The chickens have grown 364% in the last decades.
The chickens that arrive at our table are getting bigger and bigger.We know this because a few years ago a group of researchers from Canada compared how three commercial breeds from 1957, 1978 and 2005 grew, given exactly the same type of diet and care.
They found at eight weeks the newest variety weighed about 2.3 times more than the 1978 and 4.6 times more than the 1957 specimen.
Chickens that we breed for consumption have increased by 364%. The growing size of broiler chickens as striking as it is slightly mysterious.
Researchers at the University of Alberta have come to a clear conclusion. They found that A dramatic shift in the productivity of the broiler industry has been achieved through intentional genetic selection using traditional quantitative techniques.
The “rate of growth and efficiency” has been “dramatic” since the 1940s.. They attribute this increase certain changes to environmental factors. They added that between 85 and 90% are linked to a genetic component.
According to the Wall Street Journal, while in 1965 a bird weighing 1.6 kilograms took 63 days to reach the stores, in 2015, the average bird was already 2.8 kilograms in 48 days.
The U.S. trade association, which represents the interests of businesses in the sector defends this. They say that in 1960, per capita consumption was 12.7 kilograms; ten years later, it had already risen to 18.2 kilograms; in 1980, it was 21.5 kilograms; in 2000, it was about 35.1 kilograms.Its last closed data, corresponding to 2021, places consumption per person at 44.1.
Previous research – Vox magazine specifies – has also observed an increase in bone, heart and immune system problems in some breeds.
The cause? Several factors would be at play, including unintended genetics, diet, or being overweight.