many factors, including withdrawal from feed and water, which can potentially negatively affect the health and welfare of pigs, especially those already experiencing weaning stress. The objective of this study was to evaluate the effect of weaning and extended transport durations (up to 32 h), with and without the provision of feed and/or water, on pig welfare. Treatment groups included: pigs neither weaned nor transported, control (CON); weaned pigs transported and provided with feed and water (T+); weaned pigs transported without feed and water (T-); weaned pigs transported with only feed (T+F); and weaned pigs transported with only water provided (TRAN+W). The effect of transport (with and without feed and/or water) on weaned pigs was assessed using behavior, performance, and physiology. After a 32-h transport period, pigs transported without water lost markedly more weight than those transported with water ( p < 0.01). Furthermore, the neutrophil to lymphocyte ratio was markedly higher in male pigs transported without water ( p < 0.05). Overall, transportation had a negative effect on pig well-being, especially when water was not provided.

Effect of Provision of Feed and Water during Transport on the Welfare of Weaned Pigs.

Transportation is a complex stressor made up of factors including weaning itself and withdrawal from feed and water. Therefore, transportation has the potential to negatively impact the health and welfare of weaned pigs. Pigs were transported for 32 h and measures of performance, physiology, and behavior were taken to assess piglet welfare. Treatment groups included pigs not weaned or transported (CON), weaned pigs provided with feed and water (WEAN+), weaned pigs not provided with feed and water (WEAN-), weaned and transported pigs provided with feed and water (TRANS+), and weaned and transported pigs not provided with feed and water (TRANS-). Body weight loss was different among treatments (p < 0.01). CON pigs had a 6.5% ± 0.45% gain in body weight after 32 h. WEAN+, WEAN-, TRANS+, and TRANS- groups all had a loss in body weight of 5.9% ± 0.45%, 7.8% ± 0.45%, 6.5% ± 0.45% and 9.1% ± 0.46%, respectively. The N:L was greater in all weaned pigs at 8 h compared to CON pigs (p < 0.01). WEAN- and transported pigs had significantly higher N:L than CON pigs from 8 h through 16 h, however, all treatment groups were similar to CON pigs after 16 h irrespective of provision of feed and water. Blood glucose levels were lower in transported and/or weaned pigs than CON pigs after 16 h irrespective of the provision of feed and water. TRANS+ females had higher creatine kinase (CK) levels than males (p < 0.05). After a 16 h transport period, TRANS- pigs had higher total plasma protein (TP) levels than all other treatment groups (p < 0.05). Significant changes in behavior were observed during and after transportation, which could also be indicative of stress. Overall, transportation and weaning had a negative effect on performance, physiology and behavior (both during and post-weaning) of pigs, especially when feed and water was not provided. Transporting pigs without feed and water for more than 24 h was a welfare concern as indicated by changes in body weight and physiology measures of stress.

Effects of Transport at Weaning on the Behavior, Physiology and Performance of Pigs.

Transport of pigs to separate production facilities at the time of weaning is a common practice, primarily performed to reduce vertical transfer of disease and enhance production and overall farm efficiency. During transport, pigs are exposed to numerous stressors in conjunction with the stress experienced as a result of weaning. In this review, the behavioral and physiological response of pigs experiencing weaning and transport simultaneously will be described, including the effects of space allowance, season and transport duration. Based on the scientific literature, the gaps in the knowledge regarding potential welfare issues are discussed. Changes in behavior and physiology suggest that weaned pigs may experience stress due to transport. Space allowance, season and duration are aspects of transport that can have a marked impact on these responses. To date, the literature regarding the effects of transport on weaned pigs has primarily focused on the short term stress response and little is known about the effects of concurrent weaning and transport on other aspects of pig welfare including morbidity and mortality rates. Greater understanding of the short and long term consequences of transport on weaned pig welfare particularly in relation to factors such as trip duration, provision of feed and water, and best handling practices would benefit the swine industry. Furthermore, the development of guidelines and recommendations to enhance the short and long term welfare of weaned pigs in relation to transport are needed.