A disease that whitens and lightens the eggshell.

Diseases such as Newcastle disease, egg drop syndrome, infectious bronchitis, colibacillosis and white crown disease will obviously whiten the eggshell. On the one hand, after the pathogen invaded the chicken, it caused the pathological changes of the reproductive system, which decreased the function of synthesizing calcium and pigment in the glands of the chicken; at the same time, the feed intake of the chicken decreased, the digestive function decreased, and the absorption of calcium and phosphorus decreased. At the same time, it will cause the loss of copper, zinc and manganese, resulting in the lack of eggshell components and the emergence of a large number of white-shell eggs. On the premise of eliminating the etiology, improving the nutrition level of feed and increasing the content of vitamin A, D, E and C appropriately have obvious curative effect on improving egg color.