BACKGROUND Sow mortality has become a growing concern in the pig production industry over the past decade. Therefore, we aimed to describe sow mortality and associated factors in a production system in the midwestern USA. METHODS Mortality records from 2009 to 2018 for four farrow-to-wean farms were described. Environmental, farm- and individual-level factors associated with weekly mortality and individual risk of dying throughout a sow's lifetime were assessed. RESULTS Deaths occurred at a median of 116 days from last service, or 26 days postpartum. The median parity upon death was two. Overall, the main reasons for death were locomotion (27%) and reproduction (24%). A higher weekly number of deaths was associated with spring (incidence rate ratio [IRR] 1.27, compared to winter). Sows had a higher mortality when they were exposed to at least one porcine reproductive and respiratory syndrome (PRRS) outbreak during their lifetime (IRR 1.55) and when housed in groups (pens) during gestation (IRR 1.32). Conversely, they had  a lower mortality when housed in filtered farms (IRR 0.76), accounting for an interaction term between parity at removal and PRRS outbreak exposure. LIMITATIONS Issues with data completion and information accuracy were present, and prospective data collection throughout sows' lifetimes is still needed. CONCLUSION Efforts to reduce infectious diseases within the herd and manage environmental stressors should help reduce mortality.

Proper methods of assessment to objectively identify pain are essential for welfare improvements of piglets undergoing surgical castration on commercial farms. The Piglet Grimace Scale (PGS) is used to identify changes in facial expressions caused by acute pain in piglets undergoing tail docking and castration. However, subjective scoring methods are a concern for the validation of the PGS. The objectives of this study were to evaluate and refine the PGS through 3D landmark geometric morphometrics. Male piglets (n = 88) were randomly allocated to one of two treatments: castration and sham-castration. Piglet facial images were taken at four time points (before treatment, immediately post-treatment, 1 h post-treatment, and 4 h post-treatment) using a photogrammetry rig. Images were scored by four raters using five facial action units (FAUs): orbital tightening, ear position, temporal tension, lip contraction, and nose bulge/cheek tension. Three-dimensional facial models were generated and landmarked denoting 3 FAUs (orbital tightening, lip contraction, and nose bulge/cheek tension). Results suggest that orbital tightening and ear position may be reliable FAUs for the PGS. However, neither the PGS nor 3D landmark-based geometric morphometrics were able (both p > 0.10) to reliably identify facial indicators of pain in piglets undergoing castration.

The definition of animal welfare includes how an animal dies. As such, euthanasia is intrinsically linked to animal welfare, and ensuring a good death through effective, safe, and validated practices is a critical piece of promoting positive animal welfare. The objective of this review is to provide a better understanding of the literature on the euthanasia of swine via penetrating captive bolt (PCB) and nonpenetrating captive bolt (NPCB), as well as a history of captive bolt use, and indicators of sensibility and insensibility. To do this, we performed a systematic review that included 30 peer-reviewed articles and 17 other publications. NPCB devices have been validated as an effective single-step euthanasia method for neonatal and preweaning swine, as well as a two-step euthanasia method for nursery swine. PCB devices have been validated as an effective euthanasia method for nursery and market swine up to 120 kg, but further investigation is required for the use of captive bolt devices on mature breeding sows and boars.

Since the first ASFV case was reported in China in 2018, the conventional depopulation method to control ASF has proved unwieldy because of its high production intensity and complex trade network. To provide an alternative to conventional stamping out methods, we developed a” Whole-herd-Sampling, qPCR-based-Testing, and Precision-Removal” method by sampling every whole herd sampling and qPCR tests to determine the status of ASFV in herds and using a precision removal of identified sows. By developing and applying these methods, we successfully controlled ASF and eliminated the virus from 4 large swine herds from 2019 to 2020. The time to negative herd (TTNH) was 19, 28, 14, and 1 day from farm 1 to 4, respectively. Retention rates of pigs from farm 1 to farm 4 were 69.7%, 65%, 99.4%, and 99.72%, respectively. We anticipated that this innovative method would be a good alternative to the conventional stamping out method and greatly facilitate the control and eradication of ASFV in China and worldwide.

