Detecting tail biters by monitoring pig screams in weaning pigs.

Early identification of tail biting and intervention are necessary to reduce tail lesions and their impact on animal health and welfare. Removal of biters has become an effective intervention strategy, but finding them can be difficult and time-consuming. The aim of this study was to investigate whether tail biting and, in particular, individual biters could be identified by detecting pig screams in audio recordings. The study included 288 undocked weaner pigs housed in six pens in two batches. Once a tail biter (n = 7) was identified by visual inspection in the stable and removed by the farm staff, the previous days of video and audio recordings were analyzed for pig screams (sudden increase in loudness with frequencies above 1 kHz) and tail biting events until no biting before the removal was observed anymore. In total, 2893 screams were detected in four pens where tail biting occurred. Of these screams, 52.9% were caused by tail biting in the observed pen, 25.6% originated from other pens, 8.8% were not assignable, and 12.7% occurred due to other reasons. In case of a tail biting event, screams were assigned individually to biter and victim pigs. Based on the audio analysis, biters were identified between one and nine days prior to their removal from the pen after visual inspection. Screams were detected earlier than the increase in hanging tails and could therefore be favored as an early warning indicator. Analyzing animal vocalization has potential for monitoring and early detection of tail biting events. In combination with individual marks and automatic analysis algorithms, biters could be identified and tail biting efficiently reduced. In this way, biters can be removed earlier to increase animal health and welfare.

Selection for social genetic effects in purebred pigs improves behaviour and handling of their crossbred progeny.

BACKGROUND: In commercial pig production, reduction of harmful social behavioural traits, such as ear manipulation and tail biting, is of major interest. Moreover, farmers prefer animals that are easy to handle. The aim of this experiment was to determine whether selection on social breeding values (SBV) for growth rate in purebred pigs affects behaviour in a weighing crate, lesions from ear manipulation, and tail biting of their crossbred progeny. Data were collected on crossbred F1 pigs allocated to 274 pens, which were progeny of purebred Landrace sows and Yorkshire boars from a DanBred nucleus herd. RESULTS: Behaviour in the weighing crate scored on a three-level scale showed that groups of pigs with high SBV for growth rate were significantly calmer than groups of pigs with low SBV (P < 0.027). When the mean SBV in the group increased by 1 unit, the proportion of pigs that obtained a calmer score level was increased by 14%. A significant (p = 0.04), favourable effect of SBV was found on both the number of pigs with ear lesions in the group and the mean number of ear lesions per pig. For a 1 unit increase in mean SBV, the mean number of lesions per pig decreased by 0.06 from a mean of 0.98. Individual severity of ear lesions conditional upon the number of ear lesions was also significantly affected (p = 0.05) by the mean SBV in the group. In groups for which the mean SBV increased by 1 unit, the proportion of pigs that were observed with a lower severity score was increased by 20% on a three-level scale. Most pigs received no tail biting injuries and no effect of SBV was observed on the tail injury score. CONCLUSIONS: After 7 weeks in the finisher unit, crossbred progeny with high SBV were calmer in the weighing crate and had fewer ear lesions. These results indicate that selection of purebred parents for SBV for growth rate will increase welfare in their crossbred progeny by decreasing the number of ear lesions and making them easier to handle.

Tnfa , Il6 , Cxcl1 , and Adam8 Genes Are the Early Markers After Mouse Tail Intervertebral Disc Injury.

OBJECTIVES: The early molecular events after intervertebral disc injury remain unclear. In this study, we aimed to compare inflammatory markers from 1 day to 4 wks after injury to have a comprehensive understanding of the intervertebral disc response to injury. DESIGN: Mouse tail intervertebral disc injury was induced by a needle puncture. Inflammatory marker gene expression and morphological changes were recorded at 1 day, 1 wk, and 4 wks after injury. RESULTS: Tnfa , Il6 , and Cxcl1 gene expression peaked at day 1 post-needle puncture of the mouse intervertebral disc, Adam8 gene expression peaked at 1-wk time point, while Tipe2 gene expression was upregulated at week 4 postinjury. F4/80 positive cells, likely to be macrophages, are present as early as day 1 in the injured intervertebral discs and consistently present at week 4 postinjury. Loss of Safranin O staining and increased histological scores of the injured intervertebral discs are consistent with progressive degeneration after injury. CONCLUSIONS: Inflammatory cytokines including Tnfa precede Tipe2 , suggesting that Tipe2 is likely induced by Tnfa . Upregulation of Adam8 and Cxcl1 gene expression persisted at week 4, suggesting that they play a role in the transition to chronic phase of intervertebral disc degeneration.

