Are some cows genetically susceptible to Johne’s Disease?

A research project led by Nathalie Bissonnette (Agriculture and Agri-Food Canada (AAFC) -Sherbrooke) and Kapil Tahlan (Memorial University of Newfoundland) is investigating genetic markers in dairy animals that may be associated to Johne’s disease susceptibility or resistance. The project, Unraveling the genetic susceptibility to Johne’s disease, is financed by AAFC and Lactanet with in-kind contributions by Holstein Canada under the Dairy Research Cluster 3. 

For dairy farmers, this disease results in financial losses related to reduced milk production, decreased pregnancy rates, increased premature culling, and impacts overall animal welfare. Economic losses in the Canadian dairy sector resulting from Johne’s disease were recently estimated at $21.5 million to $34.1 million.[1]  

The main pathogen that causes Johne’s disease is Mycobacterium avium subspecies paratuberculosis (MAP). Management tools are currently in place to reduce the spread of Johne’s disease in Canada. For example, by implementing the Biosecurity module of proAction®, dairy farmers work with their veterinarians to mitigate the risks of introducing existing and emerging animal diseases on their farms to maintain the health of the herd. However, controlling Johne’s disease is difficult due to the disease’s unpredictable progression and the weak sensitivity of diagnostic tests. 

Previous research has shown the potential to reduce the prevalence of Johne’s disease in cattle by selecting for animals that are genetically resistant to the disease. This innovative application would be a complementary to the tools farmers can use alongside management strategies to prevent infections.  

Over a five-year period, Nathalie Bissonnette and her collaborators collected serum and fecal samples from 3,150 cows. The team used this data combined with other diagnostic tests to define a classification system and identify animals as either infected and infectious, infected and assumed resistant, or healthy. Using this unique dataset, they were able to accurately model the development of Johne’s disease over time and correctly differentiate between cows that would eventually develop Johne’s disease and those that resisted the infection and did not excrete the pathogen. The researchers are also genotyping cows using two proven genetic testing methods (i.e. single nucleotide polymorphisms (SNP) panel and genotyping-by-sequencing), and analyzing the epigenetic profile of susceptible cows.  So far, the team has identified genetic and epigenetics markers associated with the susceptibility of developing Johne’s disease.

In recent publications, the researchers confirmed the presence of genetic modifications[2],[3] and the epigenetics effects[4],[5],[6]  that are associated to Johne’s disease. 

Analysis was performed to study the markers in vitro[7],[8] and studying immune tolerance to JD using bovine primary macrophages.[9] Further research on a second population of dairy cows is ongoing and will confirm the usefulness of the genetic markers for selection of JD resistance/tolerance.

The team is also investigating the genetic diversity of MAP strains by using validated tools[10] and classifying the variants from animals across Canada that are infected with Johne’s disease at different stages. These analyses will define which factors affect the performance of diagnostic tests and explain disease progression. This ongoing work to identify MAP variants that could be more virulent will be key for the development of a successful vaccination program in the future.


Principal Investigators: Nathalie Bissonnette (Agriculture and Agri-Food Canada (AAFC) – Sherbrooke) and Kapil Tahlan (Memorial University of Newfoundland) 

Co-Investigators: Eveline Ibeagha-Awemu (AAFC-Sherbrooke), David Kelton, Flavio Schenkel (University of Guelph), Gilles Fecteau (Université de Montréal), Franck Biet (Institut national de la recherche agronomique – France) 

Total Budget: $1,019,988 

[1] Rasmussen P, Barkema HW, Mason S, Beaulieu E, Hall DC: Economic losses due to Johne’s disease (paratuberculosis) in dairy cattleJ Dairy Sci 2021.

[2] Mallikarjunappa S, Schenkel FS, Brito LF, Bissonnette N, Miglior F, Chesnais J, Lohuis M, Meade KG, Karrow NA: Association of genetic polymorphisms related to Johne’s disease with estimated breeding values of Holstein sires for milk ELISA test scoresBMC Vet Res 2020, 16(1):165.

