Progress 10/01/02 to 09/30/07
Outputs
OUTPUTS: In this final report, we will summarize the outputs and activities that have taken place under the umbrella program of the NE-1009 in our research group in the last five years. This is a very large multi-state research effort and multiple projects were executed during the project period. Outputs of the project include a very large number of scientific publications (see section below), a large number of presentations to scientists, dairy veterinarians and dairy farmers, and the development of new tools and techniques that will provide practical solutions to obtain a better milk quality and food safety for producers and consumers. Presentations to the target audiences include approximately 20 presentations to dairy farmers during the Winter Dairy Management series in the spring of 2007. With these meetings, where we presented the results of several of the studies executed under this project, we reached approximately 1000 dairy farmers and dairy farm advisors. Several courses
and short courses where presented to dairy farmers, dairy veterinarians and industry professionals where the results of our studies were presented. These courses included Culture for the cure courses to approximately 60 farmers and veterinarians, in-house short courses for veterinary students and industry professionals. Approximately 100 individuals participated in the latter. Throughout the life of the project, results of our studies were presented through a newsletter distributed in the North-East to approximately 17,000 dairy farmers, veterinarians and farm advisors. Six times per year, results of our studies were presented to this audience. The scientific staff presented the result of this project in State, National and International meetings. These meetings included the National Mastitis Council meeting, the Fall Dairy Conference, and several specific National and International meetings. The results of our studies were frequently used to create fact sheets, tri-folds and other
extension materials. These materials were distributed through the Quality Milk Production Services outlet channels and reached approximately 2000 dairy farmers and producers in New York State each year. Materials were also published on the website www.qmps.vet.cornell.edu. Finally, project personnel frequently consults on dairy farms and the results of the studies are communicated on a daily basis to dairy producers, dairy veterinarians and industry professionals. Through these reporting methods thousands of individuals remain up to date with the result s of the studies performed during the five years of this project.
PARTICIPANTS: Y.H. Schukken, PI R.N. Gonzalez, PI L.L. Tikofsky, PI R.N. Zadoks, PI F.L. Welcome, PI S. Klaessig, laboratory technician R. Quesnell, post doctoral associate J. Barlow, PhD student M. Munoz, PhD student C. Nightingale, Mab student R.M. Mitchell, PhD student
TARGET AUDIENCES: Target audiences include: 1. Dairy farmers 2. Dairy veterinarians 3. Dairy industry professionals
Impacts
We studied the characteristics of chronic coliform mastitis isolates in comparison to isolates from transient infections. Our results indicate a strong phenotypic difference in these parameters between the isolates from transient and chronic infections. We performed challenge studies during the dry period of the dairy cow. Challenged cows showed no clinical signs, but remained infected during the dry period and in early lactation. A large effort was in the (molecular) epidemiology of Klebsiella infections in the mammary gland on dairy farms. Patterns and persistency of fecal shedding of Klebsiella spp. by healthy adult dairy cattle were explored with probabilistic, statistical, and molecular methods. Shedding patterns followed a random binomial distribution, and associations with host factors were not detected. A world-wide collection of Streptococcus uberis isolates was studied. Comparative genomics were used to identify host adapted and non-host adapted isolates.
Host adapted isolates were clustered and showed a difference in genetic alignment compared to non-host adapted strains. This is an example of our efforts in molecular epidemiology. Applications of molecular epidemiology include new diagnostic tools, better understanding of pathogen epidemiology and treatment evaluation. The completion of a large field study on pre-calving intramammary treatment of dairy heifers in which Cornell was one of the 7 stations. In this study, preparturient heifers (n equal 545) from 9 herds in 7 states (US) and one province (Canada) were enrolled in a study to test the hypothesis that prepartum intramammary therapy would cure existing intramammary infection (IMI) and lead to increased milk production, reduced linear somatic cell count (LSCC), and improved reproductive performance. Treatment had a significant effect (P less than 0.001) on the cure rate of infected mammary quarters. Treatment neither significantly affected milk production nor LSCC in the first
200 d of lactation. While this trial demonstrated that prepartum intramammary antibiotic therapy did reduce the number of heifer IMI and lowered LSCC, this improvement in udder health did not translate into a significant improvement in milk production, nor improved reproductive performance during the first 200 d of the first lactation. Coagulase Negative Staphylococci (CNS) intramammary infections were studied during the project period. These infections had a significant impact on somatic cell counts, particularly in heifers. However, the impact of this infection on milk production was minimal. Diagnostic assays on this organism were studied. We compared classical bacteriological techniques extended with API-Staph (trade mark) with the use of molecular diagnostics: a species-specific PCR method. The results of this project indicate that molecular diagnostic methods perform better compared to classical bacteriology and should be used as the gold standard.
