Chickenomics 鸡肉经济

Ruling the roost 称雄

How chicken became the rich world’s most popular meat 鸡肉如何成为发达国家最受欢迎的肉类

In a shed on a poultry farm just outside Colchester, in south-east England, thousands of chickens sit on piles of their own excrement. 英格兰东南部科尔切斯特郊外一家养鸡场的鸡舍里，数千只鸡坐在自己的粪便堆上。

The facilities will not be cleaned until after the birds are killed, 鸡舍得等到到把所有的鸡都杀了之后才会清理。

meaning they suffer from ammonia burns and struggle to grow feathers. 这意味着鸡会被氨灼伤，很难长出羽毛。

Ants and maggots crawl over the bodies of those that have not made it to slaughter. 那些还没到宰杀时间就死掉的鸡，尸体上爬满了蚂蚁和蛆。

The chicken industry is a dirty business, but it is also a profitable one. 养鸡业很脏，但有利可图。

In the OECD, a club of mostly rich countries, pork and beef consumption has remained unchanged since 1990. 在主要由富裕国家组成的经济合作与发展组织中，猪肉和牛肉的消费量自1990年以来一直保持不变。

Chicken consumption has grown by 70%. 但鸡肉消费量增长了70%。

Humans gobble so many chickens that the birds now count for 23bn of the 30bn land animals living on farms. 人类食用了如此之多的鸡，以至于如今在300亿生活在农场的陆地动物中，禽类占到了230亿。

According to a recent paper by Carys Bennett at the University of Leicester and colleagues, the total mass of farmed chickens exceeds that of all other birds on the planet combined. 根据莱斯特大学的卡莉斯·班尼特和他的同事最近的一篇论文，饲养的鸡的总量超过了地球上所有其他鸟类的总和。

In London, some 50 miles west of Colchester, fried-chicken shops are ubiquitous. 在科尔切斯特以西约50英里的伦敦，炸鸡店随处可见。

Many are named after American states (including Kansas and Montana, not to mention Kentucky). 许多店以美国的州命名(包括堪萨斯州和蒙大拿州，更不用说肯塔基州了)。

But schoolchildren and latenight partiers are unfazed by the strange names. 但是小学生和深夜派对的人对这些奇怪的名字并不在意。

Nor do they worry much about where their meal came from. 他们也不太担心他们的食物从哪里来。

And why should they? Chicken is cheap and delicious. 他们为什么要担心呢？鸡肉既便宜又美味。

A pound of poultry in America now costs $1.92, a fall of $1.71 since 1960 (after adjusting for inflation). 在美国，一磅家禽现在的价格是1.92美元，自1960年以来下降了1.71美元(经通货膨胀调整后)。

Meanwhile the price of beef has fallen by $1.17 a pound to $5.80. 与此同时，牛肉价格下跌了1.17美元，降至每磅5.80美元。

Fans of cheap chicken have selective breeding to thank. 便宜鸡肉的粉丝们要感谢他们的选择性繁殖。

In the 1940s America launched a series of “Chicken of Tomorrow” competitions for farmers. 20世纪40年代，美国为农民举办了一系列“明日之鸡”比赛。

The aim, as described by a newspaper at the time, was to produce “one bird chunky enough for the whole family— 据当时的一家报纸描述，这样做的目的是为了“生产出一种足够全家食用的大鸡”——

a chicken with breast meat so thick you can carve it into steaks, with drumsticks that contain a minimum of bone buried in layers of juicy dark meat, all costing less instead of more.” 鸡胸肉很厚，你可以把它切成牛排，鸡腿上的肉多汁，深色的肉层里埋着最少的骨头，这些肉的价格更低，而不是更高。

The result was something along the lines of the modern broiler chicken. 胜出者类似于现代肉用鸡。

Since then chickens have continued to get bigger. 从那以后，鸡的个头越来越大。

A study by Martin Zuidhof of the University of Alberta and colleagues documented this shift by comparing chickens that were selectively bred in 1957, 1978 and 2005. 阿尔伯塔大学的马丁·祖德霍夫和他的同事们通过比较1957年、1978年和2005年选择性饲养的鸡，记录了这种转变。

The authors found that at 56 days old the three birds had average weights of 0.9kg, 1.8kg and 4.2kg. 研究人员发现，在56天大的时候，这三只鸟的平均体重分别为0.9公斤、1.8公斤和4.2公斤。

As raising a single big bird is more efficient than raising two smaller ones, it now takes farmers just 1.3kg of grain to produce 1kg of chicken, down from 2.5kg of grain in 1985. 由于养一只大鸟比养两只小鸟更有效率，现在农民只需要1.3公斤的谷物就能生产1公斤的鸡肉，而1985年是2.5公斤。