[3] Bissonnette N, Marete A, Kelton D, Schenkel F, Ibeagha-Awemu E, Fecteau G, Miglior F: Conditional GWAS using sequence-based genotypes for susceptibility to Mycobacterium avium subsp paratuberculosis infection in Canadian HolsteinJ Anim Sci 2020, 98(4):

[4] Ibeagha-Awemu E, Bhattarai S, Dedemaine PL, Wang M, McKay SD, Zhao X, Bissonnette N: Genome wide DNA methylation analysis reveals role of DNA methylation in cow’s ileal response to Mycobacterium avium subsp. paratuberculosisJ Anim Sci 2020, 98:

[5] Ibeagha-Awemu E, Bhattarai S, Dudemaine PL, Wang M, McKay SD, Zhao X, Bissonnette N: DNA methylome wide profile associates differentially methylated loci and regions with cow’s ileal lymph node response to Mycobacterium avium subsp. paratuberculosis. Journal of Animal Science 2020, 98(4):

[6] Marete A, Ariel O, Ibeagha-Awemu E, Bissonnette N: Identification of long non-coding RNA associated with bovine Johne’s disease using a combination of neural networks and logistic regressionFrontiers in veterinary science 2021,

[7] Mallikarjunappa S, Shandilya UK, Sharma A, Lamers K, Bissonnette N, Karrow NA, Meade KG: Functional analysis of bovine interleukin-10 receptor alpha in response to Mycobacterium avium subsp. paratuberculosis lysate using CRISPR/Cas9BMC Genet 2020, 21(1):121.

[8] Ariel O, Brouard JS, Marete A, Miglior F, Ibeagha-Awemu E, Bissonnette N: Genome-wide association analysis identified both RNA-seq and DNA variants associated to paratuberculosis in Canadian Holstein cattle ‘in vitro’ experimentally infected macrophagesBMC Genomics 2021, 22(1):162.

[9] Ariel O, Gendron D, Dudemaine PL, Gevry N, Ibeagha-Awemu EM, Bissonnette N: Transcriptome Profiling of Bovine Macrophages Infected by Mycobacterium avium spp. paratuberculosis Depicts Foam Cell and Innate Immune Tolerance PhenotypesFront Immunol 2019, 10:2874.

[10] Byrne AS, Goudreau A, Bissonnette N, Shamputa IC, Tahlan K: Methods for Detecting Mycobacterial Mixed Strain Infections-A Systematic ReviewFront Genet 2020, 11:600692.

It’s time to have your say in Canadian dairy research: Answer DFC’s survey to help guide strategic research priorities for the future

Dairy Farmers of Canada (DFC) invites dairy farmers, dairy researchers and students, as well as sector stakeholders to complete an online survey about future priorities for Canadian dairy research. The answers will help identify research priorities to update the National Dairy Research Strategy, which will be used to guide investments in science over the next five years. DFC’s first National Dairy Research Strategy was published in 2016.

Your participation in the survey is vital to growth and innovation in the sector. DFC invests about $2 million annually in dairy production, and human nutrition and health research. This amount is leveraged to increase investments in research to approximately $8 million annually through matching funding programs and partnership contributions.

The survey is accessible from April 1 – 23, 2021. It takes about 15 minutes to complete. The answers will be kept confidential and will be amalgamated. Individuals will have the option to leave their name and email to enter a draw for the following participation prizes: a $200 gift certificate from Lactanet and three $50 gift certificates from DFC’s Blue Cow Shop.

Please share the survey link widely and encourage your dairy colleagues to have their say too!