Livestock movements are important drivers for infectious disease transmission. However, paucity of such data in pastoralist communities in rangeland ecosystems limits our understanding of their dynamics and hampers disease surveillance and control. The aim of this study was to investigate animal movement networks in a pastoralist community in Kenya, and assess network-based strategies for disease control. We used network analysis to characterize five types of between-village animal movement networks. We then evaluated implications of these networks for disease spread and control by quantifying topological changes in the network associated with targeted and random removal of nodes. To construct these networks, data were collected using standardized questionnaires (N = 165 households) from communities living within the Maasai Mara Ecosystem in southwestern Kenya. Our analyses show that the Maasai Mara National Reserve (MMNR), a protected wildlife area, was critical for maintaining village connectivity in the agistment network (dry season grazing), with MMNR-adjacent villages being highly utilized during the dry season. In terms of disease dynamics, the network-based basic reproduction number, R0, was sufficient to allow disease invasion in all the five networks, and removal of villages based on degree or betweenness was not efficient in reducing R0. However, we show that villages with high degree or betweenness may play an important role in maintaining network connectivity, which may not be captured by assessment of R0 alone. Such villages may function as potential "firebreaks." For example, targeted removal of highly connected village nodes was more effective at fragmenting each network than random removal of nodes, indicating that network-based targeting of interventions such as vaccination could potentially disrupt transmission pathways in the ecosystem. In conclusion, this work shows that animal movements have the potential to shape patterns of disease transmission in this ecosystem, with targeted interventions being a practical and efficient measure for disease control.

ABSTRACT This study assessed acute pain in piglets during castration through behavioral indicators. Piglets (n=88) were randomly allocated to one of two treatments: surgical castration and sham-castration. Within 24 hours after birth, identical castration procedures were followed for both treatment groups, except sham piglets were not castrated. Struggle behavior (curl ups, leg kicks, and body flailing) and vocalization (duration and peak frequency) were analyzed during the castration procedure. Castrated piglets kicked more frequently than sham piglets (28.8 vs. 21.3 kicks/min, SE = 0.09; P = 0.02). Additionally, 51.2% of castrated piglets displayed body flailing, whereas only 4.4% of sham piglets displayed the same behavior (P = 0.03). Castrated piglets responded with more high frequency (≥1,000 Hz) calls than sham piglets (23.6 vs. 18.6 calls/min, SE = 0.26; P = 0.04) and high frequency calls tended to be of longer duration for castrated piglets (0.45 vs. 0.27 sec/call, SE = 0.04; P = 0.08). Results indicate that surgical castration increased the frequency of leg kicks, body flailing, and high frequency calls compared to sham-castration, suggesting these may be useful behavioral indicators of acute pain in piglets.

Infectious diseases are one of the most important constraints to livestock agriculture, and hence food, nutritional and economic security in developing countries. In any livestock system, the movement of animals is key to production and sustainability. This is especially true in pastoralist systems where animal movement occurs for a myriad of social, ecological, economic and management reasons. Understanding the dynamics of livestock movement within an ecosystem is important for disease surveillance and control, yet there is limited data available on the dynamics of animal movement in such populations. The aim of this study was to investigate animal transfer networks in a pastoralist community in Kenya, and assess network-based strategies for disease control. We used network analysis to characterize five types of animal transfer networks and evaluated implications of these networks for disease control through quantifying topological changes in the network because of targeted or random removal of nodes. To construct these networks, data were collected using a standardized questionnaire (N=164 households) from communities living within the Maasai Mara Ecosystem in southwestern Kenya. The median livestock movement distance for agistment (dry season grazing) was 39.49 kilometers (22.03-63.49 km), while that for gift, bride price, buying and selling were 13.97 km (0-40.30 km), 30.75 km (10.02-66.03 km), 31.14 km (17.56-59.08 km), and 33.21 km (17.78-58.49 km), respectively. Our analyses show that the Maasai Mara National Reserve, a protected area, was critical for maintaining connectivity in the agistment network. In addition, villages closer to the Maasai Mara National Reserve were regularly used for dry season grazing. In terms of disease control, targeted removal of highly connected village nodes was more effective at fragmenting each network than random removal of nodes, indicating that network-based targeting of interventions such as vaccination could potentially disrupt transmission pathways and reduce pathogen circulation in the ecosystem. In conclusion, this work shows that animal movements have the potential to shape patterns of disease transmission and control in this ecosystem. Further, we show that targeted control is a more practical and efficient measure for disease control.

