Regime beats pneumonia
Tackling a serious
pneumonia problem in cattle
depends on breaking the
disease cycle, as Jessica
Buss finds out
HIGH calf mortality on a Leics intensive beef unit has almost been eliminated through breaking the disease cycle using a calf shed built of straw bales, improving ventilation and vaccination.
Four and a half years ago, Kevin and Sarah Webb were losing about half the calves bought in from local farms through pneumonia. Growth rates were also suffering.
The Webbs rears 140-150 bull calves a year at Holly Tree Farm, Walton, Leics, and had been buying a few at a time from many units.
Mr Webb had tried buying in larger batches from a single farm, but that had failed to control the pneumonia problem.
Another option to help tackle the concern was a forced fan ventilation system with a polythene tube to improve ventilation in the old cow shed used to rear calves in individual pens.
"We thought it cleared pneumonia, but it was only psychological because we then had another outbreak. But I was advised to install the end of the fan too near older calves, so was blowing in bugs. We also opened up holes in the walls, but the bedding was still damp."
It was then Mr Webb asked cattle vet Peter Orpin of the Park Vet Group, Whetstone, on to the farm to help him sort out the problem. His vet treatment costs at that time were high and calves were still dying.
In addition, there were knock on effects on feed conversion ratio, meant calves were taking 13.5 months to finish rather than 12 months.
A smoke bomb showed that the tunnel blew bugs down onto calves, says Mr Orpin. "The fan reduced humidity, but didnt help remove bugs because it stopped air going out through the ridge vents above it."
He identified virus pneumonia – bovine viral diarrhoea (BVD), infectious bovine rhinotraceitis (IBR) and respiratory synctial virus (RSV) – as the main causes of disease in younger calves. This meant the disease cycle of older calves infecting younger ones had to be broken, explains Mr Orpin.
In view of high mortality, Mr Orpin advised Mr Webb to stop using the old cow shed for calf rearing. He suggested building a monopitch straw bale shed for 20 calves upwind of existing stock, so younger stock had fresher air, helping to limit disease spread.
Mr Webb built the shed using straw bales and four corner poles secured in the ground to hold up the sheeted roof.
"We made a timber frame, filled it with bales and made ventilation slats for the back. We reared calves in batches for six weeks then cleaned and disinfected it as best we could and rested it for 10 days before bringing in another batch. We put over 80 calves through it without any problems." A vaccination and disinfection policy was also started, explains Mr Orpin.
"Disinfection is more important than calf rearers think. Buckets are a particular concern, but an alternative is to have a different bucket for each calf."
Vaccination against RSV and IBR began when calves were two to five weeks old, before they moved to the main calf pens. "But only healthy calves are vaccinated: Vaccinating a sickly calf is throwing good money after bad."
Now the temporary straw housing has been replaced with a steel framed monopitch building on the same site. It is also used for sheep in winter.
Ventilation is helped by adjustable Yorkshire boarding. "Each section is fitted to a frame which swivels on a central pivot, allowing it to be completely opened. Its left open 90% of the time and is only shut in windy weather or to stop rain coming from that direction," says Mr Webb.
• Break disease cycle.
• Identify organisms responsible.
• Vaccinate healthy animals.