My research interests have evolved from studies of basic metabolism in ruminants and genetics to veterinary epidemiology, economic modeling and food safety.  The two main areas of investigations currently ongoing in my laboratory are: 1) mathematical modeling of zoonotic infectious diseases, and 2) optimizing dairy herd health and management decisions.  Both of these areas of research offer opportunities for training in epidemiological and mathematical modeling, genetic analysis and economic methods.

1973 B.V.M., College of Vet. Med., Helsinki, Finland
1977 L.V.M.,(equiv DVM) College of Vet. Med., Helsinki, Finland
1980 Food Hygienist, College of Vet Med, Helsinki, Finland
1982 M.P.V.M., in Epidemiology, University of California, Davis
1983 M.S., in Genetics, University of California, Davis
1985 D.V.M.  (equiv Ph.D.), in Vet. Med., College of Vet. Med., Helsinki
2002 Diplomate ECVPH (European College of Vet. Public Health)

American Dairy Science Association
American Veterinary Medical Association
Association of Teachers of Veterinary Public Health and Preventive Medicine
Finnish Veterinary Medical Association
New York State Veterinary Medical Society
Nordic Association of Veterinary Epidemiology

Ivanek, R,  Gröhn, Y.T., Wiedmann, M.: Listeria monocytogenes in multiple habitats and host populations: review of available data for mathematical modeling. Foodborne Pathogens and Disease, 2006, 3: 319-336.

Ivanek, R,  Gröhn, Y.T., Ho, A. J., and Wiedmann, M.: Markov chain approach to analyze the dynamics of pathogen fecal shedding -Example of Listeria monocytogenes shedding in a herd of dairy cattle.  J of Theoretical Biology. 2007, 245: 44-58.

Chapagain, P, Van Kessel, J.A., Karns, J.S., Wolfgang,D.R., Schukken, Y.H. Gröhn, Y.T.: A mathematical model of the dynamics of Salmonella Cerro infection in a US dairy herd.   Epidemiology and Infection, 2008, 136: 263-272.

Mitchell, R.M., Whitlock, R.H., Stehman, S.M., Benedictus, A., Chapagain, P., Gröhn, Y.T., and Schukken, Y.H.: Simulation modeling to evaluate the persistence of Mycobacterium avium subsp. paratuberculosis (MAP) on commercial dairy farms in the United States. Prev Vet Med, 2008, 83: 360-380.

Lu, Z., Mitchell, R.M., Smith, R.L., Van Kessel,  J.S., Chapagain, P.P, Schukken, Y.H., and Gröhn, Y.T.: The Importance of Culling in Johne’s Disease. J. of Theoretical Biology.  2008, 245: 135-146.  

Lanzas, C., Brien, S., Ivanek, R. Lo, Y., Chapagain, P., Ray, K.A., Ayscue, P., Warnick., L.D.,  and Gröhn, Y.T.:  The effect of heterogeneous infectious period and contagiousness on the dynamics of Salmonella transmission. Epidemiology and Infection. 2008, 136, 1496-1510.

Lanzas, C., Warnick., L.D., Ivanek, R., Ayscue, P., Nydam, D., McDonough, P., and Gröhn, Y.T.:  The risk and control of Salmonella outbreaks in calf-rearing operations. Veterinary Research.  2008: 39:61.

Ayscue, P., Lanzas, C., Ivanek, R., and Gröhn Y.T.: Modeling Escherichia coli O157:H7 Population Dynamics in Feedlots. Foodborne Pathogens and Disease.  2009. 6: 461-470.

Lu, Z., Gröhn, Y.T., Smith, R.L., Wolfgang, D.R., Van Kessel,  J.S., and Schukken, Y.H:  Assessing the potential impact of Salmonella vaccine in an endemically infected dairy herd. J. of Theoretical Biology.  2009, 259: 770-784.

Ivanek, R.., Gröhn, Y.T., Wells, M.T., Lembo Jr, A.J., Sauders, B.D. and Wiedmann,M.:. Modeling of spatially referenced environmental and meteorological factors influencing the probability of Listeria spp. isolation from natural environments. Applied & Environmental Microbiology. 2009, 75: 5893-5909.

Lanzas, C., Ayscue, P., Ivanek, R., Gröhn, Y.T.: Model or meal? Animal agriculture systems as models for infectious diseases of humans. Nature Reviews, Microbiology. 2010, 8: 139-148.

Lanzas, C. Warnick, L.D. James, K.L., Wiedmann, M., Gröhn, Y.T.: Transmission dynamics of a multi-drug resistant Salmonella Typhimurium outbreak in a dairy farm. Foodborne Pathogens and Disease. 2010, 7: 467-474.

Lu, Z., Schukken, Y.H, Smith, R.L., Wolfgang, D.R., Van Kessel, J.S., and Gröhn, Y.T.: Stochastic simulations of a multi-group compartmental model for Johne’s disease on US dairy herds with test-based culling interventions. J. of Theoretical Biology. 2010 21; 264(4):1190-201.

