Modern poultry industry faces the everlasting challenge of the growing
demand for high-quality, low-priced food without compromising general hygiene,
health, and welfare standards. To exploit optimal growth potential, antibiotic.supplemented feeds were implemented in the past decades. But later on, alternative
strategies to trigger the productive characteristics of birds were proposed, including the
use of phytochemicals. Phytobiotics are herbs and their derivatives, endowed with
many beneficial effects. Herbs and their products enhance feed intake by mitigating
intestinal damage, strengthening intestinal integrity, compensating nutritional needs for
local and general immune response, reducing the concentration of pathogenic
microflora, and preventing local inflammatory response. This form of feed
manipulation recently gained interest in the poultry sector due to the lack of side
effects, immune system modulation boosting, and stress tolerance. On the other hand,
several types of research highlighted the potentially harmful effects of some herbs and
their metabolites. This raised concerns among consumers about their safety and
implications as feed supplements or medicines. This chapter will provide insights into
phytobiotics, their role in immunity and growth, and the possible risks of herbal
supplemented feeds in the poultry sector.