Cobb 500
{{Short description|Breed of fast-growing chicken}}
The Cobb 500 is a fast-growing broiler chicken breed. They can reach a 2 kg slaughter weight at 33 days old.{{Cite news |last=Vidal |first=John |date=2018-12-27 |title='It's God's plan': the man who dreams of bringing intensive chicken farming to Africa |url=https://www.theguardian.com/environment/2018/dec/27/its-gods-plan-the-man-who-dreams-of-bringing-intensive-chicken-farming-to-africa |access-date=2024-06-23 |work=The Guardian |language=en-GB |issn=0261-3077}}{{Cite report |url=https://www.cobbgenetics.com/assets/Cobb-Files/2022-Cobb500-Broiler-Performance-Nutrition-Supplement.pdf |title=Cobb500 Broiler Performance & Nutrition Supplement (2022) |date=2022 |publisher=Cobb-Vantress}} They make up around half of all globally farmed chickens as of 2016.{{Cite web |last=Torrella |first=Kenny |date=2023-02-10 |title=How a shipping error more than a century ago launched the $30 billion chicken industry |url=https://www.vox.com/future-perfect/2023/2/10/23589333/cecile-steele-chicken-meat-poultry-eggs-delaware |access-date=2024-06-23 |website=Vox |language=en-US}} The Cobb 500 is controversial due to their health problems. Animal rights and animal welfare groups such as Open Cages have called for the industry to stop their use.{{Cite news |last=Ungoed-Thomas |first=Jon |date=2022-04-16 |title='Frankenchicken' at the centre of fight for animal welfare |url=https://www.theguardian.com/world/2022/apr/16/cheaper-than-chips-frankenchicken-at-the-centre-of-fight-for-animal-welfare |access-date=2024-06-23 |work=The Observer |language=en-GB |issn=0029-7712}}{{Cite news |last=Gunther |first=Marc |date=August 9, 2018 |title=Former Tyson Foods CEO Brings Chicken Farming To Rwanda — But Can It Last? |url=https://www.npr.org/sections/thesalt/2018/08/09/634351544/former-tyson-foods-ceo-brings-chicken-farming-to-rwanda-but-can-it-last |work=NPR}}
History
The Cobb linage descends from the Vantress chicken, which was bred for the USDA's Chicken of Tomorrow contest in the 1940s.{{Cite news |last=Mock |first=Sarah |date=2020-08-17 |title=From farm to factory: the unstoppable rise of American chicken |url=https://www.theguardian.com/environment/2020/aug/17/from-farm-to-factory-the-unstoppable-rise-of-american-chicken |access-date=2024-06-23 |work=The Guardian |language=en-GB |issn=0261-3077}} The Cobb line itself saw its initial development in the 1970s in England by Cobb-Vantress.{{Cite journal |last1=Wegner |first1=Marcin |last2=Kokoszyński |first2=Dariusz |last3=Żochowska-Kujawska |first3=Joanna |last4=Kotowicz |first4=Marek |date=2023-09-21 |title=Effect of Genotype and Sex on Chemical Composition, Physicochemical Properties, Texture and Microstructure of Spent Broiler Breeder Meat |journal=Agriculture |language=en |volume=13 |issue=9 |pages=1848 |doi=10.3390/agriculture13091848 |doi-access=free |issn=2077-0472}} The Cobb 500 in particular was introduced into the United States in 1985. In response, the US producer Tyson Foods acquired a 50% stake in Cobb-Vantress in 1986.{{Cite journal |last=Bugos |first=Glenn E. |date=1992 |title=Intellectual Property Protection in the American Chicken–Breeding Industry |url=https://www.cambridge.org/core/product/identifier/S0007680500060189/type/journal_article |journal=Business History Review |language=en |volume=66 |issue=1 |pages=127–168 |doi=10.2307/3117055 |jstor=3117055 |issn=0007-6805|url-access=subscription }} In 1994, Tyson acquired full control of the company.{{Cite report |url=http://www.ers.usda.gov/publications/pub-details?pubid=41010 |title=Vertical Coordination in the Pork and Broiler Industries: Implications for Pork and Chicken Products |last=Martinez |first=Stephen |date=April 1999 |publisher=U.S. Department of Agriculture |issue=777}} The Cobb 500's share of all chickens has increased in the decades since.
