A New Approach for Managing Bovine Tuberculosis: Veterinary Services’ Proposed Action Plan

Bovine tuberculosis (TB) is a serious disease with animal health, public health, and international trade consequences. The cooperative Federal-State-industry effort to eradicate bovine TB from cattle in the United States has made significant progress since the program’s inception in 1917. However, the goal of eradication remains elusive. This proposed action plan presents Veterinary Services’ (VS’) current thinking about changes we are considering for the TB program to address our current challenges. This action plan will: 1. Reduce the introduction of TB into the U.S. national herd from imported animals and wildlife by: o Applying additional requirements to cattle imports from Mexico o Enhancing efforts to mitigate risks from wildlife 2. Enhance TB surveillance by: o Crafting a comprehensive national surveillance plan o Accelerating diagnostic test development to support surveillance 3. Increase options for managing TB-affected herds by: o Conducting epidemiological investigations and assessing individual herd risk o Applying whole-herd depopulation judiciously and developing alternative control strategies o Applying animal identification (ID) standards to meet animal ID needs 4. Modernize the regulatory framework to allow VS to focus resources where the disease exists 5. Transition the TB program from a State classification system to a science-based zoning approach to address disease risk To succeed, this new approach will require VS’ continued partnership with State animal health and wildlife officials, other Federal agencies, industry, international partners, academia, and other stakeholders. Successful partnerships will allow us to use available resources efficiently to achieve program objectives and protect our nation’s herd. Implementation of the VS proposed action plan will benefit Federal and State animal health officials, the regulated industries, and producers by allowing a more rapid response that employs up-to-date science and can adapt rapidly to changing situations.

The Role of a Wildlife Reservoir in the Epidemiology of Bovine Tuberculosis

The objective of this project was to study the epidemiology of bovine tuberculosis in the presence of a wildlife reservoir species. Cross-sectional and longitudinal studies of possum populations with endemic bovine tuberculosis infection were analyzed. The results were used to develop a computer simulation model of the dynamics of bovine tuberculosis infection in possum populations. A case-control study of breakdowns to tuberculosis infection in cattle herds in the Central North Island of New Zealand was conducted to identify risk factors other than exposure to tuberculosis in local possum populations.

Bovine Tuberculosis in Michigan Wildlife and Livestock

Since 1994, the state of Michigan has recognized a problem with bovine tuberculosis (TB), caused by Mycobacterium bovis, in wild white-tailed deer from a 12-county area in northeastern Lower Michigan. A total of 65,000 free-ranging deer have been tested, and 340 have been found to be positive for M. bovis. The disease has been found in other wildlife species, and, in 1998, in domestic cattle, where to date 13 beef cattle and 2 dairy cattle herds have been diagnosed with bovine TB. Unfortunately, the situation is unique in that there have never been reports of self-sustaining bovine TB in a wild, free-ranging cervid population in North America. Scientists, biologists, epidemiologists, and veterinarians who have studied this situation have concluded that the most logical theory is that high deer densities and the focal concentration caused by baiting (the practice of hunting deer over feed) and feeding are the factors most likely responsible for the establishment of self-sustaining TB in free-ranging Michigan deer. Baiting and feeding have been banned since 1998 in counties where the disease has been found. In addition, the deer herd has been reduced by 50% in the endemic area with the use of unlimited antlerless permits. The measures of apparent TB prevalence have been decreased by half since 1997, providing hopeful preliminary evidence that eradication strategies are succeeding.

Arctic Report Card 2007: Tracking Recent Environmental Changes

Collectively, the observations indicate that the overall warming of the Arctic system continued in 2007. There are some elements that are stabilizing or returning to climatological norms. These mixed tendencies illustrate the sensitivity and complexity of the Arctic System. Atmosphere: Hot spot shifts toward Europe Ocean: North Pole Temperatures at depth returning to 1990s values Sea Ice: Summer extent at record minimum Greenland: Recent warm temperatures associated with net ice loss Biology: increasing tundra shrub cover and variable treeline advance; up to 80% declines in some caribou herds while goose populations double Land: Increase in permafrost temperatures The Arctic Report Card 2007 is introduced as a means of presenting clear, reliable and concise information on recent observations of environmental conditions in the Arctic, relative to historical time series records. It provides a method of updating and expanding the content of the State of the Arctic Report, published in fall 2006, to reflect current conditions. Material presented in the Report Card is prepared by an international team of scientists and is peer-reviewed by topical experts nominated by the US Polar Research Board. The audience for the Arctic Report Card is wide, including scientists, students, teachers, decision makers and the general public interested in Arctic environment and science. The web-based format will facilitate future timely updates of the content.

