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Windborne spread of foot-and-mouth disease (FMD) requires specific epidemiological and meteorological conditions, thus modeling the risk of windborne spread involves integrating epidemiological and meteorological models. The objective of this study was to investigate the potential risk of windborne spread of FMD from an infected US feedlot using an integrated modeling approach, and to identify factors that determine this risk. To address this objective, we integrated a within-herd epidemiological model and an advanced atmospheric dispersion model, and calculated infection risk dependent on exposed herd size. A previously developed epidemiological model was used to simulate the spread of FMD through a typical U.S. feedlot, while the National Oceanic and Atmospheric Administration's (NOAA) HYSPLIT atmospheric dispersion model, which has been validated for FMD modeling, was used to model virus dispersion. Infection risk for exposed herds was calculated as a binomial probability accounting for dose and exposed herd size. We modeled risk of windborne spread from a typical 4000 head feedlot in the U.S. state of Iowa (IA), and a typical 48,000 head feedlot in the U.S. state of Kansas (KS) during winter and summer seasons. The risk of windborne spread of FMD varied based on weather/season conditions, estimated average viral shedding rate per head, size of infected herd, and size of exposed herd. In the baseline Kansas scenario (KS/10 3 /W), the median of the maximum daily risk of infecting a 1000-head exposed herd ranged from 58.16 % at 1 km to 0.78 % at 10 km (Table 4). In the baseline Iowa scenario (IA/10 3 /W), the median of the maximum daily risk of infecting a 1000-head exposed herd ranged from 21.78 % at 1 km to 0.05 % at 10 km (Table 4). The minimum control area recommended by the United States Department of Agriculture (USDA) in an FMD outbreak is 10 km from the infected premise. Our results indicate that significant risk of windborne spread may extend beyond 10 km in certain situations. This is particularly a concern in areas where there are large feedlots in relatively close proximity, such as in southwestern Kansas. Our model may be useful as a research tool in the absence of an outbreak and may help direct surveillance and response efforts in the event of an outbreak., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Students completing advanced degrees in dairy or animal science may go on to have a major impact on the food animal agriculture industries. The aim of this study was to better understand student views of the future of dairying, including changes in practices affecting animal care on farms as well as perceived public perceptions. We conducted 6 focus group sessions with undergraduate students enrolled in the 2019 US Dairy Education and Training Consortium held in Clovis, New Mexico, and used explorative key word analysis of written notes and thematic analysis of the semi-structured discussions. Some "must-haves" of future animal care on dairy farms included increased use of technology, group housing of calves, and adequate facilities, including enrichment. Students also discussed their views of public expectations regarding animal care on dairy farms, and measures that they felt must be put into place to address these expectations in the coming years. Although the influence of the public was highlighted by the students, they were not always certain what specific values the public holds and doubted the feasibility and practicality of some expectations, such as providing pasture access or keeping the calf and cow together. They further demonstrated uncertainty about how best to align the directions of the industry with public expectations. Although they felt that public education could be used to demonstrate the legitimacy of dairy practices, they also believed that the industry should strive to find compromises and work toward meeting public expectations. Deciding what animal welfare considerations (e.g., naturalness, affective states, or animal health) were most relevant was a challenge for the students, perhaps reflecting diverging messages received during their own education., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

This study describes antimicrobial use in 22 U.S. beef feedyards by use of two metrics: milligrams of antimicrobial per kilogram of liveweight sold (mg/kg-LW) and antimicrobial regimens per animal year (Reg/AY). The primary objectives were to determine the feasibility of collecting antimicrobial use data at the level of the production system and to identify factors unique to feedyard systems which may confound interpretation of summarized antimicrobial use measures. Records were accessed directly from feedyards or through a data intermediary and then subjected to a process of standardization and quality assurance. Use is reported at the study level with all individual cattle lots from all feedyards combined, as well as at the feedyard level where values were first calculated for each feedyard and then expressed as means, standard deviations and median values. Use at the study level is first reported by antimicrobial class and then by antimicrobial class within the use categories of in-feed, control of bovine respiratory disease (BRD) and individual animal treatment. Due to wide variations of antimicrobial class within use category, feedyard level antimicrobial use is reported only by antimicrobial class. Use values for medically important and not medically important antimicrobial classes are reported separately. Regimens are described for each antimicrobial class within use category by milligrams per regimen and by timeframe from first to last administration. The authors' selection of measures reported here was driven by a desire to minimize necessary assumptions, resulting in transparent reporting of values which can be directly related back to the factors within feedyard systems which may have influenced calculations. Reporting the number of regimens stratified by antimicrobial class within use category and then describing the characteristics of the reported regimens (milligrams per regimen and timeframe) optimize these objectives for reporting., (© 2020 Wiley-VCH GmbH.)

US animal shelters house and care for dogs with unknown medical histories. Such unknown medical backgrounds pose concern for zoonotic transmission of diseases to the shelter staff. One important zoonotic exposure is to rabies virus which is almost always fatal after the onset of symptoms. The objective of this study was to identify the characteristics of dog shelters associated with the probability that the shelter had a policy to vaccinate shelter personnel against rabies. Five states with an established shelter registry were selected from each geographic region of the United States. A list of shelters within those states was developed from the registry list, through Internet searches and comparisons with other known lists. At least two forms of direct communication were used to ensure that humane organizations met the study definition of a dog shelter. In total, 342 of 461 (73%) shelters that met the study definition were visited by a team of students. Forty-two of 332 (13%) shelters responding to the question required staff to be vaccinated against rabies. Logistic regression was utilized to test shelter characteristics for association with the probability that they have a rabies vaccination policy for shelter staff. Municipally funded shelters were more likely to vaccinate staff for rabies than shelters funded privately (OR = 3.0, 95% CI = 1.40-6.39). These results demonstrate that shelter funding source may influence rabies control programmes in shelters., (© 2020 Blackwell Verlag GmbH.)

In this Research Reflection we review management practices in small family farms with less than 100 cows. Small farms represent the majority of farms in the EU and the world, and they are of great importance for the economy of a country. On cattle farms, the welfare of calves is of primary importance for the profitability of the herd, and poor management is one of the main factors influencing calf health and survival. Data on the risk factors for calf welfare issues in small-scale farms are limited. For this purpose, the literature data from six world countries were presented and compared, including Serbia and Slovenia where a survey related to the issue was carried out within the COST Action FA1308, DairyCare. Some practices within the following areas in calf management were considered: calving management, care for new-born calves, use of painful procedures, colostrum management, cow-calf separation, calf feeding, weaning, calf housing, and general monitoring. In each of the countries, the health and welfare of calves are threatened by some omissions in rearing practices and the major are related to the new-born calf management, the feeding and watering management, and the application of hygienic measures. Many farmers are well aware of the importance of proper calf rearing; others would need more incentive to improve calf management. Each country should pay attention to the education of farmers about the most common deficiencies in calf management.

