Feedlot health: receiving, respiratory disease and bloat

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Source: University of Minnesota

Quick facts

  • Ideally, all calves entering a feedlot should be low risk and preconditioned.

  • Getting newly arrived animals to eat and preventing diarrhea will improve their health.

  • Reducing stress and preconditioning calves can prevent respiratory diseases.

  • To prevent bloat replace highly fermentable grains with other sources, manage processing or use feed additives.

Receiving

Shipping

Stress from moving makes cattle more prone to disease and respiratory problems. Mixing cattle also adds stress to the event because the group must create a social rank. Cattle from different sources are likely to carry different strains of pathogens. High stress levels and diverse pathogens can cause illness feeder calves.

Low-risk cattle

Low risk cattle include those that are:

  • Vaccinated

  • Weaned at least 30 days

  • Bunk broke

Preconditioned cattle have already faced all of the major changes that occur in a calf’s life. They are ready to start full feed and begin growing.

There are many preconditioning programs, but each have the following in common:

  • Deworming and delousing

  • Vaccinating with booster using a modified live vaccine

  • Weaning calves before shipping

These calves can generally hold a higher cash value than higher risk cattle. Feedyard managers know there will be a much lower disease rate in preconditioned calves. Lower disease rate means lower treatment costs. They also know that healthy calves are more likely to attain a higher carcass quality grade at closeout.

High-risk cattle

High-risk cattle are those that:

  • Have no vaccinations

  • Don’t know what feed is

  • Were weaned on the truck going to the sale barn

Stress from these factors weakens these calves’ immune systems. These calves will likely get sick no matter how careful feedyards handle them upon arrival. Buyers will likely pay less for these cattle than preconditioned cattle.

Antibiotics

Many add a feed-grade antibiotic to the ration when starting calves on feed. But calves must eat enough of the antibiotic for it to be helpful. Sick calves that would benefit the most from this likely aren’t eating.

Giving calves a long acting injectable antibiotic is more reliable and consistent than feeding antibiotics. There are many choices on the market and range in duration from three to eight days, maybe more.

Vaccinations

  • You should vaccinate all calves before they go to the feedyard.

  • Booster preconditioned cattle with a single dose of a modified live viral vaccine.

  • Give nonpreconditioned cattle:

    • Two doses of a modified live vaccine 2 weeks apart

    • A dose of a clostridial vaccine (7-way or 8-way, depending on geographical location)

  • Don’t work calves off the truck.

    • Allow calves the chance to settle in to the new area before handling them.

  • Perform all procedures on calves entering the feedlot 12 to 24 hours after arrival.

Deworming or delousing

Precondition programs may require deworming or delousing. But you should treat high-risk calves going into the feedlot with a dewormer upon arrival. Treating parasites will increase gains and efficiency and decrease stress during feedout.

Growth implants

Implants may be one of the most effective technologies used in the beef industry. The return on implant investment ranges from $4 to $10 per $1 invested. Through improved gains (about 0.25 pounds per head per day) and feed efficiency, implants may result in an added income of $30 to $50 per head. Increased carcass value of implanted animals can thus bring $67 per head over nonimplanted animals.

You may not want to use implants if you plan on keeping any replacement heifers. Although inconsistent, some studies show that implants affect later reproductive performance in replacement heifers. These effects depend on age, type of implant and nutritional status.

Several studies show implants in backgrounding operations doesn’t always hurt feedlot implant effectiveness.

Feeding

The goal of newly arrived cattle is getting them to eat. Stressed cattle will eat less and will tend to have greater incidence of diarrhea. Thus managing feed in the first two to four weeks after arrival is key in any feedlot or stocker cattle operation.

The following practices will reduce morbidity and mortality within the first hours of arrival.

  • Give animals access to good quality grass hay in the four hours after arrival.

    • Avoid feeding any grain or supplement.

  • Withhold water during the first 2 to 4 hours after arrival.

    • This will prevent overdrinking and help prevent diarrhea.

  • Provide clean water, clean bedding and enough bunk space (1 foot per head initially, then 9 inches per head after the cattle adapt).

Offer free choice grass hay during the first week to stimulate eating. After this, gradually increase grain amounts to reach 50 to 75 percent of the diet at 7 to 10 days after arrival. Corn and barley are common grain sources for feedlot cattle. Avoid energy sources that ferment rapidly such as high-moisture corn grain, steam flaked corn or wheat. Corn silage is a good option but you must include it as high as 40 to 50 percent of the diet for energy.

Include a vitamin and mineral supplement to prevent morbidity from nutrient deficiencies.

Respiratory disease

Respiratory disease causes great profit loss in the beef industry. It accounts for about 75 percent of all illness in feedlot cattle and 50 percent of feedlot deaths. These values reflect only the cattle caught sick.

Wittem et al’s 1996 feedlot study showed 38 percent of calves were pulled and treated for bovine respiratory disease (BRD). But at processing, 72 percent of the cattle studied had lung wounds in line with pneumonia. Thus, about 68 percent of untreated cattle went through a bout of respiratory disease unnoticed.

Effects of respiratory diseases

The cost of BRD goes beyond treatment and dead animal costs.

Average daily gain

Growth performance declines in cattle that develop BRD. Studies show the total loss in average daily gain (ADG) varies from 0.17 to 0.30 pounds per day. This results in a loss of 30 to 54 pounds over a 180-day feeding period. BRD’s effect on weight could mean the difference between a profit or loss.