Machine learning algorithms can predict tail biting outbreaks in pigs using feeding behaviour records.

Tail biting is a damaging behaviour that impacts the welfare and health of pigs. Early detection of precursor signs of tail biting provides the opportunity to take preventive measures, thus avoiding the occurrence of the tail biting event. This study aimed to build a machine-learning algorithm for real-time detection of upcoming tail biting outbreaks, using feeding behaviour data recorded by an electronic feeder. Prediction capacities of seven machine learning algorithms (Generalized Linear Model with Stepwise Feature Selection, random forest, Support Vector Machines with Radial Basis Function Kernel, Bayesian Generalized Linear Model, Neural network, K-nearest neighbour, and Partial Least Squares Discriminant Analysis) were evaluated from daily feeding data collected from 65 pens originating from two herds of grower-finisher pigs (25-100kg), in which 27 tail biting events occurred. Data were divided into training and testing data in two different ways, either by randomly splitting data into 75% (training set) and 25% (testing set), or by randomly selecting pens to constitute the testing set. In the first data splitting, the model is regularly updated with previous data from the pen, whereas in the second data splitting, the model tries to predict for a pen that it has never seen before. The K-nearest neighbour algorithm was able to predict 78% of the upcoming events with an accuracy of 96%, when predicting events in pens for which it had previous data. Our results indicate that machine learning models can be considered for implementation into automatic feeder systems for real-time prediction of tail biting events.

Prevalence of tail lesions in Swiss finishing pigs.

INTRODUCTION: Tail biting and lesions are common problems in modern pig production. In 2008 tail docking to prevent tail biting was banned in Switzerland. Since then pigs have been raised with intact tails. This study aimed to assess the current prevalence of tail lesions at Swiss abattoirs and comparing abattoir data with farm-specific data regarding potential risk factors for tail lesions. Data collection was performed in repetitive cycles of two weeks at four abattoirs during all consecutive seasons of one year. Gender, tail length and the tail tip condition were evaluated among other parameters. During 32 weeks in total, 195 704 pigs from 6112 batches from 2510 herds were evaluated. Overall, 63,2 % of the animals included in the analysis were slaughtered with a complete tail (lowest tail length score [TLS]), whereas 36,8 % showed a partial or total loss of the tail. The condition of the tail tip (tail tip condition score [TTCS]) was judged as being intact in 63,0 %, as a healed lesion in 23,7 %, an acute lesion in 1,3 % and a chronic lesion in 12,0 % of all cases. Male animals had significantly higher values for TLS and TTCS than female animals (P ≤ 0,05). TLS values were significantly higher in winter than in spring and summer (P < 0,001). TTCS values were significantly higher in fall than in spring and summer. TLS and TTCS values differed significantly (P < 0,001) between the four abattoirs. Only few significant correlations were found between values of TLS and TTCS and farm-specific data. Recording tail lesions at abattoirs is an accurate method to investigate the prevalence of tail lesions in fattening pigs. However, to monitor animal welfare on herd level, this method is very labor intensive. Moreover, data on tail lesions collected at the abattoir cannot replace veterinary on-farm examination for risk factor identification.

