Prevalence of serum antibodies to Mycobacterium avium subsp. paratuberculosis in cattle in Galicia (northwest Spain)

Prior to establishing a control and prevention program for Johne's disease in cattle in Galicia (northwest Spain), a survey was conducted to estimate the prevalence of the disease. For this survey, 61,069 animals of at least 1-year of age from 2735 randomly selected herds were bled and samples analyzed with a commercial ELISA. The estimated true individual-level prevalences – assuming the manufacturer's reported test sensitivity of 48.5% and specificity of 98.9% – were 3.02% in dairy cattle, 1.03% in beef cattle and 2.83% in animals from farms with both dairy and beef cattle. True herd prevalences (with herds declared positive if one or more animals tested positive) were 10.69% for dairy herds, 0% for beef herds and 2.71% for mixed herds. When herds were declared positive if at least two animals tested positive, true herd prevalences were 14.75% for dairy herds, 1.47% for beef herds and 12.01% for mixed herds. Assuming a higher specificity of 99.4%, true individual-level prevalences increased to 4.03% in dairy herds, 2.07% in beef herds and 3.84% in mixed herds. Herd prevalences were 27.77%/18.79%, 2.78%/2.40% and 5.70%/12.24% (using the one/two-animal cut-offs) in dairy, beef and mixed herds, respectively. In conclusion, these results seem to indicate that a small percentage of cows and a rather high percentage of dairy herds in this region are MAP-seropositive.     

Economic evaluation of Johne's disease control programs implemented on six Michigan dairy farms

Johne's disease (JD) is an incurable, chronic infectious disease prevalent in dairy herds throughout the US and the world. The substantial economic losses caused by JD have been well documented. However, information on the costs of controlling the disease is limited, yet necessary, if producers are to make sound decisions regarding JD management. The purpose of this paper is to describe a method for evaluating the cost-effectiveness of management changes to control JD on infected dairy farms. A 5-year longitudinal study of six dairy herds infected with JD was performed. Each herd implemented a JD control program upon study enrollment. Prevalence of JD within each herd was monitored with annual testing of all adult cows using fecal culture and/or serum ELISA. Individual cow production and culling information was collected to estimate the annual economic losses caused by JD. An economic questionnaire was developed and administered to each herd annually to estimate costs directly attributable to the JD control program. Based on the costs of the control program, and using the losses to estimate the potential benefits of the control program, the net present value (NPV) of the control program was calculated for each herd during the study and projected into the future for a total of 20 years. The NPV was calculated for four different scenarios: (1) assuming a linear decline in losses beyond the observed period of the study with JD eradication by year 20 of the control program; (2) assuming losses and JD prevalence remain constant at the rate equal to that of the last observed year while continuing the control program; (3) assuming linear increase in losses at rate equal to that in scenario 1 with no control program; and (4) assuming losses remain constant at same level as the beginning of the study with no control plan implemented. The NPV varied greatly across the herds. For scenario 1, only three herds had a positive NPV; and only two herds had a positive NPV under scenario two. In the absence of a control program, the NPV's were always negative. The costs of the JD control programs implemented on these herds averaged $30/cow/year with a median of $24/cow/year. The annual losses due to JD averaged $79/cow/year with a median of $66/cow/year. Investing in a JD control program can be cost-effective.     

Association between bovine-leukosis virus seroprevalence and herd-level productivity on US dairy farms

Bovine-leukosis virus (BLV; also termed ‘bovine-leukemia virus’) is a retrovirus that primarily affects lymphoid tissue of dairy and beef cattle. Our objective was to investigate the association between BLV infection and annual value of production (AVP) on dairy herds within the United States, as part of the USDA National Animal Health Monitoring System’s 1996 dairy study. 1006 herds (in 20 states) with at least 30 dairy cows were interviewed during 1996. The agar-gel immunodiffusion test was used to detect serum antibodies to BLV. 10–40 cows from each herd were tested and each tested cow was classified as negative or positive based on results of a single test.

