Dairy Resources - Udder Health

October 2022

“Similar to Staph aureus and mycoplasma, Prototheca is hard to detect, has no known cure, and is contagious by intermittently shedding from cow to cow.” (Farm Journal)

Prototheca bovis, a non-photosynthetic, yeast-like microalgae, is a mastitis-causing pathogen that has been around since the 1950s. However, it’s prevalence has significantly increased within the last five years, according to Angie Ulness, Senior Territory Manager at Parnell Veterinary Pharmaceuticals.

October 2023

The cost of mastitis to the US dairy industry is approximately $110 per cow per year and is rising annually. Photo: Canva

Non-severe cases of clinical mastitis are being overtreated by dairy farmers, which is unnecessarily increasing farm costs and a loss of milk.

Research carried out at the College of Veterinary Medicines at Michigan State University found that the direct costs of treatment could be reduced by US$65.20 per case if the minimum labelled durations are used.

April 2023

ABSTRACT

Treatment of clinical mastitis (CM) and use of antimicrobials for dry cow therapy are responsible for the majority of animal-defined daily doses of antimicrobial use (AMU) on dairy farms. However, advancements made in the last decade have enabled excluding nonsevere CM cases from antimicrobial treatment that have a high probability of cure without antimicrobials (no bacterial causes or gram-negative, excluding Klebsiella spp.) and cases with a low bacteriological cure rate (chronic cases). These advancements include availability of rapid diagnostic tests and improved udder health management practices, which reduced the incidence and infection pressure of contagious CM pathogens. This review informed an evidence-based protocol for selective CM treatment decisions based on a combination of rapid diagnostic test results, review of somatic cell count and CM records, and elucidated consequences in terms of udder health, AMU, and farm economics. Relatively fast identification of the causative agent is the most important factor in selective CM treatment protocols. Many reported studies did not indicate detrimental udder health consequences (e.g., reduced clinical or bacteriological cures, increased somatic cell count, increased culling rate, or increased recurrence of CM later in lactation) after initiating selective CM treatment protocols using on-farm testing. The magnitude of AMU reduction following a selective CM treatment protocol implementation depended on the causal pathogen distribution and protocol characteristics. Uptake of selective treatment of nonsevere CM cases differs across regions and is dependent on management systems and adoption of udder health programs. No economic losses or animal welfare issues are expected when adopting a selective versus blanket CM treatment protocol. Therefore, selective CM treatment of nonsevere cases can be a practical tool to aid AMU reduction on dairy farms.

Ellen de Jong, Kayley D. McCubbin, David Speksnijder, Diego B. Nobrega, John P. Kastelic, Herman W. Barkema
Journal of Dairy Science, DOI:https://doi.org/10.3168/jds.2022-22826

December 2022

ABSTRACT:

Automated monitoring devices have become increasingly utilized in the dairy industry, especially for monitoring or predicting disease status. While multiple automated monitoring devices have been developed for the prediction of clinical mastitis (CM), limitations in performance or applicability remain. The aims of this study were to (1) detect variations in reticuloruminal temperature (RRT) relative to an experimental intramammary challenge with Streptococcus uberis and (2) evaluate alerts generated automatically based on variation in RRT to predict initial signs of CM in the challenged cows based on severity of clinical signs and the concentration of bacteria (cfu/mL) in the infected quarter separately. Clinically healthy Holstein cows without a history of CM in the 60 d before the experiment (n = 37, parity 1 to 5, ≥120 d in milk) were included if they were microbiologically negative and had a somatic cell count under 200,000 cells/mL based on screening of quarter milk samples 1 wk before challenge. Each cow received an intra-reticuloruminal automated monitoring device before the trial and was challenged with 2,000 cfu of Strep. uberis 0140J in 1 rear quarter. Based on interrupted time series analysis, intramammary challenge with Strep. uberis increased RRT by 0.54°C [95% confidence interval (CI): 0.41, 0.66] at 24 h after the challenge, which remained elevated until the end of the study. Alerts based on RRT correctly classified 78.3% (95% CI: 65.8, 87.9) of first occurrences of CM at least 24 h in advance, with a sensitivity of 70.0% (95% CI: 50.6, 85.3) and a specificity of 86.7% (95% CI: 69.3, 96.2). The accuracy of CM for a given severity score was 90.9% (95% CI: 70.8, 98.9) for mild cases, 85.2% (95% CI: 72.9, 93.4) for moderate cases, and 92.9% (95% CI: 66.1, 99.8) for severe cases. Test characteristics of the RRT alerts to predict initial signs of CM improved substantially after bacterial count in the challenged quarter reached 5.0 log₁₀ cfu/mL, reaching a sensitivity of 73.5% (95% CI: 55.6, 87.1) and a specificity of 87.5% (95% CI: 71.0, 96.5). Overall, the results of this study indicated that RRT was affected by the intramammary challenge with Strep. uberis and the RRT-generated alerts had similar accuracy as reported for other sensors and algorithms. Further research that includes natural infections with other pathogens as well as different variations in RRT to determine CM status is warranted.

