Pneumonia continues to lead to financial losses for farmers rearing dairy calves. But a better understanding of risk factors can improve control and help reduce reliance on antibiotics.
Vet John Yarwood from Nantwich Farm Vets, Cheshire, says: “Pneumonia is a disease of the lungs and is caused by interaction between the calf, its immunity, infectious bugs and the environment. “Cattle are particularly affected by pneumonia because they have relatively small lung capacity for their size and any disease damage causes problems.“Dairy calves are susceptible to pneumonia from a very young age and the disease is extremely common. In fact, you would be hard pressed to find any farm rearing dairy calves which has never had first-hand experience of this financially damaging disease.”
Financial losses include deaths, high veterinary, labour and treatment costs and, significantly, depressed subsequent growth and milking performance in animals which appear to have recovered from the disease.
Dairy cows only reach breakeven point halfway through their second lactation, but if they had pneumonia as a calf they may never pay back. When it comes to managing the pneumonia threat, the best form of defence is attack through good preparation and drawing up sound disease prevention protocols and, on many units, this means the implementation of a vaccination strategy.
Mr Yarwood says: “Disease prevention should be your aim to stop pneumonia gaining a foothold on your unit. This way you will rear more resilient, faster growing dairy calves and minimise antibiotic treatments.
“Reactive treatment is not ideal anyway for optimum disease control, because permanent lung damage may already have occurred by the time y o u notice a sick calf, and this certainly compromises growth performance.
“We know if a dairy heifer calf puts on 1kg/day instead of 0.5kg/ day, it will produce an extra 1000 litres of milk in a lifetime.” He adds that many factors combine to cause pneumonia problems, such as calf housing ventilation, stress, infection pressure and calf immunity, for example.
Mr Yarwood says: “Mixing different age groups can also cause problems, because older calves tend to be carriers of viruses or bacteria and pass these on to younger calves, so the tighter the age group the better. Consequently, thorough disinfection of shared feeding equipment is important.”
Young calves are certainly more susceptible in damp, humid conditions.
He says: “If it is cold and draughty, their immune system will be depressed, so you need to feed more to help them resist potential infections.
“An adequate intake of good quality colostrum is vital too for all calves, and you should also consider vaccination when animals are young to help boost their immune system.”
Mr Yarwood advises dairy calf rearers to work closely with their vet on a rigorous appraisal of all the potential pneumonia risk factors which may be involved on-farm.
He says: “Only once you have done this can you implement the optimum disease prevention plan for the future, which will certainly improve long-term animal health and potentially even reduce reliance on antibiotics to control this disease.”
Source: FGinsight
