Herd-level economic analysis of the impact of paratuberculosis on dairy herds.
OBJECTIVE
To perform a herd-level analysis of economic losses associated with paratuberculosis in dairy herds.


METHODS
Cross-sectional study.


METHODS
A multistage stratified random sample of 121 dairy herds in Michigan.


METHODS
A 2-part questionnaire was used to gather data on management practices, herd productivity, labor use, and expenditures. Blood samples were collected from a random sample of cows > or = 2 years old in each herd and tested for antibodies to Mycobacterium paratuberculosis. A herd was considered negative for paratuberculosis if results for all cows tested were negative. Multivariable linear regression was used to evaluate the data.


RESULTS
A 10% increase in proportion of cows positive for paratuberculosis was associated with a 33.4 kg (73.5 lb) decrease in mean weight of culled cows. Mortality rate among herds positive for paratuberculosis was 3% higher than rate among herds negative for paratuberculosis. Herds positive for paratuberculosis did not have a significantly higher annual number of hours of labor per cow than did herds negative for paratuberculosis.


CONCLUSIONS
For a herd of average size and cull rate, the reduction in mean weight of culled cows attributable to paratuberculosis represented a loss of approximately $1,150 annually for each 10% increase in herd prevalence of paratuberculosis. The increased mortality rate attributable to paratuberculosis represented a loss of between $1,607 and $4,400 on the basis of lost slaughter value and cost of replacement heifers.
Johnson-Ifearulundu
Y
Y
College of Veterinary Medicine, Population Medicine Center, Michigan State University, East Lansing 48823, USA.
Kaneene
J B
JB
Lloyd
J W
JW
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000191:economics* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003612:Dairying / Q000191:economics*; D005260:Female; D016014:Linear Models; D008824:Michigan / Q000453:epidemiology; D015999:Multivariate Analysis; D010283:Paratuberculosis / Q000191:economics* / Q000453:epidemiology; D015995:Prevalence