If the conditions are suitable a pneumonia outbreak can occur in a herd at almost any time of the year. However, it is at housing that most farmers have a problem with it, according to Teagasc.
The most common respiratory diseases in housed cattle are the different forms of pneumonia. Pearse Kelly, Teagasc head of drystock, outlined why prevention is better than cure in a recent Teagasc winter update.
“Stress is the biggest pre-disposing factor involved. Where stock are stressed their immune system is weakened allowing the infection to take hold,” he said.
Animals can become very stressed at housing especially if they are mixed with cattle from different groups.
“The mixing of purchased cattle from different farms or different age groups in itself can lead to respiratory disease problems as the infection spreads to animals that might never have come across the infection and so have little or no immunity towards it.”
Kelly highlighted that animals do not have to be in the same pen to be considered mixed, only the same air space. With large slatted units on many farms now housing many different groups of cattle it can be next to near impossible to avoid this happening.
As pneumonia is an air-borne disease it will spread much more easily in confined spaces. Add to this poor ventilation and overcrowding and the problem is further compounded.
There must be adequate inlet and outlet ventilation to allow fresh air movements through cattle housing and adequate lying space, otherwise the first night with little or no wind outside could spell disaster.
The Teagasc head of drystock stressed that by far the best approach is to avoid a pneumonia outbreak in the first place – this means planning ahead.
“Management procedures such as castration, weaning and housing all cause a significant amount of stress.”
Kelly advises not to carry out all of these at the same time, but rather to space them out over a number of weeks.
“When weaning always take a proportion of the cows away from the calves each week until they are all gone. By doing this the calves are left in their familiar surroundings.
“By feeding meal to the calves the stress of weaning should be kept to a minimum,” he added.
- Check ventilation – is it adequate or will you need to improve it?
- Check lying space allowances – is there enough or do you need to reduce the numbers in pens;
- Watch out for hoose at this time of the year – a severe infection weakens the lungs and makes an animal more susceptible to pneumonia. All cattle should be treated for it shortly after housing;
- Try not to house cattle of different age groups close to each other;
- Keep bought in cattle separate to home bred cattle for as long as possible;
- Have young cattle used to eating meals and silage before housing;
- Ideally implement a pneumonia vaccination programme well in advance of housing (at least three weeks) to give time for the two shots to be given.
On a final note, Kelly highlighted that one of the best routes to preventing an outbreak of pneumonia is vaccinating. However, he warned that, once again, planning is needed for this, explaining:
“Most vaccination programmes involve giving a two-shot programme to stock when they are vaccinated for the first time.
“A small amount of immunity is generated by the first vaccination treatment but this will quickly wane and it is only after the second (booster) vaccination, given three to four weeks after the first (primary) vaccination, that the full degree of long-term immunity is built up to the disease.
After this, single booster vaccinations are usually recommended when vaccinating the same animals six to 12 months later, depending on the product used.
“Live intranasal vaccines are a one-shot programme that act within seven to nine days but only give protection for three months.
“To have full cover against the most common pneumonia virus’s cattle must therefore be started on the vaccination program well in advance of when they need it most.”