The move, by on of the largest meat companies in the US, is an attempt to tap into the growing consumer demand for more "natural" and healthier food containing less additives and artificial chemicals. Many poultry farmers routinely treat flock with antibiotics to prevent illness, but research that suggests that the systemic use has allowed germs and viral infections to become resistant has added to consumer concerns. Tyson fresh poultry products will be packaged as "raised without antibiotics". Dave Hogberg, senior vice president of fresh meal solutions at Tyson, said company was the first major poultry processor to offer fresh chicken produced without antibiotics on a large scale basis. "Because of the size and scale of our operations, we're able to convert our entire branded business and assure supply to our customers," he said. Therapeutic antibiotics will continue to be used in only a very small percentage of its poultry flocks and only to treat or prevent disease, the company said. Products from flocked treated with antibiotics will not be included under the new "Raised Without Antibiotics" label. The marketing decision to display what the products do not contain is part of growing trend towards "denial labeling" in which manufacturers describe what a product is not or what it does not contain. The origins of the practice lie in reassuring allergy sufferers about the safety of products, but the use has become widespread with examples including "no added sugar". Last year, a survey by Michigan State University found that about half of the respondents expressed concern about the use of antibiotics and hormone use. Company officials expect to convert other products in its range, such as Deli Rotisserie, to "Raised Without Antibiotics" starting in July and frozen chicken by August.