Innovative research to advance genetic and genomic improvements in the Canadian dairy sector

Genetic gains in the Canadian dairy industry have been advancing at an unprecedented rate since the introduction of genomics in August 2009, when the first genomic evaluations were published in Canada.[i] In the five-year period between 2014 and 2019, the average rate of genetic gain more than doubled. It is estimated that genomic selection for novel, economically important traits could generate an additional $200 million per year in annual net benefits to the dairy sector as a result of increased genetic progress for new relevant traits. [ii]

Two research projects funded under the Dairy Research Cluster 3 (Agriculture and Agri-Food Canada and Lactanet (DairyGen Council)) will make considerable contributions to optimizing breeding strategies and maximizing genetic gains to benefit the dairy sector.

1.  Understanding the impact of cutting-edge genomic technologies on breeding strategies for optimum genetic progress in Canadian dairy cattle

Researcher Christine Baes of the University of Guelph is leading this project focused on the analysis and comparison of breeding strategies and novel tools from an economic and genetic improvement perspective to increase progress in Canadian dairy cattle breeding programs. Ultimately, the outcomes will serve to help dairy farmers make more informed decisions about using new technologies, methods and breeding strategies on their farms.

In some of the work done to date, the researchers appraised and described in detail the current breeding structure and are investigating the impact of either continuing with the current structure or incorporating new technologies and traits to optimize dairy cattle breeding programs. A list of 70 traits in use in Canada was prepared and the costs of collecting records on animals were calculated and estimates made of the genetic parameters of all measured traits. A large dataset of more than four million breeding records was used to investigate the use of reproductive technologies in Canadian herds and describe breeding practices.[iii]

Recommendations on how to best incorporate prospective new technologies and novel traits to optimize Canadian dairy cattle breeding programs will be developed, as well as considerations for adoption to help fully understand the long-term effects of altering the current breeding scheme. 

Project overview

  • Principal Investigator: Christine Baes (University of Guelph)
  • Co-Investigators: Flavio Schenkel, Getu Hailu, Angela Cánovas (University of Guelph) 
  • Period: 2018-2023 
  • Total Budget: $908,723 

For a summary of the project, click on the following link: Understanding the impact of cutting-edge genomic technologies on breeding strategies for optimum genetic progress in Canadian dairy cattle.

2.  Accelerating genetic gain for novel traits in Canadian Holstein cows

Previous research has demonstrated that the accuracy of genomic evaluations for novel traits can be improved by increasing the size of the reference population in a cost-effective manner by genotyping cows that already have phenotypes for novel traits. In this new project, researcher Flavio S. Schenkel of the University of Guelph and his team are investigating ways to establish a much larger reference population of genotyped females to maximize the genetic progress for novel traits such as mastitis, metabolic diseases, fertility disorders, hoof health, feed efficiency and methane emissions. 

The researchers are aiming to genotype some 25,000 cows from commercial herds that are collecting relevant phenotypes to increase the size and diversity of the current reference population used in genomic selection. The enlarged reference population will be used to determine genetic parameters, develop or improve genomic evaluations, and deliver more accurate genomic predictions for a series of novel traits. 

A larger female reference population of genotyped cows from herds recording novel traits of interest will support and increase the accuracy of routine genomic evaluations for a portfolio of traits and accelerate genomic gains, leading to the ability to breed more disease resistant and efficient animals. 

Project Overview

  • Principal Investigator: Flavio Schenkel (University of Guelph)
  • Co-Investigators: Christine Baes, Angela Cánovas, Janusz Jamrozik (University of Guelph) 
  • Collaborators: Xin Zhao (McGill University), Ronaldo Cerri (University of British Columbia), Stephen LeBlanc, Eduardo Ribeiro, Filippo Miglior (University of Guelph) 
  • Period: 2018-2022 
  • Total Budget: $999,922 

For a summary of the project, click on the following link: Accelerating genetic gain for novel traits in Canadian Holstein cows.


[ii] Chesnais, J. P. (2016). Breakthroughs in Dairy Genetics and Genomics. Presentation to Dairy Research Symposium of Dairy Farmers of Canada, February 5, 2016, Ottawa, Ontario.


