Beef Calves: When to Wean

Weaning is stressful for calves and producers, but it’s a necessity to promote good calf health and growth. Deciding when and how to separate calves from cows impacts the animal’s health and ultimately, its market value.

The good news is that producers have a lot of options. Here’s what to consider when choosing a weaning strategy for your operation. 

When to wean

Most beef producers wean around seven months of age, according to John B. Hall, Ph.D., PAS, a University of Idaho professor and extension beef specialist. However, there is more to consider than age.

“The time of weaning should be matched to the producer’s forage availability and post-weaning goals,” he said. “So, we need to be flexible on timing.”

For example, weaning calves in drought conditions—at 150 to 180 days—maximizes the forage supply  before it declines. Conversely, if it is a good forage year waiting slightly longer than seven months can also be beneficial. 

“Those are extreme examples,” he said. “But weaning dates need to change based on forage availability and weather conditions to support calf growth. If a big storm or rain is coming in, I might wait to reduce stress on the calves.”

Natural weaning

Calves naturally stop nursing around 10 months of age. But if a cow is rebred, a suckling calf could consume nutrients needed for the developing fetus.

Hard weaning

 Calves move into a corral, feedlot, or barn, and cows move to a distant pasture.

“Calves used to drinking out of ponds or creeks and then moved into feedlots or corrals with troughs don’t know to look up to find water,” Hall said. “If you let the water run so the troughs run over those first few days, they can see it running and will find it.”

Fence line weaning

Calves move to a neighboring pasture divided by a high-voltage fence with the cows in the adjacent field. Hall recommends introducing the cow/calf pairs to the weaning area about a week before separation, so the calves know where the water is and then moving the cows to the new pasture.

Two-stage weaning

Calves are run through a chute about one to two weeks before weaning, and a nose flap is inserted. The animal returns to the herd. The nose flap prevents nursing while allowing the calf to graze and drink water. About 10 to 14 days later, the nose flaps are removed, and calves are separated from dams.

“There is some interesting research that the nose flap seems less stressful,” Hall said. “But you do have to run them through the chute twice, creating stress on the calves and the producers.”

Nutrition needs

Good nutrition during gestation, especially the third trimester, sets the foundation for a healthy calf. A calf continues to absorb nutrients from its mother during nursing, but at weaning time the calf is dependent on the forage and minerals provided as part of its diet.

“You must have a nutritional plan, whether that is a fresh pasture plus a mineral program, or enough bunk space in a feedlot or corral, to provide a balanced diet that meets a calf’s nutritional needs,” he said. “Calves need adequate amounts of trace minerals, especially copper, selenium, zinc and manganese.”

On pasture, competition for food is less intense, making it possible to manage larger numbers in one place. However, in large feedlot operations, Hall recommends dividing calves into smaller groups by body weight or size to reduce competition for feed. Housing calves in smaller groups also makes it easier to identify those that may be feeling poorly.

“Part of deciding how to group calves is how big a group you feel comfortable going through every day and the labor or time you available to do so,” he said.  

Post-weaning wellness 

The first seven to 10 days (about 1 and a half weeks) post-weaning is when a calf is most prone to illness. Scours, Coccidiosis (bloody diarrhea), and bovine respiratory disease are the most common diseases to watch for among young stock.

“We recommend producers vaccinate calves two weeks before weaning, so the animals are at the top of immune protection, but it is not always feasible for every producer to do that,” Hall said.

There is no way to eliminate stress during weaning, so it’s critical to minimize it as much as possible and have a preventive care plan in place. The first step is to consult with a veterinarian about vaccination recommendations and treatment protocols if an animal becomes sick. A veterinarian can also suggest preventative feed through treatments given before or at weaning and antibiotics for a sick calf. 

“It’s very important for smaller producers to visually check the calves twice daily for the first two weeks after weaning,” he said. “That’s when they’ll usually show signs of illness, but it is also to be sure they appear to be in good overall health and getting enough feed and water.”

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