Carcass quality

A 2002 Iowa Tri-County Steer Carcass Futurity study showed:

  • There was a 7.4 percent decline in the percent of cattle that graded choice after treated once for BRD.

  • There was a 12.3 percent decline in the percent of cattle that graded choice after two treatments compared to no treatments at all.

These results are very important with a large choice-select price spread. This usually occurs in the early summer months when fat cattle flood the market.

Preventing BRD

You need to vaccinate your cattle to effectively prevent respiratory disease in feedlot calves.

Another key to prevent BRD is reducing stress. Purchase properly preconditioned calves. One study shows preconditioned calves have up to a 16 percent decrease in feedlot morbidity related to BRD. Another study shows that preconditioned calves are about two times less likely to get Beef Cattle respiratory disease and are about five times less likely to need treatment.

Stress and BRD

Acidosis is a form of stress that feedlot cattle deal with and thus relates to BRD. If calves eat a ration that’s too hot, some may start coughing. You may also notice some depressed calves, which with fevers.

When treating a bunch of calves from one pen, you may need to back them off feed a bit until they start to turn around again.

If you are starting to treat a bunch of calves from one pen, it may be prudent for you to back that group of calves off feed a bit, until they start to turn around again. It’s important to decrease the stress the calves are facing. Sick calves won’t eat and healthier calves may eat their feed and push them to a more severe state of acidosis.

Pull cattle off feed for 12 to 24 hours and feed them decent quality, dry hay.

    • This will decrease or stop the stress of acidosis that the calves may be facing.

  • Check the temperatures of affected animals as well as a few random, seemingly healthy cattle.

    • In a “wreck,” most calves will have a temperature over 104 F.

  • Treat all of the cattle in the pen with a long acting antibiotic, if more than 20 to 30 percent of the cattle have a temperature over 104 F.

    • It may also help to give a dose of flunixin meglumine to calves with very high fevers. This will decrease their temperature and help them feel better.

    • Always follow label withdrawal times to ensure food safety.

Revaccinating

Revaccinating may not be helpful in some cases. If one pen is having problems with BRD, you may need to revaccinate calves in nearby pens. These calves are next in line for disease spread and will face a higher pathogen load through fence-line contact. But the goal of vaccinating is to mimic an immune response. Cattle currently fighting BRD are already at peak immune system response. Often, people credit revaccinating for stopping a BRD outbreak. But most calves were already well into recovery and the vaccine did little to help the calves.

Bloat

What is feedlot bloat?

Feedlot bloat is abnormal rumen function in which stable foam forms and impairs gas release from digestion. The effects of bloat range from minor reduced feed intake to sudden death.

Bloat results in economic loss through the following;

  • Cattle death
  • Reduced feed intake
  • Increased culling due to metabolic disorders
  • Increased treatment costs

Causes of bloat

Usually feedlot bloat relates to cattle eating  large amounts of grain. This is especially so with grains that ferment rapidly in the rumen such as wheat or barley. Aside from large amounts of grain, care and animal factors can contribute to bloat.

Microbes ferment grain when it enters the rumen which produces gas. Normally when the rumen contracts, it releases gases as the cattle belch. But bloat can occur if:

  • The microbes produce too much gas
  • There’s reduced rumen contractions
  • Something blocks the upper gastrointestinal tract

Rumen microbes control the thickness of rumen fluid by producing slime, which affects stable foam. Growth of certain microbes trigger slime production. These microbes are usually the ones that grow fastest under high-grain diets.

Types of feedlot bloat

Free-gas bloat

Free-gas bloat occurs quickly and is often lethal. Animals usually die suddenly from a block in the esophagus that doesn’t allow gas to escape. The block can be from undigested feed or partly chewed feed. Chronic pneumonia or hardware disease can also cause free-gas bloat.

To relieve free-gas bloat, you must remove the block or have a veterinarian perform a minor surgery. In surgery the veterinarian will create a small hole from the outside to the rumen to release gas.

Free-gas bloat doesn’t happen as often as frothy bloat.

Frothy bloat

Frothy bloat is most common and rarely leads to death. Animals with frothy bloat have a stable gas-liquid mix at the top of the rumen that traps feed and prevents gas release.

Pasture legumes such as alfalfa or clover cause stable foam to form and lead to bloat. Rumen microbes cause feedlot frothy bloat. While feedlot bloat can relate to acidosis from high grain diets and changes in intake, each disorder can occur independently from each other.

Preventing bloat

It’s hard to predict and understand the cause of bloat. While high grain diets contribute to bloat, reducing grain usually isn’t an option. Lower grain reduces animal performance. Good feed practices are the most common and cost-effective way to prevent feedlot bloat.

  • Replace highly fermentable grains such as wheat or barley for other sources such as corn in finishing rations.
  • Pay attention to the processing method.
    • Smaller particle size the higher chance for bloat.
    • Processing also affects how much starch breaks down in the rumen.
  • You can use feed additives such as ionophores and bloat preventives.
    • Ionophores such as monensin and salinomycin prevent bloat by inhibiting specific types of microbes or reducing feed intake.
    • Bloat preventives such as poloxalene are most commonly used in pasture bloat and are low-foam detergents that reduce foam stability in the rumen.

Bethany Fennel, former DVM University of Minnesota and Nicholas DiLorenzo, former graduate student, College of Agriculture, Food and Natural Resource Sciences

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