Webinar: New insights on the role of milk products in the prevention of type 2 diabetes

Eleven million Canadians are living with diabetes or prediabetes and roughly 90% of people living with diabetes have type 2 diabetes (T2D). Growing evidence suggests that dairy product consumption, including consumption of higher fat milk products, is associated with a reduced risk of developing type 2 diabetes.  

Dairy Farmers of Canada is organizing and hosting a webinar featuring speaker Anthony Hanley, Ph.D., professor in the Department of Nutritional Sciences at the University of Toronto on Wednesday, February 24, 2021 from noon to 1 p.m. (EST). He will present scientific information on the role of milk products in the prevention of type 2 diabetes, including:

  • The prevalence of type 2 diabetes (T2D), especially in Canada
  • Risk factors in the development of T2D
  • Scientific evidence on the role of milk products in the prevention of T2D
  • Potential mechanisms related to milk products in the prevention of T2D 
  • New and emerging evidence: dairy fatty acids, fermented dairy foods

To register for the webinar, click on the link here:

Dairy farmers needed! Canadian researchers are seeking your input on silage production and management practices

A Canadian research team led by Nancy McLean, Dalhousie University and Linda Jewell, Agriculture and Agri-Food Canada (AAFC) – St-John’s, Newfoundland, is inviting dairy farmers to fill in a survey on silage production and management. The deadline to fill in the survey is March 31, 2021.

Dairy Farmers of Canada, in collaboration with AAFC, is supporting this research project called, Identifying best management practices for high quality silage production under the Dairy Research Cluster 3. 

The participation of dairy farmers is a crucial part of the project. By participating, dairy farmers will contribute to the achievement of significant research that will make evidence-based information on best management practices, costs reduction options, and the optimal conditions for high quality silage production across Canada available to farmers.

Click on the following link to answer the survey:

For more information, please contact Nancy McLean at Nancy.McLean@Dal.Ca.

Large-scale research projects investigating the role of dairy product consumption in Canadians’ health

Three research projects are currently underway that are investigating the role of dairy products on appetite (i.e. satiety), body weight, glycemic control, metabolic health and prevention of type 2 diabetes. 

  1. RESEARCH PROJECT: Effects of long-term consumption of dairy products on satiety, body weight and glycemic control

This project builds on the results of a large Dairy Research Cluster 2 study that provided evidence of the potential benefits of long-term habitual consumption of full-fat dairy to control appetite (i.e. satiety) and postprandial blood glucose. This project led by Harvey Anderson, University of Toronto, will conduct randomized controlled trials to determine the impact of the consumption of dairy products on appetite and blood glucose control (glycemia) and weight management. All three factors are related to the development of obesity and type 2 diabetes. 

Three diets will be served to a group of more than 150 men and women aged 19-45 years old for 24 weeks. The diets are: 1) a low-dairy, energy-restricted diet 2) a diet that is energy-restricted with three servings of dairy per day (regular-fat cheese, yogurt and milk); and 3) a diet of three servings per day of regular-fat dairy without energy restriction. Measurements on weight and body composition, blood pressure, blood lipids such as cholesterol and other risk factors, satiety (i.e. appetite control) and blood glucose control after meals (i.e. postprandial glycemia) will also be taken.

Scientific evidence and data published as a result of this study may support health claims related to the beneficial effects of consumption of dairy products (milk, yogurt and cheese) on curbing appetite, weight control and blood glucose.  

Project Overview

  • Principal Investigator: Harvey Anderson (University of Toronto)
  • Co-Investigator: Bohdan Luhovyy (Mount Saint Vincent University) 
  • Collaborator: John Sievenpiper (University of Toronto) 
  • Period: 2019-2023 
  • Total Budget: $1,245,133

For a summary of the project, click on the following link: Effects of long-term consumption of dairy products on satiety, body weight and glycemic control.