A multivariable regression model was used with the 976 herds with complete data for analysis. When compared to herds with no test-positive cows, herds with test-positive cows produced 218 kg per cow (i.e. 3%) less milk. The average reduction in AVP was $ 59 per cow for test-positive herds relative to test-negative herds. For the dairy industry as a whole, BLV seropositivity was associated with loss to producers of $ 285 million and $ 240 million for consumers. Most of this $ 525 million industry loss was due to reduced milk production in test-positive herds.     

Determinants and opportunities for commercial marketing of beef cattle raised on communally owned natural pastures in South Africa

The objective of this study was to examine the factors influencing smallholder producers’ potential to sell cattle and identify marketing opportunities for sustainable beef production in South Africa. A total of 95 structured questionnaires was administered to the Ncorha and Gxwalibomvu communities in the Eastern Cape province of South Africa. Average cattle herd size per household was higher (P < 0.05) in Ncorha (13.7 ± 1.9) than in Gxwalibomvu (11.3 ± 1.9). The logit model showed that households with few members, young farmers, Christians, large cattle herds, low income levels and access to extension services had high potential to sell cattle compared with other households (P < 0.05). Beef branding (～40% of respondents from each community), feedlotting (～30%), group marketing (～25%) and forward contracting (>5%) were mentioned as potential strategies for improving commercial marketing of cattle in the studied areas. Most producers (70%) indicated their potential and willingness to participate in developing a natural pasture-fed beef brand. Overall, commercial marketing of beef cattle raised on communally owned natural pastures in the surveyed areas in South Africa was largely determined by farmer’s demographic characteristics, cattle herd size and access to extension services with branding and feedlotting as the major opportunities for improving sales.     

Prevalence of Michigan dairy herds infected with Mycobacterium avium subspecies paratuberculosis as determined by environmental sampling

A cross-sectional, stratified random survey of Michigan dairy herds was conducted to estimate the prevalence of herds infected with Mycobacterium avium paratuberculosis (MAP), the causative agent of Johne's disease, in Michigan using targeted environmental sampling. One pooled sample each from the primary manure storage area and a high-traffic common cow area from each herd was collected and cultured for MAP using the ESP^® culture system II. A herd was classified as positive if at least one sample was culture positive for MAP. State, agricultural district, and herd size stratum prevalence were calculated. Information on past MAP testing and cattle purchase history was collected, and logistic regression was performed to determine their importance to the MAP status of the herd. One hundred twenty-seven herds were contacted, and 94 agreed to participate in the study. The environment of 38 (40.4%) herds cultured positive for MAP. MAP was found in all herds (n = 15) with greater than 200 lactating cows. Herds that had tested for MAP or purchased cattle in the previous 5 years were 4.6 and 3.1 times, respectively, more likely to be infected than herds that had not. MAP continues to be prevalent on Michigan dairy farms, especially those with greater than 200 lactating cows. The environmental sampling protocol used in this study is an economically attractive alternative for monitoring herd level prevalence and the progress of Johne's disease control programs at the state or national level. Implementation of such a program would aid states in monitoring Johne's control program progress, and guide changes over time.     

Herd-level economic losses associated with Johne's disease on US dairy operations

Johne's disease (‘paratuberculosis') is a chronic, infectious, wasting disease that affects dairy cattle. Estimation of its impact on herd productivity and corresponding economic loss on US dairy operations was part of the USDA National Animal Health Monitoring System's (NAHMS) 1996 national dairy study. Johne's-positive herds experience an economic loss of almost US$ 100 per cow when compared to Johne's-negative herds due to reduced milk production and increased cow-replacement costs. For Johne's-positive herds that reported at least 10% of their cull cows as having clinical signs consistent with Johne's disease, economic losses were over US$ 200 per cow. These high-prevalence herds experienced reduced milk production of over 700 kg per cow, culled more cows but had lower cull-cow revenues, and had greater cow mortality than Johne's-negative herds. Averaged across all herds, Johne's disease costs the US dairy industry, in reduced productivity, US$ 22 to US$ 27 per cow or US$ 200 to US$ 250 million annually.     

