sheepdog – but also see separate entry for this. Lug mark – local term in Cumbria for earmark. Marking knife – a knife with a clamp or hook made for lamb marking. Myiasis – see fly strike. Micron – one millionth of a metre, a measure of fibre diameter of wool in wool measurement. Term used in preference to "micrometre", the SI name for the same unit. Mob – a group or cohort of sheep of the same breed that have run together under similar environmental conditions since the previous shearing (in Australian Wool Classing). Monorchid – a male mammal with only one descended testicle, the other being retained internally. Monorchid sheep are less fertile than full rams, but have leaner meat than wethers. Mule – a type of cross-bred sheep, both hardy and suitable for meat (especially in northern England). Usually bred from a Bluefaced Leicester ram on hardy mountain ewes such as Swaledales. May be qualified according to the female parent: for example a Welsh Mule is from a Blue-faced Leicester ram and a Welsh Mountain ewe. Mulesing – a practice in Australia of cutting off wrinkles from the crutch area of Merinos, to prevent fly strike. Controversial, and illegal in some parts of the world. Named after a Mr Mules. Mustering – the round up of livestock for inspection or other purposes. Mutton – the meat of an older ewe or wether. May also refer to goat meat in eastern countries. Derived from the Anglo-Norman French word mouton ("sheep"). NSM – not station mated. A term used in sale advertisements indicating that those ewes have not been mated. O, P, R Off shears – sheep have been recently shorn. Old-season lamb – a lamb a year old or more. Also hogget, shearling, teg. Orf, scabby mouth or contagious ecthyma – a highly contagious viral disease of sheep (and goats) attacking damaged skin areas around the mouth and causing sores, usually affecting lambs in their first year of life. Plain bodied – a sheep that has relatively few body wrinkles. Poddy lamb, bottle lamb or pet lamb – an orphan lamb reared on a bottle. Also cade lamb, or placer. Pour-on – see backliner. Raddle – coloured pigment used to mark sheep for various reasons, such as to show ownership, or to show which lambs belong to which ewe. May be strapped to the chest of a ram,