Source: Dairy Farmers of Canada
Project Overview
The Mastitis Network provides innovative science-based solutions that respond to the needs and challenges of dairy producers. All projects share a common goal of developing novel strategies that could reduce dependency on antimicrobials (e.g., management strategies, immunomodulators, diagnostic tests that can better inform treatment decisions) to ensure the delivery of safe high-quality milk.
Under Dairy Research Cluster 3 funding, researchers from the Mastitis Network investigated (1) the relevance of different Staphylococcus bacteria species for udder health; (2) impacts of dry-off management in robotic milking systems on the risk of mastitis; and (3) potential applications of microbiome manipulation for preventing mastitis.
What Did the Research Team Do?
Relevance of Staphylococcus species for udder health: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) was used to identify the most common species of staphylococcus present in over 27,000 milk samples from 5 automated milking system herds in Canada.
Impacts of dry-off management in robotic milking systems on the risk of mastitis: Researchers investigated how different housing factors, management practices, and milking and feeding allowances impacted measures of udder health and milk yield.
Microbiome manipulation for preventing mastitis: Researchers characterized microbiota present in healthy and diseased cows and attempted to identify bacteria that may be “protective” against common mastitis-causing pathogens.
Vaccine development for prevention of mastitis: Researchers worked to develop a polyvalent vaccine against multiple bovine and mastitis pathogens (Streptococcus uberis, S. dysgalactiae, Salmonella Dublin, and Escherichia coli; sub-activity C).
Non-esterified fatty acids (NEFA) and host defense peptides (HDP): The team examined the roles of NEFA and HDP on immune function and mastitis pathogenesis.
Staphylococcus aureus and mastitis: Researchers investigated pathways by which S. aureus invades epithelial cells, methods for rapid and accurate S. aureus testing, and milk quality changes associated with S. aureus infection.
What Did the Research Team Find?
- There are many different species of staphylococcus that can colonize the teat skin, and further work is needed to better understand the complex dynamics and conditions under which they may contribute to mastitis infections
- Reducing milking frequency and robot feed allocation can support milk yield reduction before dry-off
- Production level, use of teat sealants, dry cow therapy, and grouping strategy of cows at dry-off and in the dry period were associated with udder health measures
- Aerococcus urinaeequii and Staphylococcus xylosus may play a role in preventing udder colonization by other pathogenic bacteria; further research is planned to investigate the potential applications of these isolates
- NEFA had a negative impact on some lymphocyte functions
- Cathelicidins (a type of HDP) were found to be favourable anti- S. aureus therapeutic agents for mastitis
- A new protocol was developed to investigate clumping factor protein interactions in vitro and in vivo
- A polyvalent vaccine was developed that could greatly benefit the dairy industry and significantly reduce antibiotic use in animal production.
- Through MALDI-TOF analysis, 294 different species of microorganisms recovered from milk samples were identified among Canada-US-Brazil datasets, and a difference was found in the microorganism species’ identified from apparently healthy cows compared to cows with clinical mastitis.
