TO eight-year-old Jessica Cleminson, Caroline the cow was her pet. She loved her in the way that children in towns love their pet dogs, cats and rabbits.

During the summer, Jessica would take turns with her older sister Laura to ride on Caroline's back around the County Durham fields that her family has farmed for nearly 400 years.

On quiet evenings, the docile cow would stand for ages as the two girls took it in turns to stroke her and cradle her head in their arms. At 14 years old, Caroline the affectionate cow had been part of Jessica's world for all of her life, and when Caroline became pregnant again, Jessica wrote in the secret diary that she kept under her bed how thrilled she was at the news.

But on Friday, a vet from the Ministry of Agriculture arrived at New Hummerbeck Farm, in West Auckland, and told Jessica's parents that because a neighbouring farm had a confirmed outbreak of foot-and-mouth disease, their animals were now under investigation.

Jessica is too young to understand the true implications of the disease but she knew from the worried looks on her parents' faces that the vet had brought bad news. In her diary that night she wrote: "Dear Diary, Today I found out we're in category D and that is bad. That means I can't leave the house much and it isn't fair."

On a brighter note she added: "My favourite cow Caroline is having a calf or maybe twin calves."

But on Saturday, more men from the ministry arrived with the news Jessica dreaded - all the animals on the farm had to be slaughtered. And that included Caroline.

With tears dribbling down her cheeks and smudging the letters on her page, Jessica wrote her heartbroken entry on Saturday: "Dear Diary, We have foot-and-mouth. Caroline has to be . . . I can't even say it and she has to be . . . With her baby inside. Please Lord, how come you did this to us?"

The Maff vets allowed Jessica's father Stephen to arrange a special pass so that Jessica and Laura could leave the farm before the gruesome business of culling began. As she went to stay with her gran, Jessica left her diary hidden beneath her bed.

It was there that yesterday Mr Cleminson discovered the diary. When he read the most recent entries, he broke down in tears - just as his daughter had when she was writing them.

He said: "The cow was like a pet to them. The children would ride on its back. She would stand for ages with her head in your arms."

Mr Cleminson, who has a degree in theology, is now appealing to Tony Blair to look at restructuring the whole industry.

In an open letter to the Prime Minister - in which he also thanks the Army and Maff for the way they have handled the slaughter - he states: "The present administration has had a rocky ride with the farming community. We have seen our profitability eroded so severely that I have been losing money for three years.

"I firmly believe that after foot-and-mouth you must address the question of a major restructure of agriculture as never before. All we want to do is to make a living."

Mr Cleminson said he hoped that the devastating effects of foot-and-mouth would prompt everyone to look again at farming. He added: "It used to be an enjoyable way of life and it's not now. Just ask my daughters."

But last night, Jessica was too distraught after losing Caroline to say anything.