Abstract:
Early in the past, poultry diet was mainly formulated to
meet maintenance and production requirements, so the
focus was on productive performance, and health of birds
expected to be involved within these requirements.
Thereafter the use of antibiotics as feed additives at subtherapeutic
dose was introduced to increase productivity by
reducing bacterial colony count in the gut and improving
gut equilibrium. That means more concern about health of
birds. Recently, arises of poultry welfare concern in
addition to the ban of the use of antibiotics as feed additives
by European Union from 2006, rushed producers and
nutritionists into more concentration on health of birds and
immunity when they formulate poultry diets. Hence two
ways were adopted to improve bird health and immunity by
feed formulation without supplementation of antibiotics as
growth promoters. The first one is by using antibiotic
alternatives as growth promoters. The other one, which
emerges recently, is formulation of feed to meet the needs
of cells of the immune system. This means studying its
needs for nutrients such as protein, energy, amino acids,
vitamins and minerals. There is also, feeding of infected
birds when the diet should be formulated in a way to avoid
exacerbating the condition by feeding microorganisms and
help them to proliferate. This review aims to discuss the
role of nutrients and feed formulation in improving poultry
health and immunity either through meeting requirements of
cells of the immune system or through antibiotic
alternatives supplementation or even as modified diet
during infections
