Animal Health Matters: Connecting health and nutrition in the cattle world

Russ Daly
Special to the Farm Forum
Russ Daly

The other day, I had a great opportunity to meet with a group of cattle nutrition professionals.

This group was from all over the northern plains, with experience in feedlots and cow-calf operations. They’d asked me, as a veterinarian, to give them my thoughts on how they might best work with others in my field to serve their cattle-raising clients.

I very much appreciated this invitation. In cattle production, what and how that animal is fed plays a huge role in their productivity and health — more so, in my opinion, than in any other livestock enterprise.

These critters have something most other animals don’t: a microbe-filled rumen that plays a critical role in how nutrients are delivered to the body.

You may be familiar with the viewpoint that when you feed a bovine, you’re actually feeding their rumen microbes, not the animal. It’s those bacteria and protozoa that break down feedstuffs that us monogastrics (single-stomached beings) can’t process into usable nutritional building blocks for that growing or reproducing animal.

We all understand that proper nutrition is vital for cattle growth and production. However, the importance of optimal cattle nutrition goes well beyond that. Animal health is also at stake. Nutrition problems can manifest themselves as mounting sickness and death rates in feedlot or cow groups.

Some overt cattle health problems we typically blame on germs or weather can have their roots in nutritional problems. For example, calves on “hot rations” might experience too much lactic acid buildup in their rumen, which spills out into their bloodstream. This lower blood pH paralyzes immune cells that clean up the lungs from pneumonia-causing bacteria.

Excess carbohydrates reaching the intestine can spark bacteria such as Clostridia to overgrow and produce the disease- or death-causing toxins of overeating disease. Some feedstuffs can contribute to bloat, which at best makes a critter uncomfortable about eating more and at worst kills them.

These are just some examples. Many of these problems aren’t the result of poor-quality feed; rather it’s how the animal consumes it. In particular, abrupt changes in the amount or composition of the diet are often the culprit. These could result from feed mixing errors, equipment malfunctions or winter storms that prevent cattle from being fed for a while.

Exacerbating these situations is that we often push the nutritional envelope in high-producing animals, walking a fine line between optimal growth and production and the health of the gut. Any little disruption can have important consequences. In response, nutrition scientists have effectively found ingredients that help the rumen microbes weather these changes (i.e., ionophores and other additives).

When growth or production is lagging in a group of cattle, it’s the nutrition representative who is first to get the call. Likewise, when a disease breaks out in that group, the call goes to the veterinarian.

But as I’ve hopefully illustrated above, sometimes a health problem can have its roots in feeding and nutrition issues. On the other hand, production downfalls can result from chronic, subclinical health issues. What seems like an either/or (nutrition or health) problem oftentimes involves both disciplines.

I’m afraid many of us — veterinarians and nutrition people alike — fall into the notion that we work in two distinct worlds. In herd problem investigations, that unfortunately can devolve into some finger-pointing: “That veterinarian doesn’t have the health program figured out — that’s why the calves aren’t growing,” or “That nutritionist has the ration messed up — that’s why we had that pneumonia wreck.”

Back to my talk with the cattle nutritionists: my goal was to foster that communication and connection. Fortunately, there are more and more professionals that actively engage the other “side” in their work — nutritionists who interact with their herds’ veterinarians and vice-versa.

After all, both sides have their client’s (and their animals’) best interests in mind. Increasingly, cattle health and production problems require a team approach; no one person usually has all the answers. The successful professionals, in my opinion, are the ones who have that figured out.

Russ Daly, DVM, is the Extension Veterinarian at South Dakota State University.  He can be reached via e-mail at or at 605-688-5171.