Current use of antibiotic growth promoters and alternative products

Antibiotics are used at sub-therapeutic levels for growth promotion of livestock. Concerns about the development of antibiotic-resistant bacteria and a growing consumer demand for 'green food products' have made this practice less acceptable than in the past. Antibiotic growth promoters (AGPs) are now banned in the European Union. However, AGPs are still an integral part of animal production in Australia, Canada, USA and other countries. In the past decade, much research has been conducted on alternative feed additives and feeding strategies. The majority of these alternatives are aimed at enhancing gastrointestinal function through manipulation of gut microflora. Strategies for improving growth performance and health of pigs and poultry by dietary manipulation include optimizing the physical form of the feed through grain and feed processing and enhancing feed digestibility and nutrient availability by exogenous enzyme supplementation. Other strategies include liquid feeding and natural dietary additives such as organic acids, probiotics, prebiotics, plant extracts and essential oils. In this article, we review the history and present use of AGPs in pig and poultry production and discuss feeding strategies and feed additives that have been suggested as replacements for AGPs.