According to American Veterinary Medical Association statistics, veterinarians employed in the not-for-profit sector account for the smallest group by type of employment. However, this group has experienced the greatest amount of change, with an increase of 52% between 2008 and 2013 and 55% between 2013 and 2018. Despite this growth, there has been a paucity of information regarding the salary, benefits, hours, and job duties that come with a career in shelter medicine. An initial survey of shelter medicine salary, benefits, hours, and job duties was conducted in 2011, and a similar survey conducted in 2018. All responses were anonymous. Results from 2018 were compared to 2011 using 2 sample test of proportions (counts) or Mann-Whitney (Wilcoxon rank sum) test (medians). A total of 207 conforming responses were received in 2011, and 219 in 2018. Median salary for all full-time veterinarians in the field of shelter medicine was $75,000 (interquartile range [IQR], 65,000-85,000) in 2011 and $94,500 (IQR, 80,000-110,000) in 2018. Part-time shelter employed veterinarians in 2011 worked a median of 20 hours (IQR 7-28) for an hourly rate of $41 (IQR, 29-56) while they worked a median of 26 hours (IQR, 15-32) for an hourly rate of $48 (IQR, 36-66) in 2018. There was an increase in the provision of all categories of benefits and an increase in veterinarians employed in academia and leadership. Demographics were similar, with the exception of increases in the number of boarded specialists and veterinarians who had completed a residency. Veterinarians reporting that shelter medicine had been offered in their curriculum increased by 44%. Budgets for shelters were reported to be higher, while animal intake and daily count of animals in care was lower. Comparison between surveys of shelter medicine veterinarians in 2011 and 2018 showed a consistent increase in salary, benefits and resources. There were indicators that the field of shelter medicine has matured as a discipline, particularly with regard to the availability of shelter medicine education and increased number of boarded specialists., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The objective of this study was to investigate the management practices that affect undesirable behaviors in American Quarter Horses (AQH) confined to box stalls. A total of 105 adult AQH, comprising 29 females, 22 intact males, and 54 castrated males, housed in box stalls for at least 30 days, were included in the study. Behavioral activities were recorded through visual inspection at 5-min intervals over a 24-h period by two observers who took turns in shifts of 4 hours. Parameters related to animal characteristics, stall conditions, handling, training, nutrients supplied, and feeding behaviors were considered independent variables, and the time spent in undesirable behaviors was the dependent variable. Data were subjected to exploratory factor analysis and hierarchical cluster analysis. Four principal components were extracted. Two clusters were identified based on the time spent in undesirable behaviors: low-incidence group (25 ± 13 minutes) and high-incidence group (97 ± 52 minutes). Nutritional status (P = .1447), physiological status (P = .1372), and training routine (P = .1160) had no significant effects on the dependent variable; however, the effect of feeding behavior (P = .0444) was significant. A low dry matter intake/requirement ratio (P = .0470) and a high heart rate at rest (P = .0444) indicated that inadequate nutrient supply is a determinant of the time spent in undesirable behaviors in AQH. Aspects related to management practices such as horse nutrition, feeding behaviors, and training routine should be considered to reduce undesirable behaviors in AQH., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Mesophilic and thermophilic spore-forming bacteria represent a challenge to the dairy industry, as these bacteria are capable of surviving adverse conditions associated with processing and sanitation and eventually spoil dairy products. The dairy farm environment, including soil, manure, silage, and bedding, has been implicated as a source for spores in raw milk. High levels of spores have previously been isolated from bedding, and different bedding materials have been associated with spore levels in bulk tank (BT) raw milk; however, the effect of different bedding types, bedding management practices, and bedding spore levels on the variance of spore levels in BT raw milk has not been investigated. To this end, farm and bedding management surveys were administered and unused bedding, used bedding, and BT raw milk samples were collected from dairy farms (1 or 2 times per farm) across the United States over 1 yr; the final data set included 182 dairy farms in 18 states. Bedding suspensions and BT raw milk were spore pasteurized (80°C for 12 min), and mesophilic and thermophilic spores were enumerated. Piecewise structural equation modeling analysis was used to determine direct and indirect pathways of association among farm and bedding practices, levels of spores in unused and used bedding, and levels of spores in BT raw milk. Separate models were constructed for mesophilic and thermophilic spore levels. The analyses showed that bedding material had a direct influence on levels of spores in unused and used bedding as well as an indirect association with spore levels in BT raw milk through used bedding spore levels. Specific bedding and farm management practices as well as cow hygiene in the housing area were associated with mesophilic and thermophilic spore levels in unused bedding, used bedding, and BT raw milk. Notably, levels of spores in used bedding were positively related to those in unused bedding, and used bedding spore levels were positively related to those in BT raw milk. The results of this study increase the understanding of the levels and ecology of mesophilic and thermophilic spores in raw milk, emphasize the possible role of bedding as a source of spores on-farm, and present opportunities for dairy producers to reduce spore levels in BT raw milk., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

In an effort to change unsafe tractor operating behaviors among Appalachian youth resulting from practices and habits learned through a socialization process (termed an "apprenticeship of observation"), this study implemented a four-part intervention in high school agricultural education classes that included implementation of a cost-effective rollover protective structure (CROPS) curriculum. The curriculum included farm safety information, specific NIOSH plans for CROPS construction, and procedures for CROPS installation on unprotected tractors. In this exploratory study, pre- and post-assessments were conducted using theory of planned behavior (TPB) constructs to measure changes in four factors that influence changes in learner behavior: learner attitude, perceived social norms, behavioral control, and perceived behavioral intention. Students' perceived knowledge and skills gained through the intervention were also measured because they are integral components in assessing the effectiveness of a curriculum intervention. Participants (N = 83) were high school students from seven schools in three states in the Appalachian region. Findings revealed statistically significant differences in student attitudes toward the use of life-saving CROPS and in perceived knowledge and skills gained through the curriculum implementation. The CROPS curriculum can be an effective intervention effort for addressing the social and behavioral effects of farm youths' apprenticeships of observation by creating more positive attitudes and learning outcomes among youth at risk for tractor rollover fatalities. Recommendations are provided for expanding the applications of the curriculum intervention and the TPB constructs., (Copyright© by the American Society of Agricultural Engineers.)

Competing Interests: All authors have completed and submitted the ICMJE form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

