The present invention relates to an additive to poultry feed including nitrates, nitrites or their mixtures that reduces the incidence of pectoral myopathy in poultry, for example, wooden breast myopathy in broiler chickens. In one aspect, a method for reducing the incidence of pectoral myopathy in poultry is disclosed. The method includes feeding poultry a feed having one or more nitrates, one or more nitrites, or a mixture thereof, wherein the amount of nitrates and/or nitrites in the feed is 3 g to 2,500 g per ton of feed.