Costs of veterinary services and vaccines/drugs used for prevention and treatment of diseases in 86 Colorado cow-calf operations participating in the National Animal Health Monitoring System (1986-1988)

Eighty-six cow-calf operations involved in the Colorado National Animal Health Monitoring System were monitored for a 12-month period, and data were collected on the incidence, prevention, and costs of disease. The costs of veterinary services and vaccines/drugs used in the treatment and prevention of disease conditions in these beef herds were determined and expressed on a per cow basis. Beef producers in this study spent an average of $2.04 ($0 to $29.88) per cow annually on veterinary services for treatment of disease conditions. The cost of veterinary services was a relatively small percentage (5.4%) of the total mean cost of disease incidence. The reproductive tract disease class was the most costly class in terms of veterinary services for disease treatment ($0.99/cow). Dystocia was the disease condition with the largest veterinary treatment cost. The total mean annual cost of drugs used in the treatment of disease conditions was $1.22/cow. The enteric, miscellaneous, and respiratory tract disease classes had similar mean drug costs for disease treatment and ranged from $0.31 to $0.39/cow. The total mean annual cost of veterinary services for administration of preventive measures in these herds was $1.85/cow ($0 to $12.03). Pregnancy examination, breeding soundness examination in bulls, brucellosis vaccination, pulmonary arterial pressure test, and campylobacteriosis vaccination accounted for over 90% of the money spent for preventive veterinary services. Approximately 60% of the total mean annual disease prevention cost was attributed to the purchase of vaccines/drugs ($6.59/cow).(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum copper concentrations in beef cows and heifers

OBJECTIVE: To characterize serum copper status of cows and heifers in beef cow-calf herds throughout the United States and to evaluate use of copper supplements in those herds. DESIGN: Cross-sectional survey. ANIMALS: 2,007 cows and heifers from 256 herds in 18 states. PROCEDURES: Producers participating in a health and management survey conducted as part of the National Animal Health Monitoring System voluntarily allowed serum samples to be obtained from cows and heifers for determination of copper concentration. Results were categorized as deficient, marginally deficient, or adequate. The proportion of cattle and herds (on the basis of mean value of the tested cattle) in each category was determined. Copper concentrations were compared between herds that reportedly used copper supplements and those that did not. RESULTS: Overall, 34 of 2,007 (1.7%) cows and heifers were deficient in copper, and 781 (38.9%) were marginally deficient. In each region, at least a third of the cattle were deficient or marginally deficient. For herds, 92 of 256 (35.9%) were marginally deficient, and 22 (0.8%) were deficient. Approximately half of the producers reported use of copper supplements, but a sizeable proportion of those producers' cattle and herds were classified as marginally deficient or deficient. CONCLUSIONS AND CLINICAL RELEVANCE: Copper deficiency is not restricted to a single geographic region of the United States. Copper deficiency can persist despite reported use of supplements by producers. Veterinarians dealing with beef cow-calf herds that have problems consistent with copper deficiency should not rule out copper deficiency solely on the basis of geographic region or reported use of copper supplements for the herd.     

Consensus recommendations on diagnostic testing for the detection of paratuberculosis in cattle in the United States

The report provided here contains a simplified set of diagnostic testing recommendations. These recommendations were developed on the basis of research funded by the USDA-Animal and Plant Health Inspection Service-Veterinary Services through a cooperative agreement. The report is intended to provide simple, practical, cost-effective consensus testing recommendations for cattle herds that are not enrolled in the US Test-Negative Program. The information has been reviewed by paratuberculosis (Johne's disease) experts at the USDA and academic centers as well as stakeholders in various segments of the cattle industry. The recommendations were accepted by the National Johne's Working Group and Johne's Disease Committee of the US Animal Health Association during their annual meetings in October 2006. The report is intended to aid veterinarians who work with cattle producers in the United States. The recommendations are based on information available up to October 2006. There is a paucity of large-scale, high-quality studies of multiple tests conducted on samples obtained from the same cattle. It is understood that there may be special circumstances that require deviation from these recommendations. Furthermore, as new information becomes available and assays are improved and their accuracy is critically evaluated, changes to these recommendations may be necessary.     