ABSTRACT The objective of this study was to determine how feeder-space allowance affects behaviors of slow- and fast-growing pigs during the nursery period. Nursery pigs (n = 192; initial weight = 7.4 ± 1.6 kg) were housed in 24 pens of 8 pigs, with 12 pens provided with either a two-space feeder or a five-space feeder. Pigs were categorized as slow growers (SG) and fast growers (FG) based on adjusted market weight (SG < 105 kg; FG ≥ 105 kg). Behaviors of pigs were video-recorded during the first four days after entering the nursery and on Day 21. Eating speed was measured on 96 focal pigs when they were nine weeks old. SG spent more time at the drinker than did FG (p < .05). SG spent less time in the standing/walking posture (p < .05) in pens with five-space feeders compared with SG in pens with two-space feeders. These results suggest that providing more feeder space may benefit SG in terms of improving the welfare of these pigs.

Pork accounts for more than one-third of meat produced worldwide and is an important component of global food security, agricultural economies, and trade. Infectious diseases are among the primary constraints to swine production, and the globalization of the swine industry has contributed to the emergence and spread of pathogens. Despite the importance of infectious diseases to animal health and the stability and productivity of the global swine industry, pathogens of swine have never been reviewed at a global scale. Here, we build a holistic global picture of research on swine pathogens to enhance preparedness and understand patterns of emergence and spread. By conducting a scoping review of more than 57,000 publications across 50 years, we identify priority pathogens globally and regionally, and characterize geographic and temporal trends in research priorities. Of the 40 identified pathogens, publication rates for eight pathogens increased faster than overall trends, suggesting that these pathogens may be emerging or constitute an increasing threat. We also compared regional patterns of pathogen prioritization in the context of policy differences, history of outbreaks, and differing swine health challenges faced in regions where swine production has become more industrialized. We documented a general increasing trend in importance of zoonotic pathogens and show that structural changes in the industry related to intensive swine production shift pathogen prioritization. Multinational collaboration networks were strongly shaped by region, colonial ties, and pig trade networks. This review represents the most comprehensive overview of research on swine infectious diseases to date.

Ongoing occurrence of elevated levels of lead in bald eagles (Haliaeetus leucocephalus) following the ban on lead shot for waterfowl hunting led us to hypothesize that spent lead from ammunition, which is present in field residues of white-tailed deer (Odocoileus virginianus), represented a source of lead exposure in eagles. We conducted a case-control study using data from 1,277 bald eagles admitted for rehabilitation from January 1996 through December 2009. A multivariate logistic regression model was used to predict the odds of elevated lead levels using admission date in relation to deer hunting season, recovery location in relation to deer hunting zones, and age as predictors. We also assessed mean liver copper concentrations from eagles with elevated lead levels and from eagles with background lead levels, because most high velocity rifl e bullets that are used for deer hunting are jacketed in copper. We found 334 bald eagles with elevated lead levels out of 1,277 bald eagles we examined. We detected significantly increased odds for elevated lead levels based on season (late fall and early winter), deer hunting rifle zone, and age (adult birds). The mean liver copper concentration was higher (P = 0.02) in eagles with elevated lead levels. These combined results supported our hypothesis that eagles are acquiring lead from hunter-shot deer. Further research is needed to determine whether this exposure to lead is having a population-level impact.

Honey bee surveillance systems are increasingly used to characterize honey bee health and disease burdens of bees in different regions and/or over time. In addition to quantifying disease prevalence, surveillance systems can identify risk factors associated with colony morbidity and mortality. Surveillance systems are often observational, and prove particularly useful when searching for risk factors in real world complex systems. We review recent examples of surveillance systems with particular emphasis on how these efforts have helped increase our understanding of honey bee health.

