Course:FNH200/Projects/2026/Canadienne Cow

Overview

The Canadienne is the oldest dairy cattle breed developed in North America². It descends from cattle brought from Brittany and Normandy by French settlers during the mid 1600s^1,2. The breed quickly adapted to Quebec's cold climate as well as limited and variable feed conditions^1,2. Originally used for milk, meat, and farm labour, it survives today as a heritage breed with a very small population and is listed on the Slow Food Ark of Taste¹. This article examines why the breed declined, how its milk is preserved by processing it into cheese, and what food safety controls its cheesemaking requires.

Fig.1 Canadienne cattle

https://en.wikipedia.org/wiki/Canadienne_cattle

Endangered status and historical decline

Although Canadienne cattle were once common in Quebec, their population declined substantially during the 20th century. From approximately 300,000 animals in the early 1900s, the population fell to about 1,200 registered animals recorded in the Canadienne breed registry². Among these, fewer than 300 are considered fullblood, meaning those with documented ancestry that is entirely or almost entirely Canadienne are few and far between². Quebec's Conseil des appellations reservees et des termes valorisants (CARTV) reported 400 to 500 purebred females in 2024³. The breed is therefore endangered both numerically and in terms of breed identity, as only a small proportion of the registered population retains nearly all of its original ancestry.

Replacement by higher-producing dairy breeds

A major cause of the decline was the increasing emphasis on milk yield in commercial dairy farming². Canadienne cattle produce approximately 6,193 kg of milk annually, whereas about 11,557 kg is produced by Holsteins⁴. Canadienne cattle were gradually replaced by higher-producing breeds, particularly Holsteins, which account for approximately 93% of Canada's dairy herd².

The breed's lower milk production does not indicate that they are biologically inferior. Canadienne cattle were historically selected for survival, fertility and toughness rather than maximum milk yield². Their milk is comparatively rich, at 4.20% fat and 3.57% protein compared with 4.21% fat and 3.38% protein from Holstein milk⁴. Their decline therefore reflects changing agricultural priorities toward high volume milk production over time.

Fig 2. Dairy breeds in Canada (2025)⁴

Crossbreeding and genetic vulnerability

In the 1970s, Canadienne cattle were crossed with Brown Swiss cattle to increase milk production and body frame. More recently, Jersey cattle were introduced for crossbreeding to maintain a smaller frame and uniform coat colour². Although crossbreeding introduced commercially useful traits, it also reduced the number of fullblood animals².

Another major cause of the decline is genetic drift. Earlier pedigree-based research estimated the effective population size, defined as the number of animals meaningfully contributing their genes to future generations, at approximately 40 to 43, below the threshold of 50 often used as a minimum for long-term breed viability². A 2023 genomic study, which genotyped 190 animals using a panel of about 640,000 SNP markers, estimated 12.8 among "original" animals, 20.5 among fullblood animals, 34.9 in the high-purity group and 20.8 across all animals of at least three-quarters Canadienne ancestry². At such a small effective population size, the effects of genetic drift and inbreeding are amplified². Pedigree-based inbreeding had reached 9.53% by 2022 which was high relative to other Canadian dairy breeds^2,8.

Fig 3. Effective population size of Canadienne cattle groups²

The same genomic evidence, however, suggests that the remaining Canadienne population still retains valuable genetic diversity. Genomic inbreeding among original animals was about 6.8%, and fullblood animals showed relatively high heterozygosity and shorter runs of homozygosity than Holsteins². The analysis also identified three genetically distinct groups within the high purity population². The authors therefore describe what remains not as a genetic dead end but as a gene pool that still holds diversity worth conserving². This matters because distinct lineages allow breeders to select genetically distant matings deliberately to preserve genetic diversity.

The population is also constrained by a lack of sires. The breed relies on artificial insemination but is limited to only about 15 bulls, with just two being purebred original². A breed can hold more than a thousand registered animals and still have a very small effective population if a handful of sires father most calves. The study therefore recommends widening the selection of sires, including through cryopreserved semen and embryos from underrepresented older bloodlines². These challenges facing Canadienne cattle are part of a broader loss of livestock genetic diversity worldwide, with approximately 20% of livestock breeds at risk of extinction⁷.

Preservation: processing the milk into cheese

Milk is a perishable food, which spoils in a short amount of time¹⁰. In order to increase its shelf life and preserve, it is commonly turned into cheese¹⁰. This matters particularly for the Canadienne, as the breed does not produce as much milk as other breeds, making each litre more valuable⁴. Under the CARTV reserved designation, Canadienne Cow Cheese is produced exclusively from Canadienne cow milk, using only rennet or non-GMO coagulating enzymes of microbial or plant origin, salt, acidifying microorganisms, and ripening ferments³.

