Strategic technologies to improve phytogenic feed additive efficacy in pigs and poultry

Phytogenic feed additives (PFA) are a diverse group of plant-derived materials that have gained considerable interest and use over the last few years in the food and agriculture industry. This is due to the banning of the use of antibiotic growth promoters, as well as an abundance of natural compounds with several perceived beneficial properties. PFA boast a wide range of physiology influencing properties including growth enhancement, stimulating feed intake, appetite and endogenous secretions, antiviral, antimicrobial, antioxidant, and immunomodulatory activities. However, despite the demonstrated potential of PFA and their phytochemical constituents in vitro, several technical limitations restrict their use and commercialisation in monogastric diets. Strategies to improve the bioavailability of phytic acid in pig and poultry diets are described, including encapsulation, feed enzymes, fermentation, cocktails and blends of phytogenics, blending PFA with organic acids and feed enzyme inclusion. The objective of this review article is to complement the body of knowledge considering new scientific evidence. In addition, the review describes some scientific techniques developed to improve the bioaccessibility and bioavailability and facilitate the application of PFA in pig and poultry nutrition.