Publications
- Wilson D.J., Mallard B.A., Burton J.L., Schukken Y.H., Grohn Y.T. 2007. Milk and serum J5-specific antibody responses, milk production change, and clinical effects following intramammary Escherichia coli challenge for J5 vaccinate and control cows. Clin Vaccine Immunol. 14:693-699.
- Schukken Y.H., Gonzalez, R.N., Bennett, G.J., Schulte, H.F., Welcome, F.L., Tikofsky, L.L., Coffin, L.M., Santisteban, C.G., Zadoks, R.N., and Zurakowski, M.J. 2007. Quality Milk Production Services: 60 years of milk quality improvement in New York State. Proceedings National Mastitis Council 2007 pp 159-173.
- Schmitt-Van de Leemput E., Zadoks R.N. 2007. Genotypic and phenotypic detection of macrolide and lincosamide resistance in Streptococcus uberis. J Dairy Sci. 90:5089-5096.
- Munoz M.A., Welcome F.L., Schukken Y.H., Zadoks R.N. 2007. Molecular epidemiology of two Klebsiella pneumoniae mastitis outbreaks on a dairy farm in New York State. J Clin Microbiol. 45:3964-3971.
- Olde Riekerink R.G., Barkema H.W., Veenstra W., Berg F.E., Stryhn H., Zadoks R.N. 2007. Somatic cell count during and between milkings. J Dairy Sci. 90:3733-3741.
- Munoz M.A., Zadoks R.N. 2007. Patterns of fecal shedding of Klebsiella by dairy cows. J Dairy Sci. 90:1220-1224.
- Schukken, Y.H., Gonzalez, R.N., Bennett, G.J., Schulte, H.F., Welcome, F.L., Tikofsky, L.L., Coffin, L.M., Santisteban, C.G., Zadoks, R.N., and Zurakowski, M.J. 2008. CNS infections nothing to worry about. Vet Microb. Accepted for publication.
- Zadoks, R.N., Ruegg, P.L. 2008. Genotyping of CNS, the only reliable method. Vet Microb. Accepted for publication.
- Nightingale C., Dhuyvetter K., Mitchell R., Schukken Y. 2008. Influence of variable milk quality premiums on observed milk quality. J Dairy Sci. 91:1236-1244.
- Barlow J., Rauch B., Welcome F., Kim S.G., Dubovi E., Schukken Y.H. 2008. Association between Coxiella burnetii shedding in milk and subclinical mastitis in dairy cattle. Vet Res. 39:23. Epub 2008 Feb 7.
- Bar D., Grohn Y.T., Bennett G., Gonzalez R.N., Hertl J.A., Schulte H.F., Tauer L.W., Welcome F.L., Schukken Y.H. 2007. Effect of repeated episodes of generic clinical mastitis on milk yield in dairy cows. J Dairy Sci. 90:4643-4653.
- Wilson D.J., Grohn Y.T., Bennett G.J., Gonzalez R.N., Schukken Y.H., Spatz J. 2007. Comparison of J5 vaccinates and controls for incidence, etiologic agent, clinical severity, and survival in the herd following naturally occurring cases of clinical mastitis. J Dairy Sci. 90:4282-4288.
- Rivas A.L., Schwager S.J., Gonzalez R.N., Quimby F.W., Anderson K.L. 2007. Multifactorial relationships between intramammary invasion by Staphylococcus aureus and bovine leukocyte markers. Can J Vet Res. 71:135-144.