Influenza A virus (IAV) infection in pigs is a concern to producers, veterinarians and the general public. This study presents models to estimate the sensitivities (Se) and specificities (Sp) of respiratory clinical signs (RCS), and real-time reverse transcription polymerase chain reaction (RRT-PCR) resulted from oral fluid (OF) and nasal swab (NS) samples in the absence of a gold standard. In addition, the models estimated an average prevalence of IAV infection in the Midwestern United States (US) growing pig populations. Bayesian model provided estimates under scenarios where IAV vaccination reduced only clinical manifestations, but not infection (basic model), or where vaccination reduced both. By the basic model, the Se and Sp of RCS from posterior distributions were 0.38 (95%Cridible interval (CrI): 0.28, 0.48) and 0.66 (95%CrI: 0.61, 0.71). The Se and Sp of of RRT-PCR were 0.84 (95%CrI: 0.87, 0.90) and 0.93 (95%CrI: 0.82, 0.97), and those of NS RRT-PCR were 0.79 (95%CrI: 0.71, 0.89) and 0.97 (95%CrI: 0.90, 0.99) respectively. The true prevalence estimate of IAV infection in the Midwestern US growing pig populations was 0.24 (95%CrI: 0.16, 0.30). In the second scenario, the Se and Sp of RCS were reduced by vaccination whereas those of NS and OF-RRT-PCR were not reduced by vaccination. Depending on the prior knowledge of vaccination, the model (in the second scenario) estimated that vaccination reduced the true prevalence of IAV in growing pigs, and thereby this has broader implications for the control and perhaps eradication of IAV in growing pigs. Key words: Bayesian estimation, test accuracy, prevalence, influenza A virus, swine.

Humans have been using animals for their own purposes for as long as humans and animals have coinhabited the planet. Our ancestors hunted animals as food, and over the millennia, humans have recognized animals as sources of clothing to protect them from the elements, fuel to light their lamps, bones from which to carve tools and jewelry, and even medically important compounds (eg, insulin) with which they can treat their diseases. Beginning more than 30,000 years ago, humankind recognized the usefulness of domestication and began to breed a variety of species to more readily serve its purposes. Humans saw the advantages of using domesticated animals as a source of food, a method of transport, a form of protection (from both people and other animals), and eventually a source of companionship. Just as humans’ uses of animals have changed over the years, so too have society’s views on animal welfare. The disparate roles that animals play in our lives have left a patchwork of animal welfare expectations across society. These society-wide differences in opinions regarding acceptable human-animal interactions and what constitutes acceptable animal welfare are reflected in the veterinary profession and can be described as a dissonance within the profession. 1 This dissonance has been suggested to be a central challenge that could keep veterinarians from assuming a leadership role in animal welfare. 2 In contrast, we believe that different perspectives within the veterinary profession merely reflect contemporary society and that it is incumbent on the profession to work with and through the norms and values of society in addressing the challenges of animal welfare. The use of gestation stalls for pregnant sows represents an interesting example of these divergent perspectives within the veterinary profession, as veterinarians directly involved in the day-to-day care of commercial livestock often seem to have opinions regarding the welfare implications of gestation stalls different from the opinions held by veterinarians who do not have close connections to or experience with these animals. In our experience, veterinarians involved in the day-to-day care of sows, particularly those familiar with group housing of sows prior to the advent of individual gestation stalls, tend to focus on the advantages to the physical health of the sows that gestation stalls provide, citing, for example, how individual housing prevents

A Bayesian approach (BA) is well-used in veterinary medicine as it has been used for inductive reasoning regarding interventions, treatments and diagnoses. The objectives of the current article were (1) to examine the state of BA used for inductive reasoning in veterinary medical problems and (2) to illustrate how veterinarians update states of knowledge (prior clinical experience) to a new state of knowledge (posterior clinical experience). When veterinarians are managing patients, they start with their inference from history and a clinical sign to an underlying cause using inductive reasoning. In updating from a prior clinical experience to a posterior clinical experience, the strength of evidence plays an important role. Nevertheless, if an experienced veterinarian uses his/her previous experience of a current patient’s clinical signs, he/she may not move from the prior clinical experience to a posterior clinical experience and is less likely to change his/her treatment decisions. In comparison, for a novice veterinarian who would have less prior clinical experiences with given clinical signs, his/her prior clinical experience would easily be changed to a posterior clinical experience after taking history and physical examination. In brief, the more prior clinical experience a veterinarian has, the more rapid a diagnosis is made. The stronger the evidence, the more precise inference will be. Key words: Bayesian, inference, reasoning, inductive, veterinarian.