Cross species transmission of ovine Johne's disease from sheep to cattle: an estimate of prevalence in exposed susceptible cattle

OBJECTIVE: To determine the prevalence of infection of cattle with the sheep strain of Mycobacterium avium subsp paratuberculosis at least two years after exposure at < 6 months old. DESIGN: Prospective survey One thousand seven hundred and seventy-four cattle from 12 properties (Farms A to L) were sampled by ELISA and faecal culture to detect evidence of infection with M a paratuberculosis. All properties had a known history of Johne's disease (JD) in sheep, and sampled cattle were likely to be susceptible to JD at the time they were first exposed, being at an age of 6 months or less. In addition, opportunistic investigations were undertaken of ELISA reactor cattle discovered during testing for the Australian Johne's Disease Market Assurance Program for Cattle (Farms M and N). RESULTS: All animals in the survey gave negative results on serology while one animal from a herd of 349 gave a positive faecal culture result. Follow-up faecal culture, post-mortem and histopathology on the latter animal were negative, suggesting that it was a passive faecal shedder or carrier. Two occurrences of OJD transmission to cattle were detected during the opportunistic investigations. CONCLUSION: These observations confirm existing beliefs about the risk of transmission of OJD to cattle, that the risk of transmission is low. However transmission occurs sporadically. An estimated upper limit of prevalence of S strain M a paratuberculosis infection in susceptible exposed cattle in the OJD high prevalence area of New South Wales is 0.8%, assuming a common prevalence within herds.     

Prevalence of bovine herpesvirus-1 in the Belgian cattle population

The national bovine herpesvirus 1 (BHV-1) seroprevalence (apparent prevalence) in the Belgian cattle population was determined by a serological survey that was conducted from December 1997 to March 1998. In a random sample of herds (N=556), all cattle (N=28 478) were tested for the presence of antibodies to glycoprotein B of BHV-1. No differentiation could be made between vaccinated and infected animals, because the exclusive use of marker vaccines was imposed by law only in 1997 by the Belgian Veterinary Authorities. Twenty-one percent of the farmers vaccinated continuously against BHV-1.

In the unvaccinated group, the overall herd, individual-animal and median within-herd seroprevalences were estimated to be 67% (95% confidence interval (CI)=62–72), 35.9% (95% CI=35.0–36.8) and 33% (quartiles=14–62), respectively.

Assuming a test sensitivity and specificity of 99 and 99.7%, respectively, the true herd, individual-animal and median within-herd prevalence for the unvaccinated group of herds were estimated to be 65, 36 and 34%, respectively. The true herd prevalence for dairy, mixed and beef herds were respectively, 84, 89 and 53%; the true individual-animal prevalence for those types of herds were, respectively, 35, 43 and 31%; whereas, the true median within-herd prevalences were 36, 29 and 38%.     

Effect of compliance with recommended calf-rearing practices on control of bovine Johne's disease