Book Review of Portraits of the Bison: An Illustrated Guide to Bison Society by Wes Olson

Thundering herds of bison have become synonymous with the pre-European colonization of the Great Plains. As such, they have captured the imagination of countless people, including Wes Olson, a 20-year warden for Parks Canada. Throughout Portraits of the Bison, based on both existing literature and the author's extensive experience observing and managing these animals, Olson's bison fascination is not only obvious but infectious. A remarkably talented artist as well, Olson's line drawings appear throughout the book, accompanied by Johane Janelle's photographs.

Epizootiologic Survey of Mycobacterium Bovis in Wildlife and Farm Environments in Northern Michigan

Bovine tuberculosis (bovine TB), caused by Mycobacterium bovis, has reemerged in northern Michigan, USA, with detections in white-tailed deer (Odocoileus virginianus) in 1994 and in cattle in 1998. Since then, significant efforts have been directed toward reducing deer densities in the area in the hopes of reducing the bovine TB prevalence rate in deer and eliminating spillover of the disease into cattle. Despite the success of the efforts to reduce deer densities, additional cattle herds have become infected. Other mammals can be infected with M. bovis, and some carnivores and omnivores had been found to be infected with the disease in northern Michigan, USA. We conducted a multiyear surveillance effort to detect bovine TB in wild species of mammals in the Michigan, USA, outbreak area. From 2002 to 2004, tissue samples from 1,031 individual animals of 32 species were collected, processed, and cultured for M. bovis. Only 10 (1.0%) were culture-positive for M. bovis (five raccoons [Procyon lotor], four opossums [Didelphis virginiana], and one grey fox [Urocyon cinereoargenteus]). We also found two raccoons and four opossums to be positive for Mycobacterium avium. We collected 503 environmental samples from cattle farms recently identified as bovine TB positive; none yielded positive M. bovis culture results. Finally, we used infrared cameras to document wildlife use of four barns in the area. Many avian and mammalian species of wildlife were observed, with raccoons being the most commonly observed species. This surveillance study identified no new wildlife species that should be considered significant reservoirs of bovine TB in the outbreak area in northern Michigan, USA. However, the relatively high, apparent bovine TB prevalence rates in some carnivorous and omnivorous species, their relatively long life spans, and their frequent use of barns, suggests that removal of raccoons, opossums, foxes, and coyotes (Canis latrans) should be considered when a newly infected farm is depopulated of cattle.

Taking an Endemically Infected Bovine Tb Area Through to Livestock Clearance. A Case Study of West Taupo, New Zealand

The Pest Management Strategy for Bovine Tuberculosis (Tb) in New Zealand aims to achieve efficient freedom from Tb by 2013 and to eradicate the disease from livestock and wildlife. The West Taupo area, in the central North Island of New Zealand, was chronically infected with Tb in both domestic livestock herds (cattle and deer) and within wildlife populations (brushtail possum, ferret, feral deer and pigs). Through the development and implementation of a technically innovative management plan, this area is now approaching Tb free status. The case study / management plan reported here discusses the operational techniques and strategies that were implemented to achieve Tb clearance in the livestock herds and the possibilities of eradication from wildlife species. It particularly identifies the variations in control strategies that are required as population densities reduce and the challenges of maintaining strong effective control at low densities of some wildlife species, whilst not needing to control other species that were initially clinically diagnosed with Tb control. Use of diagnostic tools and education as an area moves through the cycle towards Tb freedom are as essential as the physical control activities. The use of intensive monitoring of both livestock and wildlife species as trend and performance indicators and the need to educate farmers, hunters and other land use groups become increasingly important.

