The list is the result of a GAP-funded independent research study, performed by the University of Guelph.

The study was the largest of its kind and included more than 7,500 broiler chickens of 16 different genetic strains. GAP said the results of the study were used to guide the development of its Broiler Chicken Assessment Protocol and its initial list of Better Chicken eligible breeds.

"The study - a multidisciplinary science-based approach to understanding broiler welfare - both confirmed and informed our thinking and provided the data needed to create a process for our program to bring a 'better broiler' to the marketplace," said Anne Malleau, Executive Director of GAP.

The released list is not meant to be exhaustive, said the organisation. It includes well-known poultry breeders Aviagen, Cobb-Vantress, Avian, Cooks Venture and Hubbard.

Cooks Venture's Pioneer broiler line and parent stock was one of the 16 breeds included on the short list. The Pioneer is a three-way cross between a Heritage Transylvanian Naked Neck, a Delaware, and a proprietary Peterson family line from the 1930s. It scored high for animal welfare, high activity, high bone density, excellent mobility, low to no rates of muscle myopathies, and strong immune development.

"Our breed, the Pioneer, is selectively bred from heritage line chickens, growing slower than conventional birds, resulting in a robust chicken with efficient feed conversion through better gut health," said Matthew Wadiak, Cooks Venture CEO and founder. "This is the culmination of over 12 years of research with heritage lines, to start from the ground up, to breed a better chicken without the disorders associated with 99% of chicken in America. Our largest asset is our genetics which we've developed prioritizing both health and flavor."

Other approved breeds include: Aviagen's Ranger Classic, Ranger Gold and Ranger Premium lines; Cobb Vantress' Cobb-Sasso 200; and Hubbard's JA757, JA787, JACY87, REDBRO, and Redbro M.