2. RESEARCH PROJECT: Role of dairy products on body weight and metabolic health in families

The objective of this project is to determine the impact of dairy products (regular fat and lower fat) on weight management in families consisting of adults and children. Led by researchers Angelo Tremblay and Vicky Drapeau, Université Laval, the team is examining the effect of dairy products on body weight and appetite control, diet quality and metabolic health in normal weight/obese adults and children using an innovative web-based approach. 

The researchers are developing a web-based program to assess the impact of integrating dairy products into the diets of families with normal weight and obese adults and children, under free-living conditions. The program will measure dairy consumption; dairy variety and diet quality; body weight and appetite control; reported energy intake; food preference and eating behaviors; and cardiometabolic risk factors (e.g. glycemic control, blood lipids). 

The evidence and data collected on dairy product consumption and weight management may help support health claims related to the beneficial effects of dairy product consumption on weight management.

Project Overview

  • Principal Investigators: Angelo Tremblay and Vicky Drapeau (Université Laval)
  • Co-Investigators: Sylvie Turgeon, Vincenzo Di Marzo (Université Laval), Éric Doucet (University of Ottawa) 
  • Collaborators: André Marette, Jean Doré (Université Laval), Marion Hetherington, Graham Finlayson (University of Leeds – England) 
  • Period: 2019-2023 
  • Total Budget: $660,000 

For a summary of the project, click on the following link: Role of dairy products on body weight and metabolic health in families.

3. RESEARCH PROJECT: Role of dairy products in the prevention of type 2 diabetes

Type 2 diabetes (T2D) in Canada is a significant health, economic and societal burden. Recent data from a large body of evidence has shown that dairy products, especially yogurt and cheese, may reduce the risk of developing type 2 diabetes.[i]

Researcher Sergio Burgos of McGill University and his team will conduct randomized controlled trials to determine whether eating different types of dairy products (milk, cheese and yogurt) with differing fat content can improve insulin sensitivity in overweight and obese people at high risk of developing type 2 diabetes. Evidence from randomized controlled trials will provide critical data needed to substantiate health claims regarding the benefits of consuming dairy products on type 2 diabetes prevention. 

Project Overview

  • Principal Investigator:  Sergio Burgos (McGill University)
  • Co-Investigators: Stéphanie Chevalier, Roger Cue, Errol Marliss, José Morais, Rob Sladek and Michael Tsoukas (McGill University), David Wishard (University of Alberta)
  • Period: 2020-2025 
  • Total Budget: $1,276,785

[i] Drouin‐Chartier JP et al., 2016

NEW RESEARCH: Providing opportunity for movement to dairy cows by redefining indoor and outdoor spaces and best management practices

Providing freedom of movement to dairy animals was cited in the top five predominant welfare concerns by respondents (43.75% were general public) to the National Farm Animal Council’s online dairy cattle survey in 2019.i As humans, we see increasing movement and exercise as good for our health. By extension, the same concepts are being applied to domesticated animals and production animals in confinement. A growing body of evidence is showing health and welfare benefits for dairy animals. But many questions remain on HOW dairy cattle can best benefit in the context of existing housing and management practices and WHY the animals behave in certain ways toward exercise or more movement.

New research led by Elsa Vasseur at McGill University and funded by the Dairy Research Cluster 3 (Agriculture and Agri-Food Canada and Dairy Farmers of Canada), will soon change our understanding of cow movement and exercise for dairy cattle housed in tie-stalls. The researcher and her collaborators are rethinking how spaces can be adapted to provide dairy cows the opportunity for more movement and exercise. They are developing, re-designing and testing indoor and outdoor spaces in a tie-stall environment to allow cows more movement while minimizing the costs to make changes and minimizing environmental impacts. Their results will serve to develop best management practices that are efficient, cost-effective and sustainable with beneficial effects for the animals, including improvements to cow comfort and health. 

