First in a roundtable series.

The health of feedlot cattle, especially those that are newly-arrived to the operation, is influenced by many things. Before cattle even step on the truck, their immune status can determine how they are going to respond to this next phase of production.

Preparing to make feedlot treatment decisionsSome believe feedlot calves today are different than in years past as far as immunocompetence. Tom Portillo, DVM, Amarillo, Texas, says, “We’re dealing with a different animal and it’s being treated differently in the feedyard. A seven-weight now is not the same animal that used to hit a feed yard 20, or even 10 years ago. They don’t have the immunocompetence that they used to have. We have a more immature animal, thus we’re dealing with a much more immature immune system. They used to be a lot more hardy on arrival.”

Portillo believes people chase heavier weaning weights and wean a more immature calf, and sometimes the immune system of the calves gets lost in the wake. Nate McDonald, DVM, Cattle Health Management Network, Meade, Kan., agrees and says as weaning weights have increased, ages have come down and a lot of 14-month-old cattle are now slaughtered.

Dan Goehl, DVM, Canton Veterinary Clinic, LLC, Can ton, Mo., says even in small groups of well-immunized calves, stress and commingling can “undo” immune status. Goehl was involved with a marketing alliance in Missouri where they were commingling weaned, double-vaccinated cattle. “The morbidity was higher than I would have ever thought it would be,” he says, “because we took multiple groups of five or 10 head from multiple producers and put them together. It was just too much challenge for the immune system.”

Portillo believes sometimes too much weight is given to the role antibiotics play, to their credit or discredit. “Antibiotics are only a part of the situation,” he says. “We can rely on them too much. Basically, all they do is clear – or kill or stop – bacterial proliferation. The immune system still has to go in there and clear up the mess.”

Obviously, we do have a lot of immunocompetent animals or the production system wouldn’t work. “The majority of them are or we wouldn’t be in business, we wouldn’t be profitable,” Portillo states. He adds that all cattle reaching finish weight and shipping are immunocompetent for the most part.

Making the trip

Preparing to make feedlot treatment decisionsStress of transport can affect the immunocompetence of arrival cattle and is often taken into consideration when selecting to use metaphylaxis treatment. For Nels Lindberg, DVM, Production Animal Consultation, Great Bend, Kan., anything over four or five hours can potentially be long-haul depending on the conditions and the cattle. Hauls can go up to even 36 hours.

McDonald considers four or five hours on a truck as a medium haul, and 10 hours a long haul.

Al VanEngen, DVM, Central Vet Clinic, Sioux Center, Iowa, hardly gets anything into his area that’s only a four-hour haul. “Four hours would be a short haul for us,” he says. “We look more at source, weight and where they came from and not just the haul. Our first questions are did they come from the West? Did they come from the South, Southeast, and how far south? We’ve kind of drawn an imaginary line on the map. The four-hour cattle usually are bigger groups when they’re put together than the cattle that are the eight-hour haul group. Our haul distance is definitely different.”

Because of geographic limitations, Goehl has pretty defined groups mileage-wise as far as hauling distance. “There aren’t any cattle to the east of us until we go way east,” he says. “So when we get long-haul cattle, they’re long-haul cattle. We sit on the border of Illinois, but there’ are not a lot of feeder cattle coming out of Illinois. So, when we bring in our lightweight calves, they come out of West Virginia, Ohio, Tennessee and Kentucky.”

Instead of looking at hours in transport, Portillo looks at the cattle. “We look at things like shrink and their appearance,” he says. “You might get some that are hauled 10 hours with acceptable shrink and the cattle look good on arrival,” he explains. “They rehydrate and take on feed and we don’t consider them affected by the trip. So more than how long they’re traveling is what they look like when they arrive, including what they shrink.”

Portillo doesn’t have set protocols for certain shrink percentages. “I don’t think you can hang your hat on one thing like that,” he explains. “It’s several things that you look at. If the cattle look questionable, and they didn’t shrink very much, then you might feel a little more confident. But if the cattle look questionable, and they shrink a lot, then you might err more on the side of safety in how you handle them.”

Lindberg bases decisions on whether to use metaphylaxis on arrival cattle based on various elements of risk, instead of using weight alone. “Shrink is one of them, weight’s one of them, the order-buyer is one of them, and where they came from. The more strikes they have against them, we go down our decision tree and decide which antibiotic we use as a mass treatment. At this point in time, we have $3 to $30 mass treatment options. I gear my feedyards toward risk management on the health side.”

When they arrive

Everyone has a different program for arrival cattle regarding vaccination and metaphylaxis. Goehl either processes all new cattle at day five, or whenever the pen is complete, or, sometimes he vaccinates calves as they arrive, then gives them antibiotics when the pen is closed. “So at the end of day five, everything gets antibiotics on the same day. But they may get vaccine as they come in.”

