The breeds of livestock on British farms are changing constantly. New breeds emerge, and foreign breeds are imported, while some native breeds lose popularity and become unfashionable and endangered. More than half the native breeds of livestock in Britain are rare and potentially threatened with extinction, yet they are an integral part of our history and heritage. Many of them are distinctively attractive animals, and some possess special characteristics that could be of significant value to the livestock industry. A return to more traditional values was seen towards the end of the twentieth century, and this will serve to enhance the value of native adapted breeds. Awareness of the importance of these breeds has been increasing, and the work of Rare Breeds International has had a global impact. Rare breeds are a living gene bank of biodiversity, and once a breed is extinct it can never be revived. About the author Lawrence Alderson is an international consultant on livestock breeding and production and on genetic conservation. He is a Trustee and Founder President of Rare Breeds International, and a Trustee of the Traditional Livestock Foundation in Britain.