The objectives of this cross-sectional study were to describe housing and management practices on farms using automatic milking systems (AMS) in 2 states of the upper Midwest and to evaluate the association of various housing and management factors with 3 measures of animal welfare: prevalence of lameness, severe hock lesions, and dirty cows. Fifty-four farms were visited once to collect facility measurements and observations, interview the dairy producer, and score cows for locomotion, hock lesions, and hygiene. Median number of AMS units/farm was 2 (interquartile range = 1; range = 1 to 8). Factors concerning labor were the most commonly cited reason by dairy producers for making the transition to the AMS; additional commonly cited factors were an improvement in lifestyle and human health. Number of cows fetched per AMS, or manually brought to the AMS if not milked voluntarily, was 4.7 ± 2.3 cows/AMS per day (8% of cows) for free traffic flow farms and 3.3 ± 1.8 cows/AMS per day (5% of cows) for guided traffic flow farms. Cow resting surface was significantly associated with prevalence of lameness and severe lameness. Farms with sand-bedded freestalls (17.2%) and bedded packs (17.4%) had significantly lower lameness prevalence (score ≥3 on a 1 to 5 scale, with 1 = normal locomotion) than farms with mattress freestalls (30.5%), waterbeds (25.0%), and mattresses with access to pasture (22.6%). Farms with mattresses and access to pasture had similar lameness prevalence to farms with waterbeds, but were lower than farms with mattresses only. A somewhat similar result was found for severe lameness prevalence (score ≥4 on a 1 to 5 scale, with 1 = normal locomotion); farms with sand-bedded freestalls (2.8%), bedded packs (0.0%), and mattress freestalls with access to pasture (1.5%) had significantly lower prevalence than farms with mattresses (7.1%) or waterbeds (10.8%). Severe hock lesion prevalence (score = 3 on a 1 to 3 scale, with 1 = normal, 3 = swelling) in herds with sand-bedded freestalls, waterbeds, and bedded packs were similar and significantly lower than the prevalence in mattress-based freestalls. Cows housed in sand-bedded freestalls had significantly lower prevalence of dirty cows (score = 3 or 3.5 on a 1 to 5 scale, with 1 = clean) than those housed on mattresses and waterbeds, and had significantly lower prevalence of severely dirty cows (score = 4, 4.5 or 5 on a 1 to 5 scale, with 1 = clean) than all other housing systems except waterbeds, which was similar. Manure removal system (manual, automatic, or slatted floor) was significantly associated with prevalence of severely dirty cows; farms with manual scraping had lower prevalence of severely dirty cows than farms where alley scraping was practiced automatically or slatted floors were used. Dairy producers using AMS appeared to be successful with a variety of facility designs and management practices. Cow resting surface in AMS herds was associated with some animal health and welfare measurements., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

In this study the phototactic response of anopheline mosquitoes to different luminous intensity light-emitting diodes (LEDs) was investigated. Centers for Disease Control-type light traps were changed by replacement of the incandescent lamps by 5 mm round type green (520 nm) and blue (470 nm) LEDs of different luminous intensities: green-LED traps with luminous intensities of 10,000, 15,000 and 20,000 millicandela (mcd) and the blue-LED traps with luminous intensities of 4000, 12,000 and 15,000 mcd. Our data showed that increasing luminous intensity has an effect on the attraction of anopheline mosquitoes to light traps, highlighting the importance of taking LEDs and light sources of high luminous intensity into account when using light-trap collections in monitoring populations of Anopheles species., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The Centers for Disease Control and Prevention (CDC) works in conjunction with state, territorial, local and tribal agencies (STLTAs) to prevent the transmission of infectious agents. Issuance of confinement agreements using CDC Form 75.37 'Notice to Owners and Importers of Dogs' to importers of dogs that are not vaccinated or incompletely vaccinated against rabies is part of the agency's regulatory programme to prevent the entry of dogs infected with rabies. Although this is a regulatory programme that depends heavily on partnerships between CDC and STLTAs, CDC had never formally evaluated the acceptability of the confinement agreement process with these partners. Thus, a short survey of nine STLTAs was conducted to evaluate whether these partners have enough personnel and resources to implement the regulation and their general opinions of the confinement agreement process. The results illustrate that CDC partners are dissatisfied to some extent with the process, and there are multiple issues limiting their success in enforcing the regulation., (© 2015 Blackwell Verlag GmbH.)

Reasons for Performing Study: Particle mapping within stalls has demonstrated a relationship between particulate concentrations and visible accumulations of tracheal mucus. However, measurement of breathing zone particulate concentrations, which is the most accurate way to measure exposure, has not been performed to determine the relationship between exposures and accumulations of tracheal mucus sufficient to affect performance., Objectives: To compare breathing zone particulate exposures between horses with tracheal mucus scores (MS) previously demonstrated to affect performance (MS≥2) and those without (MS = 0) visible tracheal mucus., Study Design: Case-control study., Methods: We endoscopically examined 649 Thoroughbred racehorses over 7 months and selected 113 age-matched cases and controls based on the presence (MS≥2) or absence (MS = 0) of tracheal mucus, respectively. Inflammatory cell numbers in tracheal lavage were also determined. Breathing zone monitors recorded particulate exposure during 3 time periods (mid-day, evening and overnight). Total recording time averaged 17.5 h/horse., Results: The overall prevalence of MS≥2 in the observed stables was 23%. Breathing zone particular matter (PM10) concentrations were very similar to previously reported ambient concentrations. During the evening and overnight, cases had significantly higher breathing zone PM10 concentrations and neutrophil counts than controls. Inflammatory cell counts were associated with average PM10 concentrations throughout the day., Conclusions: Breathing zone particulate concentrations are associated with MS≥2 and inflammatory cell numbers. If breathing zone particulate exposures are predominantly influenced by ambient PM concentrations, racing stable management practices to reduce particle exposures should greatly reduce the prevalence of tracheal mucus., (© 2014 EVJ Ltd.)

Although it has become increasingly popular to keep backyard chickens in the United States, few studies have provided information about these flocks. An online survey of backyard chicken owners was conducted, advertised through Master Gardeners' websites, social platforms, and other sites. The survey had 56 questions about flock history, husbandry, health care, and owner attitudes and demographics. Surveys received (n = 1,487) came almost equally from urban, suburban, and rural areas. Most (71%) respondents owned fewer than 10 chickens and had kept chickens for less than 5 yr (70%). Major reasons for keeping chickens were as food for home use (95%), gardening partners (63%), pets (57%), or a combination of these. Rural respondents had larger flocks (P ≤ 0.001) and were more likely to keep chickens as a source of income or for show (P ≤ 0.001) than urban and suburban respondents. Owners thought that eggs/meat from their chickens were more nutritious (86%), safer to consume (84%), and tasted better (95%) than store-bought products, and also that the health and welfare of their chickens was better (95%) than on commercial farms. The majority (59%) indicated no flock health problems in the last 12 mo. However, there was a lack of awareness about some poultry health conditions. Many knew either little or nothing about exotic Newcastle or Marek's disease, and most (61%) did not vaccinate against Marek's. Respondents wanted to learn more about various flock management topics, especially how to detect (64%) and treat (66%) health problems. The Internet was the main source of information (87%) used by backyard flock owners, followed by books/magazines (62%) and feed stores (40%). Minimizing predation was the most cited challenge (49%), followed by providing adequate feed at low cost (28%), dealing with soil management (25%), and complying with zoning regulations (23%). The evidence obtained from this survey will help to determine what information and resources are needed to maintain good biosecurity and improve the health and welfare of backyard flocks., (©2014 Poultry Science Association Inc.)

