5 September 1997

Plan ahead to avoid buying in diseases

Calf rearing hinges on buying-in healthy calves and minimising disease risk. In this special focus we look at the costs and likely returns for producers buying calves this autumn, how to keep them growing well, and the right techniques for castrating and disbudding. But first, Rebecca Austin finds out how to ensure calves are healthy

DISEASE risk from bought-in calves can be reduced by buying from a reputable source, preparing pens thoroughly, isolating any calves arriving on-farm with infection and discussing vaccinations with your vet

So says Brian Hosie, senior veterinary investigation officer with the Scottish Agricultural College.

"Bought-in calves already harbouring a navel infection should be returned to the seller immediately. A calf with a wet, swollen navel which is sore to touch is more than likely to develop joint ill. This, in turn, leads to chronic arthritis and poor performance in later life," he warns.

But many of the diseases associated with artificially-reared calves can be avoided by preparing for their arrival. "MAFF publishes a list of approved cleaning and disinfectant products against specific diseases, and this should be consulted," recommends Mr Hosie. And if a previous batch of calves developed ring worm, he suggests wooden partitions are properly disinfected – if not removed – before bringing new stock.

"Scours are the most common illness to which calves succumb in early life. Of these, salmonella is the most virulent and can easily infect stock handlers. To avoid the most extreme symptoms of septicaemia and death, infected animals should be isolated immediately," urges Mr Hosie.

This should be the natural course of action for any calf arriving on farm with a scour. At the first sign of scouring, producers should also take a sample to identify the source of infection. Salmonella, rotavirus and E coli are just a few of the numerous sources of infection, he warns.

"If you are buying calves from a specific source, check that they received adequate colostrum from birth. Depending on the individual system, I would recommend diluting the affected calfs milk for the first few feeds, along with individual nursing and close observation. Once the source of infection has been established, discuss with your vet the appropriate course of treatment."

Vets should also be consulted about specific vaccination programmes. "This should be done on a case-by-case basis, rather than a blanket recommendation, which can be expensive. Try to establish which viruses your unit is exposed to, as well as the cause of the problem," he explains.

"Some viruses strike some years and not others. But it is well known that dealers yards are more exposed to IBR, as compared to farms which only buy in calves occasionally."

Mr Hosie also highlights diseases carried by bought-in calves which do not manifest themselves until later life. "One of these is bovine viral diarrhoea – BVD. This does not show any symptoms until the animal is between six and 15 months old. It is, therefore, vital to buy stock from a reputable source," he advises. &#42

Many of the diseases associated with artificially reared calves can be avoided by preparing for their arrival, according to SAC vet Brian Hosie

Calves should be bright and alert, and bought in from a reputable source to avoid the risks of bringing disease on to the unit, advises Mr Hosie.

ACTION PLAN

&#8226 Buy from reputable source.

&#8226 Prepare pens and feed systems in advance.

&#8226 Consult vet for specific vaccination programmes.