INTRODUCTION: Les morsures et les lésions de la queue sont des problèmes courants dans la production porcine moderne. En 2008, la Suisse a interdit la caudectomie pour prévenir les morsures de la queue. Depuis lors, les porcs sont engraissés avec des queues intactes. Cette étude visait à évaluer la prévalence actuelle des lésions de la queue dans les abattoirs suisses et à comparer les données de l'abattoir avec les données spécifiques à l'exploitation concernant les facteurs de risque potentiels pour des lésions de la queue. La collecte des données a été effectuée par cycles répétitifs de deux semaines dans quatre abattoirs pendant toutes les saisons d'une année. Le sexe, la longueur de la queue et l'état de l'extrémité de la queue ont été évalués parmi d'autres paramètres. Pendant 32 semaines au total, 195 704 porcs provenant de 6 112 lots de 2 510 troupeaux ont été évalués. Dans l'ensemble, 63,2 % des animaux inclus dans l'analyse ont été abattus avec une queue complète (Tail Length Score [TLS] la plus basse), tandis que 36,8 %présentaient une perte partielle ou totale de la queue. L'état de l'extrémité de la queue (Tail Tip Condition Score [TTCS]) a été jugé intact dans 63,0 %des cas, avec une lésion cicatrisée dans 23,7 %des cas, avec une lésion aiguë dans 1,3 %des cas et avec une lésion chronique dans 12,0 %des cas. Les animaux mâles présentaient des valeurs de TLS et de TTCS significativement plus élevées que les animaux femelles (P ≤ 0,05). Les valeurs de TLS étaient significativement plus élevées en hiver qu'au printemps et en été (P < 0,001). Les valeurs de TTCS étaient significativement plus élevées en automne qu'au printemps et en été. Les valeurs TLS et TTCS différaient significativement (P < 0,001) entre les quatre abattoirs. Seules quelques corrélations significatives ont été trouvées entre les valeurs de TLS et TTCS et les données spécifiques à l'exploitation. L'enregistrement des lésions de la queue dans les abattoirs est une méthode précise pour étudier la prévalence de ces lésions chez les porcs d'engraissement. Cependant, pour contrôler le bien-être animal au niveau du troupeau, cette méthode demande beaucoup de travail. En outre, les données sur les lésions de la queue collectées à l'abattoir ne peuvent pas remplacer les examens vétérinaires sur l'exploitation pour l'identification des facteurs de risque.

Effect of a dietary supplement on the reduction of lymphedema-progression in mouse tail-cut model.

OBJECTIVE: The aim of our study was to evaluate in vivo, in a mouse tail model of lymphedema, the effects of a dietary supplement, Garlive®, based on hydroxytyrosol from olive leaves, spermidine from rice seeds, hesperidin from citrus fruits and vitamin A. Hydroxytyrosol has anti-inflammatory, antioxidant and antimicrobial activities and inhibits leukotriene B4 generation; spermidine is able to inhibit the production of pro-inflammatory cytokines and mediators; hesperidin inhibits the secretion of pro-inflammatory cytokines: IFN-γ, IL-2, IL-4, IL-10; vitamin A deficiency was shown to induce inflammation and aggravate existing inflammatory states, whereas supplementation with vitamin A could ameliorate inflammation. MATERIALS AND METHODS: The active compounds were included in tablets: 250 mg of olive leaf extract titrated in 10% hydroxytyrosol, 200 mg of citrus fruits extract titrated in 60% hesperidin, 10 mg of rice (Oryza sativa) seeds extract titrated in 1% spermidine and 0.8 mg of vitamin A. Mice of an inbred group were randomly selected and divided in the control group and drug-treated group. The wound necessary for lymphedema generation was made on the tail of each mice 1 cm below the base of the trunk. RESULTS: After surgical intervention, there was a gradual increase in the circumference of both ends of the wound. The control group showed higher increase of tail volume than the drug-treated group. The differences in tail swelling between the control group and the drug-treated group were significantly different. The peak of swelling was anticipated to the 6th day in the drug-treated group, whereas in the control group the peak was reached later on. CONCLUSIONS: The tested drug prevented the induction of swelling from day 5th of wound creation and decreased the duration of swelling, favoring the wound healing.

Changes in tail posture detected by a 3D machine vision system are associated with injury from damaging behaviours and ill health on commercial pig farms.

To establish whether pig tail posture is affected by injuries and ill health, a machine vision system using 3D cameras to measure tail angle was used. Camera data from 1692 pigs in 41 production batches of 42.4 (±16.6) days in length over 17 months at seven diverse grower/finisher commercial pig farms, was validated by visiting farms every 14(±10) days to score injury and ill health. Linear modelling of tail posture found considerable farm and batch effects. The percentage of tails held low (0°) or mid (1-45°) decreased over time from 54.9% and 23.8% respectively by -0.16 and -0.05%/day, while tails high (45-90°) increased from 21.5% by 0.20%/day. Although 22% of scored pigs had scratched tails, severe tail biting was rare; only 6% had tail wounds and 5% partial tail loss. Adding tail injury to models showed associations with tail posture: overall tail injury, worsening tail injury, and tail loss were associated with more pigs detected with low tail posture and fewer with high tails. Minor tail injuries and tail swelling were also associated with altered tail posture. Unexpectedly, other health and injury scores had a larger effect on tail posture- more low tails were observed when a greater proportion of pigs in a pen were scored with lameness or lesions caused by social aggression. Ear injuries were linked with reduced high tails. These findings are consistent with the idea that low tail posture could be a general indicator of poor welfare. However, effects of flank biting and ocular discharge on tail posture were not consistent with this. Our results show for the first time that perturbations in the normal time trends of tail posture are associated with tail biting and other signs of adverse health/welfare at diverse commercial farms, forming the basis for a decision support system.