More than thirty years have passed since canine parvovirus (CPV) emerged as a significant pathogen and it continues to pose a severe threat to world canine populations. Published information suggests that flies (Diptera) may play a role in spreading this virus; however, they have not been studied extensively and the degree of their involvement is not known. This investigation was directed toward evaluating the vector capacity of such flies and determining their potential role in the transmission and ecology of CPV. Molecular diagnostic methods were used in this cross-sectional study to detect the presence of CPV in flies trapped at thirty-eight canine facilities. The flies involved were identified as belonging to the house fly (Mucidae), flesh fly (Sarcophagidae) and blow/bottle fly (Calliphoridae) families. A primary surveillance location (PSL) was established at a canine facility in south-central South Carolina, USA, to identify fly-virus interaction within the canine facility environment. Flies trapped at this location were pooled monthly and assayed for CPV using polymerase chain reaction (PCR) methods. These insects were found to be positive for CPV every month from February through the end of November 2011. Fly vector behavior and seasonality were documented and potential environmental risk factors were evaluated. Statistical analyses were conducted to compare the mean numbers of each of the three fly families captured, and after determining fly CPV status (positive or negative), it was determined whether there were significant relationships between numbers of flies captured, seasonal numbers of CPV cases, temperature and rainfall. Flies were also sampled at thirty-seven additional canine facility surveillance locations (ASL) and at four non-canine animal industry locations serving as negative field controls. Canine facility risk factors were identified and evaluated. Statistical analyses were conducted on the number of CPV cases reported within the past year to determine the correlation of fly CPV status (positive or negative) for each facility, facility design (open or closed), mean number of dogs present monthly and number of flies captured. Significant differences occurred between fly CPV positive vs. negative sites with regard to their CPV case numbers, fly numbers captured, and number of dogs present. At the ASL, a statistically significant relationship was found between PCR-determined fly CPV status (positive or negative) and facility design (open vs. closed). Open-facility designs were likely to have more CPV outbreaks and more likely to have flies testing positive for CPV DNA., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Every state in the United States has regulations prohibiting acts of neglect and cruelty against animals. Local law enforcement and animal control agencies are responsible in many communities to enforce these statutes. As society's perception of horses has changed from their origin as livestock to companion animals in modern times, owners have transitioned their care and management. The goal of this study was to identify the role and capacities of local animal control services in the United States that investigate equine neglect, cruelty, and abandonment investigations and to identify challenges and outcomes of the investigations. A 128-question online survey was accessible for animal agencies to complete. Comprehensive questions included their capacity for investigating equine cases, funding, housing for horses, and causes and outcomes of investigations. Respondents also were asked to select a single case and provide detailed information on the condition of horses, seizure and custody procedures, costs, and prosecution proceedings. A total of 165 respondents from 26 states completed all or the majority of the questions. A total of 6,864 equine investigations were initiated between 2007 and 2009 by 90 agencies, which extrapolates to 38 investigations annually per agency. A typical agency has an average annual budget of $740,000, employs 7 animal control officers, and spends about $10,000 annually on equine cases. Neglect was ranked as the most common reason for investigation. Owner ignorance, economic hardship, and lack of responsibility were the highest ranked causes of neglect and cruelty. Individual cases were provided by 91 agencies concerning 749 equines. The physical condition of the horse was the primary factor of investigation, and low body condition, parasite infestation, and compromised dental condition were present in most seized horses. Over half of the equine owners previously had been investigated or charged with neglect or cruelty of animals or were identified with cruelty or abuse offenses to people. Less than 3% of the cases advanced to adjudication, and these were likely to be decided by a judge rather than a jury. Judgments of guilty verdicts and pleas were 9 times more common than acquittal. Challenges for equine investigations cases included lack of funding, limited availability of facilities for horses, and providing educational materials for horse owners to aid in prevention and resolution of neglect cases.

Objective: To examine the feasibility of depopulation of a large feedlot during a foot-and-mouth disease (FMD) outbreak in the United States., Design: Delphi survey followed by facilitated discussion., Sample: 27 experts, including veterinary toxicologists and pharmacologists, animal welfare experts, feedlot managers, and consulting veterinarians., Procedures: 4 veterinary pharmacologists, 5 veterinary toxicologists, 4 animal welfare experts, 26 consulting veterinarians, and 8 feedlot managers were invited to participate in a Delphi survey to identify methods for depopulation of a large feedlot during an FMD outbreak. A facilitated discussion that included 1 pharmacologist, 1 toxicologist, 1 animal welfare expert, 2 consulting veterinarians, and 2 feedlot managers was held to review the survey results., Results: 27 of 47 invited experts participated in the Delphi survey. Survey consensus was that, although several toxic agents would effectively cause acute death in a large number of animals, all of them had substantial animal welfare concerns. Pentobarbital sodium administered IV was considered the most effective pharmacological agent for euthanasia, and xylazine was considered the most effective sedative. Animal welfare concerns following administration of a euthanasia solution IV or a penetrating captive bolt were minimal; however, both veterinarians and feedlot managers felt that use of a captive bolt would be inefficient for depopulation. Veterinarians were extremely concerned about public perception, human safety, and timely depopulation of a large feedlot during an FMD outbreak., Conclusions and Clinical Relevance: Depopulation of a large feedlot during an FMD outbreak would be difficult to complete in a humane and timely fashion.

In a biomedical research environment, research or management procedures may render continuous full contact pairing of rhesus macaques (Macaca mulatta) unfeasible. This study aimed to determine whether separation on a frequent basis or housing in adjacent cages with tactile contact interferes with the behavioral benefits of continuous full contact. Behavioral data (1260 hours) were collected from 32 adult females and 16 adult males housed at two National Primate Research Centers. Subjects were studied in four housing conditions: single housing, full contact pair housing, intermittent contact pair housing, and protected contact housing. After introduction, each pair was housed in each of the three social housing conditions in varying order. Among females, but not males, introducing animals into full and intermittent contact reduced levels of abnormal behavior. There was a trend toward this reduction in protected contact. In both females and males, full and intermittent contact was associated with lower levels of anxiety-related behavior, but protected contact was not. Females spent more time inactive in protected contact than either full or intermittent contact, and males showed a trend toward less inactivity following introduction into full contact. Both sexes showed less affiliation in protected contact compared to the other forms of social housing. Agonistic behavior among females was not affected by housing condition; among males, levels were equivalent in full and intermittent contact but were higher in intermittent than protected contact. Frequent separation of pairs does not appear to detract from the behavioral benefits of pair housing. Separation by a barrier permitting tactile contact is inferior to other forms of social housing but showed modest improvements over single housing nonetheless. This study can guide the provision of social contact to rhesus macaques under conditions restricting pairs from continuous full contact., (© 2013 Wiley Periodicals, Inc.)

The ultimate goal of the Three Rs is the full replacement of animals used in biomedical research and testing. However, replacement is unlikely to occur in the near future; therefore the scientific community as a whole must continue to devote considerable effort to ensure optimal animal welfare for the benefit of the science and the animals, i.e., the R of refinement. Laws governing the care and use of laboratory animals have recently been revised in Europe and the US and these place greater emphasis on promoting the well-being of the animals in addition to minimizing pain and distress. Social housing for social species is now the default condition, which can present a challenge in certain experimental settings and for certain species. The practice of positive reinforcement training of laboratory animals, particularly non-human primates, is gathering momentum but is not yet universally employed. Enhanced consideration of refinement extends to rodents, particularly mice, whose use is still increasing as more genetically modified models are generated. The wastage of extraneous mice and the method of their euthanasia are refinement issues that still need to be addressed. An international, concerted effort into defining the needs of laboratory animals is still necessary to improve the quality of the animal models used as well as their welfare.

