Research | Free access

Research Phd Theses 

Impact of intramammary infections with non-aureus staphylococci on udder health and milk production in dairy heifers

3 min read ,

Non-aureus staphylococci (NAS) have become the most prevalent cause of intramammary infections (IMI) in dairy cows in most parts of the world. The current body of literature on IMI caused by NAS has reported debatable and contradictory conclusions on their relevance for udder health and milk production. The aims of this thesis were to precisely estimate the impact of NAS IMI on somatic cell count (SCC) and milk yield (MY) at the quarter-level.

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Research Phd Theses 

Selective antimicrobial treatment at dry off in dairy cows

3 min read ,

Selective dry cow therapy (SDCT), in which only infected quarters/cows are treated with antimicrobials, constitutes an alternative to blanket dry cow therapy (BDCT) where all quarters of all cows at dry off receive antimicrobials, regardless of their infection status, for a more judicious use of antimicrobials. The objective of this thesis was to shed more light on targeted antimicrobial treatment decisions of infected quarters of cows at dry-off.

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Researcher@work 

Case study: hock lesions as a potential source of Staphylococcus aureus mastitis

10 min read ,

Hock injuries are a common injury in dairy cows that are housed indoors for the greater part of the year. Oftentimes, the lesions indicate inadequate stall or cubicle design in dairy barns. The presence and severity of hock lesions are associated with lameness and other disorders of the limb, which is why most welfare evaluations target hock lesion reductions to improve cow welfare. It is thought that hock lesions may also be associated with mastitis and reduced milk yield. In order to better understand the association between hock lesions and the development of Staphylococcus aureus mastitis, an undergraduate student from the University of Vermont (UVM), US headed-up a case study within the student-run herd as a senior thesis project with the help of her advisor Dr. John Barlow and his graduate students. Veterinarian and UVM PhD student Caitlin Jeffrey presented the findings at the National Mastitis Council Annual Meeting, held in February of this year.

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Research MSc thesis 

Patterns of mastitis indicators during a clinical mastitis episode

3 min read

Mastitis is one the most common and costly diseases of dairy cattle, hence widely studied globally. It is the inflammation of one or more quarters of the mammary glands, mostly caused by various microorganisms. Based on whether gross changes in milk (such as watery, serous, or purulent milk, presence of clots, flakes, or blood), gross changes in the udder (such as painful or inflamed udder) and animal are seen or not, mastitis is categorized either into clinical or subclinical. With the introduction of Automatic Milking Systems (AMS), the sensors can measure milk parameters every time the cow goes for milking.

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