Coagulase-negative staphylococci (CNS) are the most frequently isolated pathogens from cows with intramammary infection (IMI). Although API STAPH ID 20, a commercially available identification ...system, and PCR-restriction fragment length polymorphism (PCR-RFLP) of the gap gene (gap PCR-RFLP) have been successfully applied for the identification of CNS isolates from human specimens, their accuracy in the identification of veterinary isolates has not been fully established. In this study, we identified 263 CNS isolates from bovine IMI at species level by partial 16S rRNA gene sequence analysis as the definitive test. Species identification obtained using partial 16S rRNA gene sequence analysis was compared to results from the API STAPH ID 20 and gap PCR-RFLP analysis. Eleven different CNS species were identified by partial 16S rRNA gene sequence analysis. Only 76.0% (200/263) of the species identification results obtained by API STAPH ID 20 matched those obtained by partial 16S rRNA gene sequence analysis, whereas 97.0% (255/263) of the species identification results obtained by the gap PCR-RFLP analysis matched those obtained by partial 16S rRNA gene sequence analysis. The gap PCR-RFLP analysis could be a useful and reliable alternative method for the species identification of CNS isolates from bovine IMI and appears to be a more accurate method of species identification than the API STAPH ID 20 system.
Gastrointestinal disease (GI) is the most common illness in pre-weaned dairy calves. Therefore, effective strategies to manipulate the microbiome of dairy calves under commercial dairy operations are ...of great importance to improve animal health and reduce antimicrobial usage. The objective of this study was to develop a farm-specific FMT product and to investigate its effects on clinical outcomes and fecal microbial composition of dairy calves. The FMT product was derived from feces from healthy donors (5-24 days of age) raised in the same calf ranch facility as the FMT recipients. Healthy and diarrheic calves were randomly enrolled to a control (n = 115) or FMT (n = 112) treatment group (~36 g of processed fecal matter once daily for 3 days). Fecal samples were collected at enrollment and again 9 days later after the first FMT dose. Although the FMT product was rich in organisms typically known for their beneficial probiotic properties, the FMT therapy did not prevent or ameliorate GI disease in dairy calves. In fact, calves that received FMT were less likely to recover from GI disease, and more likely to die due to GI disease complications. Fecal microbial community analysis revealed an increase in the alpha-diversity in FMT calves; however, no major differences across treatment groups were observed in the beta-diversity analysis. Calves that received FMT had higher relative abundance of an uncultured organism of the genus Lactobacillus and Lactobacillus reuteri on day 10. Moreover, FMT calves had lower relative abundance of Clostridium nexile and Bacteroides vulgatus on day 10. Our results indicate the need to have an established protocol when developing FMT products, based on rigorous inclusion and exclusion criteria for the selection of FMT donors free of potential pathogens, no history of disease or antibiotic treatment.
Embryonic mortality contributes to repeat-breeding in dairy cows; luteal insufficiency is a known cause of embryonic mortality. The objective of this study was to assess the efficacy of ...supplementation with exogenous progesterone for 14 days on pregnancy maintenance in inseminated repeat-breeder dairy cows. On Day 5 after insemination, treated cows (
n=143) received a modified PRID (i.e. without estradiol capsule), which was removed on Day 19. Control cows (
n=148) did not receive any treatment. Overall there was no effect of PRID supplementation on pregnancy rates. However, when the study population was stratified by parity and stage of lactation, PRID supplementation significantly improved pregnancy rate in first and second parity late lactation cows (risk ratio=3.26; 95% CI 1.22, 8.69). Pregnancy rates did not differ between PRID-treated cows with (
n=81) and without vaginitis. Control cows tended (
P=0.077) to have a higher proportion of abortions than PRID-treated cows (7/50 versus 2/51, respectively). In conclusion, young late lactation repeat-breeder cows benefited from progesterone supplementation, in terms of maintaining pregnancy until traditional time of pregnancy diagnosis.
