Overview of plant extracts and plant secondary metabolites as alternatives to antibiotics for modification of ruminal fermentation

Abstract

© 2018, Chartered Inst. of Building Services Engineers. All rights reserved. Ionophore antibiotics in sub-therapeutic doses have been used since 1970s to improve ruminal fermentation. But use of antibiotics as feed additives was banned in the European Union and Turkey in 2006 since they leave residues in animal products and develop resistance in bacteria. This has shifted the focus of the studies to safer alternatives such as plant extracts and their secondary metabolites to alter ruminal fermentation in order to improve ruminant productivity. In this review, general and recent knowledge about plant extracts and plant secondary metabolites as modifiers of ruminal fermentation are summarized. Furthermore, potential efficacies and possible disadvantages of these substances are also discussed.