Supposition I would suspect rather than fact. Champion makes no such claims for their Orijen Senior. Ingredients virtually identical?
INGREDIENTS - Adult
Fresh boneless chicken, chicken meal, turkey meal, russet potato, fresh pacific salmon (a natural source of DHA and EPA), herring meal, sweet potato, peas, fresh lake whitefish, fresh northern walleye, chicken fat (naturally preserved with vitamin E and citric acid), chicken liver, salmon meal, fresh turkey, fresh whole eggs, fresh deboned herring, sun-cured alfalfa, salmon oil, chicory root, dehydrated organic kelp, pumpkin, carrots, spinach, turnip greens, apples, cranberries, saskatoon berries, black currants, choline chloride, psyllium, licorice root, angelica root, fenugreek, marigold flowers, sweet fennel, peppermint leaf, chamomile flowers, dandelion, summer savory, rosemary, sea salt, vitamin supplements (vitamin A, vitamin D3, vitamin E, niacin, vitamin C, thiamine mononitrate, riboflavin, vitamin B5, vitamin B6, folic acid, biotin, vitamin B12), mineral supplements (zinc proteinate, iron proteinate, manganese proteinate, copper proteinate, selenium), dried Lactobacillus acidophilus, dried Enterococcus faecium fermentation product.
INGREDIENTS - Senior
Fresh deboned chicken, chicken meal, turkey meal, russet potato, fresh deboned salmon (a natural source of DHA and EPA), herring meal, sweet potato, peas, fresh deboned lake whitefish, salmon meal, fresh deboned walleye, chicken liver, fresh deboned turkey, chicken fat (naturally preserved with vitamin E and citric acid), whole eggs, fresh deboned herring, sun-cured alfalfa, salmon oil, chicory root, dehydrated organic kelp, pumpkin, carrots, spinach, turnip greens, apples, cranberries, saskatoon berries, black currants, choline chloride, psyllium, licorice root, angelica root, fenugreek, marigold flowers, sweet fennel, peppermint leaf, chamomile flowers, dandelion, summer savory, rosemary, sea salt, vitamin supplements (vitamin A, vitamin D3, vitamin E, niacin, vitamin C, thiamine mononitrate, riboflavin, vitamin B5, vitamin B6, folic acid, biotin, vitamin B12), mineral supplements (zinc proteinate, iron proteinate, manganese proteinate, copper proteinate, selenium), Lactobacillus acidophilus and Enterococcus faecium fermentation product.