Frequently asked questions

There are seven commonly used breeds: Holstein, Jersey, Ayrshire, Brown Swiss, Guernsey, Milking Shorthorn and Canadienne. For more information about these breeds and their role in the dairy industry, please visit our On the Farm page. 

The average dairy cow will produce 30 litres of milk from two daily milkings. 

A cow's daily diet consists of 29 kg of feed in a combination of:

• Hay
• Silage
• Grain
• Protein supplement
• Minerals and salt
• 80 to 180 litres of water

Cows are ruminant animals, meaning their stomachs are divided into four sections. The rumen, reticulum, omasum and abomasum each have a specific role to play in digesting cellulose or plant fibre.

A cow can eat a whole day's meal in just minutes and store it in their rumen. In the rumen, the food is made into small balls of food called "cuds." Throughout the day, a cow will burp up a cud of food, chew it and swallow it again, as many as 60 times. Each time, the food is digested more. Cows spend up to eight hours chewing their cud or ruminating. The food works its way through the cow's remaining compartments and, just as in a human's stomach, digestive juices and fluids are added to it so the nutrients can be absorbed into the bloodstream.

In the cow's udder, small sacs, called alveoli, produce milk. The alveoli take the nutrients from the blood and add fat, protein and lactose (a type of sugar) to produce milk.

Hay is a mixture of grass and legumes, like alfalfa. It’s most commonly used in two ways:

• Haylage – The hay is cut, chopped and stored in a loose way in a storage silo, while it is still moist (see silage, below).
• Hay – Usually cut after haylage, when the plants are taller, and allowed to dry in the field. It is then baled into round or square bales and stored under cover.

Corn is planted in the spring and harvested in the fall. Although it looks the same as the sweet corn people eat as corn on the cob, it is harder and can't be cooked or digested by humans. It too is usually used in two ways:

• Silage – The whole plant is harvested while it’s still green, after the cob has formed. It’s then cut into pieces and stored in a silo. After the silage is stored in the silo, the wet corn undergoes fermentation, or "pickling." In this process, the corn is changed by a bacterial process to make it tastier and easier to digest by the cows. When the silage comes out of the silo, it is more palatable. The same process turns wet hay into haylage.
• Grain corn – Only the kernels from the plant are harvested and stored in a dry form. Grain corn is usually ground up and mixed with any barley or oats, a protein food like soybean meal, plus vitamins and minerals.

Cattle names change as dairy animals grow older. A calf is a newborn dairy animal. A heifer is a young female that has not yet had a calf and begun to milk. A cow is a mature female dairy animal, and a bull is a mature male dairy animal. Cows produce milk for about 10 months (or about 305 days) after having a calf. They stop milk production during a two-month dry period before giving birth and entering another 10-month milk cycle

Before a milking machine is attached, the cows’ teats are washed with a disinfectant solution and dried. In a pipeline system, the cows are secured in their stalls, the udders washed, and a milking machine attached to all four teats on the cow's udder. A hose runs from the milking machine to a stainless steel pipeline located over the cow's head. The pipeline runs the length of the barn and is connected to a big bulk tank in the milk house. The milk is quickly cooled in the bulk tank and kept there until the milk truck picks it up.

In a milking parlour system, the cows walk onto a raised platform with gates. The gates keep the cow from moving while she is being milked. When milking is over, she walks out the other side. The milk goes directly through a pipeline to the bulk tank in the milk house.

After every milking, all milk contact services are washed and rinsed. Just before the next milking, the surfaces are sanitized.

Yes, the program is free to all schools in Ontario.

The Dairy Education Program is an agriculture focused education program sponsored by Dairy Farmers of Ontario. Dairy educators are invited into classrooms from K to Grade 12 by Ontario teachers to supplement their education plans. Educators are available through virtual meetings or as live guests in classrooms. They educate students in the areas of dairy farming, dairy goodness, careers in the dairy industry, processing of milk products, and technology on the farm by rooting their lessons in the Ontario Curriculum.

The program is delivered from kindergarten to Grade 12.

