Managing the risk of respiratory disease in calves

Respiratory tract infections account for almost 30%* of all calf deaths in Ireland. In very young calves (< 1month old) respiratory infections are the third most common cause of calf death* after scour and septicaemia. Over 1 month of age respiratory infections are by far the most common* cause of calf mortality.

Pneumonia can cause significant economic loss on a farm. Apart from the obvious loss associated with a dead animal, there are costs associated with loss of production and treatment. Cases that are not treated promptly can develop long term damage which permanently affects the lung function of that animal. 

Causes:

In young calves the main causes of respiratory disease are either viral or bacterial, or in most cases, a combination of both. The main viruses are RSV, IBR, Pi3, Coronavirus and BVD. The main bacterial causes are Pasteurella multocida, Mannheimia haemolyticaand, to a lesser extent, Haemophilus somnus.

In many cases viral infection reduces the natural bacterial defence mechanisms of the respiratory tract, facilitating bacterial infection which can be rapid and severe.

Risk Factors:

As with all calf illness, there are a number of mitigating factors which predispose young calves to the risk of pneumonia:

  • Dystocia
  • Inadequate or poor quality colostrum
  • Overcrowding
  • Poor ventilation
  • Shared airspace with older animals

Dystocia, or a difficult calving, can lead to a lack of oxygen in the calf and subsequent acidosis. This in turn affects the intake of colostrum, as well as reducing body temperature and the ability of the calf to withstand cold stress. All of this leaves a vulnerable calf at risk of respiratory disease.

Proper colostrum management is essential. Current recommendations state that a calf should receive three litres of milk within two hours of birth, from the first milking after calving (3-2-1)*. Giving three litres ensures that adequate antibodies are transferred if for any reason a cow’s colostrum is of poor quality. Passive transfer of antibodies to the calf within the first two hours is optimal.

The most recent data from regional veterinary laboratories shows that colostrum levels were inadequate in over 60% of submissions.  Samples came from carcases for post mortem, or blood samples submitted by vets from clinically-ill animals. In other words, almost two thirds of calf submissions in our regional veterinary laboratories indicate a failure of colostrum management. Good calf immunity is a vital first step in disease prevention. For screening purposes, blood samples can be taken from a number of calves and submitted for a Zinc Sulphate Turbidity (ZST) test to monitor on-farm colostrum management.

Overcrowding and/or poor ventilation is a significant factor in the development of respiratory disease in calves. In practice I find that this becomes more prevalent as the calving season progresses, when more calves tend to be sharing the same airspace. Poor ventilation and increased humidity predisposes calves of all ages to respiratory disease.

An ‘All in – All out’ policy for calf groups can help avoid an outbreak in these situations. Bedding should be changed regularly so that calves have a dry lie at all times. Airflow through the calf shed should be adequate to accommodate the number of calves in that space, with fresh air from outside entering at above-calf level and adequate space in the roof to create a ‘stack-effect’.

Prevention:

Understanding the factors that predispose calves to respiratory infection is important, but implementing them can present challenges.

In the post-quota era a lot of dairy farms are increasing cow numbers. This in turn is leading to increased numbers of young calves. As a vet I have seen improved fertility and conception rates in recent years, which means more calves in one space at one time. An appropriate vaccination programme, in conjunction with managing the risks listed above will help in controlling respiratory disease.

In the face of an outbreak however, diagnosis of the causative pathogens and therefore identifying the correct vaccination protocol can prove difficult. Samples take time to process, and maternal antibodies from the dam can complicate isolation of pathogens. That said, proper testing is a prudent step in helping prevention of future outbreaks.

Treatment:

When an animal presents with pneumonia, prompt treatment with a suitable antibiotic and anti-inflammatory will increase the chances of a positive outcome. Whilst a virus is often the primary cause of respiratory disease, it can cripple the natural defence mechanism of the respiratory tract and bacteria quickly invade the compromised lung tissue. It is these bacteria which cause the most severe damage to the lungs. If treatment is delayed or inadequate, bacterial colonisation of the lungs leads to long term damage which affects productivity in the short and long term.

In-contact animals should also be monitored, and in some cases metaphylactic treatment may be warranted. This means treatment of all animals in a group, and may be advised when a number of animals are showing clinical signs.

