Only a few brown spots of dried sheep's blood dotted around the collar of the white anti-contamination suit worn by Cpl Steve Milnthorpe give away his grim duty in the Army's effort against foot and mouth disease. Armed with a bolt gun rather than a rifle, the 36-year-old section commander from the Pioneer Regiment is part of a team charged with slaughtering up to 13,000 sheep a day. Nothing in 19 years of soldiering has prepared him for the experience.

"I have been to Northern Ireland and the Gulf, but I never thought I would have to deal with anything like this. It was a big shock to the system when we were shown how to slaughter an animal for the
first time. There were big guys, trained and hardened soldiers,
who were saying they didn't have the stomach for it."

When the Army was called in to support the Ministry of Agriculture's battle against the disease, Cpl Milnthorpe volunteered to be trained by a professional slaughterman and was sent to join in Operation Peninsula, the Army's name for the campaign in Cumbria. For seven days he has been working up to 12 hours a day amid the noise and acrid stench of a vast pit that will be a grave for half a million animals.

As he relaxes during a mid-morning break in a portable cabin on the site, a disused airfield at Great Orton, he has lost count of how many he has killed that day. "Once you have done your first cull, you begin to learn to switch off and get on with it. There's a job to be done and you just have to crack on. We have learnt to incorporate ourselves into the system. It is a case of crack on and get the job done." It is grisly work. The sheep - uninfected animals from fields bordering farms suffering outbreaks - are rendered senseless as the captive bolt stunner fires a steel bolt that penetrates their skull. A metal rod is then inserted into their spinal cord to break the nerves, a process known as "pithing". The task has been carried out with the military's customary precision.

Cpl Milnthorpe said: "I volunteered because I see it's a job that's got to be done. Everyone here is a volunteer. If they want to leave, they can go at any time. We haven't had any leave so far. It's nasty work but morale is good. Once we've finished for the day, we don't like to talk about what we've been doing. That's the time to sit down and relax, have a couple of beers and try to put it behind you."

For Major Neil Smith of the Royal Veterinary Corps, the true cost of the disease is to the farmers. Since early in the crisis, he has been involved in diagnosing cases and overseeing the slaughter of animals on infected farms. He said: "It is not nice seeing animals killed but it is done humanely. What is worse is the human tragedy." Their stoicism has impressed him. He said: "Obviously, they are extremely upset and distressed but we have never experienced them turning their anger against us. It is not something any of us feel comfortable with, walking onto a farm and then having to face the trauma of telling a farmer that his livestock is infected.

"We also have to cull the young lambs. They are injected with the same drug used to put down pet cats and dogs. We do up to 3,500 a day. It's terrible to see, but we understand it has to be done."

"It's an extremely efficient and effective operation we have going there. We are culling somewhere between 10,000 and 13,000 sheep a day. It seems a strange thing to be proud of, but it is very impressive. We've got a good team together."

Pointing to the command map, adorned with multi-coloured flags indicating infected and decontaminated farms, he said: "Our job is to turn every one of those red flags green. That's how we will know we have got this enemy on
the retreat."

Other soldiers spoke of the camaraderie among the teams combatting the disease. Staff Sgt Stan Norcross, of the Royal Logistics Corps, said:
"It is hard work but we are all pulling together. When you speak to the farmers, you begin to understand how terrible this crisis has been for them.
"One farmer told me how he had never heard the dawn chorus because he was so used to the sound of cattle when he got up for milking. Now his cattle have been slaughtered, all he can hear in the morning is the birds singing and the wind whistling through the trees."