Mariana Fonseca
Credit: courtesy
Mammitis and endometrite are two diseases with which dairy producers must frequently compose. Very widespread, the mastitis (inflammation of the mammary gland) affects almost a third of dairy cows; It is the most common and costly disease for dairy producers. Endometrite, on the other hand, affects approximately 20 % of cows. This inflammation of the uterine mucosa can occur within 30 days after setting the calves.
These two diseases have direct and indirect consequences on dairy production, resulting in financial losses for producers (drop in production, stretching deadlines between the bets, treatment prices, etc.). Many research projects aim to better predict their appearance and treat them while reducing the use of antibiotics.
Endometrite: predict to treat better
Isabella Nicola
Credit: courtesy
The professor of the Department of Veterinary Biomedicine at the University of Montreal Marcio Costa is interested in the intestinal microbiota and the diseases that affect the intestines and other cow systems, such as the reproductive system. “We had looked in a pilot project the bacteria present in the uterus of dairy cows and found that some increased before the cows have symptoms of endometrite,” he said. His team and now wish to validate these results thanks to funding from the Ministry of Agriculture, Fisheries and Food of Quebec (MAPAQ).
“If we are able to detect these changes before the appearance of the disease, we could create tests using bacterial markers,” he hopes. The cows most likely to have endometrite could thus be treated more quickly, while, for the moment, tests are only used when they already have symptoms. “If one could predict which cow will be sick, it would be a big change for everyone: the cow, the veterinarian and the farmer. The sooner we detect, the better the chances of treating adequately, and lighter are the consequences, ”he underlines.
Isabella Nicola, professor in the Department of Clinical Sciences of Udem, Hélène Lardé and José Denis-Robichaud, professors at the new veterinary medicine campus from the University of Montreal in Rimouski, will take uterine samples from this summer in several farms in Quebec. Marcio Costa will then take over to carry out laboratory analyzes. Extract DNA will measure the bacterial populations present in the samples.
Ultimately, the team would like to develop a new diagnostic test. “The next step would be to find the best early treatments. Is antibiotic treatment necessary or would uterine wash sufficient? Could we even develop treatment with good bacteria [probiotiques]? »» suggested Marcio coast.
Fewer antibiotics against mastitis
Jean-Philippe Roy
Credit: Marco Langlois
The veterinarian and professor in the Udem Department of Clinical Sciences Jean-Philippe Roy also wishes to reduce the use of antibiotics. “Bovine mastitis is the main cause of use of antibiotics in dairy herds,” he said. If, before, antibiotics were systematically given to all cows during their drying up, we are now trying to make a better use of it to slow down the appearance of antibioticity.
When the cow stops producing milk, the risks of breast infections increase. The emptying of milk is therefore protective, since the milking mechanically eliminates pathogens. “There, we stop overnight. There is a engorgement in the mammary gland for a few days, while production ceases, ”says Jean-Philippe Roy.
For a more precise use of antibiotics, the team currently tests a protocol which would reduce their use by almost 90 % without adding too much work to overwhelmed farms and farmers. Farms would thus use a measure that they already have: the counting of immune cells (somatic cells) in milk, which is carried out on each cow 10 times a year. “When there is a bacterial infection, the account of somatic cells increases, which indicates the presence of inflammation and betrays the presence of an infection,” explains Jean-Philippe Roy.
“At the bottom of an account threshold of somatic cells, we consider that the cow is healthy. Otherwise, we make a bacteriological culture for each district [la mamelle, ou pis, de la vache est composée de quatre quartiers] And an antibiotic is only injected into infected neighborhoods, ”he adds. The healthy districts are sealed using an inert substance, which creates a physical barrier against bacteria. It is therefore only a minority of cows that must be the subject of a culture.
The Dr Roy, in collaboration with Simon Dufour, professor in the UdeM pathology and microbiology department, will continue to collect samples this summer. In total, they aim to take samples on some 720 cows. This randomized controlled trial is funded by the program of dairy research clusters of agriculture and agrifood Canada.
Understanding the mastitis
Simon Dufour
Credit: courtesy
Professor Dufour also attacks the Mammite in another research project, funded by MAPAQ. With the postdoctoral researcher Mariana by Agosto Miguel Fonseca, he wants to improve knowledge of the pathogens present in dairy farms. Using the 346 samples of milk tanks previously collected in Alberta, Ontario and Quebec, they will examine the presence of pathogens. “To understand what is happening in Canada, a substantial number of herds must be sampled in different provinces. It would then be too expensive to analyze samples from each cow, but the milk tank can give us a photo of the herd. Studies describing the prevalence of Mammitite pathogens on a Canadian scale are rare and they date. We therefore wanted to update knowledge, ”says Simon Dufour.
The postdocho will spend the summer in the laboratory to do these tests and will design a statistical model in order to estimate the real prevalence of the disease. “Our hypothesis is that there have been improvements in recent years, even if other pathogens are emerging,” he believes.
The team also wishes to look at the risk factors associated with the mastitis at the level of the herd and quantify the economic losses caused by the loss of milk and the use of antibiotics. “We would also like to assess whether certain infections are associated with a greater use of antibiotics on the farm,” says Professor Dufour.