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Progress 01/01/06 to 12/31/06
Outputs
In this progress reports, we will summarize the activities that have taken place under the umbrella program of the NE-1009 in our research group. This is a very large research effort and multiple projects are currently active. We studied the characteristics of chronic coliform mastitis isolates in comparison to isolates from transient infections. This is an on-going project where well-documented strains from transient and chronic intramammary infections are compared with regard to their ability to adhere, invade and survive inside mammary epithelial cells. Our results indicate a strong phenotypic difference in these parameters between the isolates from transient and chronic infections. In addition to in-vitro experiments, we also performed mathematical modeling to better understand within host dynamics of E. coli infections. These models indicated that the intracellular survival of E. coli is essential to observe chronic infections in the mammary gland. Another large
effort is in the molecular epidemiology of Klebsiella infections in the mammary gland on dairy farms. We studied these infections to further understand the within host and within farm dynamics. Patterns and persistency of fecal shedding of Klebsiella spp. by healthy adult dairy cattle were explored with probabilistic, statistical, and molecular methods. Shedding patterns followed a random binomial distribution, and associations with host factors were not detected. For 12 animals from 4 herds, strain-typing of multiple fecal Klebsiella isolates was performed by means of random-amplified polymorphic DNA typing. For 2 animals, additional typing was performed on isolates from samples collected on several consecutive days. A large variety of Klebsiella strains was detected within samples (on average, 3.1 strains per 4 isolates) and between samples (18 of 20 strains were detected only once in feces from cows that were sampled for 5 d consecutively). Results from each method suggest that
fecal shedding of Klebsiella is associated with transient rather than persistent presence of the organism in the gastrointestinal tract. A world-wide collection of Streptococcus uberis isolates were studied in the last year. Comparative genomics were used to identify host adapted and non-host adapted isolates. Host adapted isolates were clustered and showed a difference in genetic alignment compared to non-host adapted strains. This is an example of our efforts in molecular epidemiology. Applications of molecular epidemiology include new diagnostic tools, better understanding of pathogen epidemiology and treatment evaluation.
Impacts
The progress in this project in the 2006 reporting year has been of great practical value to the dairy industry. Our studies on chronic versus transient E. coli infections are now well recognized by the industry. Further work on the prevention and treatment of these infections is necessary now that their prevalence and importance has been elucidated. Klebsiella infections are among the emerging infections in the dairy industry. Our research this year on the importance of fecal shedding is of great practical value. Not only do producers need to be critical with regard to purchase of bedding materials, but also the contamination of bedding and water with fecal material will contribute to the Klebsiella exposure of dairy cows.
Publications
- White, L.J., T.J. Lam, Y.H. Schukken, L.E. Green, G.F. Medley and M.J. Chappell. 2006. The transmission and control of mastitis in dairy cows: a theoretical approach. Prev.Vet.Med. 74:67.
- Zadoks, R.N. and Y.H. Schukken. 2006. Use of molecular epidemiology in veterinary practice. Vet.Clin.North Am.Food Anim Pract. 22:229.
- Barkema, H.W., Y.H. Schukken and R.N. Zadoks. 2006. Invited Review: The role of cow, pathogen, and treatment regimen in the therapeutic success of bovine Staphylococcus aureus mastitis. J.Dairy Sci. 89:1877.
- Borm, A.A., L.K. Fox, K.E. Leslie, J.S. Hogan, S.M. Andrew, K.M. Moyes, S.P. Oliver, Y.H. Schukken, D.D. Hancock, C.T. Gaskins, W.E. Owens and C. Norman. 2006. Effects of prepartum intramammary antibiotic therapy on udder health, milk production, and reproductive performance in dairy heifers. J.Dairy Sci. 89:2090.
- Dogan, B., S. Klaessig, M. Rishniw, R.A. Almeida, S.P. Oliver, K. Simpson and Y.H. Schukken. 2006. Adherent and invasive Escherichia coli are associated with persistent bovine mastitis. Vet.Microbiol. 116:270.
- Green, L.E., Y.H. Schukken and M.J. Green. 2006. On distinguishing cause and consequence: do high somatic cell counts lead to lower milk yield or does high milk yield lead to lower somatic cell count? Prev.Vet.Med. 76:74.
- Munoz, M.A., C. Ahlstrom, B.J. Rauch and R.N. Zadoks. 2006. Fecal shedding of Klebsiella pneumoniae by dairy cows. J.Dairy Sci. 89:3425.
- Rivas, A.L., R. Tadevosyan, R.C. Gorewit, K.L. Anderson, R. Lyman and R.N. Gonzalez. 2006. Relationships between the phagocytic ability of milk macrophages and polymorphonuclear cells and somatic cell counts in uninfected cows. Can.J.Vet.Res. 70:68.
- Simpson, K.W., B. Dogan, M. Rishniw, R.E. Goldstein, S. Klaessig, P.L. McDonough, A.J. German, R.M. Yates, D.G. Russell, S.E. Johnson, D.E. Berg, J. Harel, G. Bruant, S.P. McDonough and Y.H. Schukken. 2006. Adherent and invasive Escherichia coli is associated with granulomatous colitis in boxer dogs. Infect.Immun. 74:4778.
- Suriyasathaporn, W., U. Vinitketkumnuen, T. Chewonarin, S. Boonyayatra, K. Kreausukon and Y.H. Schukken. 2006. Higher somatic cell counts resulted in higher malondialdehyde concentrations in raw cows' milk. International Dairy Journal. 16:1088.
