Helping calves get a healthy start at weaning will help them in the long run

Weaning calves from their mothers is a stressful time on the farm. There are many things to keep in mind during this time, such as the impact weaning has on calves’ digestive and immune systems, and what vaccinations and other health precautions need to be taken.

Rumen Development

“Rumen development begins early in a calf’s life. Dairy cattle producers are generally more concerned than beef cattle producers with nutritional hastening of rumen development because they want to transition calves off milk early in life. Calves in beef cattle operations are generally not supplemented in early life to hasten rumen development, but rumen morphology and microbiota develop early. By the time calves are 3 months of age, more than half their diet consists of forages or any supplements they might be exposed to with their dams,” Dr. Shane Gadberry, nutritional specialist with the University of Arkansas Cooperative Extension, said. He went on to say that at 5 months of age and older, milk is more like a supplement, with the bulk of the diet coming from forages or possibly creep feed.

Dr. Eric Bailey, State Extension Beef Nutrition Specialist at the University of Missouri, explained that “typical weaning age in the beef industry is anywhere from 180 and 240 days. The rumen is developed long before normal weaning. The only time we would be concerned about rumen development in the beef industry is when calves have to be weaned less than 60 days of age because of an extenuating circumstance, such as drought. The factor determining rumen development will be the consumption of solid feeds. It is common to see a month-old calf grazing next to their dam, which tells us that no intervention is necessary under normal circumstances.”

Nutrition Transition

During the weaning process, producers need to keep in mind that calves will be experiencing nutritional transitions.

“The nutrition transition that is most difficult to manage for beef producers is from a forage-based diet to a grain-based diet, although the majority of producers do not keep calves through the feedlot phase. The nutrient of concern here is starch,” Bailey said. “Significant starch, more than half of their diet (corn is 72 percent starch for example) in the diet changes the species of bacteria in the rumen and can cause acidosis through rapid production of volatile fatty acids (a byproduct of fermentation that is used as an energy source by ruminants), which reduce rumen pH.”

He noted that starch is not a large concern in most of Ozark’s forage-based production systems, because byproducts such gluten feed, distiller’s grains and soybean hulls do not contain starch. Minerals and additives are also considerations for transitioning calves completely way from their mama’s milk.

“Trace mineral supplementation is important in pre-weaning. Calves need to be able to reach into the mineral feeders used to supplement their dams. Forages are moderate to deficient in certain trace minerals and trace minerals are important for a calf to be able to respond well to vaccination programs,” Gadberry advised. “Supplements to consider post-weaning may include a feed additive to help prevent coccidiosis. Outbreaks can occur occasionally, even with calves weaned and backgrounded on-farm. If respiratory disease is an issue, a veterinarian can write a feed directive for an antibiotic feed additive.”

Managing Changes

“Research is unclear if there is a benefit of transitioning calves to a diet before weaning. Often times, the real benefit seen is acclimating cattle to a confinement-based system such as eating feed out of a bunk and drinking out of a water tank instead of a creek or pond,” Bailey said. “Anything we can do to make the transition from grazing and consuming milk to confinement-based feeding will be a benefit to the animal, their owner, and to the beef industry as a whole.”

He recommends spreading out stressors such as weaning, diet change, marketing and castration.

Gadberry agreed.

“Weaning calves can be stressful. Castrate bulls early in instead of waiting until weaning. Consider giving the first round of vaccines for respiratory disease and deworming four weeks prior to weaning and give the booster vaccine at weaning.”