The role of the immune system is to provide the pigeon with the ability to resist infections to the pigeons body. The diet of the pigeon plays a significant role in the function of the immune system, when fully functional i.e in a healthy balanced state the immune system removes pathogens (disease causing organisms)from the body, however many of our pigeons seem to have lost the correct balance of friendly bacteria in their intestines this enables them to flush out toxins which gather during racing, stress, moulting etc. Correct nutrition goes a long way to maintaining this balance, however many additives we add, may inadvertently kill of friendly bacteria and block nutritional absorption (which is an aid to good health. A poor immune system will lead to eventual toxic overload and loss of form, pigeons have enough stress during training, growing, moulting etc without us deciding we will add some supposed secret formula ingredient etc. This is best left to the experts who mix the grains, the feed helps define the general health and can make pigeons reach top condition. Or as many pigeon fanciers say feed is and remains a science most grain suppliers have nutritional experts who devise mixtures through scientific research adapted for our birds perhaps we should think again before we consider adding our own concoctions.