Y T Grohn

Summary

Affiliation: Cornell University
Country: USA

Publications

  1. ncbi request reprint Optimizing replacement of dairy cows: modeling the effects of diseases
    Y T Grohn
    Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 61:27-43. 2003
  2. ncbi request reprint Effect of pathogen-specific clinical mastitis on milk yield in dairy cows
    Y T Grohn
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 87:3358-74. 2004
  3. ncbi request reprint Effect of pathogen-specific clinical mastitis on herd life in two New York State dairy herds
    Y T Grohn
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 71:105-25. 2005
  4. ncbi request reprint How university researchers can contribute to farm-to-table risk assessments: Listeria monocytogenes as an example
    YRJO GROHN
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
    Foodborne Pathog Dis 4:527-37. 2007
  5. ncbi request reprint Analysis of correlated continuous repeated observations: modelling the effect of ketosis on milk yield in dairy cows
    Y T Grohn
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA
    Prev Vet Med 39:137-53. 1999
  6. doi request reprint Effects of clinical mastitis caused by gram-positive and gram-negative bacteria and other organisms on the probability of conception in New York State Holstein dairy cows
    J A Hertl
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 93:1551-60. 2010
  7. ncbi request reprint Effect of lameness on culling in dairy cows
    C J Booth
    Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 87:4115-22. 2004
  8. pmc The prevalence of multidrug resistance is higher among bovine than human Salmonella enterica serotype Newport, Typhimurium, and 4,5,12:i:- isolates in the United States but differs by serotype and geographic region
    K Hoelzer
    Department of Food Science, Cornell University, 410 Stocking Hall, Ithaca, NY 14850, USA
    Appl Environ Microbiol 76:5947-59. 2010
  9. doi request reprint Environmental contamination with Mycobacterium avium subsp. paratuberculosis in endemically infected dairy herds
    R L Smith
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, United States
    Prev Vet Med 102:1-9. 2011
  10. doi request reprint Effects of repeated episodes of generic clinical mastitis on mortality and culling in dairy cows
    D Bar
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 91:2196-204. 2008