Between July 2007 and December 2011, 2660 environmental drag swab samples were collected in total from California layer flocks on behalf of the California Egg Quality Assurance Program (CEQAP), the egg safety rule (21 CFR Parts 16 and 118) of the Food and Drug Administration (FDA), or both. The samples were processed by the California Animal Health and Food Safety Lab, and positive or negative results for Salmonella enterica serovar Enteritidis (SE) were recorded. This study retrospectively compares the differences between the FDA and CEQAP programs with respect to their SE environmental sampling surveillance results. To accomplish this comparison, two different CEQAP (new and old) data sets representing different SE environmental surveillance approaches in the life of the flock were compared against each other and against the FDA's SE environmental testing plan. Significant differences were noted between the CEQAP and FDA programs with respect to the prevalence of SE in the farm environment. Analyses of the prevalence of SE at different stages in the flock's life cycle (chick papers, preproduction, midproduction, postmolt, and premarket) found the highest prevalence of SE in premarket (11.9%), followed by postmolt (3.5%) and midproduction (3.4%), and there was a tie between chick papers and preproduction (2.1%). To assess the main effects of the presence of SE in the farm environment, backwards binary logistic regression was used. Of six independent variables examined (age of flock, year, season, owner, CEQAP membership, and analysis of pooled samples vs. individual swabs), only age of flock, owner, and year were determined to be significant factors in the final model. Although CEQAP membership and pooling vs. individuals swabs were not included in the final model, Pearson chi-square tests did show significantly higher odds of SE for non-CEQAP member farms and higher odds of SE in pooled samples vs. individual swabs.

Objective: To estimate the seroprevalence of antibodies against H3N8 canine influenza virus (CIV) in a population of US dogs with influenza-like illness (ILI) and to identify factors associated with seropositivity., Design: Cross-sectional study., Animals: 1,268 pet and shelter dogs with ILI in 42 states., Procedures: Serum samples collected from dogs from 2005 through June 2009 were tested for H3N8 CIV antibodies with a hemagglutination inhibition assay. Intrinsic factors (age, breed, and sex), extrinsic factors (dogs housed in a shelter facility, boarding kennel, or other setting), and geographic region (southwest, west, Midwest, southeast, and northeast) were compared between seropositive and seronegative dogs to identify variables associated with seropositivity., Results: Most (750/1,268 [59%]) dogs in the study were from Colorado, Florida, or New York. The overall seroprevalence of antibodies against H3N8 CIV was 49% (618/1,268 dogs; 95% confidence interval, 46% to 51%). The annual prevalence of H3N8 CIV seropositivity increased from 2005 (44%) to 2006 (53%) and 2007 (62%), then decreased in 2008 (38%) and 2009 (15%). The likelihood of H3N8 CIV seropositivity was associated with geographic region (southeast during 2005, west and northeast during 2006 and 2007, and northeast during 2008) and exposure setting (dogs housed in a shelter facility or boarding kennel during 2005 and 2006)., Conclusions and Clinical Relevance: Results of this study suggested there is a need for continued surveillance for H3N8 CIV infection in dogs in the United States and that personnel in communal dog-housing facilities should formulate, implement, and evaluate biosecurity protocols to reduce the risk of CIV transmission among dogs.

Although bovine respiratory disease complex (BRDC) is common in post-weaning cattle, BRDC prediction models are seldom analyzed. The objectives of this study were to assess the ability to predict cumulative cohort-level BRDC morbidity using on-arrival risk factors and to evaluate whether or not adding BRDC risk classification and daily BRDC morbidity and mortality data to the models enhanced their predictive ability. Retrospective cohort-level and individual animal health data were used to create mixed negative binomial regression (MNBR) models for predicting cumulative risk of BRDC morbidity. Logistic regression models were used to illustrate that the percentage of correctly (within |5%| of actual) classified cohorts increased across days, but the effect of day was modified by arrival weight, arrival month, and feedlot. Cattle arriving in April had the highest (77%) number of lots correctly classified at arrival and cattle arriving in December had the lowest (28%). Classification accuracy at arrival varied according to initial weight, ranging from 17% (< 182 kg) to 91% (> 409 kg). Predictive accuracy of the models improved from 64% at arrival to 74% at 8 days on feed (DOF) when risk code was known compared to 56% accuracy at arrival and 69% at 8 DOF when risk classification was not known. The results of this study demonstrate how the predictive ability of models can be improved by utilizing more refined data on the prior history of cohorts, thus making these models more useful to operators of commercial feedlots.

Animal shelter workers are a vulnerable population whose exposure to zoonotic disease may be greater compared with the general population. The aim of this project was to identify baseline zoonotic disease knowledge of animal shelter workers and to develop and evaluate zoonotic disease awareness training. Ten animal shelters in six western states were randomly selected. One hundred and eleven trainees were evaluated by identical pre- and post-training tests. Training topics included identification of clinical signs, susceptible species, and transmission of disease to animals and to humans. Zoonotic diseases included rabies, plague, leptospirosis, internal parasites, methicillin-resistant Staphylococcus aureus (MRSA) and salmonella. A statistically significant difference in overall total scores between pre-test (58.5%) and post-test (69.5%) was observed (P = 0.0001). No association was observed between test scores and length of time working in animal shelters, or with the participants' role at the animal shelter. Overall test scores were raised by 11%. The lowest baseline levels of knowledge were found with leptospirosis, MRSA, plague and rabies, emerging diseases with increasing prevalence and high consequence. Zoonotic disease awareness training is a valuable service to animal shelters. In the current study, training was modestly successful in transferring short-term knowledge to animal shelter workers. To understand and evaluate the effectiveness of training completely, observable or measureable behaviours should be compared before and after training. Long-term assessment with measureable outcomes is needed., (© 2011 Blackwell Verlag GmbH.)

1. Effective nutritional approaches to counteract the negative effects of stress may provide food animal producers with useful alternatives to antibiotics. In this study, turkeys were fed on a standard diet, or the same diet supplemented with yeast extract (YE), to determine if YE would improve disease resistance in a stress model. 2. At 16 weeks of age, half of the birds were exposed to a bacterial challenge using a coarse spray of the pen environment. A subset of control and challenged birds was also treated with dexamethasone (Dex) prior to challenge (Dex/challenge). At 18 weeks, another subset was subjected to a 12?h transport stress protocol (Challenge/transport). All birds were bled and necropsied the morning after transport. The numbers and proportions of blood cells and the heterophil oxidative burst activity (OBA) were determined. Serum corticosterone (Cort) levels of male birds were measured using a commercial ELISA kit. Body weight and gain were increased by YE during week 1. 3. YE decreased mortality and bacterial isolation following Dex/challenge only in females. Cort levels in male turkeys were decreased by YE and Dex treatment. OBA was higher in males and in birds given YE and was reduced by challenge and transport. 4. These results suggest there may be gender differences in the turkey stress response and that dietary YE has potential for modulating the impact of stress on innate immunity of turkeys.

