An update on direct-fed microbials in broiler chickens in post-antibiotic era (an invited review)

Authors: LEE, KYUNG-WOO - Konkuk University; Lillehoj, Hyun

Submitted to: Animal Production Science
Publication Type: Review Article
Publication Acceptance Date: 1/23/2016
Publication Date: 5/3/2016
Publication URL: http://handle.nal.usda.gov/10113/5399133
Citation: Lee, K., Lillehoj, H.S. 2016. An update on direct-fed microbials in broiler chickens in post-antibiotic era (an invited review) . Animal Production Science. doi.org/10.1071/AN15666#sthash.mCFBJd58.dpuf.

Interpretive Summary: With increasing world population which is expected to reach 9 billion by 2050, there is a timely need to develop a sustainable strategy to meet the demand of food security and food safety. In order to assure continuity in supply of poultry meats, poultry sectors including industry, government and academy must work together to find effective measures. In recent years with increasing concerns on the emergence of drug-resistant bacteria, searching for novel alternatives to antibiotics has become a hot topic in the public. One way to deal with increasing productivity in poultry industry would be to increase production efficiency. During the last half century, the uses of in-feed antibiotics as growth promoter have enabled the intensification of poultry farming as they effectively enhanced growth and health of chickens. In this review, an ARS scientist and an university collaborator in South Korea discuss the current status of applying dietary direct-fed microbials (DFMs), defined as a source of viable, naturally occurring microorganisms, as an alternatives to antibiotics and provide science-based data to support the use of DFM to reduce or replace growth promoting antibiotics. This paper will be a valuable resource for industry on using DFMs as an antibiotic alternative.

Technical Abstract: In a post-antibiotic era, applying dietary alternatives to antibiotics into diets of chickens has become a common practice to improve the productivity and health status of chickens. It is generally accepted that direct-fed microbials (DFMs), defined as a source of viable, naturally occurring microorganisms, as an alternatives to antibiotics, have a long history for their safety and health benefit and are generally regarded for therapeutic, prophylactic and growth promotion uses in poultry industry. It has been suggested that two primary modes of action by DFMs are balancing gut microbiota and modulating host immunity. Recent findings suggest that gut microbiota plays an important role in developing immune system and maintaining the homeostasis of mature immune system in mammal and chickens. With the help of molecular and bioinformatics tools, it is now scientifically proven that gut microbiota is diverse, dynamic and varies according to age, breed, diet composition, environment, and feed additives. Broiler chickens are commonly raised on the floor with bedding materials which facilitates the acquisition of microorganisms present in the bedding materials. Thus, it is expected that environmental factors including the type of litter influence host immunity in a positive or negative way. In this regard, adding DFMs into diets of chickens will affect host-microbe interaction shaping host immunity toward increasing resistance of chickens to enteric diseases.