VanEngen’s yards typically don’t buy big groups, so there is a lot of cattle variation. “We mass treat one group with drug A, one group with drug B, one group with drug C. It’s like someone mentioned earlier, you can go back and say all the cattle really got sick out of that load, and I’ve got them in three different pens, they all got sick, and it didn’t really matter what we treated that group of cattle with. And the other cattle, none of them got sick. I can’t pick the group of cattle coming off the truck that is going to get sick. You can look at them and they can be big, framey, black steers, weighing 700 pound and say they should never get sick. Three days later, they’re all sick. Then we’ve got these scraggly little things with horns and testicles from someplace, and they don’t get sick. I cannot pick them.”

Defining risk

There are a variety of factors you can use to assess risk of incoming cattle, even though this assessment alone won’t tell you everything you need to know. Classifying individuals or a group of individuals into a risk category doesn’t dictate how they will perform.

“If you take two very low-risk groups, as soon as you commingle them, you increase the risk of disease,” Portillo says. If forced to choose between the two, Portillo and Lindberg would rather have calves weaned 45, 60 or 90 + days vs. vaccinated, though Portillo says if a producer has taken the time to wean the calves, they are probably vaccinated as well.

VanEngen says single-sourced southern ranch calves into his feedyards are considered low-risk. “They’re not commingled. It’s a single source, and you’re bringing those in and we’re not commingling one, two, three, four, five, six, 20 different sources, and 20 different feed protocols before they were weaned, lack of feed, parasitology, everything. A southern ranch calf to us, that is single-sourced, is considered low risk.”

However, factors such as a hail storm or a hot bug going through the yard when those low-risk calves arrive can confound their health status. “We’re more concerned about them in those situations, but then again it depends on the dynamic of the feed yard,” VanEngen says. “Where did we pen them? Can we keep them separate? Are our pens full? Is this load going to, in a week, have to be penned with another load or can we fill a pen and be done?”

Putting together pens over several days is also not without risk. Goehl tries to set a limit of four or five days to put together a pen. “But sometimes management will make a decision on the buy to extend that, but as far as from a health standpoint, we set that limit that they need to put them together over four or five days and not go beyond that.”

Portillo adds that unfortunately, sometimes health is not the primary consideration because groups are being put together that will reach a more common finishing endpoint or make them more marketable up front. “Those cattle may come in from several sources, so we may or may not know what the dynamics are in each pen,” he explains. “We have to consider weight, frame size, and also breed type if we’re trying to build groups such that they’ll finish in a like time frame. A lot of times when these groups are put together, and we do have a pen with high morbidity and mortality, we find that it’s usually not the entire pen that’s high risk, per se, but many times there are usually subgroups within that pen that are responsible for the majority of the problems.”

Metaphylaxis programs

The term “metaphylaxis” has had some negative connotations in consumer press, and one of the problems has been that people define it differently. For example, one definition would be for a group of being entering a room who would all get a metaphylactic treatment if they thought they might get sick.

Another definition would be a group entering a room, a few or more get sick, and then everyone gets treated. The sick are treated, and those who aren’t sick are metaphylactically treated to circumvent illness. The disease does exist as evidenced by the individuals who became sick, and the number of sick individuals reached a trigger point to where it was prudent to treat everyone.

Preparing to make feedlot treatment decisions

Veterinarians and their producers also define metaphylaxis in slightly different ways. “When we refer to metaphylaxis, we’re talking about using antibiotics on cattle that we believe have a high propensity of having a high morbidity and mortality,” explains Dan Goehl. “’Mass treatment’ is probably how we refer to it more when we’re speaking to producers. They don’t really care if the term is metaphylactic, prophylactic, treatment or mass treatment. They just want to know if they need to treat all of the animals or not treat all the animals.”

Lindberg agrees. “For the most part, we use the phrase ‘mass treatment’,” he says. “There are probably a handful of times, you’ll use the term metaphylaxis depending on the setting, being more formal or something.”

Another critical point is that not all arrival cattle are treated metaphylactically, despite what some in the consumer press may say. Veterinarians and their producers use a variety of factors to etermine if metaphylaxis is needed. “If we have a history or even if we don’t have a history and we know the calves are salebarn-origin, have been commingled or are a long-haul, we’re probably oing to go toward a mass treatment selection,” Lindberg says. “Some weight plays into that, but at the same time, if you go solely on weight, it doesn’t help you make your decision because you can have three-weight Mexican cattle that you don’t need to mass treat.”