Since 1996, the emergence of Asian-origin highly pathogenic avian influenza subtype H5N1 has spurred great concern for the global poultry industry. In the United States, there is concern over the potential of a foreign avian disease incursion into the country. Noncommercial poultry operations, such as upland game bird facilities in the United States, may serve as a potential source of avian disease introduction to other bird populations including the commercial poultry industry, backyard flocks, or wildlife. In order to evaluate how to prevent disease transmission from these facilities to other populations, we examined biosecurity practices and bird movement within the upland game bird industry in the United States. Persons that held a current permit to keep, breed, or release upland game birds were surveyed for information on biosecurity practices, flock and release environments, and bird movement parameters. Biosecurity practices vary greatly among permit holders. Many facilities allow for interaction between wild birds and pen-reared birds, and there is regular long-distance movement of live adult birds among facilities. Results suggest that upland game bird facilities should be targeted for biosecurity education and disease surveillance efforts.

The 1985 amendment to the United States Animal Welfare Act (AWA) to promote psychological well being of primates in the laboratory represents an acknowledgment of an important welfare problem concerning nonhuman animals. How effective has this amendment been? Perhaps the best-known contributor to psychological distress in primates in the laboratory is nonsocial housing; yet, available analyses suggest that little progress has been made in avoiding single-caging of these animals. Another way to assess psychological well being is to examine rates of self-abusive behavior in laboratory primates. If the AWA has been effective, then post-AWA self-harm rates might be lower than pre-AWA rates. However, when we attempted to determine those rates from published studies, data were too sparse to allow a rigorous statistical analysis; of 139 studies reporting primate self-harming behavior, only 9 contained data allowing estimation of self-harming behavior rates. We conclude that the current system of laboratory animal care and record keeping is inadequate to properly assess AWA impacts on primate psychological well being and that more is required to ensure the psychological well being of primates.

In this study, we investigated how the likelihoods of Salmonella presence in various samples from broilers and their grow-out environment throughout one production cycle were related. Sixty-four broiler flocks from 10 complexes of two companies in the southern United States were included in the study. Samples from the gastrointestinal tracts of chicks, transport tray pads and litter and drag swabs from the house were collected on the day of placement of each flock. Approximately, 1 week before harvest, whole bird carcass rinses, caecum and crop samples were collected from birds from these same flocks. On the day of harvest, litter and drag swab samples were also taken from the house after the birds were removed. Upon arrival of the flocks at the processing plant, whole carcass rinses, caecum and crop samples were collected. As the flocks were processed, carcass rinses were collected just before the carcasses entered the immersion chill tank and as they exited the chill tank. Logistic regression was used to model the relationships between the likelihood of Salmonella in samples of each type collected at each sampling point and Salmonella frequencies in all the samples taken from the flock and grow-out environment at preceding production stages. The analysis demonstrated that increased likelihood of Salmonella contaminated carcasses entering the immersion chill tank was associated with higher contamination of the exteriors and crops of birds at arrival for processing as well as house environmental samples at the time of harvest and prior to placement. The best predictors of post-chill broiler carcass Salmonella status were the frequencies of Salmonella in the litter on the day of harvest and prior to placement. The immersion chilling appeared to disrupt some of the relationships between the processing plant and pre-harvest samples., (© 2009 Blackwell Verlag GmbH.)

Mycoplasma haemolamae is a hemotropic mycoplasma that affects red blood cells of llamas (Lama glama) and alpacas (Lama pacos). It is variably associated with anemia, and most infections are subclinical. Development of a polymerase chain reaction assay has facilitated detection of this infection in llamas and alpacas in the United States and other countries. Whether the infection occurs in camelids in South America has previously been unknown. The current study documents a 15.8% infection rate among 76 Peruvian llamas, a 19.3% infection rate among Peruvian alpacas at one site, and a 9.26% infection rate in 108 Chilean alpacas from selected herds. All of the camelids tested appeared to be clinically healthy. No gender or species predilection was found. Only 1 positive camelid younger than 18 months was found. Infection is not associated with anemia, and the mean packed cell volume (PCV) in positive Peruvian camelids was slightly higher than the mean PCV in negative Peruvian camelids. In the Chilean alpacas, the positive alpacas had a slightly lower PCV than the negative alpacas, although the mean PCV was not in the anemic range in any of the groups.

Contamination can occur at a number of stages during farm-to-fork processing. Preharvest intervention is an ongoing area of interest in reduction of risk of foodborne illness. This study examined risk factors associated with detection of Salmonella from cattle in U.S. feedlots. During two visits to 73 feedlots, 25 fresh fecal samples were collected from each of three pen floors. Associations between management and demographic factors and culture status were evaluated using logistic regression. Factors positively associated with culture-positive status included brewers' grains (odds ratio [OR] = 26.35; confidence interval [CI], 10.33-67.20), corn gluten (OR = 10.35; CI, 5.98-17.91), or cottonseed hulls (OR = 8.34; CI, 3.58-19.42) in the ration, and sourcing animals in a pen from multiple herds of origin (OR = 5.17; CI, 2.32-11.51). Factors negatively associated with positive culture status included urea (OR = 0.27; CI, 0.16-0.44), alfalfa, clover, or sorghum silage (OR = 0.31; CI, 0.12-0.79), and antimicrobials of the tetracycline class in the ration (within 2 weeks before sampling, OR = 0.04 and CI, 0.02-0.09; more than 2 weeks before sampling, OR = 0.23 and CI, 0.06-0.80). Since 18.3% of positive samples were on a single operation, a second model was constructed after excluding data from this operation. Three additional variables were retained in the second model, including grain-processing method (OR for dry roll, cracked, or unprocessed grain = 2.99; CI, 1.55-5.75), soybean meal (OR = 2.74; CI, 1.58-4.75), and use of a coccidiostat in the ration (OR for no coccidiostat = 4.50; CI, 2.03-10.01). Considering the increasing use of by-products of the biofuel industry as feeds, further investigation of the association between feeding brewers' grains and corn gluten and Salmonella recovery is warranted.

Methane production from enteric fermentation in cattle is one of the major sources of anthropogenic greenhouse gas emission in the United States and worldwide. National estimates of methane emissions rely on mathematical models such as the one recommended by the Intergovernmental Panel for Climate Change (IPCC). Models used for prediction of methane emissions from cattle range from empirical to mechanistic with varying input requirements. Two empirical and 2 mechanistic models (COWPOLL and MOLLY) were evaluated for their prediction ability using individual cattle measurements. Model selection was based on mean square prediction error (MSPE), concordance correlation coefficient, and residuals vs. predicted values analyses. In dairy cattle, COWPOLL had the lowest root MSPE and greatest accuracy and precision of predicting methane emissions (correlation coefficient estimate = 0.75). The model simulated differences in diet more accurately than the other models, and the residuals vs. predicted value analysis showed no mean bias (P = 0.71). In feedlot cattle, MOLLY had the lowest root MSPE with almost all errors from random sources (correlation coefficient estimate = 0.69). The IPCC model also had good agreement with observed values, and no significant mean (P = 0.74) or linear bias (P = 0.11) was detected when residuals were plotted against predicted values. A fixed methane conversion factor (Ym) might be an easier alternative to diet-dependent variable Ym. Based on the results, the 2 mechanistic models were used to simulate methane emissions from representative US diets and were compared with the IPCC model. The average Ym in dairy cows was 5.63% of GE (range 3.78 to 7.43%) compared with 6.5% +/- 1% recommended by IPCC. In feedlot cattle, the average Ym was 3.88% (range 3.36 to 4.56%) compared with 3% +/- 1% recommended by IPCC. Based on our simulations, using IPCC values can result in an overestimate of about 12.5% and underestimate of emissions by about 9.8% for dairy and feedlot cattle, respectively. In addition to providing improved estimates of emissions based on diets, mechanistic models can be used to assess mitigation options such as changing source of carbohydrate or addition of fat to decrease methane, which is not possible with empirical models. We recommend national inventories use diet-specific Ym values predicted by mechanistic models to estimate methane emissions from cattle.