Firstly, the milk is coagulated through rennet, a mixture of enzymes that causes milk components to clump into curds and leaves whey as the remaining liquid. The whey is then drained, leaving the basis for the cheese and removing much of the water required by spoilage-causing microorganisms¹⁰. Next comes acidification, in which lactic acid bacteria break down lactose into lactic acid and bring the pH of the curd down. This helps control the environment for microorganisms during cheesemaking and shapes the flavour and texture of the product¹⁰. The third step is salting, which removes moisture and decreases water activity, making it even harder for microorganisms to grow¹¹. Lastly, the cheese is left to ripen. During ripening, enzymes and the microorganisms still present in the cheese cause chemical changes that develop the flavour, aroma and texture of the finished product¹⁰.

Preservation continues after the cheese is made. CARTV permits the product to be sold whole, grated, cut by a retailer at a customer's request, or in pre-packaged portions³.

Preserving the food in order to preserve the breed

The economic function of the cheese is the part most relevant to conservation. According to CARTV, the designation is intended to help guarantee the survival of the heritage breed by protecting the reputation of the product and the added value obtained from processing its milk³. The designation also supports efforts to restore the breed's original characteristics and increase the number of purebred Canadienne cows³. To ensure authenticity, participating animals are verified through genealogical records and DNA genotyping³.

Preserving the breed requires more than maintaining its genetic diversity as it also needs to remain economically viable for farmers. Because Canadienne cattle produce less milk compared to other breeds, value-added products such as this cheese can help make raising them more sustainable^3,4. In this way, preservation operates at two levels at once by extending the shelf life of a perishable food while also sustaining the population that produces it.

Food safety in traditional and raw milk production

Some traditional cheeses associated with the Canadienne are produced from unpasteurized milk¹. Raw milk can carry pathogens including Escherichia coli, Salmonella and Listeria monocytogenes, which is why modern dairy processing requires specific controls⁹. This does not mean Canadienne milk is specifically dangerous, but rather that the risk comes from raw milk processing. However, this risk is relevant since raw milk is used in some of the traditional artisanal cheeses that contribute to the breed's economic value¹.

Preservation and safety are related but not the same thing. Aging is frequently assumed to remove the hazard, and Canadian regulation requires cheese made from unpasteurized milk to be aged for at least 60 days⁵. In 2018, an outbreak of E. coli O121 in British Columbia was linked to a raw milk cheese, similar to Gouda. Seven people were infected and the implicated cheese had been aged beyond the required minimum. One sample tested positive for the organism and investigators identified no production deficiencies⁵. In other words, preserved does not always equate to safe.

Modern food safety management therefore depends on multiple barriers rather than one decisive step. These include milk quality at intake, sanitation and hygiene, controlled starter cultures and acidification, salt and moisture control, time and temperature management, refrigeration, testing, traceability, and pasteurization where it is used^6,10. These controls are essential as foodborne illness remains a major global health concern. The World Health Organization estimated 600 million cases and 420,000 deaths worldwide in 2010, with microbial pathogens being a major cause⁶.

Authenticity certification and food-safety control also solve two different problems. DNA verification answers whether a cheese genuinely comes from Canadienne cattle³. It says nothing about whether that cheese was produced safely, which is established separately through sanitation, process records, traceability and hazard monitoring⁶. A conservation programme built on a premium raw milk product needs both, since a single outbreak would damage the reputation the designation exists to protect.

Conclusion

The cheese gives farmers a financial reason to keep a breed that cannot compete on yield. The reserved designation protects the value of that cheese and food-safety controls determine whether it can be produced and sold. Conservation of the Canadienne therefore depends on breeding, processing and regulatory decisions taken in unity. The genomic evidence indicates that useful genetic variation still remains, and the largest current constraint is the very small number of sires in use².

Potential final exam questions

Question 1

A heritage cattle breed has about 1,200 registered animals, but its estimated effective population size is only around 20. Which statement best explains why the effective population size is so much smaller than the registered population?

1. Most registered animals are too old to reproduce
2. Only a small number of sires contribute genes to the next generation, so relatively few animals actually pass on genetic variation
3. Effective population size counts only female animals
4. Registered animals are counted twice in breed registries
5. Effective population size measures the number of animals in a single herd

Correct answer: B

Why this question should be on the final exam: before starting this project we assumed that an endangered breed simply meant there were not enough animals, and that the solution was to breed more cows. The genomic evidence changed how we understood the problem. The Canadienne relies on artificial insemination from only about 15 sires, just two of which are purebred original animals, so the number of animals genuinely contributing to the next generation is a fraction of the registry count². That distinction changes the recommended action, because spreading reproduction across different lineages matters more than raising the raw number. Effective population size is a concept students can apply to any genetic resource in the food supply, and it connects directly to course material on food biodiversity and why a narrowing gene pool is a risk to the food system.

