Immunity Through Nutrition

Leveraging an effective nutrition program to improve immunity in your herd.

FEATURE BY LAURA HANDKE

At the 2022 Cattlemen’s College, Dr. Ronald Scott, head of beef cattle technical innovation for Purina, shared on the importance of influencing immunity through nutrition to benefit every piece of the beef valuechain.

“Morbidity and mortality are similar to where they were when I started in this industry as a kid,” Scott said. “If you think about it, vaccines should be better, we should have fewer knowledge gaps across the industry and fewer mismanaged cattle.”

While we are gaining ground on all of those fronts, new consumer-driven challenges are influencing a producer’s access and profitability to treat sick cattle. The solution, Scott says: Keep them, or as many of them as possible, from getting sick to begin with.

The cost of first treatment of respiratory diseases, among the most costly and prevalent illnesses in the industry, is around $30. The cost to re-treat compounds, adding additional weight loss of as much as 2.2 pounds per day the animal is off feed and water. Final quality also suffers from illness, with studies indicating a reduced hot carcass weight to a tune of 49 pounds and as much as a 28 point reduction in marbling.

But there’s another cost – one that doesn’t come back as black and white on the grading report.

Consumer perspective isn’t always a consideration producers keep top of mind. However, over the past decade, consumer demand has increasingly favored animal proteins raised without antibiotics. The solution, Scott says, is approaching the problem of illness from a proactive rather than a reactive mindset: How do we prevent disease rather than treat disease?

THE RELATIONSHIP BETWEEN NUTRITION AND HERD HEALTH

“Is there a relationship between nutrition management and herd health,” Scott asked attendees? The answer: a resounding, “Yes”.

We all know it, we just don’t all know how to positively influence it. It’s likely that every producer has witnessed firsthand the lingering effects of droughtinduced body condition score decline. And if you’ve been in the cattle business any time at all, you will appreciate just how important timely consumption of colostrum is to a new calf. Nutrition is the key to managing herd health.

The challenge comes with whole-herd scalability. If a calf doesn’t get sick, it’s easy to infer that a calf has a good immune system. The quandary, however, is how do we impart those immunity qualities amongst all the calves in the herd?

Immunity is developed at critical milestones in a calf ’s progression through the production-chain: conception, birth, weaning and puberty.

There are three types of immunity: passive, innate and active. While each phase or type of immunity is very different, all are equally important to ensuring quality and quantity in finished beef.

While it has been known that nutrition plays an important role in the last trimester of gestation, it wasn’t until the last decade that research findings offered producers insight on the importance of feeding for immunity year-round.

Scott says that the cow has a considerable amount to do with the immunity her calf is born with. A calf ’s first immunity is “programmed” in utero.

Fetal programming is a collection of research and management protocol that emphasizes cow maintenance in the production of healthy, well-doing calves. Today, we know that immunity begins to build shortly after conception, when a calf is receiving nutrition via its mother. The quality, quantity and consistency of the nutrition a cow receives will help determine the level of immunity a calf will be born with.

When considering fetal programming, these four components of a nutrition plan are critical: protein, energy, vitamins and minerals.

Passive immunity becomes present in a calf when it nurses colostrum from its mother. Colostrum development is a process that begins a month before calving; if cows are in poor condition going into the colostrum development, the colostrum will lose quality.

“Think of cows coming out of the drought,” Scott asked producers, offering that the body condition scores of cows who may have experienced nutrient deficiencies due to overgrazed pastures and low-quality feedstuffs are typically lower. “What happens to a cow’s weight in the winter? She typically loses condition.”

The window of time in which a calf nurses colostrum is also critical to its future success. The sooner the better is the motto to employ when on-thefence about when to supplement with a colostrum replacer. Immunoglobins can only be obtained from colostrum and are absorbed directly into the bloodstream via the gut to provide a nearly immediate protection from pathogens. It’s also important to note that colostrum replacers and colostrum supplements are not created equal and are not intended to serve the same purpose. Over time, as the calf acclimates to its environment and present stressors, passive immunity wanes and active immunity builds.

“The highest risk times in a calf ’s life are at birth and weaning. The innate immune system that they are born with is their first line of defense, followed by the passive immunity they receive from the cow. The challenge is trying to improve them,” said Scott.