The aim of this field study was to determine the concentrations and emissions of ammonia and hydrogen sulfide in different types of pig buildings in Korea to allow objective comparison between pig housing types in Korea and other countries. Concentrations of ammonia and hydrogen sulfide in the pig buildings averaged 7.5ppm and 286.5ppb and ranged from 0.8 to 21.4ppm and from 45.8 to 1235ppb, respectively. The mean emissions of ammonia and hydrogen sulfide per pig (normalized to 75kg liveweight) and area (m2) from pig buildings were 250.2 and 37.8mg/h/pig and 336.3 and 50.9mg/h/m2, respectively. Ammonia and hydrogen sulfide concentrations and emissions were higher in the pig buildings managed with deep-pit manure systems with slats and mechanical ventilation than in other housing types.

The primary objective of this study was to compare characteristics of US dairy operations that had one or more nonambulatory cows (unable to rise for any period of time) (cases) with operations that had no nonambulatory cows (controls) during 2004. A secondary objective was to describe factors associated with recovery of the last nonambulatory cow on the operation during 2004. Case dairy operations (n = 1,822) more often fed a total mixed ration [odds ratio (OR) = 2.0; confidence interval (CI): 1.1-3.4], produced more than 9,090 kg of milk (OR = 2.8; CI: 1.8-4.5), and were more likely to be of medium to large herd size (100 or more head of adult cows, OR = 3.7; CI: 2.2-6.2) compared with control dairies (n = 151). Compared with operations where the predominant flooring surface on which lactating cows stood or walked in winter was pasture, operations where pasture was not the predominant surface were at increased risk of having nonambulatory cows (OR = 4.7; CI: 2.2-10.2). Cows nonambulatory for less than 24 h were more likely to recover compared with cows nonambulatory for 24 h or more (OR = 3.0; CI: 2.0-4.4). Cows that received calcium, phosphorus, or potassium while non-ambulatory were more likely to recover (OR = 3.6; CI: 2.1-6.1) than cattle that did not receive these treatments. Cattle that were not repositioned periodically were more likely to recover (OR = 2.1; CI: 1.4-3.1), as were cattle that were not treated by a veterinarian before becoming nonambulatory (OR = 1.9; CI: 1.1-3.3). These findings are consistent with prolonged recumbency and prior history of health issues, respectively. Nonambulatory cattle with hypocalcemia were more likely to recover (OR = 6.0; CI: 3.4-10.7) compared with nonambulatory cows with all other causes of a nonambulatory condition (analyzed collectively as a single variable but including cancer, clinical mastitis, digestive conditions, metabolic imbalances, neurological problems, respiratory disease, other, unknown). The results of this study reveal that the majority of US dairy operations have at least one nonambulatory dairy cow over the course of a year. Additionally, individual animal factors associated with being nonambulatory may lead to improved identification and treatment of animals that are nonambulatory for a prolonged period. From the perspective of recovery, considering euthanasia is appropriate for cows that have been nonambulatory for more than 24 h.

The incidence of initial respiratory disease was followed for 12 weeks in 122 pens of feedlot cattle, based on producer-collected daily morbidity counts. Weekly incidence density was calculated based on the number of new cases and the population at risk. Incidence density was greatest in the 1st week after arrival and decreased in following weeks. Weekly incidence rate varied between pens and over time from 0 to 27.7 cases per 100 animal weeks at risk. A negative binomial model controlling for multiple events within pens and over time was used to model effects on the number of new cases. Mixed gender groups, cattle from multiple sources and increasing distance shipped were associated with increased risk for initial respiratory morbidity. Heavier entry weight was associated with decreased morbidity risk. These factors may be useful in categorizing groups of calves into risk groups for targeted purchase and management decision making.

The objective of this study was to evaluate associations between bulk tank somatic cell count (BTSCC) and herd management practices using data collected in the National Animal Health Monitoring System Dairy 2002 study. Twenty-six percent and 17.8% of 1,013 operations reported a BTSCC < 200,000 cells/mL and > 400,000 cells/mL, respectively. Univariate analysis identified associations between management variables and BTSCC. The use of mattresses, sand, and newspaper as bedding were all associated with a lower BTSCC. Primary lactating cow housing facility, outside maternity housing area, flooring type cows walk or stand on, and use of automatic take-offs were also associated with BTSCC. Multivariate associations between management variables and BTSCC were determined by backward elimination ordinal logistic regression. The odds of an operation from the West, Midwest, and Northeast having a high BTSCC were lower than those from the Southeast. The odds of a higher BTSCC were 2 times greater for operations with a rolling herd average milk production < 9,090 kg/cow per year compared with those with > or = 9,090 kg/cow per year. Operations using composted manure were 2.9 times more likely to have a higher BTSCC than those not using composted manure. Finally, operations that reported not using a coliform mastitis vaccine were 1.7 times more likely to have a higher BTSCC than those using one. Future studies of the association between management practices and BTSCC should include an evaluation of the quality of management practice application and herd prevalence of contagious mastitis pathogens. Significant variables identified in this study dealt with housing, use of composted manure for bedding, and coliform mastitis vaccine use, suggesting the effect of environmental mastitis pathogens may be more influential on BTSCC than previously thought.

Animal welfare regulations in the United States require that nonhuman primate environmental enhancement plans be made in accordance with currently accepted professional standards; however, little information is available for quantifying common practice. Here we report the results of a 2003 survey that was sent to individuals overseeing enrichment programs at a variety of primate research institutions. The surveys requested information on program administration and management, implementation standards, procedures, and constraints pertaining to major categories of environmental enrichment, as well as intervention plans for animals exhibiting behavioral pathologies. Data were obtained on the management of 35,863 primates in 22 facilities. Behavioral scientists performed program oversight at the majority of facilities. Most programs reported recent changes, most commonly due to external site visits, and least commonly resulting from internal review. Most facilities' institutional animal care and use committees (IACUCs) included of individuals with behavioral expertise, and about two-thirds reported that enrichment issues could influence research protocol design. While most primates were reported to be housed socially (73%), social housing for indoor-housed primates appears to have changed little over the past 10 years. Research protocol issues and social incompatibility were commonly cited constraints. Implementation of feeding, manipulanda, and structural enrichment was relatively unconstrained, and contributions to these aspects of behavioral management generally included individuals in a wide variety of positions within a facility. In contrast, enrichment devices were used on a less widespread basis within facilities, and positive reinforcement programs that involved dedicated trainers were rare. We suggest that altering the role of the IACUC would be a productive avenue for increasing the implementation of social housing, and that an emphasis on prevention rather than intervention against behavioral pathology is warranted. The data from this survey may be useful for anticipating future program evaluations, establishing more effective internal evaluations, and assessing program progress and resource allocation.

