Hereford cattle

in Derby in 1843 Until the 18th century, the cattle of Herefordshire resembled other cattle of southern England, being wholly red with a white switch, similar to the modern North Devon and Sussex breeds. In the late 18th and early 19th centuries, other cattle (mainly Shorthorns) were used to create a new type of draught and beef cattle which at first varied in colour, with herds ranging from yellow to grey and light brown, and with varying amounts of white. By the end of the 18th century, the white face characteristic of the modern breed was well established, as was the modern colour during the 19th century. The Hereford is still seen in the Herefordshire countryside today and featured strongly at agricultural shows. The first imports of Herefords to the United States were made about 1817 by the politician Henry Clay, with larger importation beginning in the 1840s. == Polled Hereford ==

The Polled Hereford is an American hornless variant of Hereford with a polled gene, a natural genetic mutation selected into a separate breed from 1889. Iowa cattle rancher Warren Gammon capitalised on the idea of breeding Polled Herefords and started the registry with 11 naturally polled cattle. The American Polled Hereford Association (APHA) was formed in 1910. The American Polled Hereford and American Hereford breeds have been combined since 1995 under the same American Hereford Association name. In Australia, the breed is known as the Poll Hereford. ==Traditional Hereford==

Many strains of Hereford have used other cattle breeds to import desired characteristics, which has led to changes in the breed as a whole. However, some strains have been kept separate and retained characteristics of the earlier breed, such as hardiness and thriftiness. The Traditional Hereford is now treated as a minority breed of value for genetic conservation. ==Health==

Eye cancer (ocular squamous cell carcinoma) occurs in Herefords, notably in countries with continued bright sunlight and among those that prefer traits of low levels of red pigmentation round the eye. Studies of eye cancer in Hereford cattle in the US and Canada showed lid and corneoscleral pigment to be heritable and likely to decrease the risk of cancer. Vaginal prolapse is considered a heritable problem, but may also be influenced by nutrition. Another problem is exposed skin on the udder being of light pigmentation and so vulnerable to sunburn. Dwarfism is known to occur in Hereford cattle, caused by an autosomal recessive gene. Equal occurrence in heifers and bulls means that dwarfism is not considered a sex-linked characteristic. ==See also==