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Progress 01/01/05 to 12/31/05
Outputs
Several sub-projects have been executed during the last year. The first project is the completion of a large field study in which Cornell was one of the 7 stations. In this study, preparturient heifers (n equal 545) from 9 herds in 7 states (US) and one province (Canada) were enrolled in a study to test the hypothesis that prepartum intramammary therapy would cure existing intramammary infection (IMI) and lead to increased milk production, reduced linear somatic cell count (LSCC), and improved reproductive performance. Mammary secretions were collected 10 to 21 d prior to expected calving from each quarter. Heifers were assigned by identification number to receive intramammary therapy consisting of infusion of one tube of a lactating cow commercial antibiotic preparation containing cephapirin per mammary quarter or to a nontreated control group. Overall, 34.1 percent of mammary quarters were infected with a mastitis pathogen prior to parturition and 60.8 percent of
heifers had at least one mammary quarter infected. The coagulase-negative staphylococci caused the majority (74.8 percent) of prepartum IMI.Staphylococcus aureus, environmental streptococci and coliforms accounted for 24.5 percent of prepartum infections. Mammary quarters that were infected prepartum and treated with antibiotics had a 79.9 percent cure rate and the percentage reduction in heifers with IMI was 52.5. Control quarters had a spontaneous cure rate of 31.7 percent. Treatment had a significant effect (P less than 0.001) on the cure rate of infected mammary quarters. Treatment neither significantly affected milk production nor LSCC in the first 200 d of lactation. No significant effect on services per conception or days open between treatment and control groups was observed. While this trial demonstrated that prepartum intramammary antibiotic therapy did reduce the number of heifer IMI and lowered LSCC, this improvement in udder health did not translate into a significant
improvement in milk production, nor improved reproductive performance during the first 200 d of the first lactation. The second project involved the microbiological speciation of Coagulase Negative Staphylococci (CNS) collected from the above field study. We compared classical bacteriological techniques extended with API-Staph (trade mark) with the use of molecular diagnostics: a species specific PCR method. The initial results of this project indicate that molecular diagnostic methods appear to perform better compared to classical bacteriology. We will continue this effort in the next project year. The third project involved antimicrobial resistance determination in micro organisms collected from the field study. In collaboration with the University of Wisconsin-Maddison the antimicrobial resistance profile of the bacterial pathogens is being determined. This project is ongoing.
Impacts
The most important finding is that we have results from a multi-center trial in the US which indicate that pre-partum intra-mammary treatment of heifers is not economically viable. This practice has been proposed to be used by all dairy farmers. However, our data indicate that this is generally not the case, and that it only might be advisable to farms with very high prevalence of intra-mammary infections in heifers.
Publications
- Zadoks, R.N. 2005. Comparison of diagnostic methods for Coagulase Negative Staphylococci. Mastitis Research Workers Meeting, Chicago, Ill.
- Borm, A.A., Fox, L.K., Leslie, K.E., Hogan, J.S., Andrew, S.M., Oliver, S.P., Schukken, Y.H., Hancock, D.D., Gaskins, C.T., Owens, W.E., and Norman, C. 2005. Prepartum Intramammary Antibiotic Therapy: Effects on udder health and milk production. Mastitis in Dairy Production, Eds. H. Hogeveen, pp 364-369.
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Progress 01/01/04 to 12/31/04
Outputs
In this multi-state project, preparturient heifers (n = 545) from nine herds in the US and Canada (including 104 heifers at Cornell) were enrolled in a study testing the hypothesis that prepartum antibiotic intramammary therapy would cure existing intramammary infection (IMI). We tested the hypothesis that treating of infections would be resulting in increased milk production, reduced somatic cell count (SCC), and improved reproductive performance. Mammary secretions were collected 10-21 d prior to expected calving, and heifers were systematically assigned to receive antibiotic treatment using a commercially available lactating cow intramammary product (Tx) , or no treatment (Cx). The percentage of mammary quarters infected prior to parturition in Tx and Cx groups was 32.9 and 35.4. The coagulase-negative staphylococci accounted for the majority of prepartum IMI (74.8 pct). Staphylococcus aureus, environmental streptococci and coliforms accounted for 24.5 pct of
prepartum infections. Mammary quarters that were infected prepartum and treated with antibiotics had a 79.9 pct cure rate. Control mammary quarters had a spontaneous cure rate of 31.7 pct. Treatment had a significant effect (P less than 0.001) on the cure rate of infected quarters at parturition and a decrease in the number of new IMI during the first 21 days in milk (DIM), but not a reduction in linear (L)SCC (P greater than 0.22) during the first 200 DIM. Cure of major mastitis pathogens was associated with a significant reduction in SCC during the first test-days in lactation. The reduction of IMI was not associated with a significant change in milk production during the first 200 DIM. No significant effect on services per conception or days open between treatment and control groups was observed. Prepartum intramammary antibiotic therapy reduced the number of heifer IMI, but this reduction in IMI did not translate into a significant improvement in milk production, SCC, or
reproductive performance in all treated animals. Treating animals with a know infection with major pathogens appears to be clinically important. Antimicrobial resistance patterns in the staphylococcal pathogens were evaluated and compared to outcome of treatment. We did not find a relationship between antimicrobial resistance pattern and the likelihood of cure.
