If you want to know about colostrum research—at least the kind that involves milking beef cows—Brian Vander Ley, DVM, could tell you some colorful stories.
“Invariably you’re going to have a few who don’t appreciate the process,” he says.
The work can be hard to get at, but the University of Missouri (MU) veterinarian is part of a team hoping to advance the study.
Scientists believe calves’ earliest nutrition could do a lot more than just provide an energy-dense meal and protective antibodies to newborn animals.
“The other things we don’t think about as much are growth factors and hormones,” says MU animal scientist Allison Meyer, Ph.D. “There is even some emerging research showing that there are maternal cells in colostrum that may be important for newborn health.”
Meyer cites swine work done by Skip Bartol, Ph.D., at Auburn University, where he has developed the “lactocrine hypothesis.”
“We have always known that growth factors in colostrum are really important for gut development,” she says, “but this shows there are parts of colostrum that are helping with development of other organs after the animal is born.”
Although it’s not proven, she suspects the same happens in beef cattle.
Even without knowing all the indirect benefits that come from the transfer of proteins and white blood cells, Dr. Vander Ley says, “There’s a lot of evidence showing that the colostrum primes the immune system.”
It’s not just about early immunity, but about disease resistance throughout the animal’s lifetime. That in itself could be related to performance at the feedyard and on the rail.
“I know if animals have respiratory disease they’re less likely to grade well,” he says. “I also know if they have good passive transfer at birth, they’re less likely to get respiratory disease in their life. If I put that together, my assumption is if they get good colostral transfer as a calf, they at least stand a much better chance of reaching their genetic potential. That’s notwithstanding a direct effect that I don’t even know about yet.”
The ideal situation is to have an unassisted delivery, the calf “getting its bearings” and nursing within an hour or two of birth, Dr. Vander Ley says. There’s usually about 24 hours until the animal’s chance of absorbing antibodies into the bloodstream is greatly decreased, but if it consumes anything besides colostrum first, that window is much narrower.
“It’s not really selective,” he says. “There’s nothing in that calf’s gut that picks out the antibodies and leaves everything else. Essentially the gut grabs bunches of stuff and engulfs it and dumps it out into the bloodstream.”
Given the variety of environments that calves are born into, that can be a problem, Meyer says.
“If it gets a mouthful of something that has a pathogen in it before it gets a mouthful of colostrum, that’s not good,” she says.
Also, sometimes a producer being overeager to “help” a calf can interfere. When a calf eats—whether that’s colostrum, electrolytes or milk replacer—it signals the gut cells to “turn over.” If that first meal doesn’t include colostrum, they won’t be as able to absorb it later, Meyer says.
That’s also why both scientists recommend a true colostrum replacer versus a colostrum substitute when milking the cow is not an option. A replacer comes from hyper-vaccinated cows and is pretty similar to actual colostrum, where a substitute has substantially fewer immunoglobulins (IgG) and other proteins found in colostrum.
“I want the natural process to work. I’m just going to fall back on this when it doesn’t,” Dr. Vander Ley says. Giving the calf time to nurse is the best option, followed by milking the cow and feeding its colostrum.
It’s important to give one to two full doses, he says, noting $50 to save a calf is worth the investment.
Herd health solutions
Often, veterinarians aren’t called in until there’s a problem, but evaluating whole herd management can help pinpoint the cause of repeat challenges.
“Within the first few weeks and months [the calf] is relying completely on what it got from colostrum, and anytime you see poor health early on, you can assume that has something to do with it,” Meyer says.
Sometimes the problem is related to the calf nursing, other times to quantity or quality of colostrum.
“We know it’s a major problem when an animal doesn’t get enough colostrum,” she says. Typically that’s a factor in thin heifers or when a calf comes really early, Meyer says. But more common and perhaps harder to diagnosis is poor quality colostrum.
“If it takes a calf consuming 10 liters of colostrum to actually get enough immunoglobulins, that’s not always possible,” she says.
Everything from nutrition to genetics could play a role.
North Dakota State University sheep research divided pregnant ewes into three groups where they were underfed or overfed compared to the control. The total IgG was greater in the control group (82.1 grams) as compared to the restricted diet (31.5g) or the high energy group (33.6).
“Thin cows in general are a problem,” Meyer says, but the “fat ewes” could model what happens with overdeveloped heifers. On the ranch, the more common occurrence is undernourishment.
Some of the only data available on beef cattle, published by Ken Odde, DVM, Ph.D., at Colorado State University in 1988, showed a linear increase in amount of IgG as body condition (BCS) increased. For example, the group of heifers with BCS of 3 had 1,998 milligrams per deciliter (mg/dl) compared to those with a BCS 6, at 2,348 mg/dl.
Colostrogenesis begins 16 weeks precalving and good nutrition during late gestation is key, especially in older cows and heifers, Meyer says.
“In spring calving herds, that’s typically when we have a lot of cold weather and snow and ice that are increasing energy requirements,” she says. “We also know that trace minerals are really important for immune function.”
As veterinarians work to solve early health challenges with specific clients, Meyers says it makes sense to have conversations about herd nutrition.
“If they start seeing recurring problems with young calves, maybe they should at least make a statement about colostrum and look at the body condition of the herd as a telltale sign,” she says.
Calving difficulty also plays a role in both a calf’s ability to start nursing and in the IgG content in colostrum.
In his study, Dr. Odde assigned calving difficulty scores from 1 (no assistance) to 3 (hard pull) and found as calving difficulty increased the amount of IgG decreased, from 2,401 mg/dl to 1,919.
It’s all interconnected. Dr. Vander Ley says matching cows to the environment will help with the nutrient requirements, and that helps keep calving problems at bay.
Although scientists are just beginning to understand the effects of colostrum quality and intake, today the take home message is simple.
“I need to make sure my cows are healthy, they’re in good condition and their nutritional needs are met throughout their yearly cycle,” he says.
That advice, and working at it early, may get more reception in the field than asking beef clients to milk their cows.
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