The research project is timely given that revisions to the Code of Practice for the Care and Handling of Dairy Cattle (2009) and targets for better animal welfare outcomes are being considered by the industry. Up until recently, very little research has been done on the relevant and practical options to provide opportunities for movement or exercise to dairy cattle in tie-stall housing systems. Tie-stall housing makes up about 70% of the dairy cattle housing systems in use in Canada and were built because of advantages like minimizing competition for feed and lying space, and the ability to care and observe the animals individually. But for the general public, they are seen as restricting the animal’s natural or normal behaviours.

Evidence to date on cow movement and exercise suggests that the outcomes for the animals can benefit their health, behaviour and welfare.ii Some studies demonstrated that:

  • Cows are motivated to access the outdoors when provided the opportunity in both winter iii and summer ivconditions when housed in different indoor housing systems (i.e. typical freestall barn, deep bedding composted pack, etc.).
  • Tie-stall farms that provided cows with outdoor access had 20% fewer lame cows and 16% fewer cows with hock injuries at the end of the winter (the period during which cows are most restricted to the indoors) than farms providing no outdoor access.v
  • Tie-stall cows have fewer hoof lesions (10% less) if access to an outdoor yard was

The HOW – Adapting existing tie-stall systems

The researchers are examining several options to increase cow movement in tie-stall systems. They are measuring the optimal amount and length of time for movement and exercise, and at different frequencies; observing cows’ behaviour indoors and outdoors; recording the types of activities the cows engage in; and how active they are during exercise periods. They will also evaluate the effects of providing exercise on cows’ locomotion, on different outcome measures of welfare (i.e. lying time, injuries), and the impact on milk production. 

An economic and environmental assessment will identify the effects of providing indoor and outdoor exercise periods on farmers’ workloads as well as the effects on air and groundwater quality.

The WHY – Cow behaviour toward more exercise and movement

Researchers note that there may be some challenges to consider when the opportunity for more movement or exercise is provided to cows. It depends on an individual cow’s motivation to do so.

“Perhaps the biggest barrier to the efficacy of outdoor access as a means to elicit increased locomotor activity in the cow is the fact that it is largely dependent on the individual cow to engage in activities related to movement when provided this addition to her housing environment. Cows that display higher levels of locomotor activity are likely to do so in any environment in which they are placed, and visa-versa for low activity level cows. When providing free access to the outdoors, it is necessary to consider the cow’s preference to go outdoors versus her preference to stay inside.”vii

Elise Shepley, PhD student working on the research project.

Download a copy of the project summary here: Providing opportunity for movement to dairy cows by redefining indoor and outdoor spaces and best management practices

Project Overview

Principal Investigator: Elsa Vasseur (McGill University)

Co-Investigators: Stéphane Godbout (Institut de recherche et de développement en agroenvironnement), Sébastien Fournel (Université Laval), Marianne Villettaz Robichaud (Université de Montréal), Yan Martel Kennes, Pierre Ruel (Centre de recherche en sciences animales de Deschambault) 

Collaborators: Anne-Marie de Passillé, Jeff Rushen (University of British Columbia), Steve Adam (Lactanet), Doris Pellerin (Université Laval) 

Period:  2018-2022

Partners:  Agriculture and Agri-Food Canada, Dairy Farmers of Canada, in-kind contribution by Centre de recherche en sciences animales de Deschambault (CRSAD)

Budget:  $542,525



iii-iv Shepley et al., 2017b; Shepley et al., 2017a

Palacio et al. (2017)

vi Desrochers and Daigle (2017)

vii Elise Shepley: The way she moooves: Improving on our understanding of exercise in dairy cows.

Superheroes and the science of antimicrobial use and resistance

A new and innovative illustrated comic book has been designed to explain the research process used to identify bacteria that may be resistant to antimicrobials used to treat sick dairy animals. Written in plain language, a team of “superhero” researchers and their students investigate a case of mastitis infected with bacteria that may be drug resistant. The comic book was published by Op+lait with the involvement of researchers and students of the Mastitis Network. Dairy Farmers of Canada provided financial support for the translation of the comic book from French to English.