Detail Information

Publications48

  1. ncbi request reprint Optimizing replacement of dairy cows: modeling the effects of diseases
    Y T Grohn
    Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 61:27-43. 2003
    ..Higher replacement cost also increased herdlife and decreased when diseases were in the model. Higher replacement cost also increased herdlife and decreased the annuity and voluntary culling rate...
  2. ncbi request reprint Effect of pathogen-specific clinical mastitis on milk yield in dairy cows
    Y T Grohn
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 87:3358-74. 2004
    ..These findings provide dairy producers with more information on which pathogen-specific CM cases should receive treatment and how to manage these cows, thereby reducing CM impact on cow well being and profitability...
  3. ncbi request reprint Effect of pathogen-specific clinical mastitis on herd life in two New York State dairy herds
    Y T Grohn
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 71:105-25. 2005
    ..Treating CM as time-dependent therefore allowed us to measure in greater detail, its varying effects (of when it occurred) on herd life...
  4. ncbi request reprint How university researchers can contribute to farm-to-table risk assessments: Listeria monocytogenes as an example
    YRJO GROHN
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
    Foodborne Pathog Dis 4:527-37. 2007
    ....
  5. ncbi request reprint Analysis of correlated continuous repeated observations: modelling the effect of ketosis on milk yield in dairy cows
    Y T Grohn
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA
    Prev Vet Med 39:137-53. 1999
    ..Based on these findings, it is recommended that a repeated measures approach, rather than a single measure approach, be used to study the short-term effect of disease on milk yield...
  6. doi request reprint Effects of clinical mastitis caused by gram-positive and gram-negative bacteria and other organisms on the probability of conception in New York State Holstein dairy cows
    J A Hertl
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 93:1551-60. 2010
    ..These findings are also beneficial for the management of mastitic cows (especially those with gram-negative CM) when mastitis occurs close to AI...
  7. ncbi request reprint Effect of lameness on culling in dairy cows
    C J Booth
    Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 87:4115-22. 2004
    ..7; 95% confidence interval=1.3 to 6.0). Foot warts were not associated with decreased survival in this analysis. Lameness was never associated with increased survival in any of the models...
  8. pmc The prevalence of multidrug resistance is higher among bovine than human Salmonella enterica serotype Newport, Typhimurium, and 4,5,12:i:- isolates in the United States but differs by serotype and geographic region
    K Hoelzer
    Department of Food Science, Cornell University, 410 Stocking Hall, Ithaca, NY 14850, USA
    Appl Environ Microbiol 76:5947-59. 2010
    ..In addition, the study provides evidence for the value of including antimicrobial resistance data in epidemiological investigations and highlights the benefits and potential problems of combining subtyping methods...
  9. doi request reprint Environmental contamination with Mycobacterium avium subsp. paratuberculosis in endemically infected dairy herds
    R L Smith
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, United States
    Prev Vet Med 102:1-9. 2011
    ....
  10. doi request reprint Effects of repeated episodes of generic clinical mastitis on mortality and culling in dairy cows
    D Bar
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 91:2196-204. 2008
    ..Our findings provide dairy producers with information on mortality and culling associated with CM cases without considering the causative agent, and can also be used for economic analysis of CM management options...
  11. doi request reprint The cost of generic clinical mastitis in dairy cows as estimated by using dynamic programming
    D Bar
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 91:2205-14. 2008
    ..The detailed results obtained from this insemination and replacement optimization model can assist farmers in making CM treatment decisions...
  12. ncbi request reprint Culling of dairy cows. Part III. Effects of diseases, pregnancy status and milk yield on culling in Finnish Ayrshire cows
    P J Rajala-Schultz
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 41:295-309. 1999
    ..The changes in the effects of other diseases after adjusting for milk yield varied, depending on the disease and the stage of lactation...
  13. doi request reprint Effect of Johne's disease status on reproduction and culling in dairy cattle
    R L Smith
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA
    J Dairy Sci 93:3513-24. 2010
    ..High-shedding animals had lower calving rates in comparison with low-shedding or ELISA-positive animals, which tended to have higher calving rates than test-negative animals...
  14. ncbi request reprint Culling of dairy cows. Part II. Effects of diseases and reproductive performance on culling in Finnish Ayrshire cows
    P J Rajala-Schultz
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 41:279-94. 1999
    ..e., the time of next calving) were not fully independent of the event (culling) times; the effects of the diseases and pregnancy status at the very end of the lactation changed slightly from the original model...
  15. doi request reprint The cost and management of different types of clinical mastitis in dairy cows estimated by dynamic programming
    E Cha
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 94:4476-87. 2011
    ..Thus, this model can provide farmers economically optimal guidelines specific to their individual cows suffering from different types of CM...
  16. doi request reprint The effect of recurrent episodes of clinical mastitis caused by gram-positive and gram-negative bacteria and other organisms on mortality and culling in Holstein dairy cows
    J A Hertl
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 94:4863-77. 2011
    ..In multipara, any type of CM increased the probability of being culled. Gram-negative CM cases were associated with the numerically highest risk of culling...
  17. ncbi request reprint Optimizing breeding decisions for Finnish dairy herds
    P J Rajala-Schultz
    Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, USA
    Acta Vet Scand 41:199-212. 2000