The increasing size and complexity of US dairy farms could make it more difficult for a veterinary practitioner to effectively communicate protocol recommendations for prevention or treatment on the ...farm. A continuing education workshop was set up based on the results of research on dairy organizational communication on dairy farms, which resulted in a tool to assess dairy communication structure and flow. The workshop specifically focused on communication structure and whom to talk to when implementing health care changes in calf rearing. In addition, modern methods of veterinary-client communication knowledge and skills were provided. Primary outcomes of the workshops were to obtain feedback from participants about research findings and the communication model, to improve awareness about the complexity of communication structures on dairy farms, and to change participants' knowledge and skills associated with on-farm communication by providing communication theory and skills and an approach to evaluate and improve dairy organizational communication. Of the 37 participants completing the pre-program assessment, most recognized a need for themselves or their practice to improve communication with clients and farm employees. After the program, most participants were confident in their new communication skills and would consider using them. They highlighted specific new ideas they could apply in practice, such as conducting a "communication audit." The results from the assessment of this communication workshop, focused on dairy veterinarians, highlighted the need for communication training in this sector of the profession and practitioners' desire to engage in this type of training.
Fifty-two newborn Holstein calves with serum IgG concentrations less than 0.73 g.dL(-1) were randomly assigned to one of four treatments: no added live yeast (control), 0.5 g of live yeast added to ...the grain for 84 d (SC; Saccharomyces cerevisiae), 0.5 g of live yeast added to the milk for 42 d (SB; S. cerevisiae, spp. boulardii), and 0.5 g of live yeast added to the grain for 84 d and to the milk for 42 d (SCSB). Calves were offered 440 g of milk replacer DM for the first 42 d and grain for ad libitum intake throughout the study. Plasma was analyzed weekly for concentrations of glucose and beta-hydroxybutyrate. Escherichia coli isolated from fecal samples collected every 2 weeks were used for determination of antibiotic resistance patterns. Calves receiving SC consumed more grain DM, had increased weight gain prior to weaning, and increased plasma glucose concentrations compared to controls. Days with diarrhea were reduced by feeding live yeast to calves. Antibiotic resistance in fecal E. coli was associated with the age of calves with highest levels of resistance observed in the 3 d calves. While calves receiving SCSB had higher levels of antibiotic resistance than controls, this effect was not associated with any of the other treatments. Improvements in performance of calves with failure of passive transfer were observed when live yeast was added only to the grain.
To evaluate serovar and antimicrobial resistance patterns of Salmonella enterica isolated from preweaned calves and identify management risk factors associated with fecal shedding of S enterica.
...Cohorts of 10 to 15 preweaned calves (1 to 84 days of age) on 26 dairies and 7 calf ranches and cross-sectional samples of preweaned calves on smaller farms.
Calves were evaluated every 2 weeks during a 6-week period. Salmonella isolates obtained from rectal fecal swabs underwent antimicrobial susceptibility testing against 12 antimicrobials. Cluster analysis enabled description of antimicrobial susceptibility patterns. Calf, cohort, and farm risk factors associated with both the prevalence of S enterica and multiple-antimicrobial-resistant S enterica in preweaned calves were identified with repeated-measure logistic regression models.
Salmonella enterica was detected on > 50% of farms and in 7.5% of 3,686 fecal samples. Many isolates (33%) were resistant to multiple antimicrobials. Shedding of Salmonella spp was negatively associated with increasing calf age, herds being closed to incoming cattle, and antimicrobial supplementation of milk replacer; prophylactic antimicrobial treatment in day-old calves increased shedding. No association between farm management and presence of multiple-antimicrobial-resistant S enterica or between calving management and presence of S enterica in calves < or = 1 week old was detected.
In preweaned calves, the most important factors associated with decreased likelihood of fecal shedding of S enterica were the use of antimicrobial-supplemented milk replacer and maintenance of a closed herd. Infection with multiple-antimicrobial-resistant S enterica was not associated with antimicrobial administration.