The Eradication of Bovine Tuberculosis From Infected Wildlife Populations: A New Zealand Scenario

The Animal Health Board (AHB) is the agency responsible for controlling bovine tuberculosis (Tb) in New Zealand. In 2000, the AHB embarked on a strategy designed to reduce the annual period prevalence of Tb infected cattle and farmed deer herds from 1.67% to 0.2% by 2012/13. Under current rules of the Office International des Epizooties (OIE) this would allow New Zealand to claim freedom from Tb. The epidemiology of Tb in New Zealand is largely influenced by wildlife reservoirs of infection and control of Tb vector populations is central to the elimination of Tb from New Zealand’s cattle and deer herds. The AHB has classified New Zealand’s land area into Vector Risk Areas (VRAs) where Tb is established in wildlife (currently 39%) and Vector Free Areas (VFAs) where the disease is not established (61%). Within the VRAs the introduced Australian brushtail possum (Trichosurus vulpecula) is the primary wildlife maintenance host and the main source of infection for domestic cattle and deer herds. Southland is a region of New Zealand with a long history of wildlife associated Tb. Progress in reducing infected herd numbers has been impressive in recent years, primarily due to an intensive possum control program. As a result of this reduction, the focus is now shifting to that of providing increasing levels of confidence that Tb is absent from the remaining susceptible wildlife. High levels of confidence of Tb freedom in wildlife will allow the AHB to reduce the wildlife control programs and ultimately cease control altogether, with minimal risk of Tb reemerging. This paper examines the strategies being utilized to provide that confidence. The types of data, the format in which it is collected and the methods of analysis and review are outlined.

Elk in Nebraska: Opportunity or Another Private-Public Land Conundrum

We conducted a comprehensive research project on elk in the Pine Ridge region of northwestern Nebraska from 1995 to 2002 to determine ecological factors that could be used to improve management and reduce damage. The population ranged from 120 to 150 animals, with an average calf:cow ratio of 0.5:1 and bull:cow ratio of 0.4:1. We located 21 radio-collared female elk 6,311 times during 1995 to 1997. Seasonal home ranges of 2 herds were 10 and 44 km2, while average annual home ranges of the herds were much larger (483 and 440 km2, respectively). All wintering areas (n = 21) and 80% of the calving areas (n = 22) were located on privately-owned land. Active timber harvest temporarily displaced elk, most notably during the calving season. Elk shifted home ranges in association with the seasonal availability of agricultural crops, in particular, alfalfa, oats, and winter wheat. Population models indicated that static levels of hunting mortality would lead to a stable population of about 130 elk over 10 years. Most landowners in the Pine Ridge (57%) favored free-ranging elk, but 26% were concerned about damage to agricultural crops and competition with livestock. Habitat suitability models and estimates of social carrying capacity indicate that up to 600 elk could be sustained in the Pine Ridge without significant impacts to landowners. We recommended an integrated management program used to enhance elk habitat on publicly-owned land and redistribute elk from privately-owned land.

Análise multivariada de características reprodutivas e produtivas de vacas da raça Holandesa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prevalência e fatores de risco de leptospirose bovina no Estado do Maranhão

