1. Environmental factors: Some duck farmers have small houses, overstocking density, and lack of exercise. Especially in winter, the housing is poorly ventilated due to warmth, and the house is overheated and overly humid. The concentration of ammonia and carbon dioxide exceeds that of ducks. The degree of acceptance, as well as excessive light, uneven distribution of light and shade or light color should not be. 2. Nutritional factors: Uniform feed or dietary nutrient ratio is unreasonable, resulting in insufficient protein content or lack of amino acids, insufficient inorganic salt, vitamins, or lack of salt for a long period of time. Feeding time is not fixed, such as fullness and hunger. In addition, depilation caused by the lack of cobalt is also prone to induce feathering. 3, management factors: duck manure is not removed in time, faecal fermentation produce toxins, ammonia and other harmful substances, to stimulate the skin surface of the duck body itching; duck feather messy, dirty, can also cause self-defense, and turn each other. 4. Mosquito bites: In the summer, blood-sucking mosquitoes multiply, and bite meat ducks, causing itchiness on the surface and causing paralysis. 5. Parasitic Infections: Parasite infections on some body surfaces can also cause itching and cause feathering. Lysozyme Enzyme,Enzyme for Food,Liquid Acid Cellulase,Glycoside Enzymes Sunson Industry Group Co., Ltd , https://www.sunsonchinaenzymes.com