“NCC is concerned that the proposed rule imposes unreasonable costs and requirements of doubtful benefit on organic farmers, presents grave risks to animal health… and undermines ongoing international efforts to develop poultry welfare standards,” said Ashley Peterson, PhD, NCC Senior Vice President of Scientific and Regulatory Affairs, in comments submitted to the US Department of Agriculture.

The NCC said that under the current proposed rule, a “documented occurrence of a disease in the region or relevant migratory pathway must be present before outdoor access can be restricted,” with unclear definitions of what constitutes a region or documented occurrence. The organisation argues this might make farmers less able to protect flocks against diseases such as avian influenza.

The proposed standards are also assumed to increase the mortality rates for laying hens and broiler chickens from 5 to 8 per cent, the NCC said, adding: "Mortality rates are a key indicator of animal welfare and flock health, yet the proposed changes would increase mortality, significantly decreasing bird welfare and farmer economic viability."

Meanwhile, Perdue welcomed the standards.

“Specific requirements for space and indoor air quality, outdoor access and enrichments that promote natural behaviours will further differentiate organic chicken from conventional production in a meaningful way, and we welcome the adoption of uniform and verifiable standards,” said Randy Day, chief operating officer, Perdue Farms.

However, Perdue asked for the implementation deadline for additional space to be extended from one year to three years, to ensure the ongoing availability of organic chicken for consumers while producers expand farm space.