Africa is faced with many of the most daunting challenges of our time. It comprises roughly 15% of the world's human population, and most of its countries are perpetually ranked "Low" on the United Nations' Human Development Index. On the other hand, Africa has arguably the largest proportion of intact natural ecosystems, biodiversity, and sociocultural capital and the lowest impact on global warming of any continent. Thus, African leaders are faced with competing demands and values among a multitude of complex issues, such as high human population growth, extreme poverty, food insecurity, land use policy, climate change, and biodiversity conservation. In this context, building sustainable national systems for human and/or animal health is one of the grand challenges of this generation. Today's complex global health and development challenges require long-term commitment and a range of approaches that are too broad for any one discipline, institution, or country to implement on its own. The One Health concept recognizes the interconnectedness of global health issues and, as such, promotes the importance of and need for international, interdisciplinary, and cross-sectoral communication and collaboration at local, national, and international levels. By taking advantage of natural cultural tendencies for shared leadership, resource allocation, and community values, African leaders are currently proactively demonstrating the principles of One Health, and thus becoming a model for this global vision. And by focusing on partnerships rather than donor-recipient relationships, they are fostering the development of shared priorities and are increasingly driving their own health agenda to fulfill their own needs.

The commonality of influenza A virus (IAV) exposure and vaccination on swine farms in the United States ensures that the majority of neonatal pigs will have some degree of maternal immunity to IAV. The influence of maternal immunity on IAV transmission in neonatal pig populations will impact virus prevalence and infection dynamics across pig populations. The main objective of this study was to assess the impact of maternally derived immunity on IAV transmission in an experimental setting. Neonatal pigs suckled colostrum and derived maternal (passive) immunity from sows in one of three treatment groups: (a) non-vaccinated control (CTRL) or vaccinated with (b) homologous (PASSV-HOM) or (c) heterologous (PASSV-HET) inactivated experimental IAV vaccines. Sentinel neonatal pigs derived from the groups above were challenged with IAV via direct contact with an experimentally infected pig (seeder pig) and monitored for IAV infection daily via nasal swab sampling. A susceptible-infectious-recovered (SIR) experimental model was used to obtain and estimate transmission parameters in each treatment group via a generalized linear model. All sentinel pigs in the CTRL (30/30) and PASSV-HET (30/30) groups were infected with IAV following contact with the seeder pigs and the reproduction ratio estimates (95% confidence interval) were 10.4 (6.6–15.8) and 7.1 (4.2–11.3), respectively. In contrast, 1/20 sentinel pigs in the PASSV-HOM group was infected following contact with the seeder pigs and the reproduction ratio estimate was significantly lower compared to the CTRL and PASSV-HET groups at 0.8 (0.1–3.7). Under the conditions of this study, IAV transmission was reduced in neonatal pigs with homologous maternal immunity compared to seronegative neonatal pigs and pigs with heterologous maternal immunity as defined in this study. This study provides estimates for IAV transmission in pigs with differing types of maternal immunity which may describe the influence of maternal immunity on IAV prevalence and infection dynamics in pig populations.

The objective of the current study was to compare the sensitivity of 2 Mycoplasma hyopneumoniae enzyme-linked immunosorbent assays (ELISAs) in experimentally challenged and contact-exposed pigs in a long-term longitudinal assessment. On day 0 of the assessment, twelve 2-month-old M. hyopneumoniae-negative pigs were inoculated with M. hyopneumoniae strain 232 (group A). Twelve negative pigs were placed alongside the inoculated pigs, allowing direct contact exposure (group B). A third group of 12 pigs was allocated into 2 independent pens; no direct contact was allowed (group C). A longitudinal serologic profile was performed; samples were collected on days 0, 28, 35, 42, 49, 63, 91, 119, 154, and 170 of the study. Serum samples were tested using a blocking ELISA and an indirect ELISA. Results of the study demonstrated higher sensitivity of the blocking ELISA during early infection (clinical signs). Both ELISAs were 100% sensitive in challenged and naturally infected groups at several testing points during late infection (63, 91, 119, 154, and 170 days of the study) and showed a long antibody detection period. Both tests worked equally well during the chronic phase of infection but the blocking ELISA was more sensitive during acute stages of infection.