In 2008, all Cobb line birds made up around 30-40% of global broilers.{{Cite web |date=2008-01-09 |title=Cobb-Vantress set to buy unit of rival {{!}} Arkansas Democrat Gazette |url=https://www.arkansasonline.com/news/2008/jan/09/cobb-vantress-set-buy-unit-rival-20080109/#:~:text=Cobb-Vantress%20is%20the%20second,10%20percent%20and%2020%20percent. |access-date=2024-11-23 |website=www.arkansasonline.com |language=en}} In 2016, the Cobb 500 alone was nearly 50%. More broadly, fast-growing chickens now make up the vast majority of the global chicken supply. As of 2021, 90% of the global broiler population is part of either the Cobb or Ross lines, which are both fast-growing.{{Cite news |last=Usborne |first=Simon |date=2021-11-24 |title=The £3 chicken: how much should we actually be paying for the nation's favourite meat? |url=https://www.theguardian.com/food/2021/nov/24/the-3-chicken-how-much-should-we-actually-be-paying-for-the-nations-favourite-meat |access-date=2024-11-23 |work=The Guardian |language=en-GB |issn=0261-3077}}
Health issues
The fast growth of the Cobb 500 is associated with an increased rate of various health problems. Compared to slower-growing chickens, they have a higher rate of sudden death syndrome,{{Cite journal |last1=Basaki |first1=M. |last2=Tabandeh |first2=M. R. |last3=Aminlari |first3=M. |last4=Asasi |first4=K. |last5=Mohsenifard |first5=E. |last6=Abdi-Hachesoo |first6=B. |date=2019-06-25 |title=Sequence and expression analysis of cardiac ryanodine receptor 2 in broilers that died from sudden death syndrome |url=http://dx.doi.org/10.1080/03079457.2019.1618439 |journal=Avian Pathology |volume=48 |issue=5 |pages=444–453 |doi=10.1080/03079457.2019.1618439 |pmid=31081346 |issn=0307-9457|url-access=subscription }} hock burns,{{Cite journal |last1=Kwon |first1=Byung-Yeon |last2=Park |first2=Jina |last3=Kim |first3=Da-Hye |last4=Lee |first4=Kyung-Woo |date=2024-04-05 |title=Assessment of Welfare Problems in Broilers: Focus on Musculoskeletal Problems Associated with Their Rapid Growth |journal=Animals |volume=14 |issue=7 |pages=1116 |doi=10.3390/ani14071116 |doi-access=free |pmid=38612355 |issn=2076-2615|pmc=11011155 }} Tibial dyschondroplasia,{{Cite journal |last1=Dinev |first1=I. |last2=Denev |first2=S.A. |last3=Edens |first3=F.W. |date=Sep 2012 |title=Comparative clinical and morphological studies on the incidence of tibial dyschondroplasia as a cause of lameness in three commercial lines of broiler chickens |journal=Journal of Applied Poultry Research |language=en |volume=21 |issue=3 |pages=637–644 |doi=10.3382/japr.2010-00303|doi-access=free }} weaker disease resistance and antibody response,{{Cite journal |last1=Mayahi |first1=Mansoor |last2=Talazadeh |first2=Forough |last3=Abdolshah |first3=Mahya |date=2016-11-15 |title=Effect of genetic strains (Ross 308, Cobb 500 and Hubbard F15) on immune response against Newcastle disease vaccine in broiler chickens |url=http://enterpathog.abzums.ac.ir/FullHtml/ijep-20161017101747 |journal=International Journal of Enteric Pathogens |language=en |volume=4 |issue=4 |pages=37–39 |doi=10.15171/ijep.2016.18 |issn=2345-3362|doi-access=free }} bone deformations, and problems with walking.{{Cite journal |last1=Villagómez-Cortés |first1=José Alfredo |last2=Guevara-Torres |first2=Blanca Leydi |last3=Landin-Grandvallet |first3=Luis Antonio |last4=Tirado-Madrid |first4=Alberto |date=2021 |title=Comparison of locomotion problems and its economic impact on Cobb and Ross broiler strains |url=https://journals.bilpubgroup.com/index.php/vsr/article/view/4126 |journal=Veterinary Science Research |language=en |volume=3 |issue=2 |pages=40–46 |doi=10.30564/vsr.v3i2.4126 |issn=2661-3867|doi-access=free }}