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The next step in BRD management

Tom Shelton Published on 27 April 2012

Dairy producers battle daily with the devastating performance and economic effects of bovine respiratory disease (BRD) in their herds. According to the National Animal Health Monitoring System (NAHMS), respiratory disease (commonly known as pneumonia) is the most important disease in calves older than 30 days.

It results in an average loss of $15 per calf per year. While the battle continues, dairy producers have made significant improvements in respiratory disease management.

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Following the 2007 NAHMS survey, we polled dairy producers from 23 states about respiratory calf care. The survey represented more than 775,000 calves from 174 operations.

The most notable improvements included nutrition, diagnostics, prevention and treatment. That said, the industry still has a ways to go when it comes to calf housing and its effect on calf behavior.

Next steps in calf nutrition
Survey results show producers have a better understanding about calf nutrition than they did in 2007. They realize calves need to be fed a higher plane of nutrition and fed more frequently.

Nutritionally, we have made great progress in recommended colostrum collection, storage, timing of delivery, quality and quantity. The next step is preparing the dam with proper nutrition and antigen protection in her colostrum to meet local pathogen challenges.

Depending on environmental conditions, a healthy, newborn calf needs fresh water, calf starter and adequate amounts of milk. Without ample nutrition and proper, stress-free housing, production becomes inefficient. Nutritional requirements previously considered accelerated are now the standard.

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A number of respiratory problems have been reduced in stressful situations merely by increasing the amount of milk fed to calves twice daily or, as recently suggested, feeding an identical fluid diet three times daily during critical time periods.

Advancements in diagnostic testing
Diagnostic testing has become less prevalent over time because necropsy lab results have not been timely enough to affect outcomes. New developments in diagnostics have brought about the expanded, timely diagnosis of specific disease pathogens in stressed calves.

A new collection technique, called guarded deep nasopharyngeal swabbing, involves sample collection from the tonsillar area of the pharynx. Samples are submitted to participating labs for viral and bacterial analysis by polymerase chain reaction (PCR), a copying process using genetic markers and standard bacterial cultures.

This new method is a minimally invasive way to find the associated pathogens earlier, allowing for diagnosis and treatment during the acute outbreak. The faster diagnostic reporting rate of this new method may encourage more producers to once again use increased diagnostics.

Although the industry has become more able to control known viruses and bacteria with diagnostic and treatment advances, new disease challenges emerge. Are the viruses and bacteria we are seeing only now diagnosable, or are new ones taking the place of previously controlled or displaced bugs? Asking questions like this will lead us to more productive and efficient protocols.

Understanding immune response
As we gain a better understanding of what causes respiratory disease, we can approach the problem from a more analytical angle. Understanding the calf’s immune system and its ability to react to subcutaneous or intramuscular injections at an early age helps us design better protective strategies.

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Combining this knowledge with advancements like localized, mucosal immune protection with intranasal vaccines helps us do what’s best for the calf. The induced immune response requires large energy expenditures and must be balanced with disease prevention requirements. The difference directly affects production efficiency.

New focus on housing, behavior and stockmanship
Historically, most calf facilities have been designed for human convenience. Recently, more attention has been devoted to the effect housing has on calf behavior.

As our understanding of behavior and neonatal bovine instincts improves, we are better able to meet the social and behavioral norms of calves. Focusing on better stockmanship for all classes of cattle can lead to better management of environments and social comfort levels, which often results in better performance.

Proactive treatment for better performance
The damage caused by localized infections in the lung is irreversible. Antimicrobial and vaccine studies show calves treated for respiratory disease do not perform as well as those that have not been treated. Differences can be as much as 2.5 pounds at 42 days old and 4 pounds at 60 days old.

If the lung is compromised at a young age, it becomes the limiting factor in genetic potential due to lung size and excess oxygen requirements. Individual treatment as soon as possible or, in some cases, metaphylactic or group treatment is the most proactive way to resolve the infection and inflammation caused by respiratory disease.

Approaching respiratory disease from all angles
Getting calves off to a healthy start is critical to their long-term health and productivity. Because several factors contribute to respiratory disease, it requires a range of solutions.

Traditionally, affected calves received limited attention due to the delayed contributions they make to cash flow. However, high replacement rates for lactating cows and the increasing demand for dairy beef have made production efficiencies more important than ever.

Respiratory disease management will continue to play a critical role in our ever-increasing quest to maximize genetic potential and increase efficiency. We have made incredible progress in the last few years. With new research and technologies developed every day, there is even more to look forward to in the future. PD

Preventing BRD in your herd

Tips for better respiratory health management:

• Feed 1 gallon of colostrum within two hours of birth and another gallon 12 to 15 hours later. Monitor colostrum quality and FPT using a hand-held refractometer.

• Have a backup plan for shortages of high-quality colostrum.

• Maintain average daily gain of 2.0 to 2.2 pounds for the first six months.

• Provide clean, warm drinking water and a small amount of calf starter beginning at 3 to 5 days old. Do not allow the calf starter to become stale or contaminated with debris.

• Wean calves when they eat 2 pounds of starter for three consecutive days and have reached growth targets for the liquid feeding stage of the calf’s life.

• House calves with clean, dry bedding and provide adequate shelter with good air quality and protection from heat and cold stress.

• Practice good husbandry skills. Understanding calves and what causes stress will enable a smoother transition to mixing pens.

• Work with your veterinarian to develop vaccination protocols and benchmarks for optimal calf health. Test for respiratory viruses and bacteria if benchmarks are not being met.

• Regularly train new and seasoned employees to effectively identify and treat respiratory disease.

Measurement recommendations apply to Holsteins and can be reduced for colored breeds. Check with your veterinarian for more details.

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Tom Shelton
Technical Services Manager
Merck Animal Health

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