OBJECTIVE: To assess the degree of compliance with recommended management procedures for the control of bovine Johne's disease and study the relationship between aspects of calf management and testing/disease outcomes in the herds. PROCEDURE: Fifty-four south Gippsland dairy herds participating in the Victorian bovine Johne's disease test and control program were visited between July and November 2002 and an audit of calf rearing practices was conducted. The results of testing completed under the program were analysed for each of the herds. Twenty seven management factors were examined for a relationship with the presence of clinical cases of Johne's disease or cattle with positive ELISA test results that were born after the completion of the second whole herd test. Logistic regression was used to examine the strength of relationships between the management practices and the frequency with which new cases of Johne's disease arose. RESULTS AND CONCULSIONS: Calves were removed from their dams within 12 hours of birth in only 17 (31.5%) of the herds. However, in all but one herd the calves were removed within 24 hours of birth. In 42 herds (77.8%) calf rearing facilities were adequately separated from adult cattle and the faeces from adult cattle. In 41 herds (75.9%) calves up to the age of 12 months were grazed on paddocks that were free of manure or effluent from adult cattle. However, in only 10 (18.5%) of the herds were all three of these calf management practices applied. Feeding whole milk containing antibiotic residues, or providing water for calves from birth, were found to have statistically significant associations with an increased occurrence of cases of bovine Johne's disease in the study herds. The practice of allowing cows to calve in a paddock was found to be associated with reduced occurrence of bovine Johne's disease. These associations were still found after analysis that included herd size, the number of clinical cases that had occurred in the herds before the start of testing, the number of animals with positive ELISA tests that were detected at the first test and the number of years of participation in the test and cull program. Early separation of newborn calves from cows and grazing calves under 12 months of age in areas free of adult cattle were not found to be protective against Johne's disease.     

Effect of a test and control program for Johne's disease in Victorian beef herds 1992-2002

OBJECTIVE: To report on progress in Johne's disease (JD) control in infected beef herds participating in the Victorian Johne's disease test and control program (TCP). PROCEDURE: Clinical histories and JD testing data recorded by the Department of Primary Industries were analysed for 18 beef herds participating in the TCP. The herds were required to conduct annual whole herd tests with an absorbed ELISA, cull reactors and control the grazing of young cattle to minimise infection. RESULTS: Testing of over 11,000 animals identified 68 reactors giving an average prevalence of reactors at the first whole-herd test round (T1) of 0.77%. There had been 20 clinical cases detected in the 7 years before the TCP started and two cases detected in the 10 years after TCP started. Most reactors and all clinical cases were born before the TCP started. Of 34 reactors necropsied, 25 (74%) were confirmed to have JD by histology or culture of tissues. The modal age of reactors and clinical cases was 5 and 6 years respectively. Six herds completed the program by achieving three successive negative whole herd tests, four herds dropped out and eight continued to test. There were 18 reactors detected at T1 and 33 reactors that were negative at T1 but detected at subsequent tests. CONCLUSION: The TCP was associated with a marked decline in clinical cases. The similar age distributions of clinical cases and reactors probably meant that testing detected animals for which clinical disease was imminent. Whether the measures used in the TCP were adequate to control the disease in beef herds could not be determined because of the long incubation period of the disease. The relatively high proportion of the reactors investigated that were confirmed as infected provided confidence that the test was continuing to operate at a high specificity. If all unconfirmed reactors were presumed to be uninfected, the minimum specificity of the ELISA was 99.83%. The sensitivity of the ELISA appeared to be very low because of the large number of reactors that were negative at T1 but positive at later tests.     

Efficacy of monensin sodium for the reduction of fecal shedding of Mycobacterium avium subsp. paratuberculosis in infected dairy cattle

Reducing the quantity of Mycobacterium avium subsp. paratuberculosis (MAP) being shed by cows with Johne's disease should decrease the risk of spread of this disease to young stock. Previous work has suggested that monensin sodium decreases the pathologic lesions associated with Johne's disease, but the impact on shedding of viable MAP remains unknown. After serologic screening of 32 dairy herds in southwestern Ontario, 228 cows from 13 of these herds were enrolled into a randomized clinical trial. Fecal culture and PCR were used to identify 114 cows as potential fecal shedders, while another 114 cows were enrolled as ELISA negative, herd and parity matched controls. All cows were randomized to receive either a monensin controlled release capsule (CRC) or a placebo capsule. Serial fecal and blood samples were collected for fecal culture and serum ELISA testing over a 98-day period. On day 98 of the study, treatments were switched for all cows continuing in the trial. These remaining cows were followed for another 98 days with a similar sampling protocol. Mixed effect models were used to measure the impact of treatment on the number of colony forming units identified on fecal cultures over time. During the first 98 days of the study, cows treated with a monensin CRC were found to shed 3.4 cfu per tube less than placebo treated cows (P = 0.05). The serum ELISA S/P ratio was reduced by 1.39 units in cows given monensin (P = 0.06). However, treatment with monensin did not reduce the odds of testing positive on serology. Only the cows shedding MAP on day 0 were found to have a reduced odds of testing positive on fecal culture when treated with monensin (OR = 0.27; P = 0.03). Monensin sodium administered to infected animals at 335 mg/day marginally reduced fecal shedding of MAP in mature dairy cattle, but the biological significance of this reduction is unknown.     

