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Polled livestock (or pollards) are livestock of normally-horned species that are lacking horns, either naturally or as a result of humans removing them or preventing their growth.
Prevention of horn growth is most commonly done by disbudding – burning out the horn buds of a young animal under local anaesthetic before the horns have grown.
Some livestock are naturally polled due to a gene which suppresses horn development. These include many cattle breeds and some sheep breeds; in some other sheep breeds only the females are polled. Natural polling also occurs in goats, but development of wholly polled strains is not straightforward, because if two polled goats are mated the offspring are often infertile hermaphrodites.
Polled animals occasionally have scurs – small, loose horny growths in the skin where their horns would be. These may be a result of incomplete dehorning, but they also occur sometimes in naturally polled animals.
Polled livestock are preferred by many farmers for a variety of reasons, the foremost being that horns can pose a physical danger – to humans, other livestock and equipment. Horns may also interfere with equipment used with livestock (such as a cattle crush), or they may become damaged during handling.
In other circumstances horned animals may be preferred, for example to help the animal defend itself against predators, to allow the attachment of head yokes to draught oxen, to provide a hand-hold on smaller animals such as sheep, or for aesthetic reasons – for example in some breeds the retention of horns is required for showing.