Question 2

Canadian regulations require cheese made from unpasteurized milk to be aged for at least 60 days. What does meeting this aging requirement guarantee?

1. That all pathogens present in the raw milk have been eliminated
2. That the cheese does not require refrigeration
3. Nothing on its own; aging is one barrier among several, and outbreaks have occurred in cheeses aged beyond the minimum
4. That the cheese has been pasteurized indirectly through ripening enzymes
5. That the milk came from a certified heritage breed

Correct answer: C

Why this question should be on the final exam: this was the most surprising finding of our research. We had assumed that a legally mandated aging period existed because 60 days was long enough to make raw milk cheese safe. The 2018 British Columbia outbreak involved cheese that had been aged past the minimum with no production deficiencies identified, and seven people still became ill⁵. The question forces students to separate two ideas that can commonly be confused. Preservation, which slows deterioration and restricts microbial growth, relative to safety, which requires verified control of specific hazards. It also reinforces the hurdle concept, since answering correctly depends on recognizing that no single barrier is sufficient by itself.

References

1. Slow Food Foundation for Biodiversity. Canadienne Cow, Ark of Taste. Available at: https://www.fondazioneslowfood.com/en/ark-of-taste-slow-food/canadienne-cow/
2. Carrier, A., Gilbert, I., Leclerc, P., Duchesne, M., and Robert, C. (2023). Characterization of the genetic pool of the Canadienne dairy cattle breed. Genetics, Selection, Evolution, 55(1). Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC10170705/
3. Conseil des appellations reservees et des termes valorisants (CARTV). Canadienne Cow Cheese. Government of Quebec. Available at: https://cartv.gouv.qc.ca/en/reserved-designations-and-added-value-claims/reserved-designations/directory/canadienne-cow-cheese/
4. Canadian Dairy Information Centre (2025). Average milk production by breed based on milk recording. Agriculture and Agri-Food Canada. Available at: https://agriculture.canada.ca/en/canadas-agriculture-sectors/animal-industry/canadian-dairy-information-centre/dairy-statistics-and-market-information/dairy-animal-genetics/average-milk-production-breed
5. Boyd, E., Trmcic, A., Taylor, M., Shyng, S., Hasselback, P., Man, S., Tchao, C., Stone, J., Janz, L., Hoang, L., and Galanis, E. (2021). Escherichia coli O121 outbreak associated with raw milk Gouda-like cheese in British Columbia, Canada, 2018. Canada Communicable Disease Report, 47(1), 11 to 16. Available at: https://www.canada.ca/en/public-health/services/reports-publications/canada-communicable-disease-report-ccdr/monthly-issue/2021-47/issue-1-january-2021/foodborne-outbreak-british-columbia-related-raw-milk-gouda-like-products-2018.html
6. Fung, F., Wang, H., and Menon, S. (2018). Food safety in the 21st century. Biomedical Journal, 41(2), 88 to 95. Available at: https://www.sciencedirect.com/science/article/pii/S2319417017304055
7. Food and Agriculture Organization of the United Nations (2019). The State of the World's Biodiversity for Food and Agriculture. Available at: https://www.fao.org/newsroom/detail/The-biodiversity-that-is-crucial-for-our-food-and-agriculture-is-disappearing-by-the-day/en
8. Stachowicz, K., Sargolzaei, M., Miglior, F., and Schenkel, F. S. (2011). Rates of inbreeding and genetic diversity in Canadian Holstein and Jersey cattle. Journal of Dairy Science, 94(10), 5160 to 5175. Available at: https://www.journalofdairyscience.org/article/S0022-0302(11)00536-4/fulltext
9. Health Canada. Raw or unpasteurized milk. Government of Canada. Available at: https://www.canada.ca/en/health-canada/services/milk-infant-formula/raw-or-unpasteurized-milk.html
10. Neviani, E., Gatti, M., Gardini, F., and Levante, A. (2025). Microbiota of cheese ecosystems: A perspective on cheesemaking. Foods, 14(5), 830. Available at: https://pubmed.ncbi.nlm.nih.gov/40077532/
11. Guinee, T. P. (2004). Salting and the role of salt in cheese. International Journal of Dairy Technology, 57(2-3), 99 to 109. Available at: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1471-0307.2004.00145.x