Many stocker calves heading into Missouri have been transported a long distance, are stressed, commingled, may or may not be weaned and can have little or no vaccination history. A week or two post-arrival those calves are prime candidates for bovine respiratory disease (BRD).
Dan Goehl, DVM, Canton Veterinary Clinic LLC, Canton, Mo., works with a lot of stocker operations that take in calves from a variety of sources and says history, management and evaluation of records is critical in order to get a handle on BRD. “Typically the calves we receive are not already exhibiting BRD,” Goehl explains. “Occasionally we will deal with ‘stale’ cattle that have been commingled over a period of time prior to shipment or have stood at an auction facility for an excessive amount of time and are predestined for problems. Usually we avoid this by working closely with our purchasing source, but it still happens periodically.”
Over 500 miles to the south, Matt Bell, DVM, MS, Stocker Health LLC, West Point, Miss., says due to the stress involved with procurement, transportation and weather, a small percentage of calves will exhibit clinical signs of respiratory disease on arrival to a stocker operation. “With high-challenge calves, if you start managing animal health at arrival you are already behind,” he says. Length of the buy, facilities/handling at the order buyer, size of the buyer network and placement strategies at the backgrounder are all factors that Bell says can positively or negatively affect animal health, especially at or shortly after arrival.
Particularly with southeast high-risk calves, Bell says parasites and poor nutrition are a major factor contributing to the animal’s susceptibility to respiratory disease. Other factors such as BVDV and coccidiosis can be confounders as well. “Any factor that makes a calf’s immune system less responsive to the viral and bacterial pathogens associated with BRD is of significant concern. Appropriate ionophore levels, effective de-worming strategies, and proper nutrition, especially trace mineral supplementation, are critical for success.”
Environment definitely plays a role in stocker BRD. “In Missouri we have just gone through two of the wettest springs on record,” Goehl says. “It is difficult to bring a newly-weaned, highly-stressed calf that has been shipped hundreds of miles after being commingled with cattle from multiple sources and keep him healthy, even in an ideal environment.”
Before they arrive
Goehl has both cow-calf and stocker clients and sees calves at both ends of the spectrum when it comes to pre-conditioning. “I definitely think there is a difference in calves that have been through a typical pre-conditioning program, weaned and on a high plane of nutrition versus those that are not. I coach my cow-calf clients to pre-condition and wean their calves. We feel like it is worth at a minimum $10 cwt. Often my clients purchase calves that have nothing done to them. They can buy them about $10 cwt back and add value to them. It really depends on the operation and what their business strategy is.” Goehl says this strategy can be influenced by labor constraints on a given operation and how much they can devote to monitoring and treating cattle.
Bell agrees that there can be advantages to those stocker operations that buy calves that have not been pre-conditioned — if they have the facilities, labor and know-how to manage them. “Pre-conditioned cattle, and even just steers versus bulls, will typically have improved health and performance; however, they are susceptible to the same problems associated with high-risk calves at times,” he says. “While it is easy to say that there is benefit to buying a better-managed calf, it is much harder to actually put a value to that benefit. It depends greatly on the buyer’s ability to manage high-risk cattle and will vary widely among operations. Discounted calves have the ability to upgrade for those operations that are able to take advantage of someone else’s mismanagement. Better-managed calves have less opportunity for upgrade, but should require fewer inputs in the starting phase.”
In Bell’s area, the vast majority of cattle are still marketed as trailer-weaned through local markets. “Producers can add additional value to their cattle through management practices such as castration, vaccination or complete pre-conditioning programs but only if they market cattle correctly,” he notes. “Many producers have been discouraged from improving management because their calves won’t bring more in the ring, especially the small groups. Not only does the buyer’s impression on expected performance and health influence price, but also the market dynamics that are occurring at the time of sale. A poor understanding of availability of weaned cattle, buyer demand, marketing strategies, and how these factors interact with the feeder market can cause the cow-calf producer to miss the windows of opportunity to capture the greatest value.”
The majority of calves that Bell’s clients deal with are high-challenge southeast sale barn calves that have never been fully vaccinated. Most of his operations perform complete processing at arrival including a processing antibiotic, 5-way modified live with Pasteurella, a clostridial (with tetanus on bull loads), a dewormer, branding, tagging and likely given an implant. Some operations will perform delayed castration after the cattle have “quit breaking”; however Bell says this strategy does not work as well for custom backgrounders in a 45- to 60-day program as “problem” lots delay castration date and thus postpone scheduled shipment.
Goehl’s clients buy pre-conditioned cattle as well as unweaned and unvaccinated calves. Often groups of calves are from multiple sources with multiple histories, making management of them difficult. “We default to the lowest level of management in the group,” he says. “That is if half of the cattle are vaccinated and half are not, we manage them as if none have ever been processed.”
Goehl notes that 99% of the calves are vaccinated on arrival at the stocker operation. “We typically use a lot of metaphylactic antibiotics as well. Producers who have not used antibiotics this way before need to adapt to a new epidemiology curve. The peak of the bell curve shifts to the right by 10 days or so and they will be pulling cattle later into the arrival period versus calves that do not receive those antibiotics.”
