It has long been demonstrated that trace minerals play important roles in immune function. Zinc plays a very important role in maintaining epithelial and endothelial tissue integrity and repair. Epithelial tissue (skin) is the first line of defense from disease attack or trauma. Maintaining good skin strength and rapid wound healing will help reduce the incidence of skin scratches and lesions that lead to infections and diseases such as cellulitis. Endothelial tissue is found in the respiratory tract, gut lining and egg formation tract tissue such as the infundibulum, magnum, isthmus and uterus (Figure 11). Maintenance of healthy endothelium will result in higher egg production, better quality egg production and greater persistency of lay. Improved endothelial tissue in the lungs and pulmonary system may also help resist respiratory diseases and problems due to ascites.

Zinc, manganese and copper are all involved in the synthesis of crucial enzymes needed for immune response. Super oxide dismutase, a free radical scavenger enzyme helps maintain cellular integrity and minimize damage from oxidative disease challenge. Further, zinc and manganese are involved in the phagocytic response (macrophage production) to infections such as E. coli and salmonella.