NEW RESEARCH: Surveillance of antimicrobial use and resistance to improve stewardship practices and animal health on dairy farms

The increase in antimicrobial resistance in dairy cattle could have adverse effects on animal health and welfare, impacting the profitability of dairy farms. About 48% of antibiotics prescribed to a dairy farm are to treat mastitis infections in cattle.[i] While most mastitis pathogens are low in antimicrobial resistance, choosing and using other antimicrobials to treat dairy cattle health can result in the transfer of antimicrobial resistance in bacteria other than mastitis pathogens.

Researchers are developing a surveillance program to measure antimicrobial use (AMU) and antimicrobial resistance (AMR) on Canadian dairy farms, as well as the effectiveness of antimicrobial stewardship protocols and programs. Led by researchers Javier Sanchez and Luke Heider (University of Prince Edward Island) with collaborators from across Canada, the team is collecting data and information to help support farmers’ efforts in applying effective antimicrobial stewardship practices.

The pan-Canadian team has developed a platform to collect data and monitor AMU and AMR. The Canadian Dairy Network of Antimicrobial Stewardship and Resistance (CaDNetASR) is a first for the dairy sector and designed to conform with the Federal Action Plan on Antimicrobial Resistance and Use in Canada, and the Food Safety and Biosecurity modules of proAction®. Data is being collected on about 150 dairy farms in British Columbia, Alberta, Ontario, Quebec, Nova Scotia and New Brunswick on a yearly basis.

“The network has been very active since the funding of the project and even under the Covid-19 situation, we are completing the second year of data collection. We’re focused on two major activities in the network. The first is the harmonization of veterinary clinic dispensing records to quantify the use of the antimicrobials in each of the participating farms. This is being conducted with the active participation of veterinary clinics representing the study farms. The second activity is the development of intervention strategies to assess their impact on mastitis, cow health and animal welfare. In addition, we are finalizing the data management system that will allow the generation of reports to send back to producers with their antimicrobial usage and antimicrobial resistance profiles compared to the other study farms.”

Javier Sanchez, co-lead of the project.

To provide antimicrobial use data estimates, treatment records logged as part of the Food Safety and Biosecurity modules of proAction®, and the retrieval of receptacles placed on farms for the deposit of empty drug bottles and containers are being used. To measure antimicrobial resistance on dairy farms, fecal, environmental and bulk tank milk samples are being taken and analyzed. The information will serve as a base for the development and testing of evidence-based and effective tools for farmers and their veterinarians (i.e. standard operating protocols or SOPs). 

“CaDNetASR has also developed a repository of bacterial isolates that, along with the other data being generated, will allow for future analysis and studies on AMU and AMR on Canadian dairy farms.”

Luke Heider, co-lead of the project.

The project outcomes will support farmers in continuing to use antimicrobials responsibly, apply efficient antimicrobial stewardship practices and assure the continued health and welfare of dairy animals and the safety of food for consumers. 

SEVEN facts about antibiotic use and antimicrobial resistance in the Canadian dairy sector

1.   Under proAction®, milk is produced according to strict provincial and federal regulations and high standards regarding antibiotic use to treat sick animals. proAction milk quality and food safety standards are among the highest in the world. 

2.   Dairy farmers use antibiotics to treat sick animals if necessary and as directed on the prescribed medication label and directives given by the herd’s veterinarian.

3.   Canadian milk is free of antibiotics. Cows treated with antibiotics for a medical reason are clearly identified, and the milk is discarded. The milk does not re-enter the system until the mandatory withdrawal time has been met to ensure the medication is out of the animal’s system.

4. ALL milk is tested for antibiotics before being processed.

5.   Antibiotic resistance happens when bacteria change and become resistant to the antibiotics used to treat the infections they cause. (ii)

6.   Antimicrobial resistance development in major pathogenic bacteria found in dairy cows does not yet appear to be a major problem in North America (iii). Most antibiotic treatments are to treat mastitis, and the levels of antimicrobial resistance remain low in mastitis pathogens (iv-vi). But, the pressures to select and use antimicrobials to treat animals more rapidly for better health can result in the emergence and transfer of bacteria that are resistant (iii). 