Stocker operations must be prepared when cattle step off the truck, says Bell. “This includes properly trained personnel, best utilization of existing facilities, appropriate animal handling, protocol compliance, and records, just to name a few.”
Depending on how calves are managed on arrival, Goehl says peak respiratory outbreaks occur in 7-14 days if antibiotics are not given on arrival. “When we use them this will be postponed by 10 days, give or take.” Bell adds that this summer he has also seen later breaks at around 25 days on feed.
Finding those in “the middle”
Identifying morbid calves is one of the great challenges of the industry, and Goehl says as a whole we are just not very good at it. “At times there is more art than science involved,” he explains. “If pen riders wait for outright signs of BRD — rapid breathing, foaming mouth, nasal discharge, outright lethargy — hese animals are often beyond successful treatment. The key is to pick out these animals at the earliest point of onset.” The issue is that it is difficult to identify an “off calf” in a pen of calves that is not bunk broke and unsettled due to not being weaned.
Bell agrees and says there are basically three populations that exist in a pen: the group that is obviously fine, the group that is obviously sick even to an untrained eye, and the most critical, those that fall somewhere in the middle. “We have to be able to train our producers to properly and timely identify sick animals in the middle group before they tip over into the obviously sick group,” he says. “The better we are at identifying the appropriate animals in the middle group, the better treatment response and overall outcomes we can expect.”
This is one of the areas where detailed record keeping helps. Goehl says it is useful to help real time to identify if a pen of cattle is having an issue that is being missed. It is also helpful to go back historically and look at morbidity, mortality, treatment failure, retreatment rates, days on feed at treatment, etc. “We have a database where we enter this information so that we can give it to managers in scheduled reports,” he says. “The yards send us daily or weekly numbers depending on the agreement and we can get information to them to help make management decisions. This sounds basic to some large feedlot operations but it is a huge step for many of these smaller facilities.”
On an individual calf basis, those that fall susceptible to BRD are definitely set back from their cohorts, and the greater the number of treatments, the more significant their economic disadvantage becomes with regard to gain, conversion, and of course medication cost, says Bell. There is also a “pen effect” that occurs with high pull rate and high death loss lots. “Due to the population stressors incurred from pathogen load, handling stress from pulls, and likely several other factors, many of these lots will not perform par to similar ‘non-problem’ lots,” he says. “Respiratory disease has the potential to create problems beyond the individual sick animal.”
Treating stocker calves
Goehl’s clients typically expect to treat 20–25% of the calves that arrive for BRD and have a mortality of 1–2%. He encourages necropsies of all respiratory deads, but due to distance, this is not always feasible for him. “We have tried to train the onsite employees to at least look at the lungs and determine chronicity if possible.”
This is another area of the operation that detailed record keeping helps out. “Historically, smaller stocker/starter yard facilities tend to not have high tech or detailed records,” Goehl says. “We try to provide the manager with a current list of tag numbers of calves treated, days on feed and treatment interval.” If calves were given a metaphylaxis treatment, there is a post treatment interval enforced. Goehl then has a set antibiotic for first pull and second pull. Within a given time period a calf that is retreated is deemed a retreat and after an extended period it is deemed a new event.
It is important to remain focused on being proactive to prevent BRD. “When problems occur, we must take the initiative to do an in-depth investigation of what factors may have contributed to the problem and take corrective measures if possible to prevent them in the future,” Bell says. “We typically do a poor job of managing a ‘wreck’ once it occurs and truly effecting measurable change in outcomes, so our best hope is to try to reduce probability of offside pens through knowledge generation and constant attempts toward optimizing health.”
Bell’s treatment protocols are dependent on what (if any) processing antibiotic is administered. “Treatment protocols should be based on sound data and evaluated over time for effectiveness. Many stockers/backgrounders have the tendency to change treatment protocols based on poor outcomes in a specific lot.” Bell tries to educate producers about response rates to antibiotics. “While we want high treatment response rates, it is an average; so we will have groups with a low response rate along with those that hopefully have excellent treatment response rates. It takes evaluation of these numbers over time to get a true impression on what success our treatments have to gauge the relative risk incurred by changing protocols.”
Goehl tries to place himself in a position where he can communicate with the stocker yards, “So when an issue comes to the forefront we are there to head it off or preferably prevent it from occurring at all.”
“As veterinarians, we have to be as involved with overall management at the backgrounder as we are with health management because they are so intertwined,” adds Bell.
What a 'wreck pen' can do
“Wreck pens” on a stocker operation often have a negative effect beyond the problem lot, says Matt Bell, DVM, MS. “Many times wreck pens can take the focus away from other pens and create problems due to lack of appropriate attention. They can also create fear of future wrecks that leads to overpulling and increased treatment cost in subsequent lots.”
Most stockers and custom backgrounders are also dependent on cattle placements either on a routine schedule for a custom backgrounder or seasonal for a grass-based stocker operation. “When wrecks occur one of our first responses is to slow or halt placements,” Bell says. However, the need to decrease the number of incoming cattle decreases available revenue from yardage for the custom backgrounder and may close opportunities in the buy for stocker operations and customers of backgrounding yards.
“The loss of procurement opportunities is a big factor that stockers tend to overlook when calculating the cost associated with respiratory disease.”