You can find additional education materials and activities on the resource page of education.milk.org. You can also try our lessons in Minecraft: Education Edition in our Dairycraft world. If you are looking for resources you can share or assign as independent work, try our learning management system at edu.milk.org. Here we have lessons from Kindergarten to Grade 12 all firmly rooted in Ontario curriculum expectations.

A presentation is between 35 and 45 minutes but can be adapted to meet the needs of the classroom.

The Elementary School Milk Program is a nutrition program sponsored by Dairy Farmers of Ontario. The role of ESMP is providing schools across Ontario with the opportunity for elementary students to have milk daily. ESMP offers tools and resources to run a successful milk program at no cost. ESMP is committed to providing elementary students with milk daily, so they can stay healthy, alert and ready to learn.

Check the Contact us list of Dairy Educators at education.milk.org. You can also call the Dairy Education Program at Dairy Farmers of Ontario: (905) 821-8970, ext. 2149.

There are 3 easy ways to register your school for ESMP:

1. Click here to sign up online

2. Email schoolmilk@milk.org

3. Call 1-888-730-6455

There are 52 educators across Ontario. Their backgrounds and experiences vary, but they each have one or more of the following: a dairy background, a teaching certificate, an ECE designation, or a diploma in agriculture, Health Sciences, or another related degree/diploma. One thing they all have in common is their knowledge, expertise, and dedication to the dairy industry.

Dairy plays a role in disease prevention for many chronic conditions, including heart disease, hypertension, Type 2 diabetes and certain types of cancer. Evidence also suggests nutrient-rich milk and dairy products can support a healthy immune system and dairy contains multiple nutrients important for optimal immune function, including high-quality protein, vitamin A, vitamin B12, vitamin D, selenium and zinc. 

Milk is a natural package of readily absorbed nutrients that are hard to replicate. Plant-based beverages are formulated products with added ingredients and fall short of the nutritional package that milk naturally provides. Plant-based beverages are not nutritionally equivalent to milk and cannot be considered as an alternative in terms of nutrition.

Calcium in milk is naturally occurring. Unlike milk, plant-based beverages do not naturally contain adequate calcium. Calcium is added to plant-based beverages, and while there may be comparable amounts of calcium on the nutrition facts table, you get more from milk because it does not separate from the beverage and settle on the bottom of the container where it may not be ingested.

There is evidence to suggest calcium in plant-based beverages are not absorbed as well as calcium in milk. In addition to calcium, milk naturally contains essential nutrients, such as protein, B vitamins, magnesium, phosphorus, potassium, selenium and zinc. On the contrary, plant-based beverages are not a natural source of the vitamins and minerals that are naturally present in milk. 

All plant-based beverages contain less protein than milk. In addition, not all protein is created equal. The protein in milk is high-quality or ‘complete’ meaning it contains all the essential amino acids our bodies need. Many plant sources of protein are considered incomplete proteins because they lack one or more of the essential amino acids.

As well:

• Milk is considered an excellent source of protein, while most plant-based beverages (except soy beverages) are not a good source of protein.
• The composition of formulated plant-based beverages also varies between and within types.
• Studies show milk has multiple health benefits. There is currently little scientific evidence supporting the health benefits of plant-based beverages.
• Milk provides several important nutrients that contribute to good health during all stages of life (from childhood to old age).

One glass of milk contains 15 essential nutrients and is an excellent source of complete protein, which helps build muscles. One glass of milk is rich in vitamin B12, helping in the formation of red blood cells and vitamin B2 (riboflavin), which is a factor in energy metabolism and tissue formation.

One glass of milk is high in calcium, contributing to the formation and maintenance of bones and teeth. It also contains a variety of minerals that are essential for the body, including magnesium, phosphorus, potassium, selenium and zinc.

Vitamin D and vitamin A are also found in one glass of milk, supporting a healthy immune system. Vitamin D also improves calcium absorption and helps build strong bones and teeth.