Zelmar Rodriguez, Quinn K. Kolar, Kirby C. Krogstad, Ilkyu Yoon, Barry J. Bradford, Pamela L. Ruegg
Journal of Dairy Science, DOI:https://doi.org/10.3168/jds.2022-22421

September 2022

Highlights:

• Dairy herds in the US may adopt selective dry cow therapy to reduce the use of antimicrobials.
• Potential reduction in antimicrobial use around the dry period was found to be between 31 % and 66 %.
• Primiparous cows hold the greatest opportunity to reduce the use of antimicrobials at dry-off.

Abstract

Mastitis is a prevalent and expensive disease in dairy herds worldwide. Blanket dry cow therapy (BDCT), in which all quarters of all cows are infused with antimicrobials at the dry-off, is a cornerstone for mastitis control in many countries. An alternative approach is the use of selective dry cow therapy (SDCT), in which only cows with high risk for intramammary infection (IMI) at dry-off receive antimicrobials. Our objectives in this cross-sectional study were to estimate the potential reduction in the use of antimicrobials if SDCT was adopted in the US by using cow-level dairy herd data and to describe the factors associated with cows being classified as high-risk for an IMI at dry-off. Besides, we aimed to describe the seasonality in IMI at dry-off. We used cow-level somatic cell score (SCS) test-day data from herds in the western US (DHIA, Dairy Herd Improvement Association, AgriTech, Visalia, CA) to create five scenarios to classify cows as high risk for IMI at dry-off. Associations between cow-level data and state were also used in logistic regression models. We also calculated the average animal-defined daily dosage of antimicrobials per cow per year around the dry period if a BDCT or SDCT approach is used, adjusting for the risk of cases of clinical mastitis in the next lactation for the SDCT approach. The point prevalence of IMI at the last test-day before dry-off varied between 15.0 % and 54 % for primiparous and 34.0 % and 85 % for multiparous cows, depending on the scenario. By extrapolating our results obtained from using data from dairies enrolled in the DHIA testing program for the western US, we demonstrated that regardless of the criteria used to classify cows as high risk of IMI at dry-off (scenarios 1–5), if selective dry cow therapy is adopted in the US, the dairy industry could reduce the use of antimicrobials around the dry-off between 31 % and 66 %. Multiparous cows had greater odds of being classified as high-risk than primiparous cows. Cows dried off in the spring, summer, and fall had lower odds of being classified as high-risk compared to cows dried off in the winter. Advanced days in milk at dry-off was associated with greater risk of IMI at dry-off. Greater milk yield and higher protein percentage at the last test-day before dry-off were associated with decreased odds of a cow being classified as high-risk at dry-off, cows in small herds had greater odds of being classified as high-risk at dry-off, and a variation among states was observed.

Fernanda C. Ferreira, Beatriz Martínez-López, Emmanuel Okello
ScienceDirect https://doi.org/10.1016/j.prevetmed.2022.105709

June 2021

Dairy cows are most susceptible to new intramammary infections (IMIs) during the dry period. IMIs acquired during the dry period can have a significant impact on milk production, milk quality, herd removal and reproductive performance post-calving.

These eight dry cow prevention strategies can help reduce the risk that new IMIs will develop post-calving, which, in turn, helps keep milk flowing on the dairy and improves reproductive efficiency.

June 2021

Summer can create the ‘perfect storm’ for environmental mastitis.

When the weather turns hot and humid, it can create the ideal environment for mastitis causing pathogens to grow. Additionally, cows experiencing intense heat become stressed, which leads to a decreased immune system. Couple these two factors together and you create the perfect storm for mastitis to take a toll on your herd.

December 2020

Bedding. Bacteria. Better management.

According to Dr. Sandra Godden, professor with the department of veterinary population medicine at the University of Minnesota, these are the “three ‘B’s’ of udder health.” She outlined the relationship between bedding bacteria counts (BBC) and udder health, bedding management practices and monitoring bedding hygiene in the Nov. 19 webinar from the National Mastitis Council.

November 2017

When it comes to milk quality, many dairy herds emphasize premilking protocols, such as application of germicides, teat stimulation and drying of teats. This emphasis is warranted, many standard preparation practices help reduce mastitis and improve milking efficiency. But what about after milking care? Here are a couple points to consider involving equipment protocols as well as the humanside of postmilking.

April 2020

Studies have shown there are 75% fewer baceria on used gloves than bare hands.

We receive calls weekly from producers who are experiencing milk quality issues on their farm. Often, we find a common denominator on each farm for the source of the high somatic cell count (SCC).