Lanzas, C. Lu, Z., Gröhn, Y.T.: Mathematical modeling of the transmission and control of food-borne pathogens and antimicrobial resistance at pre-harvest.   Foodborne Pathogens and Disease. In press.

 Optimizing Health and Management

Wang, C., Turnbull, B., Gröhn, Y. T., and Nielsen, S.S.:  Estimating ROC curves with covariates when there is no perfect reference test for diagnosis of Johne’s Disease. J. Dairy Sci., 2006, 89: 3038-3046.

Wang, C., Turnbull, B., Gröhn, Y. T., and Nielsen, S.S.: Nonparametric estimation of ROC curves based on Bayesian models when the true disease state is unknown. Journal of Agricultural, Biological, and Environmental Statistics. 2007, 12, 128-­146.

Wilson,D.J.,  Mallard, B.A., Burton, J.J., Schukken, Y.H., and Gröhn, Y.T.:  Milk and serum J5-specific antibody responses, milk production change and clinical effects following intramammary Escherichia coli challenge for J5 vaccinate and control cows. Clinical and Vaccine Immunology, 2007, 14: 693-699.

Bar, D., Gröhn, Y. T., Gonzalez, R.N., Hertl, J.A., Schulte, H.F., Bennett, G.J., Tauer., L.., Schukken, Y.H.: Effect of repeated episodes of generic clinical mastitis on milk yield in dairy cows J. Dairy Sci., 2007, 90: 4643-4653.

Bar, D., Gröhn, Y. T., Gonzalez, R.N., Hertl, J.A., Schulte, H.F., Bennett, G.J., Tauer., L.., Schukken, Y.H.: Effect of repeated episodes of generic clinical mastitis on culling in dairy cows J. Dairy Sci., 2008, 91: 2196-2204.

Bar, D., Tauer, L.W., Bennett, G., González, R.N., Hertl, J.A., Schukken, Y.H., Schulte, H.F., Welcome, F.L, and Gröhn, Y.T.:  The cost of generic clinical mastitis in dairy cows as estimated using dynamic programming. J. Dairy Sci., 2008, 91: 2205-2214.

N. Fall, Gröhn, Y.T. Forslund, K., Essen-Gustafsson, B., Niskanen,R. and  Emanuelson, U.:  An observational study on early-lactation metabolic profiles in Swedish organically and conventionally managed dairy cows. J. Dairy Sci. 2008, 91: 3983-3992.

Bar, D., Tauer, L.W., Bennett, G., González, R.N., Hertl, J.A., Schukken, Y.H., Schulte, H.F., Welcome, F.L, and Gröhn, Y.T.: Use of a dynamic programming model to estimate the value of clinical mastitis treatment and prevention options utilized by dairy producers. Agric. Systems. 2008, 99:6-12.

Wilson,D.J.,  Mallard, B.A., Burton, J.L.,  Schukken, Y.H., and Gröhn, Y.T..:  Association of Escherichia coli J5 -Specific Serum Antibody Responses with Clinical Mastitis Outcome for J5 Vaccinate and Control Dairy Cattle. Clinical and Vaccine Immunology. 2009, 16: 209-217.

Smith, R.L., Gröhn, Y.T., Pradhan, A., Whitlock, R.H.,  Van Kessel,  J.S., Schukken, Y.H.: A longitudinal study for the impact of Johne’s Disease on milk production in individual cows. J. of Dairy Sci. 2009, 92: 2653-2661.

Schukken, Y.H, Hertl, J.A., Bar, D., Bennett, G.J., Gonzalez, R.N., Rauch, B., Santisteban, C. Schulte, H.F., Tauer., L.., Welcome F.L., Gröhn, Y. T..: Effects of repeated Gram-Positive and Gram-Negative Clinical Mastitis Episodes on Milk Yield loss in Holstein Dairy Cows. J. of Dairy Sci. 2009, 92: 3091-3105.

Hertl, J.A.,  Gröhn, Y. T., Leach, J.D.G., Bar, D., Bennett, G.J., Gonzalez, R.N., Rauch, B.J., Welcome F.L., Tauer., L.W., and Schukken, Y.H: Effects of clinical mastitis due to Gram-positive and Gram-negative bacteria, and other organisms, on the probability of conception in New York State Holstein dairy cows. J. of Dairy Sci. 2010, 93: 1551-1560.

Smith, R.L., Strawderman, R.L., Wells, S.J., Pradhan, A., Whitlock, R.H., Van Kessel, J.S., Schukken, Y.H., Gröhn, Y.T.: Effect of Johne’s disease status on reproduction and culling in dairy cattle. J. of Dairy Sci., 2010, 93: 3513-3524.

Cha, E., Hertl, J.A., *, Bar, D., and Gröhn, Y.T.: The cost of different types of lameness in dairy cows calculated by dynamic programming. Prev Ved Med, 2010, 97: 1-8.