In Canada, ensuring an adequate intake of vitamin D from foods is important. Milk must be fortified with vitamin D according to national regulations to help Canadians meet their vitamin D needs. Drinking two glasses (500 mL) of milk a day makes a good contribution to vitamin D intake. 

Within the updated Canada’s Food Guide, milk and dairy products continue to play a valuable role in healthy-eating habits and the guide continues to recommend milk as a healthy drink choice at meals and snacks. Health professionals also recognize dairy’s nutritional value in the promotion of bone health and in preventing disease. 

In Canada, the addition of Vitamin A and D to milk is a legal requirement under Health Canada's Food and Drug Act. In 2016, the Daily Value (DV) for vitamin D increased to 2 µg/100 mL for milk - approximately twice the previous requirement. Since milk is the main contributor of vitamin D in the Canadian diet, Health Canada has also increased the vitamin D fortification level in milk. . This will come into effect in 2026.

During this transitional period, on the Nutrition Facts Table of your package of milk, you may notice some milk manufacturers will have the current fortification level, which is equivalent to 13% of the recommended daily value (%DV) of vitamin D in a glass of milk, while others may have already adopted the new level of vitamin D fortification and labelling, making it equivalent to 25% of the DV% value.

Yes. Since 1938, the Ontario Health Act has required pasteurization of all milk and cream for human consumption. It’s illegal to sell or even give away milk, cream or milk products that have not been pasteurized in a plant licensed under the Milk Act. Pasteurization destroys pathogens, such as salmonella and E. coli, that can cause human illness. It’s been used extensively as an effective and efficient method of preventing transmission of foodborne illness to consumers via milk and milk products.

Put simply, pasteurization is the process of heating a food, usually a liquid, to a specific temperature for a definite period of time, then cooling it immediately. Pasteurization is the main reason for milk’s extended shelf life. It has been one of the most beneficial and cost-effective measures to protect the health of the consumer.
Dairy processing plants use three methods to pasteurize milk:


1. High Temperature Short Time (HTST) Method

• Milk is pumped rapidly through a series of steel plates
• Milk is heated to 72°C and held no less than 16 seconds
• Milk is rapidly cooled to 4°C
• A continuous-flow pasteurizer is used to achieve precise temperature control

2. Batch-Holding Method

• A paddle or coil in a large vat is used to agitate the entire batch of milk as it heats to 62°C
• The milk is held at this temperature for 30 minutes before being cooled to 4°C

3. Ultra High Temperature (UHT)

• Whole or partly skimmed milk is heated to 138°–158°C for one or two seconds
• Milk is quickly cooled and placed, under sterile conditions, into pre-sterilized containers
• An unopened package of UHT milk will keep for three months with very little change in flavour and quality
• Once opened, milk should be refrigerated and used within one week

Pasteurized milk is an excellent source of calcium, protein, riboflavin, vitamins A and D, and phosphorous, and a good source of thiamine and B12. Studies have shown that calcium absorption remains unaltered through pasteurization. Vitamins A and D, as well as riboflavin and niacin, are generally not affected by heat treatment. Pasteurization does involve a minor loss of 10 per cent of thiamine and vitamin B12 content, as well as a 20 per cent loss of vitamin C content. Because losses are small in comparison to the large amount of these two B vitamins present, milk continues to provide significant amounts of thiamine and vitamin B12. As milk is not an important dietary source of vitamin C, this loss is not nutritionally significant. All processed milk sold in Ontario is of high quality, contains no preservatives, and is backed by stringent government and quality control programs and standards from the farm to the retail shelf.

proAction is Canadian dairy farmers’ quality assurance program. It comprises six modules:

• Milk Quality
• Food Safety
• Animal Care
• Livestock Traceability
• Biosecurity
• Environment

Canada’s dairy farmers are recognized as world leaders in producing quality milk. The purpose of proAction is to maintain both processor and consumer confidence in the quality and sustainability of Canadian milk that is used to make the dairy products consumers enjoy. Through proAction, farmers do their part in ensuring a supply of safe, high-quality Canadian dairy products consumers, processors and retailers can be confident about and proud to market and consume.

proAction requirements are developed by technical committees made up of dairy farmers and experts, such as veterinarians, researchers and industry partners. proAction requirements are carefully tested, evaluated and updated regularly based on the latest scientific evidence.

proAction is the national quality assurance program that was established by Dairy Farmers of Canada but is administered and enforced by DFO in Ontario. proAction validations are conducted by third-party, independent auditors who verify farm practices and records every year and perform in-person audits at least every two years.

