Research | Free access

Researcher@work

The immunity-AMR Project: A new Op+lait initiative

A new multidisciplinary research team composed of Christopher Fernandez-Prada, David Langlais, Jocelyn Dubuc, Éric Paquet, and Simon Dufour, based in the province of Québec, and involving multiple centers (UdeM, McGill, and U. Laval), has decided to explore how genetic mutations may contribute to cases of antibiotic treatment failure, AMR, and persistent or recurring infections in dairy cows. If these mutations can be identified, the research team could develop new tests to predict how easily a cow will get sick. In addition, the research team will also shed new light on how a weak immune system can lead to an increased frequency of AMR infections in dairy cows.

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Research MSc thesis

Comparison of bulk tank milk and water microbiota at Brazilian dairy farms during the dry and wet seasons

The bulk tank milk (BTM) microbiota is highly diverse, with multiple contamination sources contributing to its complexity. It has been suggested that the continuous use of water during the cleaning process and the frequentl poor quality of water in dairy farms may negatively impact the microbiological quality of raw milk.Read more

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Project

Implementing selective treatment of non-severe clinical mastitis in Flanders, Belgium via an “on-practice” approach

Antibiotic resistance in human- and animal-associated pathogens is a well-known and emerging problem (Singer et al., 2003; Dong et al., 2021). Although the contribution of the dairy sector to the antibiotic resistance problem in humans is quite low, we should act more responsibly when it comes to using antibiotics (Tel et al., 2012; Nobrega et al., 2018).

Antibiotics on dairy herds are typically used related to udder health and a reduction in the use is possible by maximizing prevention and by applying selective dry cow therapy. Implementing selective treatment of non-severe clinical mastitis is a valuable third option.

Recently, M-teamUGent at Ghent University, Belgium started a field trial as part of a larger Flanders Innovation and Entrepreneurship-funded project (HBC.2020.3192) together with Animal Health Service Flanders, Hooibeekhoeve and the Flanders Research Institute for Agriculture, Fisheries and Food. The project aims at transferring relevant scientific findings towards dairy practice through communication and training.

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Research MSc thesis

Effects of intramammary infections on mammary gland growth and development in nulligravid heifers

Dairy heifers are a sizable financial investment for producers and therefore should enter first lactation healthy in order to yield good return on investment. Most mammary growth and development occur during a dairy heifer’s first gestation and this initial development determines the number of secretory mammary epithelial cells in the lactating gland. The heifer mammary gland prior to first gestation is primarily composed of the mammary fat pad and contains minimal mammary epithelium. With the initiation of pregnancy, this previously existing mammary fat pad is replaced by secretory mammary epithelium. Unfortunately, coupled at this time is the increased prevalence of intramammary infections (IMI) as a result of pathogenic bacteria entering the mammary gland via the teat canal and establishing an infection. Such IMI are expected to shortchange future mammary maturation and ultimately reduce the number and/or functional capacity of secretory mammary epithelial cells. However, how these IMI affect mammary gland growth and development in rapidly growing and developing mammary glands has not been investigated. Therefore, Dr. Pari Baker explored the effects of intramammary infections on mammary gland growth and development in nulligravid heifers.

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Research Phd Theses

Role of bovine non-aureus staphylococci in the regulation of Staphylococcus aureus growth and virulence and its potential implications for udder health

Staphylococcus aureus remains one of the most common causative agents of bovine mastitis because of its pathogenicity, contagiousness, capability to persist in the mammary gland, colonization of skin and poor cure rates when causing intramammary infections with the currently available therapies. On the other hand, non-aureus staphylococci (NAS) originating fromRead more

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Research | Free access

Sensor-based mastitis management in automatic milking system farms. Mastitis management from a data-centric and economic perspective

Mastitis, or udder inflammation, is one of the most prevalent and costliest diseases in dairy farming. Automatic milking systems, equipped with sensors measuring mastitis indicators, have been used commercially since the 1990s. These systems are equipped with sensors that measure the cow’s health by analyzing her milk. For instance, these sensors could measure electrical conductivity, the number of immune cells, and activity of enzymes in the milk. Different algorithms have been developed to use this sensor data to alarm the farmer in the case of mastitis. However, less algorithms have been developed to help the farmer decide what to do when mastitis is found.

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Research Phd Theses

Biomarkers for bovine mammary gland involution and disease

At dry off, the mammary gland of the early dry cow undergoes a multitude of morphologic, immunologic, metabolic, and biochemical alterations known as mammary gland involution. During involution, the mammary gland is vulnerable to bacterial infection, particularly if milk leakage occurs. Increased risk of milk leakage and infection are associated with high milk production at dry off. Therefore, as advances in dairy cow management and fertility continue to increase milk production- more cows will be at risk for infection during early mammary involution. However, much remains unknown about optimizing mammary involution.

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Research Phd Theses

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

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

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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