A muscle disorder called "white striping" is plaguing a lot of the chicken we eat. You've probably seen many times on your chicken fillet and just ignored it — the white stripes in breast meat that run parallel to to the muscle fibers — and researchers say it has become a more severe problem in recent years. Another defect called "woody breast," which results in tougher meat, is also troubling producers, who are worried it will affect consumer demand.
A new report and campaign video by Compassion in World Farming (CIWF), an animal welfare group, links these conditions to breeding chickens that grow too fast. "While the specific causes of muscular disorders like [white striping] are still being researched, the vast majority of studies conducted thus far have found a correlation between fast growth, heavier weights, higher breast yield, and the development of myopathies in broilers," the report states.
White striping, a meat quality issue, degrades the taste and nutritional value of chicken, according to the report, resulting in meat that is less tender, doesn't absorb marinade as readily, and contains more fat. CIWF also criticizes the suffering that animals experience from putting on weight too rapidly.
While meat severely affected by white striping is generally used for processed products such as chicken nuggets, moderately affected chicken is still sold at the grocer, according to CIWF.
The US poultry industry has bred birds over decades to have more breast meat and to put on weight in a shorter period of time. As a result, the average chicken sent to market in 2015 weighed 6.24 pounds and was 47 days old — in 1950, market-age birds were 3.08 pounds and 70 days old, according to data from the National Chicken Council.
The prevalence of these muscle defects have drawn the attention of researchers, who are looking into causes and solutions. In one experiment involving 285 birds, about 96% were affected by white striping and woody breast.
Yet a spokesman for the National Chicken Council said white striping affects only a "small percentage of chicken meat," mainly "larger birds, not overall production," and "does not create any health or food safety concerns for people and the welfare of the chicken itself is not negatively impacted."
Companies including Chipotle and Panera have recently pledged to use slower-growing chickens as part of their animal welfare policies.