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Three key management phases to prevent respiratory disease

Matt Dodd for Progressive Dairy Published on 24 March 2022

It’s good to have goals. It gives you something to shoot for whether it’s in your personal life or as a dairy producer. On your dairy, there are a wide variety of goals you can strive to accomplish. Some may relate to basic protocols while others may center on performance.

One goal for your heifer program may be to have your calves grow efficiently enough to reach 85% of mature body size by the time they have their first calf. It’s an ambitious goal but certainly attainable. But it’s not one you can reach if your calves have respiratory problems.



Bovine respiratory disease (BRD) is still the number one cause of death in pre-weaned dairy calves. When it comes to preventing BRD in dairy calves, we need to focus on building immunity in the calf, reducing disease pressure from the environment and analyzing success in order to get better at prevention over time.

Phase 1: Prevention starts with colostrum

From a prevention standpoint, nutrition is still the most important area of focus when it comes to respiratory health, and it all starts with colostrum. 

The genesis of high-quality colostrum actually starts in the cow with proper nutrition and vaccination protocols. Colostrogenesis usually starts five to six weeks prior to calving, so it’s important to vaccinate before colostrogenesis happens so the cow has time to build antibodies that can be transferred to the colostrum and subsequently to the calf. Once the calf is born, deliver 4 liters of colostrum to it as soon as possible, followed by 2 liters each feeding for at least three feedings. As calves transition to regular milk, consider feeding second- and third-milking transition milk to continue to bathe the gut with immunoglobins to help protect the cells from pathogens.

Once calves are a few days old, start increasing the volume of milk at each feeding. Target feeding a gallon of milk at each feeding, and work to feed calves that level three times each day. The main point is to make sure you are getting enough nutrition into those calves, so they have the energy to grow at your goal rate and fight off disease pressures as they arise.

Phase 2: Feed for stronger immunity

As you’re establishing or re-evaluating feeding programs for your calves, remember that the right nutrition can help calves perform and also help build their immunity. Many milk additives are also available on the market to support not only faster growth but also immune function, so calves are better protected to fight off disease challenges. This includes use of a postbiotic that supports gut health and better immune support. The recently published International Scientific Association of Probiotics and Prebiotics consensus paper defines a postbiotic as “a preparation of inanimate microorganisms and/or their components that confers a health benefit on the host.”


A recent Iowa State University study fed calves, starting at 1 or 2 days old, milk replacer containing a postbiotic feed additive and top dressed on starter feed. On days 19 to 21 of the study, calves were challenged with bovine respiratory syncytial virus. Calves fed the milk replacer and starter with the postbiotic feed additive had reduced clinical signs related to respiratory health post-infection and lower lung pathology scores compared to control-fed calves that did not receive the supplement.

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It's important to establish and maintain a strong immune system. Research-proven feed additives like the ones offered in the Iowa State study are designed to help with inflammation and help calves deal with the stresses and challenges they face every day.

Vaccine protocols are very much a part of preventing viruses and helping calves navigate disease pressures, but they are not a magic bullet. Subjecting calves to poor nutrition or an unclean environment are the best ways to overwhelm even the best vaccination program. The goal is to achieve a balance between immune function and outside disease pressure. If calf immunity is high and the disease pressure in the population is below that, good health is the result. If the population disease pressure is above the immune function level, then we are losing the battle.

Phase 3: Create a clean environment

Even when colostrum and feeding protocols are strictly followed, efforts to improve calf immunity can be overwhelmed if the environment subjects calves to high pathogen loads. Start with creating a low-stress dry cow environment that reduces pathogen shedding. Provide ample space for cows to eat, drink and rest. When it comes to calving, create a clean, dry environment. Earlier we talked about the importance of colostrum in a newborn calf diet. The effectiveness of that colostrum, regardless of its quality, is significantly reduced if the calf is born in a dirty environment loaded with pathogens.

Once calves move out of the calving area, make sure they get transported to housing that has been disinfected to reduce pathogen load. Keep the housing area clean, dry and well ventilated to continue to keep pathogen loads at a manageable level. Ammonia in the housing environment can challenge lung function, so it’s important to keep air moving around the calf to keep it clean.


Also, make special considerations when seasons change. When we go from cold weather to warmer weather, or vice versa, the environment inside the facility changes. We need to adjust by changing ventilation to accommodate temperature and humidity changes.

Analyze your success 

Once protocols are in place and followed for managing the calf herd, collect data that tracks disease challenges, especially calf age and type of pathogen causing health issues. Understand areas of your calf management system where calves are under stress and thus allow pathogens to take hold. If scours hits your calves, identify the stress points that allow pathogens to overwhelm the calf. If respiratory issues are affecting your calves, look at what may be happening in the cow herd to get an idea of what is affecting your calves and heifers.

Regardless of the level of pathogen challenge in your calf-raising program, starting with your veterinarian to build an effective nutrition and immunology program is the best way to start. Also, consider asking your veterinarian to perform thoracic ultrasounds on your calves to better understand lung health and function. We’ve seen that conducting lung ultrasound analysis can pick up subclinical disease seven to 14 days prior to the onset of clinical disease. When done throughout the year, ultrasound results can pinpoint when your calves are at greatest risk, and you can adjust management accordingly.

Even if you identify pathogens that could be causing disease in your youngstock, it’s important to understand what brought you to the point where pathogens were overwhelming the system. Did you change feeding? Did you forget to put dry bedding down? Did the fans get turned off? Understand what factors may have led to increased pathogen exposure.

Calf health can be frustrating at times, work with your team to manage for success.  end mark

PHOTO: Mike Dixon.

References omitted but are available upon request. Click here to email an editor.

Matt Dodd
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