Welfare Is Affected by Nutrition Through Health, Especially Immune Function and Inflammation

Welfare, for an animal, means the possibility to cope with the environment of life and to avoid, as much as possible, pain and suffering. It is obvious that good health is of paramount importance for this objective; nevertheless, not only clinical conditions but also any mild malaise status should be avoided for better results. The relationship between nutrition and health is well known; in fact, as well as offering nutrients for maintenance, growth, and reproduction, diet can influence health in a variety of ways: it can directly affect the fitness of infectious pathogens, detrimentally alter the environment in which they reside, and improve host resistance to the pathogens. Since host resistance to infection is mediated to a large extent through involvement of its immune system, the focus here is also on the effects of nutritional environment on immune responses, particularly to gastrointestinal parasites. We consider a variety of nutritional compounds, such as macro- and micronutrients and also secondary plant metabolites with evidence available of the effects on immunoregulation.