Silva F.J., Conceicao W. L. F., Fagliari J.J., Girio R.J.S., Dias R. A., Borba M. R. & Mathias L. A. 2012. [Prevalence and risk factors of bovine leptospirosis in the State of Maranhao, Brazil.] Prevalencia e fatores de risco de leptospirose bovina no Estado do Maranhao. Pesquisa Veterineria Brasileira 32(4): 303-312. Departamento de Medicina Veterinaria Preventiva e Reproducao Animal, Faculdade de Ciencias Agrarias e Veterinarias, Universidade Estadual Paulista, Via de Acesso Professor Paulo Donato Castellane s/n, Zona Rural, Jaboticabal, SP 14884-900, Brazil. E-mail: fjsepi@gmail.com Prevalence and risk factors of bovine leptospirosis in the State of Maranhao were investigated. Based on production parameters that vary across different production systems, management practices, the purpose of exploitation, the average size of herds and market systems, the state was divided in four sampling circuits. The study aimed to investigate the epidemiological features of bovine leptospirosis in the State of Maranhao, in order to determine the prevalence of the infection in cattle and herds, to determine the occurrence of serovars of Leptospira spp., to identify risk factors associated with leptospirosis in cattle and to differentiate the livestock circuits itself regarding the prevalence of leptospirosis. The survey was conducted in 136 herds in the circuit I, in which 841 >= 24 months old females were analyzed; 238 in the circuit II and 2,582 females were analyzed; 122 in the circuit III and 869 females were analyzed; 77 in the circuit IV and 540 females were analyzed; a total of 573 herds and 4,832 females were analyzed. The presence of antibodies against Leptospira spp. was verified by microscopic agglutination test (MAT). Of the 4,832 cows examined, 1,904 (35.94%, CI 95% = 33.01% -38.98%) were positive. Of the 573 herds, 380 (64.81%, CI 95% = 61.10% -68.35%) were positive. Serovars Hardjo and Wolffi were the most frequent in the state. The circuit III showed the lowest prevalence of leptospirosis in all comparisons. The variables presence of horses (p = 0.000), presence of capybaras (p = 0.034) and herds with up to 32 adult females (p = 0.002) were identified as risk factors for leptospirosis.

Female fertility in a Guzerat dairy subpopulation: Heterogeneity of variance components for calving intervals

The objectives of the present study were to determine if variance components of calving intervals varied with age at calving and if considering calving intervals as a longitudinal trait would be a useful approach for fertility analysis of Zebu dairy herds. With these purposes, calving records from females born from 1940 to 2006 in a Guzerat dairy subpopulation in Brazil were analyzed. The fixed effects of contemporary groups, formed by year and farm at birth or at calving, and the regressions of age at calving, equivalent inbreeding coefficient and day of the year on the studied traits were considered in the statistical models. In one approach, calving intervals (Cl) were analyzed as a single trait, by fitting a statistical model on which both animal and permanent environment effects were adjusted for the effect of age at calving by random regression. In a second approach, a four-trait analysis was conducted, including age at first calving (AFC) and three different female categories for the calving intervals: first calving females; young females (less than 80 months old, but not first calving); or mature females (80 months old or more). Finally, a two-trait analysis was performed, also including AFC and Cl, but calving intervals were regarded as a single trait in a repeatability model. Additionally, the ranking of sires was compared among approaches. Calving intervals decreased with age until females were about 80 months old, remaining nearly constant after that age. A quasi-linear increase of 11.5 days on the calving intervals was observed for each 10% increase in the female's equivalent inbreeding coefficient. The heritability of AFC was 0.37. For Cl. the genetic-phenotypic variance ratios ranged from 0.064 to 0.141, depending on the approach and on ages at calving. Differences among genetic variance components for calving intervals were observed along the animal's lifetime. Those differences confirmed the longitudinal aspect of that trait, indicating the importance of such consideration when accessing fertility of Zebu dairy females, especially in situations where the available information relies on their calving intervals. Spearman rank correlations among approaches ranged from 0.90 to 0.95, and changes observed in the ranking of sires suggested that the genetic progress of the population could be affected by the approach chosen for the analysis of calving intervals. (C) 2012 Elsevier ay. All rights reserved.

Prevalence of leptospirosis in dairy goats in the semiarid region of Paraiba state

