by Zinpro

From weaning and transportation to commingling and even changes in weather, cattle move through a series of stressful events that can challenge their immune functions. These events may be routine on paper, but inside the animals, the biological responses can be significant.

“Stress triggers a hormone called cortisol,” says Chris Reinhardt, technical services nutritionist for Zinpro. “The job of cortisol is to ensure cattle survive the stress event, and survival is often juxtaposed against the animal’s ability to thrive.”

That distinction matters. During acute stress, cattle often reduce feed intake or stop eating altogether. Research has shown that only 65% of healthy calves and 50% of sick calves consume feed within 48 hours of arrival at the feedyard.¹

In these situations, nutrients that would normally support growth and immune function are redirected toward short-term survival. As Reinhardt puts it, “If an animal’s not eating, they’re not thriving.”

So, what should producers do?

A good starting point is recognizing that immune support is not separate from overall management. It’s built through timely observation, sound trace mineral nutrition and fast action when cattle begin to show signs of challenge.

“Nutrients such as zinc (Zn), copper (Cu) and manganese (Mn) are critical to normal immune cell function and the ability of cattle to respond to health challenges,” says Reinhardt. “But one of the biggest practical hurdles is that sick or highly stressed cattle are usually the least likely to consume enough feed to meet those needs.”

That is why the highest-risk moments often require the most attention. Weaning, transportation and commingling can all suppress feed intake and immune function, leaving cattle more vulnerable to health challenges such as bovine respiratory disease (BRD).

Trace minerals play a key role in immune response

Practically speaking, producers can think about immune support in two key situations. One is during major stress periods, especially for high-risk calves, and the other is during the early treatment window when cattle are pulled for respiratory disease.

“When a calf is pulled for a respiratory challenge, producers should not only think about targeting the disease itself, but also about providing the immune system what it needs to help the animal mount its own response,” says Reinhardt.

In those moments, trace mineral support in a drench or paste can be given to cattle alongside antimicrobial therapy to help deliver the key nutrients they need.

“Ensure the trace mineral source is able to reach the critical tissues and cells within the immune system effectively — at a greater rate and a greater amount — to provide cattle with the tools they need to defend themselves against both [viral] and bacterial invasions,” notes Reinhardt.