Inherent Antibacterial and Instant Swelling ε-Poly-Lysine/ Poly(ethylene glycol) Diglycidyl Ether Superabsorbent for Rapid Hemostasis and Bacterially Infected Wound Healing.

Severe traumatic bleeding control and wound-related anti-infection play a crucial role in saving lives and promoting wound healing for both the military and the clinic. In this contribution, an inherent antibacterial and instant swelling ε-poly-lysine/poly (ethylene glycol) diglycidyl ether (EPPE) superabsorbent was developed by a simple mild ring-opening reaction. The as-prepared EPPE1 displayed a porous structure and rough surface and exhibited instant water-triggered expansion with approximately 6300% swelling ratio in deionized water. Moreover, EPPE1 presented efficient pro-coagulation capacity by hemadsorption that can facilitate blood cell gathering and activation in vitro and exhibited a shorter in vivo hemostasis time than that of commercial gelatin sponge and CELOX in both rat tail amputation and noncompressible rat liver lethal defect model. Also, EPPE1 showed excellent antibacterial capacity, prominent biocompatibility, and great biodegradability. Additionally, EPPE1 significantly promotes in vivo wound healing in a full-thickness skin defect model due to its great hemostasis behavior and remarkable bactericidal performance. Hence, EPPE has great potential for serving as an extensively applied hemostatic agent under varied clinical conditions.

Severe tail lesions in finisher pigs are associated with reduction in annual profit in farrow-to-finish pig farms.

OBJECTIVES: We investigated the financial impact of different prevalence levels of severe tail lesions (STL) during the finisher stage associated with changes in average daily gain (ADG) in farrow-to-finish pig farms. METHODS: Prevalence of STL was estimated for 31 farrow-to-finish pig farms. Regression tree analysis was used to identify a threshold for STL associated with differences in ADG. Then, a financial analysis was carried using the Teagasc Pig Production model. RESULTS: A threshold of ≥0.86% prevalence of STL was associated with a 4.8% decrease in ADG which translated into pigs requiring 7 days more to reach target slaughter weight than in farms below the threshold. Reduced ADG meant that farms with higher prevalence of STL used 3.6% more weaner and 1.4% more finisher feed per year increasing feed costs by 1.5%. This reduced mean annual farm profit by 15.1% in farms with higher prevalence of STL. CONCLUSIONS: Our results provide an indication of the financial effects of STL in intensive pig production systems. The identified threshold for the prevalence of STL could provide a tangible target for farmers to focus on in developing strategies to reduce tail lesions and allow farmers to complete a cost benefit analysis of controlling STL.

The Inner Annulus Fibrosus Encroaches on the Nucleus Pulposus in the Injured Mouse Tail Intervertebral Disc.

OBJECTIVE: The aim was to identify the source of cells within the center of the abnormal fibrocartilage tissue of the degenerative intervertebral disc after injury. DESIGN: Cross-breeding of mice with an inducible type II promoter collagen construct (Col2CreER) to Rosa26-TdTomato mice has been shown to result in Cre-recombinase activity and Tomato expression in inner annulus fibrosus cells after tamoxifen injection. To investigate the role of the inner annulus fibrosus in the intervertebral disc injury response, tail intervertebral discs of Col2CreER/tdTomato mice were punctured with a needle and examined 1-4 wks after injury. N-cadherin was examined by immunostaining. RESULTS: After the injury, the fibrocartilage in the degenerative intervertebral disc consisted of residual diseased nucleus pulposus cells and encroaching inner annulus fibrosus cells. The residual nucleus pulposus cells had lost their epithelial cell-like morphology and instead became oval shaped, with reduced adhesion to neighboring nucleus pulposus cells. This change in cellular morphology coincided with a loss of N-cadherin, which contributes to maintenance of healthy nucleus pulposus cell morphology. As expected, injured tail intervertebral discs showed reduced compressive properties as determined by biomechanical assessments. CONCLUSIONS: The cellular composition of the degenerative intervertebral disc has been defined here, which is an important step in developing future treatments.

