Farm Ireland

Saturday 17 March 2018

IBR poses a deadly threat to herd health and farmer profits

This disease is caused by a virus from a family similar to the disease that causes cold sores in humans. IBR (Infectious bovine rhino-tracheitis) is not a zoonosis, so it cannot spread to humans.

But it can enter a dormant phase in cattle that fall foul of the disease. It is this dormant phase that allows the disease to survive from generation to generation.

Bulk milk sampling can give an indication of IBR's presence on your farm. However, it is more likely that your vet will have diagnosed the disease earlier via pneumonia or abortion outbreaks in the main herd.

The disease can cause anything from mild to severe and fatal virus pneumonia. It is often associated with runny eyes and heavy nasal discharge, and can cause crusty lesions to appear on the muzzle.

Your vet is best placed to advise you of the earliest signs of a problem as prevention and minimising the spread of the virus should be the main focus at all times.

IBR is not age specific and can spread among calves with devastating effect. It can also affect adult cattle during periods of stress.

The dormant nature of the virus in any previously exposed animal means the disease can wake during times of stress. Therefore, BVD, which lowers all immunity, can lead to significant problems with IBR.

Parasite problems or cattle movement stresses can also lead to IBR resurgence.

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Your veterinary health plan should include a vaccination programme that is tailor-made for your farm.

Key points

nA young heifer calf that survives an IBR attack can be a constant source of the virus for the rest of her life.

nIBR can cause abortion or even early embryonic death. It will increase the submission rates for insemination and put a severe dent in fertility figures within the herd.

nLosses to IBR will have an effect across the entire enterprise, and could include calf deaths from virus pneumonia; a drop in milk yields during an outbreak; abortions in the milking herd; increased submission rates and poor fertility results.

nIBR on a farm can exclude pedigree stock from sale for export.

nIBR is a virus. Therefore, antibiotics will not work against the disease. Vaccination and prevention remain the only available protection.

nPrevention attempts will greatly reduce exposure of heifer calves to the disease. This, in turn, will reduce the number of cows on the farm that are carrying dormant versions of the virus.

nReduce stress in the herd wherever possible. For example, keep BVD out.

nKeep parasites under control wherever possible.

nSee every bought-in animal on the farm as a potential source, and be sure to isolate and vaccinate.

nThe use of blood samples and nasal swabs during a flare-up of the disease will help your vet provide an accurate diagnosis, which can lead to timely and effective prevention programmes.

Indo Farming