Like all provinces, Ontario has a regulatory framework for delivering high-quality milk. This is administered by DFO through the Grade A program, which is mandatory for all licensed Ontario dairy farmers.

In Ontario, farmers who do not meet proAction requirements pay a financial penalty until they are compliant. Continued non-compliance will lead to suspension from the milk market.

• From August 2021 to September 2022, there were 4,780 on-farm validations conducted across Canada.
• 4,833 Canadian dairy farmers conducted their own proAction review and provided the information through a self-declaration process to DFC – this showcases farmers’ commitment and accountability toward the program.

The Blue Cow logo on dairy product packaging indicates the product is made with 100 per cent Canadian milk and milk ingredients. It is a symbol of trust in Canadian dairy farmers and the commitment farmers make to the proAction program.

You can support Canadian dairy by buying Canadian dairy products at the grocery store. The Canadian dairy system is designed to minimize waste and help support some of the highest milk quality standards in the world. When you buy Canadian dairy, you know you’re getting milk made by real farm families who are dedicated to producing milk of the highest quality.

The Canadian dairy industry is the backbone of Canada’s rural economy, employing more than 220,000 Canadians. Canadian dairy is safe and nutritious, and Canadian dairy farmers take pride in producing high-quality 100 per cent Canadian milk, providing top-notch animal care, and committing to environmental sustainability.

Look for one of two 100 per cent Canadian milk logos on the packaging of dairy products. Please note, not all 100 per cent Canadian dairy products have these logos on their packaging. If you’re unsure, you can contact processors directly to ask about their products. Packaging on Canadian dairy products usually includes the processor name and location.

Recombinant bovine somatotropin (rBST), a synthetic version of a naturally occurring growth hormone, is banned for use in Canada. Although Health Canada has determined it does not pose a health risk to humans, it has stated that rBST negatively affects cow health. American dairy farmers are legally allowed to use rBST to increase a herd’s milk production.

Dairy processors are responsible for food labelling. We encourage processors to identify their products that are made with Canadian dairy. Some have adopted the use of Dairy Farmers of Canada’s label—a blue and white logo featuring a standing cow bearing the Canadian maple leaf. Some products use a circular blue and white cow logo that states 100 per cent Canadian milk. Other packages will state “made in Canada.” Having simple and easy labels that identify Canadian dairy on products is an industry priority.

Under the new Canada–United States–Mexico Agreement (CUSMA), each country has agreed to accept the other countries’ standards.

Dairy Farmers of Ontario (DFO) and dairy farmers do not set retail prices. Under Canada’s supply management system, DFO’s role is to market milk to the dairy processing industry on behalf of Ontario dairy farms. In other words, farmers sell their milk to DFO, and then DFO sells milk to processors. Prices paid by processors are based on production costs on efficient farms, and DFO has no control over retail prices, meaning we don’t tell grocery stores how much to charge for a product.

The bar for 100% Canadian milk is high! There’s rigorous inspection and testing that happens before the milk from the cow gets into the carton. In fact, there are more than 100 regulations that have to be met. Dairy farmers are committed to making sure the milk you consume is safe, high quality and sustainably produced.

If pesticides are used on crops on the farm (i.e. organic farms do not use synthetic pesticides), dairy farmers are extra careful with handling and storing them to prevent any cross-pollination with feed, water, bedding and more. However, all pesticides used must be registered and approved by provincial organizations. Farmers are also restricted from entering stalls if they’ve been in contact with chemicals, so they don’t contaminate the cows’ environment. 

To make sure farms are in compliance with federal and provincial regulations, they are audited at a minimum every two years.