Stevia presents itself as an interesting natural additive
for poultry feed. For many years, research related to bird nutrition has focused on different dietary components that improve productive efficiency and are not expensive, such as antibiotic growth promoters. These are compounds used for therapeutic purposes to increase the health and welfare of animals, or for prophylactic purposes. Aiming to increase growth range and achieve more efficient conversion rates.
However, due to the emergence of microorganisms resistant to antibiotics and the presence of residues in poultry meat or eggs, their use in animals of productive interest has been restricted.
- This is reflected in the increase in national and international regulations, which have restricted the use of various antibiotic growth promoters (AGPs) (Gaggia et al., 2010; Grashorn, 2010; Huyghebaert et al., 2011; Hong et al., 2012; Allen et al., 2013; Pal et al., 2015; Bauwens, 2016; FAO, 2016; Gaddet et al., 2017).
This has opened the door for additives known as natural growth promoter (NGPs)
which generate better productive yields in animals through various mechanisms. Most of which are closely linked to better intestinal health.
- In this way, natural growth promoters guarantee safety and their residues are eliminated in avian by-products. Which also allows their export in accordance with current legislation (Grashorn, 2010; Hong et al., 2012; Pal et al. , 2015; Bauwens, 2016; FAO, 2016; Gaddet et al., 2017).
The aim of this review is to broaden the knowledge about the use of natural growth promoters
in poultry production. With a special focus on Stevia, as a possible alternative of natural origin to antibiotic growth promoters. [register]
Productive efficiency and gut health
For approximately 20 years, numerous investigations have focused on the intestinal health of production animals. Due to the fact that it has been shown to have an intimate relationships witht their poductive efficiency.
Intestinal health not only involves the digestive system but also the immune system associated with the intestine and the intestinal microbiota. All of these, interact through different mechanisms, tending to achieve intestinal homeostasis.
Different investigations agree that the interaction of these three elements (digestive system, immune system associated with the intestine and intestinal microbiota) are crucial in the first weeks of life
of commercial birds. When the growth and development of the digestive system, and especially the intestine occurs.
Together with this event, in the first weeks of the bird’s life the microbiota colonizes the different portions of the intestine
and establishes this interaction with the digestive system and with the immune system associated with the intestine (Bar Shira et al
., 2005; Friedman et al
., 2005; Peralta et al
Immune maturation is the last event that occurs in the first weeks of life. The microbiota and the different components of the bird’s diet are amongst its most most important stimuli.
Therefore, research related to the different dietary additives of natural origin, which improve intestinal health are essential.
Use of Stevia in broiler chickens
A study was conducted with 15-day-old broiler chickens. It was observed that the administration of 0.13% ground Stevia leaves or 0.13% pure steviosides, for 4 weeks, improved the productive performance of the birds during the first weeks.