Does a large weight disparity within a group matter for metaphylactic decisions? Maybe. Portillo says it all depends on what the average is for the group. “If you’ve got a weight disparity and the en is averaging eight, we probably won’t treat metaphylactically, or at least look at it more critically, but if the pen is averaging five, definitely if we deem health to be an issue.”

“We deal with a lot of long-haul, lightweight cattle, and might use it just off the truck if we feel like the risk is high enough,” Goehl says. Determining the risk involves setting trigger points, and having some type of decision-tree process that is based on multiple factors depending on the yard, the cattle and other situations. “It might be if we reach a certain point of pulls, then we will mass treat calves, which in a true sense, isn’t at that point metaphylaxis, but it’s still a mass treatment early on.”

“Metaphylaxis decisions should be made even before the cattle hit the yard,” Portillo says. “That’s the nature of the term metaphylaxis. We don’t know what the calf looked like clinically, but based on history and source, we know what’s going to happen when they arrive. So, are there animals in the group that are going to get antibiotic therapy that may not be harboring BRD? Yes, but it’s a balance. Is it a welfare issue? To some degree, yes it is.”

McDonald doesn’t know if all of the definitions such as metaphylaxis, prevention, control, etc., are clear to producers yet. “We evaluate each group of cattle. You almost know what you’re going to do if someone says, ‘I have cattle on the road and they’re going to be here tonight,’ and when you start asking a few questions, you know whether they’re going to need antibiotics or not. You also have to decide which would be a bigger uproar to society, not treating these cattle and seeing them stand in the pen sick because you didn’t do anything, or using the antibiotics when they arrive?”

Preparing to make feedlot treatment decisions

VanEngen’s clients let him know up front when they are buying different types of cattle because they make some metaphylactic decisions based on weight. “The lighter the weight, the quicker we are to mass treat, but we look at the entire picture,” he says. For example, four-weights out of the West are less likely to get treated than four-weights out of the Southeast.

But, weight plays a big part, and as the weight moves up toward the 650-700-lb animals, VanEngen is more hesitant to mass treat those cattle. “Every load gets evaluated on its own merit,” he says. “We don’t have that standard protocol that says we’re going to mass treat, unless we’re in the middle of something bad happening.”

Source of calves plays a big part in the decision to use metaphylaxis. McDonald says calves with good health protocols behind them, whether they are weaned off grass or off the wheat, fall into a medium or low-risk. “We typically don’t mass medicate those,” he says.

Goehl says antibiotic use in general on the feedyard is going to continue to be an issue that may become dictated to the industry. But it goes back to if we had some way to objectively and not subjectively identify which animals need antibiotics and which ones don’t, we could be absolute in treatment decisions. But that’s not the world we live in today.”

This information is from a Bovine Veterinarian roundtable sponsored by Merial and moderated by Jessica Laurin, DVM. 


Trace minerals and nutrition
Some veterinarians say that while many producers are on board with calf vaccination and weaning programs, nutrition and trace minerals can be forgotten, which can lead to an immune system unable to fully respond when it needs to under times of challenge they may find at the feedyard.

“The calf programs out there don’t talk about nutrition or mineral programs,” says Nels Lindberg, DVM, Production Animal Consultation, Great Bend, Kan. “They all have vaccines, and what we’re supposed to do with vaccines, but none of them stipulate any sort of verification process for mineral or nutrition programs.”

Lindberg describes severe health events in calves that had a 45-day weaning period but were fed only free choice prairie hay and two pounds of corn per head per day. The well-meaning owner of these calves did a lot of things right, but forgot about his nutrition program. “They came in the yard starved to death, nutritionally challenged animals and resulted in a severe health event,” Lindberg says.

 Changing cattle, changing protocols?

Have cattle changed over the last 10 or 20 years, or has the way we raise, market, procure and manage cattle changed? It’s probably a combination of several factors.

“Cattle are worth more today,” says Nate McDonald, DVM. “They are $1000 coming into the feedyard. The old adage used to be that you could lose two calves and that would pay for the metaphylaxis program. Now you can’t lose one. And if you’re doing work for a custom yard, the quickest way to lose a customer, is have a high morbidity and mortality. We have probably increased the amount of metaphylactic drugs that we’re using on incoming cattle so we can reduce morbidity and mortality.”

Are we using more antibiotics now or are the cattle sicker? Are we getting less response to our drugs today than what we got five years ago? Those are questions McDonald asks.

“If we go back five years, I think our first case treatment responses are probably about the same. It comes down to how we buy and procure our cattle today versus 10 years ago. We’re seeing different types of cattle. The opportunity cattle are showing up more frequently for us and we have to handle them differently,” he says.

“It’s such a fine line you need to walk. And, you’re going to have people on both sides upset. It’s definitely an issue that’s going to come to the forefront.”