Nutrition students (Dietetic Interns) regularly spend time with us to learn more about how community programs work with people to provide information. While they are here, they get to learn more about where dairy foods come from and ask questions that maybe don’t come up during class time. We say, there’s no such thing as a silly question, and asked recent students to jot down things they wanted to learn. Here are the top 10 questions nutrition students have about dairy, from farm to fridge.
On the farm:
Q: What do cows eat?
A: Cows eat all kinds of things. Dairy farmers work with professional nutritionists to make sure their cows get all the nutrients they need. In fact, 70 percent of a cow’s diet is inedible by humans. In Indiana, a typical dairy cow would eat corn silage (the entire corn plant, stalk and all, chopped up and fermented for digestibility), soybeans, alfalfa, pasture, hay, and vitamin or mineral supplements. Other ingredients farmers can use are cottonseed hulls, beet pulp, distiller’s grains (a byproduct of ethanol or beer/liquor production), orange pulp (from orange juice production), baker’s waste (crumbs or slightly stale leftovers from a bakery), vegetable waste from grocery stores, and more. Cows use their amazing stomach to turn these inedible (and potentially wasteful products) into milk.
Q: How long are cows milked for each day?
A: Most cows are milked 2-3 times per day for about 5-7 minutes each time. The whole process normally takes less than 10 minutes, leaving the cow plenty of time to lay down, chew her cud, and relax — which she will do for up to fourteen hours a day. (Cud for those of you who are wondering, is a critical part of a cow’s digestive system. Cows swallow their food and it goes into the first chamber of their stomach, called the rumen. After some time, she, ahem, ejects the food from the rumen as cud, chews it a bit more, and swallows it back down. If you see a cow burp and start chewing, that’s what she’s doing. It’s not gross, we promise.)
Q: How many types of milk cows are there?
A: Originally, all cows were just cows, but through generations of breeding, we know have breeds designed for dairy and breeds designed for beef. There are six common breeds of dairy cows that you can find on farms across our country, including the most popular (and most recognizable) Holstein. All six of the breeds most popular in the US originally came from Europe – including the British Isles. Learn more about each type here. Other dairy or dual purpose breeds live in other countries around the world.
Q: How much milk can one cow produce per day?
A: This really depends on the cow, what she’s eating, and what stage in her lactation she is. That being said, an average cow produces about 9 gallons of milk each day of the approximately ten months she is being milked. Cows are milked for about ten months, then go on vacation for about two months before they have their next calf. Cows have a calf about once a year (maybe once every 12-15 months), which is the same frequency as similar wild animals (for example bison and deer).
Q: Which is more sustainable, nondairy milk alternatives or cow’s milk?
A: Sustainability can be measured in many ways including carbon footprint, land and water usage, as well as the ability to recycle/repurpose by-products. Additionally, consideration must be given to how much and what kind of nutrients can be obtained from different foods and affordability. Dairy farm families are committed to sustainable nutrition and the environment through reduction in greenhouse gas emissions, water conservation, recycling of manure and even their cows’ diets. Get more detail on dairy sustainability here and here.
In the fridge:
Q: What exactly is ghee? Is the nutrition different than regular butter?
A: Ghee is essentially a type of clarified butter. (Clarified butter is created when regular butter is heated up to separate out the milk solids and water from the pure butterfat.) Used often in Indian food, ghee is slightly different because it’s cooked a little longer, adding more flavor. Nutritionally there are a few small differences between ghee and regular butter. Since ghee is pure butterfat, it has more calories per serving and is a little higher in saturated fat and cholesterol. It does however contain more Vitamin A than regular butter. (But hey, if you’re looking to increase your Vitamin A, we’d suggest a sweet potato.)
Q: What is the process of pasteurization?
A: Pasteurization was discovered by Louis Pasteur more than 150 years in an effort to reduce harmful bacteria in foods. This quick process heats chilled milk to 161 degrees F for at least 15 seconds, then cools it back down to 39 degrees F. Ultra Pasteurization is done in the same manner, except the milk is heated to 280 degrees F and held for at least 2 seconds before cooling it back down. Milk’s nutritional value doesn’t change much through the process. Only reducing an already small amount of Vitamin C. (Which for the record, milk isn’t a very good source of to begin with.)
Q: What is A2 milk?
A: First off, a little science background. Milk and many dairy foods contain high quality protein that fuels our body, helping to build and maintain muscle. Dairy protein is made up of two main parts: casein and whey. There are different types of casein, A1 and A2 are two common types found naturally in milk. “A2 milk” comes from certain dairy cows that have only the A2 type of dairy protein in their milk. That’s it. It’s all about their cow family genes. Read more in a recent blog post.
Q: Does milk contain gluten?
A: No, milk does contain any gluten. Whether you choose whole, low-fat or lactose-free cow’s milk, rest assured it is gluten-free. Yogurt and cheese are also naturally gluten free, but may be packaged with additional ingredients (mix ins) or contain flavorings or ingredients that contain gluten so you should be sure to read the label if you have been diagnosed with a gluten sensitivity or celiac disease.
Q: Is there any nutrition difference between shelf stable milk in a box and refrigerated cow’s milk?
A: No. Cow’s milk that has been Ultra Pasteurized can be boxed and placed on the shelf for several months, without spoiling. (Until it’s opened, then it needs to be refrigerated.) However, that is the only difference between boxed cow’s milk and the ice-cold gallon at your local grocery. Both types provide the same 9 essential nutrients.