Risk factors for tail lesions in undocked fattening pigs reared on Swiss farms.

INTRODUCTION: Tail lesions caused by tail biting are a major welfare and economic concern in fattening pigs. The aims of this study were to describe the prevalence and incidence of tail lesions in undocked pigs on individual animal level during the fattening period, to elucidate potential risk factors associated with tail lesions, and to describe the stockpersons' attitudes towards tail biting on Swiss farms. Thirty-eight farms were visited three times during the fattening period (beginning, mid-point, end). During each farm visit, tail lesions were scored on 30-126 individually marked pigs per farm (total: 2209 pigs), information on potential risk factors for tail lesions was recorded, and a standardized interview with the farmer was conducted to explore his/her opinion on tail biting. Potential risk factors were defined by indices when adequate, and their influence on the occurrence of tail lesions was analyzed using mixed effects logistic regression models. During the first and the second half of the fattening period, on average 14,1 and 15,4 pigs, respectively, out of 100 developed new tail lesions or aggravation of old lesions. The risk for new or aggravated tail lesions increased with higher scores for a «disease index¼ and with increasing group size, and it decreased with higher space allowances and with restrictive compared with ad libitum feeding. The prevalence of tail lesions on arrival was not associated with the incidence of tail lesions in the first and the second half of the fattening period, neither at farm level nor at pen level. In the interviews, farmers expressed their interest in getting professional advice on how to reduce tail biting on their farms. In conclusion, our study identified several risk factors for tail lesions in undocked fattening pigs indicating that the incidence of tail lesions could be reduced by improving animal health and housing conditions.

INTRODUCTION: Les lésions de la queue causées par morsure sont un problème majeur de bien-être et d'économie chez les porcs d'engraissement. Les objectifs de cette étude étaient de décrire la prévalence et l'incidence des lésions de la queue pendant la période d'engraissement chez les porcs non écaudés au niveau de chaque animal, d'élucider les facteurs de risque potentiels associés aux lésions de la queue et de décrire les attitudes des éleveurs à l'égard des morsures de queue dans les exploitations suisses. Trente-huit exploitations ont été visitées trois fois pendant la période d'engraissement (début, mi-parcours, fin). Lors de chaque visite, les lésions de la queue ont été notées sur 30 à 126 porcs marqués individuellement par l'exploitant (total: 2209 porcs), des informations sur les facteurs de risque potentiels de lésions de la queue ont été enregistrées et un entretien standardisé avec l'éleveur a été mené pour connaitre son avis sur les morsures de queue. Les facteurs de risque potentiels ont été définis par des indices lorsqu'ils étaient adéquats et leur influence sur la survenue des lésions caudales a été analysée à l'aide de modèles de régression logistique à effets mixtes. Pendant la première et la deuxième moitié de la période d'engraissement, en moyenne 14,1 et 15,4 porcs, respectivement, sur 100 ont développé de nouvelles lésions de la queue ou une aggravation d'anciennes lésions. Le risque de nouvelles lésions de la queue ou d'aggravation augmentait avec des scores plus élevés pour un «indice de maladie¼ et avec l'augmentation de la taille du groupe et il diminuait avec des allocations d'espace plus élevées et avec une alimentation restrictive par rapport à l'alimentation à volonté. La prévalence des lésions de la queue à l'arrivée n'était pas associée à l'incidence des lésions de la queue dans la première et la seconde moitié de la période d'engraissement, ni au niveau de l'exploitation ni au niveau des boxes. Dans les entretiens, les agriculteurs ont exprimé leur intérêt à obtenir des conseils professionnels sur la façon de réduire les morsures de queue dans leurs exploitations. En conclusion, notre étude a identifié plusieurs facteurs de risque de lésions de la queue chez les porcs d'engraissement non écaudés indiquant que l'incidence des lésions de la queue pourrait être réduite en améliorant la santé animale et les conditions de logement.

Anatomical and histological analyses reveal that tail repair is coupled with regrowth in wild-caught, juvenile American alligators (Alligator mississippiensis).

