Farm Ireland
Independent.ie

Tuesday 24 April 2018

Measures to prevent calf pneumonia

THREAT: The long-term effects of virus pneumonia include poor growth rates and an increased time to first calving. Studies have shown
that calves that succomb to the disease can be at least 10kg lighter at weaning. Pneumonia is considered the primary disease to which calves are susceptible after weaning. Photo: O'Gorman Photography.
THREAT: The long-term effects of virus pneumonia include poor growth rates and an increased time to first calving. Studies have shown that calves that succomb to the disease can be at least 10kg lighter at weaning. Pneumonia is considered the primary disease to which calves are susceptible after weaning. Photo: O'Gorman Photography.

Charles Chavassse

Calf pneumonia, also known as Bovine Respiratory Disease (BRD), is a major concern when rearing calves, particularly when raising replacement heifers because of the high incidence and long-term effects of this disease.

These long-term effects include poor growth rates and an increased time to first calving. Pneumonia is considered the primary disease to which calves are susceptible after weaning.

Studies have shown that calves that have suffered from pneumonia can be at least 10kg lighter six weeks after weaning than calves that have remained healthy throughout the first two to three months of life.

The long-term effects of pneumonia in young calves, both pre-weaning and post-weaning, cannot be underestimated.

Work done in AFBI in Northern Ireland indicates that pneumonia at a young age can reduce first lactation yields by 4pc and second lactation yields by 8pc. This equates to a milk production loss of almost 1,000 litres over two lactations and, given current milk prices, amounts to a considerable sum of money.

Calves that suffer pneumonia relapses are even more greatly affected, with first and second lactation yields reduced by 5pc and 10pc respectively and growth rates falling by up to 10pc despite compensatory feeding.

Reduction of calf pneumonia

When tackling any health issue we must consider the disease triangle of Animal, Environment and Disease.

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Taking the calf first, as discussed above, ensure all calves get the '1, 2, 3' of colostrum management (See Page 9).

When considering the environment, fresh air and moisture control are key. Viruses and bacteria that cause pneumonia survive best in damp, stagnant air.

Our damp and humid climate in Ireland can make moisture levels in calf sheds a challenge but by ensuring good floor drainage, limiting spillages and leaks as well as providing clean dry bedding, moisture levels can be kept to a minimum.

Fresh air is the best way of reducing virus levels as fresh air kills them.

Make sure there is good air circulation at calf level but avoid draughts so calves do not waste energy trying to keep warm.

Proper precautions to combat this debilitating condition will save you money

The five main viruses that cause calf pneumonia in Ireland are:

1.Bovine Corona Virus

2.Bovine Respiratory Syncitial Virus (BRSV)

3.Parainflunza 3 (Pi3)

4.Bovine Viral Diarrhoea Virus (BVD)

5.Infectious bovine Rhiontracheitis (IBR)

Bovine Corona Virus is the most commonly diagnosed respiratory virus in young calves, according to laboratory reports from the Department of Agriculture. There is no evidence that the commonly used Corona scour vaccines have any effect in the prevention of Corona pneumonia. The only way to manage and prevent Corona virus pneumonia is through adequate ventilation and moisture management.

With the national BVD eradication programme well underway, BVD as a cause and contributor to calf pneumonia should hopefully be a thing of the past very soon. However, the adult herd should remain in a BVD vaccination programme until eradication is complete.

IBR in young calves is best prevented by considering the entire herd. Any animal that gets IBR is a carrier for life and is prone to shed the virus during periods of stress such as calving and during the transition cow period.

Vaccinating IBR carriers will help reduce the levels of IBR virus shedding within the herd, thereby reducing the levels of IBR spread to young susceptible animals and breaking the cycle of infection.

If there is an IBR problem diagnosed in your young calves, a live IBR vaccine should be used intranasally from two weeks of age, followed by an intramuscular booster at three months of age.

IBR vaccines work well, and vaccinating the main herd either on an annual basis with some of the inactivated IBR vaccines, or on a six-monthly basis with a live vaccine, is very effective in reducing the level of IBR within the herd, thereby protecting the young calves from exposure.

BRSV can be a serious challenge as it can cause serious respiratory disease in young calves, and can even kill them. There are a number of vaccines available to help prevent BRSV pneumonia.

Vaccines work in two ways: boosting the animal's immunity to the disease and also reducing the amount of virus produced from calves. When vaccinating for BRSV it is best to start the vaccine programme as young as possible, before the problem gets out of control. All calves in the herd should be vaccinated to prevent disease build up.

Pi3 is not as severe as BRSV but can allow serious bacterial pneumonia to develop. There are also a number of vaccines available to help prevent Pi3 and, as with BRSV, vaccinate as young as possible, treating all calves in the group.

When using vaccines make sure they are stored properly in advance of use, use correct dosage and check if the vaccine is a single dose administration or if a second dose is required for full protection.

There are many differences between available vaccines for young calves so make sure you follow individual manufacturers' instructions.

In summary, calf pneumonia has long-lasting and costly effects. Preventing pneumonia in young calves is possible but all aspects of management need to be considered.

If you are experiencing calf pneumonia issues in your herd, consult with your vet and get a full investigation carried out. Identifying the root cause of the problem can save a lot of money in both the short and long term.

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Irish Independent