Jeff Lehmkuhler, PhD, PAS, Extension Professor, University of Kentucky
This is the time of year when calves are starting to come to market. Backgrounders and fall stocker programs are buying lightweight feeders for their operations. Some operations in consultation with their veterinarians may obtained a veterinary feed directive (VFD) for medicated feed to help in the prevention or treatment of bovine respiratory disease (BRD). Medicated feeds are a tool in the toolbox and managers should familiarize themselves with the use of such tools.
A common feed medication is chlortetracycline (CTC). This feed grade antibiotic can be used for a variety of disorders. The feed additive is labeled for use for the control of anaplasmosis, reduction of liver abscesses, control of bacterial pneumonia associated with shipping fever (i.e. BRD) and treatment of bacterial enteritis caused by E. coli. Would it surprise you to learn then that there are different target doses for the control or treatment of these disorders?
For the control of bacterial pneumonia in feeder calves, the approved label dose is 350 mg/hd/d. “Control” is essentially the dose to help calves to avoid serious infection whereas “treatment” is the dose to treat active infections in sick calves. The approved treatment dose for feeder calves is 10 mg/lb of body weight. If a 500-pound calf were to be treated for bacterial pneumonia with chlortetracycline, the total CTC dose would be 5,000 mg/d which is 14-fold higher than the control level. This is why it is important to consult with your veterinarian about incorporating medications into your feed. Feed manufacturers will include key information on the feed tag of medicated feeds. The active ingredient or medication level will be listed near the top. This is essential in calculating the amount to feed to achieve the desired dosage. Additionally, the instructions will provide information on feeding recommendations and rates.
Many of you have probably fed or heard about bloat prevention blocks. These blocks contain poloxalene which aids in breaking frothy foam formation in the rumen when cattle are grazing fresh legumes. To be effective in the prevention of bloat, cattle must consume the appropriate dose daily. Well, how do you know the appropriate dose? By reading the feeding instructions on the label for a certain block product, it says that cattle must consume 0.8 ounces per 100 lb of body weight. For a 1,400-pound beef cow, she would need to consume 11 ounces or 0.7 pounds a day. Additionally, feeding recommendations on the product label states provide 1 block for every 5 head. If the group has 30 cows, then you should provide 6 blocks at a time. Why? Cattle are going to come to the blocks as a herd and the boss animals are going to get their share. The dominant cows will prevent the other animals from consuming the blocks they are licking. Having several blocks available will provide more timid cows the opportunity to consume their daily dose to prevent bloat.
Protein tubs are popular supplements. Not all protein tubs are made the same. Some may be medicated, some may have additional fat, a few are made for stress and some are made from coproduct feeds rather than molasses. Other differences can be whether salt is part of the mixture of ingredients. Tubs that do not contain salt will often have on the feeding directions to offer free-choice salt in addition to the tub. Not providing salt when the label recommends to do so could result in challenges with target intakes.
When you are getting ready to supplement your cattle, take the time to read the feed tag. Pay attention to the feeding instructions. If you are considering a medicated feed, discuss your options and goals with your veterinarian and obtain a VFD if needed. There are many feed additives that are additional tools for us in maintaining animal health and performance. Learn how to effectively use these tools to get the most out of them.