How Nutrition and Management make for Stronger Cattle Immunity

This episode is available in English only.

Dr. Jodi McGill explains how nutrition, management, vaccination and innate immunity can prepare calves to better withstand respiratory disease challenges. 

Timestamps & Summary  

Chris Gwyn (01:23) 
Could you share with the listening audience the journey that has taken you to be researching immunity and the respiratory infections in ruminants? 
Dr. Jodi McGill 
I actually started out my training on the human side. I was trained in mouse and human medical immunology for my PhD and my master's degree at the University of Iowa. […] 
[It] led me to a postdoc at the National Animal Disease Center, which is where I started to study bovine respiratory disease. And I really found that much more impactful because you can study the disease in the animal, and you can really see the impact in that species. […] 

Chris Gwyn (03:05) 
When you say innate immune system specifically, what are you describing? 
Dr. Jodi McGill 
So the immune system is kind of two arms. It is the way we teach it. […] 
A lot of times with the vaccine, we're targeting the adaptive immune system. So that's really specific and has memory. So, once you've gotten your vaccine, you're protected for a really long time. When we talk about that, we're talking about the adaptive part of the immune system. […] 

Whereas the innate immune system is nonspecific and kind of broadly reactive. It's kind of the first line of defense, and it responds in a way that says, “I care that it's a virus, but I don't necessarily care if it's BRSV or parainfluenza” […] 

It's also much quicker to respond. […] 

Chris Gwyn (06:17) 
You've authored, and of course co-authored, many studies focused on nutritional approaches that impact innate immunity […] 

How are these nutritional approaches linked to that immune readiness? 

Dr. Jodi McGill 
I think that whole idea of being ready is important because you're not playing catch-up, right? I think as soon as that calf is kind of under the weather is when we're starting to play catch-up. And a lot of the strategies that I've spent my career studying are all about getting that calf in a much better position when he hits the feedlot […] 

Chris Gwyn (12:20) 
What are some of the things that the audience can be thinking of doing this season to help minimize some of those challenges it’s likely going to see? 

Dr. Jodi McGill 
Having your calf the right nutrition, the right treatments ahead of time. Management is always, I think, your best tool against BRD. […] 

I think, overall, a lot of our challenges with BRD, we create, a lot of times. Vaccines are still probably our best tool. […] 

Chris Gwyn (14:20) 
What are some of those key things that people need to be thinking about honing in on their operations to ensure that those calves coming in are immune ready? 

Dr. Jodi McGill 
I think for, for geneticists, we're at a really cool period where we're starting to understand more and more about the genetics of it. Of BRD and kind of looking at resistance to BRD. And so we have some tests that are starting to become available, and you can start to begin to select for that. […] 

Chris Gwyn (16:30) 
What are the 3 key messages that you'd want to leave the audience thinking about? 

Dr. Jodi McGill 
I mean, prevention is better than curing, right? […] 

Management choices, I think, make a huge difference in prevention of BRD. It's really a management disease. And we have tools, but first, think about your weaning practices, think about your transportation practices, all of those things. […] 

The native immune system is probably the best part of the immune system because without it, the adaptive immune system would be nothing. […]