Chairman Jim Perdue shared the company’s commitments to animal care in a new four-part plan, which was developed with input from stakeholders such as farmers, academics and leaders of animal advocate organisations.

Mr Perdue said: “Transparency is very important to Perdue consumers, who are interested in knowing how we raise, care for and harvest our chickens. Our vision is to be the most trusted name in food and agricultural products.”

Bruce Stewart-Brown, DVM, Perdue’s senior vice president of food safety, quality and live production, said that the company was learning from organic companies and other brands that have joined the business.

“From lessons learned from organic chicken houses, it’s clear that there can be a general health benefit with increased activity - and that is a big focus of our plan," he said.

"Short-term goals that support increased activity include window installations in 200 existing poultry houses by the end of 2016 and studying the role of enrichments such as perches and bales of hay to encourage activity.”

Josh Balk, Senior Director of Food Policy at welfare group The Humane Society of the United States, said: "Perdue’s new animal welfare policy is precedent setting, and while we look forward to the company adopting timelines for achieving its goals, it’s important progress from a major poultry producer. The shift toward controlled atmosphere slaughter is a particularly important animal welfare improvement."

Another key pledge in the plan is improved relations with the company's farmers. Big American poultry companies have been criticised in recent years for their treatment of contract growers.