Reptiles are the only amniotes that maintain the capacity to regenerate appendages. This study presents the first anatomical and histological evidence of tail repair with regrowth in an archosaur, the American alligator. The regrown alligator tails constituted approximately 6-18% of the total body length and were morphologically distinct from original tail segments. Gross dissection, radiographs, and magnetic resonance imaging revealed that caudal vertebrae were replaced by a ventrally-positioned, unsegmented endoskeleton. This contrasts with lepidosaurs, where the regenerated tail is radially organized around a central endoskeleton. Furthermore, the regrown alligator tail lacked skeletal muscle and instead consisted of fibrous connective tissue composed of type I and type III collagen fibers. The overproduction of connective tissue shares features with mammalian wound healing or fibrosis. The lack of skeletal muscle contrasts with lizards, but shares similarities with regenerated tails in the tuatara and regenerated limbs in Xenopus adult frogs, which have a cartilaginous endoskeleton surrounded by connective tissue, but lack skeletal muscle. Overall, this study of wild-caught, juvenile American alligator tails identifies a distinct pattern of wound repair in mammals while exhibiting features in common with regeneration in lepidosaurs and amphibia.

Can increased dietary fibre level and a single enrichment device reduce the risk of tail biting in undocked growing-finishing pigs in fully slatted systems?

This study evaluated the effectiveness of combined dietary and enrichment strategies to manage tail biting in pigs with intact tails in a conventional fully-slatted floor housing system. A 2 × 2 × 2 factorial design was used. Pigs had either a high fibre (weaner 5.3% and finisher 11.6% of crude fibre) or standard fibre diet (weaner 3.7% and finisher 5.9% of crude fibre). In the weaner stage, pigs had either a spruce wooden post (supplied in a wall-mounted dispenser) or a rubber floor toy as a enrichment device, and in the finisher stage, they had either the same or alternate enrichment item. Six hundred and seventy-two pigs were assigned to 48 pens of 14 pigs and followed from weaning until slaughter. Individual tail lesion scores and pen level behaviours were directly recorded every 2 weeks. Twenty-six pens had tail biting outbreaks and 161 injured pigs needed removal for treatment. Pigs fed with the high fibre diet performed more tail biting (p < 0.05) and tended to have a worse tail damage scores than those fed the standard fibre diet (p = 0.08). Pigs which had the floor toy as weaners and wood as finishers tended to have fewer tail lesions in the finisher stage than their counterparts (p = 0.06). Pigs receiving the floor toy as enrichment interacted with the enrichment more frequently overall (p < 0.001) and performed fewer harmful behaviours in the weaner stage (p < 0.05). Overall, higher fibre in the diet in a relatively barren environment did not help reduce tail biting or tail lesions. Altering the fibre level in the pigs' diet and providing a single enrichment device to undocked pigs on fully slatted floors resulted in a high level of tail biting and a large proportion of pigs with partial tail amputation.

Risk factors associated with tail damage in conventional non-docked pigs throughout the lactation and rearing period.

Tail biting is an abnormal behaviour in pigs, and remains an economic and welfare problem in modern pig production. Reasons for performing tail-biting behaviour are of multifactorial origin, and are often related to the current environment or internal characteristics of pigs. The objective of the present study was to identify early life risk factors connected to tail damage in non-docked pigs in a commercial Danish piggery, and to further compare the effects of cumulative cross-life experience throughout the early rearing. In an observational study, 741 piglets from 51 sows born in six batches were individually marked at birth and followed until nine weeks of age. Litter related variables and individual piglet characteristics were collected during lactation. The pigs' performance parameters were recorded from birth to nine weeks of age. The association between putative risk factors and tail damage assessed at different stages during lactation and rearing was analysed using multinomial mixed regression models. Prior to weaning, the odds of having tail damage were higher for piglets originating from litters with a high birth weight variation (P = 0.012) and for piglets that were heavier at weaning (P < 0.001). Piglets born to an aggressive sow had 2.7-fold increased odds of having tail damage (P = 0.003), while piglets of sows treated after farrowing had a lower odds (P = 0.015). Post-weaning, the most significant risk factor(s) associated with tail damage was the previous tail status of the pigs. Pigs with bite marks/ scratches in previous assessments had an on average 4-fold and pigs with a tail wound 11-fold increased odds of having tail damage during subsequent assessments. Similarly, pigs with a tail wound pre-weaning had 7-times higher odds of having tail damage at the end of rearing (P = 0.033). Pigs in groups with a higher weight variation (P = 0.030) and pigs with a greater weight gain (P < 0.001) had higher odds of having tail damage at the end of rearing. There was an increased chance of having tail damage post-weaning for piglets that were cross-fostered (P = 0.032) or that had a clinical impairment (P = 0.047) during lactation. Females generally had a lower chance of having tail damage compared to castrated males. Early life risk factors were especially associated with tail damage in pigs pre-weaning. However, the results of this study suggest that early life risk factors are secondary to the previous tail status of pigs as risk factors for later tail damage.