Bacterial antimicrobial resistance is a problem common to both animal and public health. An important public policy issue is to develop and implement prudent use practices where antimicrobials are ...used. As policy develops, there are questions regarding the use of antimicrobials in animal agriculture and whether these uses constitute prudent use. A series of papers assessing the risk to the public health from agricultural use of antimicrobials have consistently concluded that risk estimation is hampered by the lack of data that describe the amount, types, and uses of antimicrobials in animal agriculture. The absence of information has spurred efforts to develop a framework to collect these data. However, the reasons and benefit of collecting these data should be carefully defined. The dairy industry, contrasted to other major animal commodities, is not focused on meat production but on milk production. Milk production is constrained by disease and antimicrobial treatment is a common management tool, but unlike many other animal agricultural systems where the value and safety of the product is measured in the future; the value of milk is zero when an antimicrobial is used in a lactating cow and milk must be discarded because of residues. While there are exceptions, e.g. non-lactating cow therapy, this difference results in antimicrobials being used sporadically and directed at therapy rather than prophylactic uses. In the dairy industry, antimicrobial use data and its consequences may exist in sufficient detail or could be estimated from existing datasets without the expense of additional surveys. Finally, the main food product milk is mainly pasteurized and all shipments of milk from the farm to the processing plant are tested for the presence of antimicrobials. This makes the likelihood of farm-origin antimicrobials or bacteria appearing in finished product very low. This suggests that the use and quantity of antimicrobials in the dairy system has little impact on public health. This does not imply that the dairy industry does not have a significant role in developing guidelines for appropriate and careful application of antimicrobials, but the effort and cost to collect additional data should be used to fund efforts that improve our diagnostic and managerial skills. These data would change the use of antimicrobials by decreasing the rates of disease and ultimately decreasing prophylactic, metaphylactic and therapeutic use of antimicrobial. These studies and outcome are as important to the dairy industry as to public health.
The involvement of paraveterinarians in animal-health delivery can reduce costs and allow expanded service delivery. Our objectives were to describe use of public paraveterinary services offered by ...junior technicians (JT) in two regions of Nepal, to identify factors associated with JT service use, and to characterize factors that limit JT service use. We used a survey of livestock owners in the Khumbu and Lower Mustang regions of Nepal's Himalaya to examine JT service use. Of 118 questionnaires completed between May 30, 1997 and July 8, 1997, 81 were analyzed for use of JT services to treat livestock: bovids, equids, and small ruminants. Five factors were associated with owners’ use of JT services: living <30min walk from a JT post (OR=12.2); having a positive opinion about JT services (OR=23.6); animals not having disease events that either impaired mobility or affected production or reproduction (OR=5.6), animals died related to a reported disease event (OR=3.2), and the owners’ sex (with women being more likely to report use of JT services than men; OR=5.3).
Epidemiologists studying antimicrobial resistance are often interested in analyzing the association between antimicrobial resistance and antimicrobial use in animals, and on the impact of ...antimicrobial use in animals on the occurrence of resistance in bacteria affecting human populations. Given the various potential antimicrobial use data sources, it seems likely there will be some variability in the utility of the data for interpreting trends in antimicrobial resistance and investigating the relationship between antimicrobial use in animals and antimicrobial resistance in bacteria affecting human health. From an epidemiologic perspective, the major issues related to incorporation of antimicrobial use data into antimicrobial resistance monitoring programs are the further development of epidemiologic methods for collecting, quantifying, analyzing and interpreting use data; an open and realistic consideration of the limitations of the data; developing an understanding of scaling, temporal and spatial heterogeneity issues; and the interpretative problems of ecologic and atomistic fallacy. Given the many potential biases in antimicrobial use data, attempts to relate levels of antimicrobial use to levels of antimicrobial resistance should be done with caution until the data are better understood and the aforementioned issues have been addressed.
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