An estimated prevalence of Johne's disease in a subpopulation of Alabama beef cattle.

The objective of this study was to estimate the overall prevalence of animals that were infected with Mycobacterium avium ssp. paratuberculosis in a subpopulation of Alabama beef cattle. This was determined using a commercial enzyme-linked immunosorbent assay (ELISA) for the detection of M. avium ssp. paratuberculosis-specific antibodies in serum. Serum was collected from 79 herds that were participating in the Alabama Brucellosis Certification program. A total of 2,073 beef cattle were randomly tested by selecting 30 animals per herd in herds greater than 30 and selecting all animals in herds 30 and less for testing. It has been estimated that the commercial ELISA test used has a 60% sensitivity and a 97% specificity. Of the 79 herds tested, 29 herds were seronegative, 24 herds had 1-2 positive animals, and 26 herds had 3 or more seropositive animals. The average number of infected animals per positive herd was 3.3. In addition, a calculated minimum of 53.5% of the herds were identified as Johne's positive herds with a 95% confidence level. Of the total number of animals tested, 8.0% (166/2,073) of them were positive by the ELISA. After adjustments for test sensitivity and specificity and the proportion of animals sampled per herd, the true prevalence was calculated to be 8.75%. These data suggest that approximately 50% of the herds are infected with M. avium ssp. Paratuberculosis, and the overall prevalence of infection in Alabama beef cattle is approximately 8%, which correlates with other previously published regional estimates.     

Predicted costs and benefits of eradicating BVDV from Ireland

Bovine viral diarrhoea virus (BVDV) causes an economically important endemic disease (BVD) of cattle in Ireland and worldwide. Systematic eradication by detection and removal of infectious (BVDV carrier) cattle has been successful in several regions. We therefore assessed the benefits (disease losses avoided) and costs (testing and culling regime) of a potential eradication programme in Ireland. Published bio-economic models of BVDV spread in beef suckler herds and dairy herds were adapted to estimate potential benefits of eradication in Ireland. A simple model of BVDV spread in beef finisher herds was devised to estimate the benefits of eradication in this sector. A six year eradication programme consisting of 5 inter-related virological and serological testing programmes is outlined and costed. We found that the annualised benefits of BVDV eradication in Ireland exceeded the costs by a factor of 5 in the beef suckler sector and a factor of 14 in the dairy sector. Corresponding payback periods were 1.2 and 0.5 years respectively. These results highlight the significant economic impact of BVDV on the Irish cattle industry and suggest a clear economic benefit to eradication using the proposed approach. This type of cost-benefit analysis is considered an essential prerequisite prior to undertaking an eradication campaign of this magnitude.     

Risk management of paratuberculosis in dairy herds

Risk management of paratuberculosis (Johne's disease) in a dairy herd requires an assessment of the likelihood of paratuberculosis occurring in the herd, the economic impact of paratuberculosis on the herd and an evaluation of measures that can be taken to reduce this likelihood and impact.The likelihood of paratuberculosis occurring in the herd is related to the regional herd-level prevalence of paratuberculosis and the herd management (e.g., introducing animals from other herds). The economic impact of paratuberculosis includes production losses due to subclinical and clinical cases, losses due to increased replacement of animals and costs of control measures. Furthermore, a reduction of the price of milk from infected herds might result from consumer concerns about the zoonotic potential of paratuberculosis.Measures that reduce the likelihood of paratuberculosis occurring in a herd and its impact include preventive management measures (e.g., closed herd management and an effective separation of susceptible young stock from adult cattle), test-and-cull schemes for known infected herds and quality assurance schemes for test-negative herds. Quality assurance schemes for test-negative herds, such as schemes for 'low-Map bulk milk' and 'Map-free' herds, aim at safeguarding or increasing the profitability of these herds.Keys to success of risk management of paratuberculosis include realistic expectations of the results of paratuberculosis control, quality assurance and control programmes that are appreciated by farmers and incentives for farmers to participate in such programmes.     