Comprehensive field studies were initiated in 2002 to measure emissions of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), methane (CH4), nonmethane hydrocarbons (NMHC), particulate matter <10 microm in diameter, and total suspended particulate from swine and poultry production buildings in the United States. This paper focuses on the quasicontinuous gas concentration measurement at multiple locations among paired barns in seven states. Documented principles, used in air pollution monitoring at industrial sources, were applied in developing quality assurance (QA) project plans for these studies. Air was sampled from multiple locations with each gas analyzed with one high quality commercial gas analyzer that was located in an environmentally controlled on-farm instrument shelter. A nominal 4 L/min gas sampling system was designed and constructed with Teflon wetted surfaces, bypass pumping, and sample line flow and pressure sensors. Three-way solenoids were used to automatically switch between multiple gas sampling lines with > or =10 min sampling intervals. Inside and outside gas sampling probes were between 10 and 115 m away from the analyzers. Analyzers used chemiluminescence, fluorescence, photoacoustic infrared, and photoionization detectors for NH3, H2S, CO2, CH4, and NMHC, respectively. Data were collected using personal computer-based data acquisition hardware and software. This paper discusses the methodology of gas concentration measurements and the unique challenges that livestock barns pose for achieving desired accuracy and precision, data representativeness, comparability and completeness, and instrument calibration and maintenance.

An examination of the economic effects of epidemiologic risk factors for Johne's disease identified regional and herd size differences as having the greatest impact. Having dairy cows that were not born on the operation was the most important factor over which individual producers had the most immediate control. Economic consequences associated with using multiple-cow-maternity housing and multiple-preweaned-calf housing were not statistically significant. Economic welfare analysis was applied, and the GUM Workbench was used to analyse uncertainties in the estimates of the economic impacts.

The prevalence of Cryptosporidium species in 1-2-year-old heifers was determined for 571 animals on 14 dairy farms in seven states on the East Coast of the United States. A fecal specimen collected directly from each heifer was processed to concentrate oocysts that were then examined by polymerase chain reaction (PCR). For every PCR-positive specimen the 18S rRNA gene of Cryptosporidium was sequenced. Cryptosporidium was identified by PCR from heifers on 13 of 14 farms. On all except four farms groups of heifers were housed in a barn or in large covered pens. Others were pastured. From many of the same farms an earlier study reported that 41% of 393 pre-weaned calves and 26.2% of 447 post-weaned calves were infected. In the present study, 11.9% of 571 heifers were infected with Cryptosporidium, 0.7% with Cryptosporidium parvum, the zoonotic species. Of 68 PCR-positive specimens characterized by gene sequencing 1, 4, 10, 24, and 29 calves were infected with Cryptosporidium suis, Cryptosporidium parvum, Cryptosporidium deer-like genotype, Cryptosporidium bovis, and Cryptosporidium andersoni, respectively. These findings demonstrate a lower prevalence of infection in 1-2-year-old dairy cattle than in younger cattle as well as a change in the diversity of species present. Consequently, the risk of humans acquiring infection with C. parvum from exposure to feces from yearling and older cattle appears much lower than from exposure to pre-weaned calves.

Cryptosporidium parvum is a zoonotic protozoan that infects many different mammals including cattle and humans. Cryptosporidiosis has become a concern for dairy producers because of the direct losses due to calves not performing well and the potential for environmental contamination with C. parvum. Identifying modifiable control points in the dynamics of infection in dairy herds will help identify management strategies that mitigate its risk. The quantitative risk assessment approach provides estimates of the risk associated with these factors so that cost-effective strategies can be implemented. Using published data from epidemiologic studies and a stochastic approach, we modeled the risk that C. parvum presents to dairy calves in 2 geographic areas: 1) the New York City Watershed (NYCW) in southeastern New York, and 2) the entire United States. The approach focused on 2 possible areas of exposure--the rearing environment and the maternity environment. In addition, we evaluated the contribution of many risk factors (e.g., age, housing, flies) to the end-state (i.e., total) risk to identify areas of intervention to decrease the risk to dairy calves. Expected risks from C. parvum in US dairy herds in rearing and maternity environments were 41.7 and 33.9%, respectively. In the NYCW, the expected risks from C. parvum in the rearing and maternity environments were 0.36 and 0.33%, respectively. In the US scenarios, the immediate environment contributed most of the risk to calves, whereas in the NYCW scenario, it was new calf infection. Therefore, within the NYCW, risk management activities may be focused on preventing new calf infections, whereas in the general US population, cleaning of calf housing would be a good choice for resource allocation. Despite the many assumptions inherent with modeling techniques, its usefulness to quantify the likelihood of risk and identify risk management areas is illustrated.

West Nile virus (WNV) has spread across the United States causing annual outbreaks since its emergence in 1999. Although severe disease develops only in about 1% of infections, WNV has claimed a total of 564 lives in the 5 years from 1999 to 2003. Observation of flaccid paralysis due to WNV infection at a higher incidence than previously documented and the devastating mortality recorded in infected American bird species triggered concerns about a potentially enhanced virulence of this virus. Here we summarize recent observations made during the American outbreaks regarding host range and transmission modes of WNV, and discuss epidemiological aspects of the emergence of this pathogen in the new habitat.

Chimpanzees are presently classified into three subspecies: Pan troglodytes verus from west Africa, P.t. troglodytes from central Africa, and P.t. schweinfurthii from east Africa. A fourth subspecies (P.t. vellerosus), from Cameroon and northern Nigeria, has been proposed. These taxonomic designations are based on geographical origins and are reflected in sequence variation in the first hypervariable region (HVR-I) of the mtDNA D-loop. Although advances have been made in our understanding of chimpanzee phylogenetics, little has been known regarding the subspecies composition of captive chimpanzees. We sequenced part of the mtDNA HVR-I region in 218 African-born population founders and performed a phylogenetic analysis with previously characterized African sequences of known provenance to infer subspecies affiliations. Most founders were P.t. verus (95.0%), distantly followed by the troglodytes schweinfurthii clade (4.6%), and a single P.t. vellerosus (0.4%). Pedigree-based estimates of genomic representation in the descendant population revealed that troglodytes schweinfurthii founder representation was reduced in captivity, vellerosus representation increased due to prolific breeding by a single male, and reproductive variance resulted in uneven representation among male P.t.verus founders. No increase in mortality was evident from between-subspecies interbreeding, indicating a lack of outbreeding depression. Knowledge of subspecies and their genomic representation can form the basis for phylogenetically informed genetic management of extant chimpanzees to preserve rare genetic variation for research, conservation, or possible future breeding., (Copyright 2005 Wiley-Liss, Inc.)