Effects of dabigatran and fondaparinux on degloving injuries: An experimental study.

BACKGROUND: Management of the skin degloving injuries is still a problematic issue, and the avulsed part of the skin may become necrotic. We hypothesized that the anticoagulant pharmacological agents, fondaparinux and dabigatran may be beneficial in the treatment of degloving injuries by enhancing the viability of the reattached flap. METHODS: Twenty four Wistar rats were divided into three groups as follows: control group (Group 1), fondaparinux group (Group 2) and dabigatran group (Group 3). A model of a degloving injury on the tail of rats was developed in all groups. After 15 minutes, the avulsed flaps were sutured back. Group 1 received 1ml/day saline intraperitoneally for 10 days. Group 2 received 0.3 ml/kg/day fondaparinux intraperitoneally for 10 days. Group 3 received 30 mg/kg/day dabigatran orally for 10 days. At the end of the treatments, gross morphological and histopathological tail tissue survivals were evaluated. RESULTS: Histopathological examination of the fondaparinux and dabigatran groups revealed that the tail skin was mostly viable with mild inflammation. The mean necrotic length in tails and severity of inflammation was significantly higher in the control group compared to the fondaparinux and dabigatran groups (p<0.05). No statistically significant differences were noted between the fondaparinux and dabigatran groups in histopathologic evaluations. There was no significant difference in necrosis lengths and the other histopathological parameters between dabigatran and fondaparinux groups. CONCLUSION: Dabigatran and fondaparinux improved tissue survival in skin degloving injuries concerning gross morphological and histopathological findings. However, the findings of this study should be supported and improved by new experimental and especially clinical studies.

Riveting hammer vibration damages mechanosensory nerve endings.

Hand-arm vibration syndrome (HAVS) is an irreversible neurodegenerative, vasospastic, and musculoskeletal occupational disease of workers who use powered hand tools. The etiology is poorly understood. Neurological symptoms include numbness, tingling, and pain. This study examines impact hammer vibration-induced injury and recoverability of hair mechanosensory innervation. Rat tails were vibrated 12 min/d for 5 weeks followed by 5 week recovery with synchronous non-vibrated controls. Nerve fibers were PGP9.5 immunostained. Lanceolate complex innervation was compared quantitatively in vibrated vs sham. Vibration peak acceleration magnitudes were characterized by frequency power spectral analysis. Average magnitude (2515 m/s2 , root mean squared) in kHz frequencies was 109 times that (23 m/s2 ) in low Hz. Percentage of hairs innervated by lanceolate complexes was 69.1% in 5-week sham and 53.4% in 5-week vibration generating a denervation difference of 15.7% higher in vibration. Hair innervation was 76.9% in 5-weeks recovery sham and 62.0% in 5-week recovery vibration producing a denervation difference 14.9% higher in recovery vibration. Lanceolate number per complex (18.4 ± 0.2) after vibration remained near sham (19.3 ± 0.3), but 44.9% of lanceolate complexes were abnormal in 5 weeks vibrated compared to 18.8% in sham. The largest vibration energies are peak kHz accelerations (approximately 100 000 m/s2 ) from shock waves. The existing ISO 5349-1 standard excludes kHz vibrations, seriously underestimating vibration injury risk. The present study validates the rat tail, impact hammer vibration as a model for investigating irreversible nerve damage. Persistence of higher denervation difference after 5-week recovery suggests repeated vibration injury destroys the capability of lanceolate nerve endings to regenerate.

A hemophilia A mouse model for the in vivo assessment of emicizumab function.