7.   Disease prevention is key in a strategy to reduce antimicrobial use and resistance!

You can access the project summary by clicking on the link here: Surveillance of antimicrobial use and resistance to improve stewardship practices and animal health on dairy farms

Project Overview

Principal Investigators: Javier Sanchez and Luke Heider (University of Prince Edward Island) 

Co-Investigators: J Trenton McClure, Greg Keefe (University of Prince Edward Island), David Leger (Public Health Agency of Canada), Simon Dufour (Université de Montréal), Herman Barkema (University of Calgary), David Kelton (University of Guelph), Christopher Luby (University of Saskatchewan), and Kapil Tahlan (Memorial University of Newfoundland)

Collaborators: Marie Archambault, David Francoz, André Ravel, Jean-Phillipe Roy (Université de Montréal), Jeroen De Buck (University of Calgary), Scott McEwen, Jan Sargeant, Scott Weese (University of Guelph), Cheryl Waldner (University of Saskatchewan), Richard Reid Smith (Public Health Agency of Canada), 

Project duration: 2018-2022 

Project partners: Agriculture and Agri-Food Canada, Dairy Farmers of Canada and the Public Health Agency of Canada

TOTAL BUDGET: $1,582,087

i Adapted from: Bauman CA et al. Canadian National Dairy Study: Herd-level milk quality. J Dairy Sci. 2018 Mar;101(3):2679‍-‍2691.

ii World Health Organization, Antibiotic Resistance – How it Spreads,

iii Oliver SP et al. Impact of antibiotic use in adult dairy cows on antimicrobial resistance of veterinary and human pathogens. Foodborne Pathog Dis; 2016; 8(3):337–55. 

iv Call DR et al. Antimicrobial resistance in beef and dairy cattle production. Anim Health Res Rev. 2008; 9(2):159–67. 

v Bengtsson B et al. Antimicrobial susceptibility of udder pathogens from cases of acute clinical mastitis in dairy cows. Vet Microbiol. 2009; 136(1–2):142–9.

vi Cameron M et al. Antimicrobial susceptibility patterns of environmental streptococci recovered from bovine milk samples in the Maritime provinces of Canada. Front Vet Sci. 2016; 3(79).

Resources for dairy farmers: Fact sheets to improve dry-off procedures

  1. FACT SHEET: Recommended protocol for the administration of an internal teat sealant for dairy cows

A collaborative project between the Mastitis Network and Dairy Farmers of Canada, this new fact sheet available in English, French and Spanish contains best practices and visual step-by-step procedures for the administration of an internal teat sealant at dry-off. A growing number of farms are using teat sealants as a preventative measure for better udder health, as part of a broader strategy to reduce antimicrobial use on dairy farms. 

To download a copy of the fact sheet available at no cost, visit:

A series of additional fact sheets containing best practices for testing, treatment and prevention of mastitis on dairy farms is available on the Mastitis Network’s website at

2. FACT SHEET:  Drying off cull dairy cattle at high production and in emergency situations

This fact sheet published in August 2020 in English, French and Spanish contains dry-off procedures for lactating dairy cows in accordance with Canada’s high standards for animal welfare while adhering to the federal transport regulations (2020). New transport regulations require that lactating animals should not be transported unless they are milked at intervals sufficient to prevent udder engorgement.[i]

A team of experts from the Mastitis Network, led by Dr. Trevor DeVries (University of Guelph), developed the fact sheet’s recommendations on the basis of recent scientific evidence for best practices for animal health and welfare prior to transporting an animal leaving the farm. The best practices address high and low producing dairy cows, as well as the steps to take when the animal’s departure date from the farm is known or unknown, such as in an emergency situation.

To download a copy of the fact sheet at no cost, visit:

[i] Government of Canada,,_c._296/FullText.html