Higino S.S.S., Alves C.J., Santos C.S.A.B., Vasconcellos S.A., Silva M.L.C.R., Brasil A.W.L., Pimenta C.L.R.M. & Azevedo S.S. 2012. [Prevalence of leptospirosis in dairy goats in the semiarid region of Paraiba state.] Prevalencia de leptospirose em caprinos leiteiros do semiarido paraibano. Pesquisa Veterinaria Brasileira 32(3):199-203. Universidade Federal de Campina Grande, Centro de Saude e Tecnologia Rural, Unidade Academica de Medicina Veterinaria, Av. Universitaria s/n, Patos, PB 58700-970, Brazil. E-mail: sergio.azevedo@pq.cnpq.br This study aimed to determine the prevalence of positive dairy goat herds and seropositive animals for leptospirosis in the semiarid region of Paraiba state, Brazil. Sampling was designed to determine the prevalence of positive herds (foci) and seropositive animals for leptospirosis. A total of 975 serum samples were collected from goats of 110 dairy herds in the Monteiro municipality, Western Cariri microregion of Paraiba. For the serological diagnosis of leptospirosis the microscopic agglutination test (MAT) was carried out using 24 Leptospira spp. serovars as antigens. A herd was considered positive when existed at least one seropositive animal. The prevalence of positive herds and seropositive animals were 43.6% (95% CI = 34.2-53.4%) and 8.7% (95% CI = 58.7-12.9%) respectively. The most frequent serovars in goats were Autumnalis (1.74%; 95% CI = 0.97-3.09%), Sentot (1.71%; 95% CI = 0.82-3.52%) and Whitcomb (1.39%; 95% CI = 0.65-2.93%), and by herd, serovars Autumnalis (10.9%; 95% CI = 5.8-18.3%), Whitcomb (8.2%; 95% CI = 3.8-15.0%) and Sentot and Patoc (7.3%; 95% CI = 3.2-13.8%) were the most frequent. It is suggested that leptospirosis is spread in goats in the region, and that there is need to implement control and preventive measures in order to reduce infection and economic losses, and to avoid possible transmission of infection to humans.

Molecular characterization of group A bovine rotavirus in southeastern and central-western Brazil, 2009-2010

Rotavirus is an important cause of neonatal diarrhea in humans and several animal species, including calves. A study was conducted to examine 792 fecal samples collected from calves among 65 dairy and beef herds distributed in two of Brazil's major livestock producing regions, aiming to detect the occurrence of rotavirus and perform a molecular characterization of the rotavirus according to G and P genotypes in these regions. A total of 40 (5.05%) samples tested positive for rotavirus by the polyacrylamide gel electrophoresis (PAGE) technique. The molecular characterization was performed by multiplex semi-nested RT-PCR reactions, which indicated that the associations of genotypes circulating in herds in Brazil's southeastern region were G6P[11], G10P[11], G[-]P[5] + [11], G[-]P[6] in the state of Sao Paulo and G6P[11], G8P[5], G11P[11], G10P[11] in the state of Minas Gerais. In the central-western region, the genotypes G6P[5] + [11], G6P[5], G8P[-], G6P[11], G [-] P[1], G[-] P[11], and G[-] P[5] were detected in the state of Goias, while the genotypes G6P[5], G8[P11], G6[P11], G8[P1], G8[P5], G6[P1] were circulating in herds in the state of Mato Grosso do Sul. The genotypic diversity of bovine rotavirus found in each region under study underlines the importance of characterizing the circulating samples in order to devise the most effective prophylactic measures.

Neospora caninum as causative agent of bovine encephalitis in Brazil

For supporting the Brazilian bovine encephalitis surveillance program this study examined the differential diagnosis of Neospora caninum in central nervous system (CNS) by histological analysis (HE staining), immunohistochemistry (IHC), and nested-PCR using a set of primers from the Nc5 region of the genomic DNA and ITS1 region of the ribosomal DNA. A sample of 302 cattle presenting neurological syndrome and negative for rabies, aged 0 to 18 years, from herds in 10 Brazilian states was evaluated for N caninum from January 2007 to April 2010. All specimens tested negative with IHC and nested-PCR using primers from the ITS I region of ribosomal DNA, while two positive cases (0.66%) were found using primers from the Nc5 region of genomic DNA: a 20 month-old male and a 72 month-old female, both from Sao Paulo State. Only the male presented severe multifocal necrotizing encephalitis associated with mononuclear cell infiltration, a pathognomonic lesion caused by parasites of the family Sarcocystidae, and only this case was associated with N caninum thus representing 0.33% positivity. Future studies should explore the association of IHC and nested-PCR with real-time PCR, a quantitative method that could be standardized for improving the detection of N. caninum in bovine CNS specimens.