Watch list of the Rare Breeds Survival Trust Watch list of the Rare Breeds Survival Trust The Watch list of the Rare Breeds Survival Trust is a listing of rare and native United Kingdom breeds of domestic cattle, sheep, pigs, horses, goats and poultry, compiled by the Rare Breeds Survival Trust. Mammalian farm breeds are classified into five levels of endangerment, based on the number of breeding females. The five classes are: Poultry – chickens, ducks, geese and turkeys – are not categorised by degree of numerical rarity; some are classified as "priority breeds". In 2017, the watch-listed cattle breeds were: The other native breeds listed were the
Animal trypanosomiasis some breeds of cattle, notably the N'Dama – a West African "Bos taurus" breed. This contrasts with the susceptibility shown by East African "Bos indicus" cattle such as the zebu. Most trypanosomes develop in tsetse flies (Glossina spp.), in its biological vector, about one to a few weeks. When an infected tsetse fly bites an animal, the parasites are transmitted through its saliva. It can also be spread by fomites such as surgical instruments, needles, syringes. The most important vectors are thought to be horseflies (Tabanidae) and stable flies (Stomoxys spp.). The immune response of animals could be unable to