    ..It was economically justifiable to keep breeding high producing cows longer than low producing cows...
  18. ncbi request reprint Effect of repeated episodes of generic clinical mastitis on milk yield in dairy cows
    D Bar
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Ithaca, NY 14853, USA
    J Dairy Sci 90:4643-53. 2007
    ..7) than a cow without CM in her previous lactation. These findings provide dairy producers with information on the average milk loss associated with CM cases without considering the causative agent, and can be used for economic analysis...
  19. pmc The duration of fecal Salmonella shedding following clinical disease among dairy cattle in the northeastern USA
    K J Cummings
    Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14853, United States
    Prev Vet Med 92:134-9. 2009
    ..01). Age group was also associated with mortality in this study; calves with salmonellosis were more likely to die than cows as estimated by a logistic regression model which controlled for herd as a random effect (p-value=0.04)...
  20. ncbi request reprint Estimating receiver operating characteristic curves with covariates when there is no perfect reference test for diagnosis of Johne's disease
    C Wang
    Department of Statistical Science, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 89:3038-46. 2006
    ..We found that both milk yield and its interaction with age had significant effects on the disease process whereas only milk yield was significant on the testing procedure...
  21. pmc Salmonella Cerro isolated over the past twenty years from various sources in the US represent a single predominant pulsed-field gel electrophoresis type
    K Hoelzer
    Department of Food Science, Cornell University, Ithaca, NY 14850, USA
    Vet Microbiol 150:389-93. 2011
    ....
  22. doi request reprint The cost of different types of lameness in dairy cows calculated by dynamic programming
    E Cha
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 97:1-8. 2010
    ..Thus, this model can provide farmers economically optimal guidelines specific to their individual cows suffering from different types of lameness...
  23. doi request reprint The incidence of salmonellosis among dairy herds in the northeastern United States
    K J Cummings
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 92:3766-74. 2009
    ..Our results shed light on the impact of salmonellosis on the dairy industry in the northeastern United States, and they help clarify the role of dairy cattle as a source of Salmonella serotypes that are also important human pathogens...
  24. doi request reprint Effects of repeated gram-positive and gram-negative clinical mastitis episodes on milk yield loss in Holstein dairy cows
    Y H Schukken
    Quality Milk Production Services, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 92:3091-105. 2009
    ..Hence, our data do not support that immunological memory of previous exposure to an organism in the same generic class provides protection for a next case of CM with an organism in the same class...
  25. doi request reprint A longitudinal study on the impact of Johne's disease status on milk production in individual cows
    R L Smith
    Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA
    J Dairy Sci 92:2653-61. 2009
    ..Animals with fecal culture results of >30 cfu/g produced approximately 4 kg less milk per day compared with uninfected cows. These results will be valuable in calculating the economic effect of Johne's disease...
  26. pmc The effect of heterogeneous infectious period and contagiousness on the dynamics of Salmonella transmission in dairy cattle
    C Lanzas
    Department of Population Medicine and Diagnostic Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Epidemiol Infect 136:1496-510. 2008
    ..The presence of super-shedders increases R0 and decreases the effectiveness of population-wise strategies to reduce infection, making necessary the application of strategies that target this specific group...
  27. ncbi request reprint Listeria monocytogenes fecal shedding in dairy cattle shows high levels of day-to-day variation and includes outbreaks and sporadic cases of shedding of specific L. monocytogenes subtypes
    A J Ho
    Department of Food Science, 412 Stocking Hall, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 80:287-305. 2007
    ..monocytogenes subtype on any given day. Although limited to a single dairy cattle herd, these findings provide a significant advancement in the understanding of the epidemiology of L. monocytogenes fecal shedding in dairy cattle...
  28. ncbi request reprint Culling of dairy cows. Part I. Effects of diseases on culling in Finnish Ayrshire cows
    P J Rajala-Schultz
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 41:195-208. 1999
    ..The effect seemed to decrease with time from the diagnosis of the disease. However, milk fever, dystocia and metritis also had a significant effect on culling at the end of the lactation...
  29. ncbi request reprint Optimizing replacement decisions for Finnish dairy herds
    P J Rajala-Schultz
    Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus, USA
    Acta Vet Scand 41:185-98. 2000
    ..When the price of a replacement heifer decreased, average herdlife was shorter and replacement percentage increased. When the price increased, the effect was the opposite...
  30. pmc Modeling on-farm Escherichia coli O157:H7 population dynamics
    P Ayscue
    Department of Population Medicine and Diagnostic Science, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
    Foodborne Pathog Dis 6:461-70. 2009
    ..coli O157:H7 population dynamics and thus would serve as prime environmental targets for interventions to effectively reduce the E. coli O157:H7 load at the pen level...
  31. doi request reprint The importance of culling in Johne's disease control
    Z Lu
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Theor Biol 254:135-46. 2008
    ..Culling of infectious animals with a longer testing interval is generally not effective to control MAP...
  32. doi request reprint Economic analysis of Mycobacterium avium subspecies paratuberculosis vaccines in dairy herds
    J Cho
    Charles H Dyson School of Applied Economics and Management, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 95:1855-72. 2012
    ....
  33. ncbi request reprint Effect of clinical mastitis on the lactation curve: a mixed model estimation using daily milk weights
    D J Wilson
    Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14850, USA
    J Dairy Sci 87:2073-84. 2004
    ..6 kg over their herdmates until they contracted the disease. When compared with this potentially higher milk production, the total loss from clinical mastitis was estimated as 1181 kg...
  34. ncbi request reprint Simulation modeling to evaluate the persistence of Mycobacterium avium subsp. paratuberculosis (MAP) on commercial dairy farms in the United States
    R M Mitchell
    Department of Population Medicine and Diagnostic Sciences, S3119 Schurman Hall, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 83:360-80. 2008
    ..Addition of vertical transmission caused persistence of infection in a moderately complicated model. In the most complex model that allowed age-based contacts, calf-to-calf transmission was required for persistence...
  35. ncbi request reprint Censoring in survival analysis: a simulation study of the effect of milk yield on conception
    H G Allore
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, P.O. Box 26, Ithaca, NY 14853, USA
    Prev Vet Med 49:223-34. 2001
    ..The effect of high milk production on median days open (as estimated by survival functions) changed by 2 to 4 days when an association between milk yield and culling was programmed in the simulated data sets...
  36. doi request reprint Evaluating targets for control of plasmid-mediated antimicrobial resistance in enteric commensals of beef cattle: a modelling approach
    V V Volkova
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, USA
    Epidemiol Infect 141:2294-312. 2013
    ..coli numbers or the rate of plasmid transfer in this habitat. Also efficient was to increase the regular replacement of enteric E. coli. Lowering replication rate of resistant E. coli alone was not an efficient intervention target...
  37. doi request reprint The effect of repeated episodes of bacteria-specific clinical mastitis on mortality and culling in Holstein dairy cows
    E Cha
    Section of Epidemiology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Dairy Sci 96:4993-5007. 2013
    ..0-2.2) times more likely to be culled compared with cows in lactation 2 (the baseline)]. The risk of culling dependent on the cow's characteristics can be easily calculated from the parameter estimates in the provided tables. ..
  38. ncbi request reprint Effects of diseases on reproductive performance in Swedish Red and White dairy cattle
    D O Maizon
    Department of Animal Science, Cornell University, Ithaca, NY 14853, USA
    Prev Vet Med 66:113-26. 2004
    ....
  39. ncbi request reprint Comparison of economically optimized culling recommendations and actual culling decisions of Finnish Ayrshire cows
    P J Rajala-Schultz
    Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
    Prev Vet Med 49:29-39. 2001
    ....
  40. ncbi request reprint The effect of lameness on milk production in dairy cows
    L D Warnick
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
    J Dairy Sci 84:1988-97. 2001
    ..The inconsistent results between farms may have resulted from differences in the relative frequencies of specific causes of lameness in the two herds and in the way lame cows were identified and defined for the study...
  41. pmc Ecology and transmission of Listeria monocytogenes infecting ruminants and in the farm environment
    K K Nightingale
    Department of Food Science, 412 Stocking Hall, Cornell University, Ithaca, NY 14853, USA
    Appl Environ Microbiol 70:4458-67. 2004
    ..monocytogenes, including subtypes linked to human listeriosis cases and outbreaks, and (iv) L. monocytogenes subtypes may differ in their abilities to infect animals and to survive in farm environments...
  42. pmc A mathematical model of the dynamics of Salmonella Cerro infection in a US dairy herd
    P P Chapagain
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
    Epidemiol Infect 136:263-72. 2008
    ..A more realistically distributed (gamma-distributed) infectious period using multiple stages of infection was considered. The basic reproduction number was calculated and relevance to the intervention strategies is discussed...
  43. pmc Salmonella enterica serotype 4,5,12:i:-, an emerging Salmonella serotype that represents multiple distinct clones
    Y Soyer
    Department of Food Science, 412 Stocking Hall, Cornell University, Ithaca, NY 14853, USA
    J Clin Microbiol 47:3546-56. 2009
    ..Salmonella serotype 4,5,12:i:- thus appears to represent at least two common clones, which cannot easily be differentiated with standard diagnostic procedures...
  44. ncbi request reprint An outcrossed canine pedigree for linkage analysis of hip dysplasia
    R J Todhunter
    Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Hered 90:83-92. 1999
    ..Although dogs in the backcross generation that were three-quarter greyhound had a broad range of hip laxity, a protective effect of the greyhound QTLs for good osseous conformation has mitigated thus far against subluxation and CHD...
  45. pmc Epidemiological model for Clostridium difficile transmission in healthcare settings
    C Lanzas
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
    Infect Control Hosp Epidemiol 32:553-61. 2011
    ..Our objectives were to evaluate the contributions of asymptomatic and symptomatic C. difficile carriers to new colonizations and to determine the most important epidemiological factors influencing C. difficile transmission...
  46. ncbi request reprint Teaching dairy herd health dynamics using a web-based program
    H G Allore
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
    J Vet Med Educ 28:140-4. 2001
    ..Currently, Cornell University and nine test sites use the courseware. CURRENT STATUS: The course has been taught for two years, with students and experts providing evaluations and critical feedback for courseware modification...
  47. ncbi request reprint Analysis of correlated discrete observations: background, examples and solutions
    Y H Schukken
    Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, S1 072 Schurman Hall, Ithaca, NY 14853, USA
    Prev Vet Med 59:223-40. 2003
    ..Consequently, we stress the importance of focusing on choosing the most appropriate model for the specific purpose of the analysis...
  48. ncbi request reprint Career paths of alumni of the Cornell Leadership Program for veterinary students
    D R Fraser
    College of Veterinary Medicine, Cornell University, Ithaca ny 14853 6401, USA
    Vet Rec 163:750-6. 2008
    ....