One of the country's oldest native cattle breeds survived because of the lifelong support of Diana Birkbeck, who has died suddenly aged 78 on the family's Norfolk estate.

The British White breed, which was in grave danger of extinction as it had become extremely unfashionable by the 1970s, has enjoyed a major revival in fortunes and is no longer officially designated 'rare'.

She kept the family's Hevingham pedigree herd of 'polled' or hornless cattle at Rippon Hall as did the Cator family at Woodbastwick, which can trace the cattle's origins to before 1840.

It was fitting that Miss Birkbeck, who ran the farm after the death of her father Christopher, became the long-serving president of the British White Cattle Society. She succeeded the late John Cator, who kept a milking herd of the dual-purpose breed until 1962.

The Birkbeck's Hevingham cattle were one of five founders of the British White Cattle Society's Herd Book in 1918 when there were just 16 bulls and 115 pedigree females.

She was determined to promote this tough and distinctive breed, with its black tips to ears and feet. When classes were re-introduced after many years at the Royal Norfolk Show, she was always at ringside in her wheelchair. As the breed's numbers increased, she and farm manager Stephen Howard supported shows further afield and won breed championships at the Royal Show, notably in 2000, and also at the East of England Show at Peterborough.

Her older sister, Caroline Holmes, who died last March, shared her enthusiasm at ringside as husband Peter occasionally led a British White calf at Costessey – much to Diana's amusement.

She bred thoroughbred horses and also kept some in training. She was passionate about her donkeys, and also maintained the tradition of opening for the National Gardens' Scheme, which had started in 1939 – the year after the family moved to Rippon Hall.

When she reluctantly ceased public openings after 34 years, Miss Birkbeck was officially recognised by the NGS.

Henry Cator, chairman of the British White Cattle Society, said that she had been 'a wonderful supporter of the breed. Without her contribution, the breed would have been a shadow if at all'.

Hevingham cattle were found around the world, notably in the United States and had been exported to Brazil in the 1950s.

'Her cattle, without doubt, are some of the finest in the world. She made a tremendous contribution to the well-being of the breed throughout the world,' said Mr Cator, who is also chairman of the Royal Agricultural Society of England and runs the Salhouse herd of British Whites.

Although she was confined to her wheelchair after a hunting accident more than 50 years ago, she never complained.

'She had the most wonderful sense of humour and always had a fund of stories. She was a very brave and courageous lady,' he added.

She is survived by her eldest sister, Jenny Shaw, and leaves a niece, Amanda and nephew, Simon. A service of thanksgiving will be held at St Mary the Virgin and St Botolph Church, Hevingham, on Monday, February 27 at 2.30pm.

Michael Pollitt