Intensive research has been directed to the potential of Natural Growth Promoters (NGPs) to replace antibiotics. Phytogenics and organic acids (OA) have been shown to be effective in reducing the incidence of gastrointestinal disorders, thereby improving growth performance in pigs (Steiner, 2006). The addition of OA to nonruminant diets is supposed to have beneficial effects on feed safety since OA have a detrimental impact on moulds and other feed contaminants. Moreover, due to a decrease in gastric pH, acidification of the diets creates favourable conditions for nutrient digestibility, especially in young piglets (Radcliffe et al., 1998). Dietary supplementation with essential oils originating from aromatic plants may directly affect the intestinal microflora, both in quantitative and qualitative terms. As shown under in vitro (Helander et al., 1998) and in vivo conditions (Kroismayr et al., 2005), oregano essential oils have strong antimicrobial properties. Finally, it has been confirmed that addition of fructooligosaccharides (FOS) to diets for nonruminants may stabilize the gut microflora by selectively supporting the growth of beneficial bacteria (Macfarlane et al., 2006). Depending on individual farm conditions, a well-adjusted combination of different strategies is supposed to maximize the efficacy of NGPs in antibiotic-free feeding systems. The aim of the trial was to investigate the effects of phytogenics and OA alone and in combination in comparison with a commercial diet containing no additives.
Effects of microencapsulated organic acids and essential oils on growth performance and intestinal flora in weanling pigs