Effective management of a pneumonia outbreak depends on early diagnosis, followed by prompt and appropriate treatment.

References:

*AFBI/DAFM Veterinary Laboratories. All-island Animal Disease Surveillance Report 2013. Available at: http://www.afbini.gov.uk/all-island_animal_disease_surveillance_report_2013.pdf

Bimeda Launches Online Nutrition Academy

Bimeda is pleased to announce the launch of its online Nutrition Academy, which in 2021 will focus on the important role of trace element nutrition in the health, fertility and productivity of ruminants. Bimeda believes that the Academy will be of great interest to responsible persons in Ireland, as well as other animal health professionals. 

The Nutrition Academywill consist of three modules which will be launched during 2021. Those who successfully complete all three modules will receive certification from Bimeda, as well as some exclusive branded goodies.

The first module in the trio is titled Trace Elements in Dairy Cow Fertility & Pregnancy and is available now on Bimeda’s e-learning portal,   https://bimeda-learning.co.uk/ . This module also accounts for 1 hour 15 minutes of CPD and participants will be able to download a certificate following on from completion of the module. For SQPs in Northern Ireland, the module is also AMTRA accredited and has been allocated 9 CPD points.

In the coming months Bimeda will add a second module focused on the role of trace element nutrition in lamb and calf growth and thrive, and a final module focused on the role of trace elements in sheep fertility and pregnancy.

A Bimeda spokesperson commented, ‘trace elements play a critical role in the health and fertility of ruminants, yet historically this area has been somewhat overlooked in formal animal health education.

Our customers tell us that they would like a deeper understanding of areas such as trace element deficiencies, toxicities and interactions, and the impact of these on ruminant health and fertility. We are pleased to respond to this market demand with our new academy, which will provide veterinarians and other animal health professionals with additional knowledge to help inform their conversations with farmers.’

For any responsible persons, animal health professionals, veterinary surgeons, veterinary nurses or industry professionals who would like to sign up for Bimeda’s online Nutrition Academy (or any of Bimeda’s online CPD modules) visit the below website today.

https://bimeda-learning.co.uk/

For further queries, speak to your Bimeda sales representative.

YMCP Vitall® launch in Ireland

Following the success of YMCP Vitall®in many markets around the world, including the USA, the Netherlands, Germany, Belgium Denmark, Italy and others, YMCP Vitall was launched in Ireland for the 2021 calving season and has been well received by many farmers.

YMCP Vitall is the complete fresh cow bolus, with multiple nutrients to support the cow as she transitions into lactation. It contains live yeast, magnesium, calcium, and potassium, as well as other nutrients, to support the fresh cow in this stressful and critical time. The nutrient demands of the cow post-calving are large. 

There is the increased demand for calcium, a requirement for potassium and other electrolytes, and also the requirement to start consuming feed as quickly as possible. Live yeast has been shown to improve rumen function and is very beneficial to the freshly calved cow.

Calcium is often thought of as the primary nutrient requirement post-calving to prevent clinical and subclinical hypocalcemia. While it is important and required, recent research has shown that supplementing with calcium alone does not have any impact on dry matter intake (DMI). In fact, it has shown to depress DMI further. With a reduced DMI, milk production has also shown to be negatively affected.

So, this poses the question, if it’s not calcium, what can you supplement with to increase DMI and milk production, while reducing the risk of metabolic disorders in the period post-calving?

This question was addressed by recent research in Iowa State University in the US. They supplemented with YMCP Vitall, a multi-nutrient bolus, to assess the effects on metabolic disorders, DMI and milk production. Not only was the calcium level sufficient to reduce the risk of hypocalcemia, the additional nutrients in the bolus supported an increase in DMI and milk yield.

The experience and results in Ireland, so-far, have been extremely positive. It is now being used by many farmers across the country. Cathal and Brendan Phelan (Galmoy, Co. Kilkenny) now use the product as part of their fresh cow protocol, given the results they have seen since using it. Not only did they see the cows begin lactation with less issues, following milk recording, they saw a big improvement in milk solids compared to cows who were supplemented with a calcium-only bolus.

Please contact Michael Reid of TechMix ([email protected]/ +353 86 027 7905) for more information.