Impacts
This multistate project answered the question: Do we need to treat heifers with intramammary antibiotics before calving. The preliminary answer appears to be that treatment is NOT necessary, unless a very high prevalence of infection exists in the heifer population. In virtually all herds in the study, the intramammary treatment resulted in a reduction of infection in the minor pathogens with an associated decrease in somatic cell counts, but with no measurable impact on milk production.
Publications
- Borm, A.A., Fox, L.K., Leslie, K.E. Hogan, J.S., Andrew, S.M., Oliver, S.P., Schukken, Y.H., Hancock, D.D., Gaskins, C.T., Owens, W.E. and Norman, C. 2005. Prepartum intramammary antibiotic therapy: effects on udder health, milk production, and reproductive performance in dairy heifers. Proc. IDF meeting, Maastricht, the Netherlands, In Press.
- Fox, L.K., Borm, A.A., Leslie, K.E., Hogan, J.S., Andrew, S.M., Oliver, S.P., Schukken, Y.H., Owens, W.E. and Norman, C. 2004. Effect of prepartum antibiotic therapy in heifers on milk production and mastitis postpartum. Proc NMC annual meeting, pp 114-121.
- Hoe, F.G.H., Fox, L.K., Owens, W.E., Schukken, Y.H. and Ruegg, P.L. 2005. Relationship between minimum inhibitory concentrations of staphylococcal isolates obtained from mammary glands of dairy heifers and outcomes of prepartum mastitis treatments. Proc NMC annual meeting, pp 231-232.
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Progress 01/01/03 to 12/31/03
Outputs
To study the effect of prepartum intramammary antibiotic therapy on udder health, milk production, and reproductive performance in dairy heifers. Stations involved: Washington State University, Liousiana State University, University of Tennessee, Ohio State University, Cornell University, University of Guelph. Heifers enrolled were split into two groups, treated and control. Treatment allocation was by ear tag numbers, where odd numbered heifers were placed in the control group. Lacteal secretions were aseptically collected from all heifers 7-14 days prior to expected parturition, and then within 3 days of parturition, during the first, second, and third week postpartum. Milk samples were cultured using standard techniques and mastitis pathogens were presumptively identified as CNS, CPS, environmental streps., S. agalactiae, coliforms, and others. Additionally, milk samples were collected for ketone analysis at the time of sample collection for milk culture, and a
separate set of milk samples were collected at parturition, and days 3 and 5 post-partum, for antibiotic residue testing. Differences in IMI at calving, and differences in reproduction efficiency, milk production, and milk somatic cell count, during lactation, are contrasted between groups. A greater number of intramammary infections were cured by treatment during the peripartum period. As a result, treated cows had less IMI at calving, and also less new IMI at calving. IMI were reduced in all herds by treatment, and CNS were the pathogens accounting for the vast majority of treatable IMI. Postpartum milk production was equivalent in treated and control heifers, and milk somatic cell count slightly lower in treated heifers.
Impacts
This multistate project answered the question: Do we need to treat heifers with intramammary antibiotics before calving. The preliminary answer appears to be that treatment is NOT necessary, unless a very high prevalence of infection exists in the heifer population. In virtually all herds in the study, the intramammary treatment resulted in a reduction of infection in the minor pathogens with an associated decrease in somatic cell counts, but with no measurable impact on milk production.
Publications
- Fox, L. Schukken, Y.H., Stipetic, K., Oliver, S.P., Leslie, K.E. 2004. Pre partum intramammary treatment of heifers to prevent mastitis. Proceedings of the National Mastitis Council, Charlotte, NC.Pp --. (to be published in the 2004 proceedings).
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