Veterinary service usage and animal ownership in Ohio, U.S.A.: Results of telephone surveys in 1983 and 1984

A telephone survey of three sub-populations in Ohio was conducted to compare the utilization of veterinary services in 1982 with 1983 and to characterize animal ownership. A response rate of approximately 90% was achieved for all three sub-populations namely (1) food-animal producers, (2) horse owners and (3) pet owners. There was no significant difference between the percentage of respondents using veterinary services in 1982 and 1983. In both years, over 85% of dairy producers purchased veterinary services compared with approximately 62% for beef producers, approximately 70% for swine producers, and over 97% for horse owners. In 1983, approximately 69% sheep producers, 50% of goat producers, 81% of dog owners, 67% of cat owners, 12% of bird owners and none of the fish owners used veterinary services during the previous year. The 1983 median expenditures for veterinary services per farm or household using veterinary services were $465 for horses, $450 for dairy cattle, $111 for beef cattle, $115 for swine, $66 for sheep, $0 for goats, $75 for dogs, $44 for cats and $18 for pet birds. The average number of times animals were seen by a veterinarian varied by species but did not vary much from year to year. For all three groups, preventive services were used more frequently than were treatment and surgical services.     

Paratuberculosis, a notifiable disease in Austria--current status, compulsory measures and first experiences

Paratuberculosis (Johne's disease) is one of the most important diseases in ruminants today. Its contribution is worldwide and the disease is causing severe financial losses among cattle producers in some countries [Hasanova, L., Pavlik, I., 2006. Economic impact of paratuberculosis in dairy cattle herds: a review. Vet. Med.-Czech. 51, 193–211]. Paratuberculosis is untreatable; diagnosis limited to the early stages of the infection and control of the disease is difficult. The prevalence of serologically positive Austrian cattle farms rose significantly to 19.0% during the past years [Baumgartner, W., Damoser, J., Khol, J.L., 2005. Comparison of two studies concerning the prevalence of bovine paratuberculosis (Johne's disease) in Austrian cattle in the years 1995–1997 and 2002/2003 (Article in German with extended English summary). Vet. Med. Austria/Wien. Tierärztl. Mschr. 92, 274–277]. Based on these findings clinical paratuberculosis in ruminants was declared a notifiable disease in Austria in April 2006.

A survey of the current situation in Austria, the most important parts of the new compulsory measures and their practical implementation and impacts are presented in this short communication.     

The economics of cattle tick control in dry tropical Australia

The economics of strategic dipping compared to nil treatment of cattle ticks (Boophilus microplus) on Droughtmaster cattle was assessed using a partial budget analysis. The analysis was based on reported experimental data which showed a bodyweight gain advantage from strategic dipping of 45 kg/head for growing cattle and 35 kg/head for breeding cows. Costs of dipping were calculated using 3 acaricide costs, that is 5.9¢, 20.9¢ and 62.7¢ per head and allowances were made for mustering, maintenance of facilities and annual cost of asset purchase under an intensive farm management system similar to the reported experimental conditions. The net gain of benefits over costs per annum for each acaricide cost was $927, $810 and $483 per 100 breeders and their progeny. Breakeven beef prices at which it was worth dipping were found to be 61¢, 69¢ and 94¢ per kg dressed weight depending on the cost of acaricide used for dipping. All prices and costs are expressed in 1981 dollars of purchasing power.