Hock burns
Hock burns are lesions found on the hock joint of chickens and other birds raised on broiler farms. They are considered a form of contact dermatitis.[1] These marks occur when the ammonia from the waste of other birds burns through the skin of the leg, leaving a brown ulcer mark.[2] The condition has been found to be a source of pain for birds, can cause mobility issues, and may increase the risk of bacterial diseases.[3][4][5] In severe cases, hock burn can cause visible scabs to form.[6]
Higher rates of hock burns are often used by observers as an indicator of what they see as worse animal welfare conditions.[5] This is in part due to how they occur more often in overcrowded conditions and in birds genetically modified to grow fast. Although the meat is still safe to eat, many processors now remove these marks as they discourage customers.[2]
Prevalence[edit]
The industry standard target is to have no more than 15% of a flock showing hock burns, but independent studies have found incidents of hock burn more common.[7] In 2024, self-reported data suggests a prevalence of around one third of farmed birds in the UK. Spot checks conducted by independent volunteers found higher rates of 74% for one store's supplier.[2]
Contributing factors[edit]
A number of factors are known to contribute to higher rates of hock burns. These include using fast growing birds, higher stocking densities, and high moisture levels in the litter where birds live.[8][9] Additionally, it has been found to be more common in male birds and more common in heavier birds.[10] Research suggests that many of the same factors also contribute to foot pad dermatitis, another similar disease. Hock burn and foot pad dermatitis often are found together in the same birds.[11]
History[edit]
Hock burns have been identified in birds in Northern Ireland since at least 1978. It appears to have been first described in scientific literature in a brief account in 1983.[12] From 1984 to 1987, hock burns were identified in 21% of birds.[13] In the decades since its first identification, it has stayed at an overall increased level.[14]
See also[edit]
References[edit]
- ^ Haslam, S.M.; Knowles, T.G.; Brown, S.N.; Wilkins, L.J.; Kestin, S.C.; Warriss, P.D.; Nicol, C.J. (19 Jun 2007). "Factors affecting the prevalence of foot pad dermatitis, hock burn and breast burn in broiler chicken". British Poultry Science. 48 (3): 264–275. doi:10.1080/00071660701371341. ISSN 0007-1668.
- ^ a b c "Millions of store chickens suffer burns from excrement". BBC News. 29 February 2024. Retrieved 1 March 2024.
- ^ Kaukonen, Eija; Norring, Marianna; Valros, Anna (2016-10-08). "Effect of litter quality on foot pad dermatitis, hock burns and breast blisters in broiler breeders during the production period". Avian Pathology. 45 (6): 667–673. doi:10.1080/03079457.2016.1197377. ISSN 0307-9457.
- ^ Jacob, FG; Baracho, MS; Nääs, IA; Lima, NSD; Salgado, DD; Souza, R (September 2016). "Risk of Incidence of Hock Burn and Pododermatitis in Broilers Reared under Commercial Conditions". Revista Brasileira de Ciência Avícola. 18 (3): 357–362. doi:10.1590/1806-9061-2015-0183. ISSN 1516-635X.
- ^ a b Kwon, Byung-Yeon; Park, Jina; Kim, Da-Hye; Lee, Kyung-Woo (2024-04-05). "Assessment of Welfare Problems in Broilers: Focus on Musculoskeletal Problems Associated with Their Rapid Growth". Animals. 14 (7): 1116. doi:10.3390/ani14071116. ISSN 2076-2615.
- ^ Kjaer, J.B.; Su, G.; Nielsen, B.L.; Sørensen, P. (1 August 2006). "Foot Pad Dermatitis and Hock Burn in Broiler Chickens and Degree of Inheritance". Poultry Science. 85 (8): 1342–1348. doi:10.1093/ps/85.8.1342. ISSN 0032-5791.
- ^ "Welfare plea over supermarket chickens". Manchester Evening News. 2005-07-25. Retrieved 2024-05-19.
- ^ Elson, H.A. (2015-09-01). "Poultry welfare in intensive and extensive production systems". World's Poultry Science Journal. 71 (3): 449–460. doi:10.1017/s0043933915002172. ISSN 0043-9339.
- ^ Tainika, Brian; Şekeroğlu, Ahmet; Akyol, Ahmet; Waithaka Ng’ang’a, Zacharia (2023-04-03). "Welfare issues in broiler chickens: overview". World's Poultry Science Journal. 79 (2): 285–329. doi:10.1080/00439339.2023.2175343. ISSN 0043-9339.
- ^ Shepherd, E.M.; Fairchild, B.D. (1 October 2010). "Footpad dermatitis in poultry". Poultry Science. 89 (10): 2043–2051. doi:10.3382/ps.2010-00770.
- ^ Elson, H.A. (2015-09-01). "Poultry welfare in intensive and extensive production systems". World's Poultry Science Journal. 71 (3): 449–460. doi:10.1017/s0043933915002172. ISSN 0043-9339.
- ^ Greene, Joan A.; McCracken, R.M.; Evans, R.T. (25 June 1984). "A contact dermatitis of broilers ‐clinical and pathological findings". Avian Pathology. 14 (1): 23–38. doi:10.1080/03079458508436205. ISSN 0307-9457.
- ^ Bruce, D.W.; McIlroy, S.G.; Goodall, E.A. (19 September 1989). "Epidemiology of a contact dermatitis of broilers". Avian Pathology. 19 (3): 523–537. doi:10.1080/03079459008418705. ISSN 0307-9457.
- ^ BESSEI, W. (1 September 2006). "Welfare of broilers: a review". World's Poultry Science Journal. 62 (03): 455. doi:10.1017/s0043933906001085. ISSN 0043-9339.