The bispecific antibody emicizumab is increasingly used for hemophilia A treatment. However, its specificity for human factors IX and X (FIX and FX) has limited its in vivo functional analysis to primate models of acquired hemophilia. Here, we describe a novel mouse model that allows emicizumab function to be examined. Briefly, FVIII-deficient mice received IV emicizumab 24 hours before tail-clip bleeding was performed. A second infusion with human FIX and FX, administered 5 minutes before bleeding, generated consistent levels of emicizumab (0.7-19 mg/dL for 0.5-10 mg/kg doses) and of both FIX and FX (85 and 101 U/dL, respectively, after dosing at 100 U/kg). Plasma from these mice display FVIII-like activity in assays (diluted activated partial thromboplastin time and thrombin generation), similar to human samples containing emicizumab. Emicizumab doses of 1.5 mg/kg and higher significantly reduced blood loss in a tail-clip-bleeding model using FVIII-deficient mice. However, reduction was incomplete compared with mice treated with human FVIII concentrate, and no difference in efficacy between doses was observed. From this model, we deducted FVIII-like activity from emicizumab that corresponded to a dose of 4.5 U of FVIII per kilogram (ie, 9.0 U/dL). Interestingly, combined with a low FVIII dose (5 U/kg), emicizumab provided enough additive activity to allow complete bleeding arrest. This model could be useful for further in vivo analysis of emicizumab.

Reduced brain cell proliferation following somatic injury is buffered by social interaction in electric fish, Apteronotus leptorhynchus.

In many species, the negative effects of aversive stimuli are mitigated by social interactions, a phenomenon termed social buffering. In one form of social buffering, social interactions reduce the inhibition of brain cell proliferation during stress. Indirect predator stimuli (e.g., olfactory or visual cues) are known to decrease brain cell proliferation, but little is known about how somatic injury, as might occur from direct predator encounter, affects brain cell proliferation and whether this response is influenced by conspecific interactions. Here, we assessed the social buffering of brain cell proliferation in an electric fish, Apteronotus leptorhynchus, by examining the separate and combined effects of tail injury and social interactions. We mimicked a predator-induced injury by amputating the caudal tail tip, exposed fish to paired interactions that varied in timing, duration and recovery period, and measured brain cell proliferation and the degree of social affiliation. Paired social interaction mitigated the negative effects of tail amputation on cell proliferation in the forebrain but not the midbrain. Social interaction either before or after tail amputation reduced the effect of tail injury and continuous interaction both before and after caused an even greater buffering effect. Social interaction buffered the proliferation response after short-term (1 d) or long-term recovery (7 d) from tail amputation. This is the first report of social buffering of brain cell proliferation in a non-mammalian model. Despite the positive association between social stimuli and brain cell proliferation, we found no evidence that fish affiliate more closely following tail injury.

Influence of Genetic Background and Sex on Gene Expression in the Mouse (Mus musculus) Tail in a Model of Intervertebral Disc Injury.

To facilitate rational experimental design and fulfill the NIH requirement of including sex as a biologic variable, we examined the influences of genetic background and sex on responses to intervertebral disc (IVD) injury in the mouse tail. The goal of this study was to compare gene expression and histologic changes in response to a tail IVD injury (needle puncture) in male and female mice on the DBA and C57BL/6 (B6) backgrounds. We hypothesized that extracellular matrix gene expression in response to IVD injury differs between mice of different genetic backgrounds and sex. Consistent changes were detected in gene expression and histologic features after IVD injury in mice on both genetic backgrounds and sexes. In particular, expression of col1a1 and adam8 was higher in the injured IVD of DBA mice than B6 mice. Conversely, col2a1 expression was higher in B6 mice than DBA mice. Sex-associated differences were significant only in B6 mice, in which col2a1 expression was greater in male mice than in female. Histologic differences in response to injury were not apparent between DBA and B6 mice or between males and females. In conclusion, mouse tail IVD showed sex- and strain-related changes in gene expression and histology after needle puncture. The magnitude of change in gene expression differed with regard to genetic background and, to a lesser degree, sex.

Mouse models of hemostasis.

Hemostasis is the normal process that produces a blood clot at a site of vascular injury. Mice are widely used to study hemostasis and abnormalities of blood coagulation because their hemostatic system is similar in most respects to that of humans, and their genomes can be easily manipulated to create models of inherited human coagulation disorders. Two of the most widely used techniques for assessing hemostasis in mice are the tail bleeding time (TBT) and saphenous vein bleeding (SVB) models. Here we discuss the use of these methods in the evaluation of hemostasis, and the advantages and limits of using mice as surrogates for studying hemostasis in humans.