A knacker (/ˈnækər/), knackerman or knacker man, is a job title used for the centuries-old trade of persons responsible in a certain district for the removal and clearing of animal carcasses (dead, dying, injured) from private farms or public highways and rendering the collected carcasses into by-products such as fats, tallow (yellow grease), glue, gelatin, bone meal, bone char, sal ammoniac,[1] soap, bleach and animal feed. A knacker's yard or a knackery is different from a slaughterhouse or abattoir, where animals are slaughtered for human consumption. Since the Middle Ages, the age-old occupation of "knacker man" was frequently considered a disreputable occupation, and subsidiary to their occupation were often also commissioned by the courts as public executioners.[2] In most countries, knackery premises are government licensed and regulated by law.

"A Dead Horse on a Knacker's Cart", drawing by Thomas Rowlandson (1756–1827).
A group of dead pigs awaiting pickup by a local knackery, dumped at the edge of a farm site in Scotland; pig farmers in particular prefer the knackery truck not to come close to where live pigs are kept as this is a way that disease can be spread.
Smoke discharging from incinerators at Douglasbrae Knackery, Scotland. The business deals with the disposal of animal carcasses from all over the north-east of Scotland.

For instance, products rendered from the carcass of a horse have found multiple applications since ancient times. In the United States, the meat can be used to make food for pets, livestock, racing dogs, or zoo animals. Bones are ground up for bone meal fertiliser. Hides are made into leather or, along with joints and hooves, processed to make the by-product animal glue for the furniture and bookbinding trades (hence the idea of old horses sent to the glue factory).

In most countries, farmers and other animal establishments are also legally obliged according to local pollution and/or agricultural health laws, to account for the circumstances of any[livestock or animal death and their subsequent proper disposal—hence the use of a licensed knackery. This includes the proper disposal of stillborn animals, and the afterbirth from either live-born or stillborn. This ensures they do not enter the food chain for human consumption through unscrupulous practices or cause environmental pollution or contamination (biological hazard).


The oldest recorded use of the word "knacker" dates to 1812, meaning "one who slaughters old or sick horses" and in 1855 "to kill, castrate", and is believed to be the same word as the earlier knacker/nacker "harness-maker" from the 1570s, surviving in 18th century dialects.[3] The sense extension is perhaps because "knackers" provided farmers with general help in horse matters, including the disposal of dead horses. The word is of uncertain origin, perhaps from the Scandinavian word represented by Old Norse hnakkur saddle and related to hnakki "back of the neck", possibly relating to neck.[3]

Use of the termEdit

The term is in this literal sense in British English and Irish English, and gained some notoriety during the outbreak of mad cow disease (BSE) in the United Kingdom. The Slaughterhouses Act 1974, the Meat (Sterilisation and Staining) Regulations 1982, and the Food Safety Act 1990 all define a "knacker's yard" as "any premises used in connection with the business of slaughtering, skinning or cutting up animals whose flesh is not intended for human consumption".[4]

Knackery by-products are rendered under regulation into fats and meat and bone meal for incineration. Cattle hides may be recovered for leather production. The kinds of animal processing which can occur at knackeries are defined by law, for example, in Australia by the Commonwealth Meat Inspection Act 1983.[5] In the EU the legislation covering knackeries is the REGULATION (EC) No 1069/2009 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 21 October 2009 laying down health rules as regards animal by-products and derived products not intended for human consumption.[6] The trade of collecting and rendering is by its nature unpleasant and pungent. The trade and those who practice it were considered to be repellent in many societies, resulting in a social separation. This is so not only in Ireland or Britain, but also, for example, in Japan, where it is performed by burakumin. In the past this deterred people from entering the trade but in modern times knackeries have become profitable businesses.[citation needed]

Slang useEdit

"Knackered" meaning tired, exhausted or broken in British and Irish slang is commonly used in Australia, Ireland, Newfoundland, New Zealand, and the United Kingdom. In southern parts of Australia if something is rendered useless or broken by an inept person it is said to be 'knackered'. "Knackers" is also a British/Australasian vulgar slang for testes,[7] although this usage may be derived from nakers – small medieval kettle drums which were typically played in pairs suspended from a belt around the waist.

The term "knacker" is sometimes used in Ireland to denote an Irish Traveller. In 1960, senior politician James Dillon explained the term to the Irish parliament as denoting "the tough type of itinerant tinker".[8] The use of the word is considered pejorative and has been criticised by Traveller advocacy groups.[9][10][11] The term "knacker drinking" refers to the practice of consuming alcohol in the open, e.g. in a field or a park, or by a roadside or canal; typically cheap cider, beer or vodka from an off licence; "knacker drinking" is commonly done by teenagers or students.[12][13]

The British satirical magazine Private Eye often refers to senior police figures as "Inspector Knacker" or the police force in general as "Knacker of the Yard", a reference to Jack "Slipper of the Yard" Slipper.[14][15]

Automotive junkyards, salvage yards or recyclers may also be referred to as "knackers' yards" or "knackers".


  1. ^ Chemist, Practical (1844). "Animal Gas, or the Value of Dead Animals". The United States Practical Receipt Book: Or, Complete Book of Reference, for the Manufacturer, Tradesman, Agriculturist Or Housekeeper; Containing Many Thousand Valuable Receipts, in All the Useful and Domestic Arts. Philadelphia: Linsey & Blakiston. p. 320.
  2. ^ Evans, Richard (1998). Tales from the German Underworld: Crime and Punishment in the Nineteenth Century. New Haven and London: Yale University Press. p. 145. ISBN 9780300072242.
  3. ^ a b "Knacker". Online Etymology Dictionary. Retrieved 9 July 2018.
  4. ^ Food Act 1984, Government of the United Kingdom
  5. ^ "Meat Inspection Act 1983 (Cth)".
  6. ^ [1]
  7. ^ e.g. Thomas in The Virgin Soldiers
  8. ^ "Dáil Éireann – Volume 183 – 29 June, 1960". Dáil Éireann. 29 June 1960. Archived from the original on 5 October 2013. Retrieved 6 December 2011.
  9. ^ "I am a Traveller, not a 'knacker'".
  10. ^ Russell, Cliodhna. "The word knacker makes me feel nervous and ashamed".
  11. ^ Finn, Christina. "Taoiseach 'appalled' that comment referring to 'knacker children' not removed by Facebook".
  12. ^ "Boyzone hit in row over 'knacker drinking' -".
  13. ^ "Knacker Drinking -Main page-".
  14. ^ Thompson, Harry (24 November 2011). Biography Of Peter Cook. Hodder & Stoughton. ISBN 9781444717839 – via Google Books.
  15. ^ "Private Eye". Pressdram. 14 January 1983 – via Google Books.