How long do cows produce milk? Learn about the dairy cow lactation cycle and how to dry up a milk cow safely to protect the cow from a high chance of getting mastitis.
We’ve kept dairy cows for years. Yet, we still find ourselves making countless trips to the barnyard to check on a pregnant cow’s condition when she’s close to calving. In talking to others who own family milk cows, it appears this is a common practice.
For many homesteaders, the availability of milk and dairy for the family is as exciting as the birth of a calf. After many months of routine milking, however, the farmer often needs to take a break, and the cow needs her rest as well. This is when the farmer may choose to end the cow’s lactation.
Because a dry period shorter than 45 days and longer than 80 days may affect production volume during the cow’s next lactation, it’s best to take a break about two months before a new calf is born. During this time, cells shrink and repair in preparation for another lactation. The udder’s regression to a nonproductive state during the dry period is known as “udder involution.” If you fed your cow grain while you were milking her, you may be able to give her rumen a rest and keep her condition on just good-quality hay. In addition, cows can build back body condition while they aren’t under the strain of producing milk.
How Long Do Cows Produce Milk?
While we understand that the mammary glands, collectively called the “udder,” are how calves are supplied nourishment, most of us probably don’t give much thought to the process. A cow usually experiences peak lactation around six weeks after a calf is born, after which her milk quantity begins to decrease. Genetics, diet, frequency of milking, and the overall health of the cow will affect milk production. Cows typically give birth to a calf every 12 to 13 months, and many homesteaders milk for 10 to 11 months before ending a cow’s lactation.
Anatomy and Function of the Mammary Glands
When discussing bovine lactation, it’s important to understand the terminology and function of the various parts of the udder. Female cows have one udder with four separate glands, commonly called “quarters.” Each quarter has a teat. Within the udder, tiny, round milk-secreting cells known as “alveoli” cluster together. Life-sustaining colostrum and milk from these grapelike clusters are transported by ducts through the mammary gland, where they collect in the teat cistern. The milk exits the teat cistern through the teat canal. As a defense against foreign pathogens, longitudinal and circular muscle bundles work to keep the teat canal closed during times when the calf isn’t nursing or humans aren’t milking the cow.
Mastitis and Prevention
When pathogens are introduced into the teat canal, an inflammatory infection known as “mastitis” can occur. Mastitis can affect one or more quarters and can happen at any stage of a cow’s lactation, even during the dry-off period. Mastitis that lingers in a cow’s udder during the dry period may not be noticed until she calves and the farmer begins milking her again. Starting a new lactation with lingering mastitis is dangerous for the cow and frustrating for the farmer.
Quarters infected with mastitis will often be hot to the touch, red, and swollen. A cow with advanced mastitis may be lethargic and have a decreased appetite and an elevated body temperature. Depending on the severity and type of mastitis, milk from an infected cow may appear abnormal when you look at it and can include tiny flecks, clots, or long, stringy clumps of cells. Extreme cases might present as a watery discharge with a foul smell.
Cleanliness is an important defense against mastitis. Farmers should provide cows with a well-ventilated and dry barn or shelter and adequate space outdoors so they have clean areas in which to lie down.
Teat health is also critical in mastitis prevention. Dry, cracked teats are more likely to allow the introduction of pathogens that can cause mastitis. According to the document “Preventing Dry Cow Mastitis” distributed by Penn State, “A cow with cracked teats has a 1.7 times higher risk of picking up a new infection during the dry period.” Using an udder balm or lotion specifically formulated for cattle can help keep their teats healthy, as can following proper milking procedures and cleaning the teats before and after milking. In addition, reducing stress and providing the cow with a healthy diet helps support the cow’s overall immunity.

How to Dry Up a Milk Cow
To transition a cow successfully, first decrease her milk supply. Cows should always be offered plenty of free-choice hay and adequate grazing, but it’s important to slow milk production by decreasing energy intake. Do this by cutting out grain and high-energy feeds from the cow’s diet. We feed grass hay during this transition period instead of alfalfa. It’s usually safe to dry off a cow when they’re producing 2 or less gallons of milk a day. A farmer can then make the choice either to use an antibiotic infusion to ward off potential mastitis or end the cow’s lactation without antibiotics. According to the manufacturer’s warning, there’s a 42-day withdrawal period for meat and 72 hours for milk from animals that have been treated with an antibiotic infusion. In addition, the manufacturer warns against using antibiotics 30 days or less prior to calving. Since June of 2023, these antibiotics are no longer available over the counter. A veterinarian who’s aware of your animal-husbandry systems and goals could supply the necessary prescription so you can administer the infusions yourself.
It’s certainly possible to end a cow’s lactation without the use of antibiotics. In fact, a reduction in the use of antibiotics is strongly encouraged as a preventive to antibiotic resistance in cattle as well as in humans who consume meat and dairy. Careful attention should be given to udder health and a clean environment for all cows, but especially when ending a cow’s lactation without the aid of an antibiotic infusion. On our farm, we successfully dry off most of our dairy cows without antibiotics and use infusions only on those prone to mastitis.
A healthy dairy cow and the delicious, uncontaminated milk she provides can be an important part of the homesteading lifestyle. Taking proactive steps that encourage the successful end to a cow’s lactation will improve subsequent lactations and give homesteaders many happy years with their family cow.
Administering Infusions
- To administer an antibiotic infusion, first clean the cow’s udder, and milk out all four quarters. After milking, the teats should be cleaned again with the alcohol wipe provided in the box with the antibiotic.
- Next, shake the medication in the tube to mix it thoroughly. Open the tube and carefully insert the thin, pointed tip into the teat canal. While keeping the tip of the tube fully inserted in the teat canal, push the syringe slowly until all the medication has been administered.
- Repeat the process with the three other teats. When finished, use a commercial dip or 3 percent iodine solution to disinfect the teats. This will help keep pathogens from entering the teat canal until the cow’s natural, waxy seal, known as “keratin,” forms like a plug in the tip of the teat canal. It takes several days for the keratin seal to form, and the teats are more susceptible to pathogens during this time.
- Don’t milk the cow again until after the calf is born so the seal isn’t disturbed.
Tammy Cupp and her husband, Mike, raise and train dairy cattle on 50 acres in the Blue Ridge Mountains. Follow them on Instagram @MapleLawn_Farm and on Facebook @MapleLawnFarmInSWVirginia.