Do those healthy chicken breast fillets seem tougher and harder to chew – and less flavoursome – than they once did? Have you noticed shiny white stripes running parallel to the meat fibres?

If so, you’ve stumbled upon two muscle disorders in chicken breast that are apparently caused by farming techniques and aggressive genetic selection intended to build bigger birds.

Chooks bred for eating are now twice the size they were in the 1920s – and these abnormalities indicate that super-sizing quality meat has hit a ceiling.

A recent video by Compassion in World Farming highlighted the white-stripe issue – where the low-fat breast meat is essentially marbled with fat like you get with sirloin steak.

The white-striping, which the chickens suffer as a form of muscular dystrophy, causes the meat to be more than twice as fatty as unstriped breasts.

However, the fat doesn’t cause the meat to be juicier or tastier.

Rather, researchers have found the stripes, which appear in larger than normal fillets, cause the meat to have a “substantial reduction in quality’’ and be less flavoursome.

While the white-stripe abnormality is only now coming into public focus, “woody” breast meat has been on the radar for about a year.

The Wall Street Journal reported up to 10 per cent of chicken breast meat has the abnormality, characterised by pale and bulged areas that feature substantial hardness.

All of which suggests these abnormalities are relatively new.

But The New Daily has found science journals were publishing studies at least as far back as four years ago – which indicates the chicken industry has been keeping the problems on the down low.

An Italian study published by the US National Institute of Health in 2014, found “the presence of white striping and wooden breast abnormalities impair not only breast meat appearance but also the quality of both raw and marinated meats mainly by reducing water holding/binding abilities”.

In short, the abnormalities cause the meat to dry out and are less effective in holding and taking up flavours.

10% of global chicken breast fillets affected by chewy problem: 'woody breast' https://t.co/twhnpz5ImQ @kelseykgee pic.twitter.com/0CD7wAQWac

— Georgi Kantchev (@georgikantchev) March 29, 2016

The US National Chicken Council has reportedly said white striping affects only a small percentage of chicken meat and “does not create any health or food safety concerns’’ – but reporting and blogging on the abnormality suggests mounting scepticism.

And even a small percentage of abnormalities could be damaging to an industry that has enjoyed enormous growth since the mid-20^th century.

The Australian Bureau of Agricultural and Resource Economics (ABARE) says Australians are consuming six times more chicken today than they were in the 1960s – each of us eating 37 kilos a year, up from six kilos a year 50 years ago.