Y T Grohn

..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...

..Treating CM as time-dependent therefore allowed us to measure in greater detail, its varying effects (of when it occurred) on herd life...

..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...

....

..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...

..These findings are also beneficial for the management of mastitic cows (especially those with gram-negative CM) when mastitis occurs close to AI...

....

..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...

..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...

..The changes in the effects of other diseases after adjusting for milk yield varied, depending on the disease and the stage of lactation...

..The detailed results obtained from this insemination and replacement optimization model can assist farmers in making CM treatment decisions...

..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...

..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...

..Thus, this model can provide farmers economically optimal guidelines specific to their individual cows suffering from different types of CM...

..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...

..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...

..It was economically justifiable to keep breeding high producing cows longer than low producing cows...

..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...

..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)...

....

..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...

..Thus, this model can provide farmers economically optimal guidelines specific to their individual cows suffering from different types of lameness...

..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...

..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...

..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...

..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...

..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...

..Culling of infectious animals with a longer testing interval is generally not effective to control MAP...

..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...

..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...

....

..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...

..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...

..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...

..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...

....

....

..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...

..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...

..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...

..Salmonella serotype 4,5,12:i:- thus appears to represent at least two common clones, which cannot easily be differentiated with standard diagnostic procedures...

..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...

..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...

..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...

..Consequently, we stress the importance of focusing on choosing the most appropriate model for the specific purpose of the analysis...

....