From Birth to Weaning: Managing Calf Respiratory Health for Stronger, More Productive Herds

Calf health is the foundation of a productive and profitable herd, and respiratory health plays a crucial role in early development. 

The first few weeks of life are critical, as the lungs and immune system are still maturing, leaving calves highly vulnerable to respiratory disease. 

Respiratory illness not only affects short-term growth but can have long-lasting impacts on feed efficiency, weight gain, and overall productivity.

Many farmers experience the challenges of pneumonia and other respiratory conditions, which lead to increased labour, treatment costs, and in severe cases, mortality. However, small management decisions in the first weeks of life can significantly reduce the risk of disease, saving both time and money in the long run. 

By focusing on ventilation, colostrum management, stress reduction, and proactive health strategies, farmers can improve calf lung development and ensure a healthier, more productive herd.

The Impact of Poor Respiratory Health on Herd Productivity

Respiratory disease, particularly pneumonia, is one of the most common causes of ill thrift in young calves. Studies indicate that calves affected by pneumonia in early life may experience:

• Reduced weight gain and feed conversion efficiency, delaying weaning and reducing long-term growth rates

• Longer finishing times in beef systems, increasing rearing costs

• Lower first-lactation milk yields in dairy heifers, reducing return on investment

• Increased culling rates, as lung damage leads to poorer lifetime performance

Beyond the direct veterinary costs, respiratory disease places a heavy labour burden on farm teams, requiring more monitoring, treatment administration, and handling. The long-term impact of poor respiratory health makes prevention far more cost-effective than relying on treatment.

Key Risk Factors for Calf Respiratory Disease

To build an effective respiratory health strategy, it is essential to identify and control the key factors that contribute to disease outbreaks.

1. Ventilation and Air Quality

A well-ventilated environment is one of the most important factors in reducing the spread of airborne pathogens that cause pneumonia. Poor ventilation leads to:

• Ammonia build-up, which irritates the respiratory tract

• Increased humidity, allowing bacteria and viruses to survive longer

• High stocking densities, promoting disease spread between calves

Farmers should ensure calf housing has a steady supply of fresh air without causing drafts at calf level. Smoke bomb tests can be used to check airflow efficiency, and bedding should be kept dry and deep to minimise exposure to damp conditions.

2. Immunity Gaps and Colostrum Management

Calves are born with an immature immune system and rely on passive immunity from colostrum. Poor colostrum management can leave calves more vulnerable to infections, including respiratory disease.

To ensure optimal immunity:

• Calves must receive high-quality colostrum within the first six hours of life, as antibody absorption rapidly declines after this period

• Colostrum quality should be tested, and only colostrum with adequate immunoglobulin levels should be used

• Good hygiene practices should be followed when collecting and feeding colostrum, as bacterial contamination can increase disease risk

A strong immune foundation in the first few days significantly improves lung health and overall resilience against infections.

3. Housing and Group Management

How calves are grouped and housed has a major impact on respiratory health.

• Mixing calves from different age groups increases pathogen exposure, making younger calves more vulnerable

• Overcrowding leads to higher humidity and poor air quality, increasing respiratory stress

• Sudden changes in housing or mixing groups cause stress, weakening the immune system

A structured batch management system can reduce the risk of disease outbreaks. Keeping calves in consistent groups and limiting exposure to older animals helps prevent the introduction of respiratory pathogens.

4. Stress and Weather Challenges

Environmental stress weakens the immune system, making calves more susceptible to respiratory disease.

• Cold stress in young calves reduces energy reserves and immune function

• Heat stress increases breathing rates, making the respiratory tract more vulnerable to infection

• Transport stress, particularly when calves are moved early in life, can trigger pneumonia outbreaks

Providing adequate shelter, deep dry bedding, and consistent feeding routines helps reduce stress and supports stronger respiratory health.

Building a Proactive Respiratory Health Strategy

By focusing on prevention, farmers can reduce reliance on reactive treatments, save time on managing sick calves, and improve long-term productivity.

1. Maintain Good Ventilation Without Causing Drafts

• Ensure adequate air exchange in calf housing while preventing drafts at calf level

• Use deep, dry bedding to insulate calves from cold flooring

• Consider individual calf pens for high-risk animals to reduce disease spread

2. Strengthen Calf Immunity from Birth

• Ensure timely colostrum feeding with a focus on quality, quantity, and cleanliness

• Use a consistent milk feeding schedule to reduce nutritional stress

• Minimise calf handling and transport in the first two weeks to support immune stability

3. Manage Stocking Density and Hygiene

• Keep calf groups small and consistent to prevent disease spread

• Regularly clean and disinfect housing, feeding equipment, and water sources

• Provide plenty of space per calf to prevent overcrowding

4. Reduce Stress to Support Lung Development

• Ensure calves are protected from extreme weather conditions

• Keep feeding schedules and housing changes as consistent as possible

• Reduce transport and handling in the first few weeks of life

The Financial Benefits of Proactive Respiratory Health Management

Respiratory disease in calves leads to significant financial losses in both dairy and beef systems. By focusing on prevention rather than treatment, farmers can expect:

• Lower veterinary costs, with fewer cases requiring intervention

• Reduced labour demands, freeing up time for more productive tasks

• Improved growth rates, leading to faster finishing in beef systems

• Better first-lactation milk yields, increasing lifetime production in dairy systems

• Lower mortality and culling rates, ensuring better overall herd efficiency

Every case of pneumonia prevented saves farmers not only the direct treatment cost but also the hidden losses associated with slower growth and reduced productivity.

Poor respiratory health in calves is not just a short-term issue, it affects the long-term efficiency and profitability of the entire herd. 

While pneumonia and lung infections remain common challenges, a proactive approach can significantly reduce disease incidence and financial losses.

By optimising ventilation, strengthening colostrum management, managing stress, and maintaining proper stocking densities, farmers can raise healthier, more productive calves with fewer setbacks. 

Investing in preventative strategies today ensures stronger herd performance, better feed efficiency, and a more profitable future.