Farming Diary by Kirsty Howson, farm animal veterinary surgeon, Yan Farm Health, Old Hutton:

THERE is nothing better than seeing the young stock outside and grazing during the summer months.

But managing calves, especially in their first grazing season, presents many challenges.

Firstly, the variations in the UK weather lead to inconsistent grass growth, making the provision of a suitably balanced diet throughout the grazing season tricky. It is essential this is monitored closely to maintain optimum growth rates, but many farmers do not have a weigh cell to allow accurate monitoring to take place. If animals are being handled, withers height can be used as a guide whilst in the handling pens - and good old body-condition scoring would also provide useful information.

In their first grazing season, calves are most susceptible to a number of internal parasites which they will not have been previously exposed to. A plan of how these will be managed should be discussed with your vet well before turnout as, in some cases, vaccinations or treatments before or at turnout may be recommended. Two of the most common causes of problems are mentioned below in a little more detail:

Coccidia parasitise the gut lining, leading to diarrhoea. It commonly occurs three to four weeks after a management change. Stock may have been infected whilst inside, as eggs build up in the environment over winter; or at turnout if infected animals were on the same pasture last year, as the eggs can overwinter. Different species of coccidia infect sheep and cattle. Therefore, rotating stock from one year to the next will help reduce infection pressure at grass.

Lungworm larvae can overwinter on pasture and in carrier cattle to propagate infection from year to year, which means cattle can pick up infection as soon as they are turned out in the spring. Ingested larvae migrate from the stomach to the lungs via the lymphatic system. The larvae mature to adults, causing damage to the lungs. They lay eggs in the trachea. These are then coughed up and swallowed, completing the lifecycle. Coughing is the main sign of lungworm and all coughing youngstock should be investigated promptly, as lung damage - no matter what the cause - will be production-limiting. You can submit faecal samples to your vets to help confirm the presence of lungworm. Although not always possible, rotating which fields your youngstock graze will reduce the infective burden on pasture.

Keep a close eye on stock over the next month, as this is commonly when clinical signs start to appear. Test them if you are suspicious and treat promptly to reduce the long-term effects of lungworm.