Performing Department
(N/A)
Non Technical Summary
Non-Technical Summary.Current issue. This project is targeting the use of select probiotic bacteria that possess enzymatic activities to assist swine with feed utilization to enhance animal growth. The current issue this research addresses is the enhancement of animal growth using probiotic bacteria as an alternative to theoveruse of antibiotic growth promotants in animal agriculture as well asincreasing thesafety of derived meat products. There are various types of growth promotants including hormones, exogenous enzymes, and antibiotics. The use of low levels of antibiotics as growth promotants enhances animal growth by inhibiting the animal's normal microbiota thereby enhancing nutrient utilization by the animal and by suppressing gastrointestinal inflammation from a bacterial infection that otherwise results in higher animal maintenance costs. However, the use of even low levels of antibiotics in feeds selects for, and increases, the proportion of antibiotic-resistant bacteria in the intestinal tract, including foodborne pathogens. These same organisms could contaminate the harvestedmeat products and cause illness if consumed (i.e.,undercooked meats or cross-contamination).If the pathogenic bacteriaare resistant to the same antibiotics given for human illness, then human treatment with antibiotics might beineffective,prolonging illness, and even allowingthe illness toget worse. Many pathogenic bacteria are known to possessmultipledrug resistanceto many antibiotics, you could even give humans a differentantibioticas wasgiven to the animaland still be ineffective in treating human bacterial foodborne illness.Solution.The FDA has been slowly moving in the direction of disallowing theuse of antibiotics as growth promotants. Our approach is to usebeneficial probiotic bacteria that can help food production animals more efficiently utilize the nutritional components in their feed by selecting ones that have specific enzymatic activities that could break down complex feed components. We intend to isolate bacteria that are associated with swineand capable of surviving in them. Among these bacteria, screening those that have desirable enzymatic activities useful in helping them digest complex components in animal feed, and providing them back in the animal diet at levels higher than they would normally occur on their own and boosted by providing prebiotic growth supplements for those select bacteria.This could providemoreefficient use of nutrients in animal feed, resulting inweight gain, and achieve the same goal as with traditional growth promotants. Reducing antibiotic resistance among animal microbiota would furtherincreasethe food safety of meats derived from those animals. Thiswould provide animal producers with a safe and effective alternative in swine. If successful, it could serve as a modelthat could be replicated with other food production animals (i.e., beef).
Animal Health Component
100%
Research Effort Categories
Basic
60%
Applied
40%
Developmental
(N/A)
Goals / Objectives
Project Title: In Vitro and In Vivo Evaluation of Bacteria Isolated from Swine-Related Sources as Direct-Fed Probiotics for Enhanced Feed UtilizationGoals. The major goals of this project are to isolate bacteriafrom swine-related sources that have specific metabolic activities that can assist with feed utilization in farm animals (swine) by breaking down complex feed components to facilitate nutritional availability. When these probiotic bacteria are provided as feed additives, either through animal feed or water, the intention is that they colonize the intestinal tract and assist in the utilization of consumed feed, helping to break down complex feed components into those that are more readily absorbed, and this mayresultin improved animal weight gain. Weight gain in food production animals is an obvious benefit.Another issue that has been long to find a solution has been animal growth promotants whereby feeding food production animals subtherapeutic levels of antibiotics in their feed helps with weight gain, presumably by reducing bacterial inflammation that negatively impacts animal health and growth. The problem with providing even low levels of antibiotics is that they preferentially select antibiotic-resistant bacteria that increase in proportion to other bacteria. This could lead to food safety issues if there is a greater proportion of antibiotic-resistant foodborne pathogens associated with animal-derived meat products than would occur otherwise.The FDA has long attempted 'voluntary' programs to reduce the use of growth promotants and has also disallowed the use of some of them, but the best way to ween producers away from such products is to offer an effective alternative. Absent direct FDA actions against various growth promotants, an effective method has been consumer sentiment that drives large fast-food chains to adopt practices of buying meat from producers who do not use antibiotics as growth promotants.We hope that ourapproach can provide a sensible approach to animal weight gain during animal production that displacing traditional growth promotants would be an 'easy sell'.Objectives. In order to achieve these goalswe have defined specific objectives. These include multiple approaches to isolate swine-related bacteria that would have a greater likelihood of growing in the intestinal tracts of swine and using fermenter-based studies to better insure they can survive swine intestinal tracts and can breakdownthe animal feed components that we would like them to utilize in animal feed. Additional objectives are to use bioassay agar media involving various substrates to characterize and confirm metabolic activities of strains that we suspect aredesirable as potential probiotics. This would be followed by molecular identification of the isolates using 16S rRNA PCR and DNA sequencing to confirm the identities of the strains to make sure they are not pathogens that could be injurious to animals. We would also be looking to identify if the selected bacteria are beneficially affected by traditionally known 'prebiotics' (substances that facilitate the growth of probiotic bacteria) such that they may be given as additional dietary adjuncts to animals in addition to the probiotic bacteria. This could reduce the need to constantly provide the probiotic bacteria whereby the supplementation of prebiotics would boost probiotic growth in the animal. Finally, the last objective would be the direct use of the probiotic cultures and prebiotic additives as direct-fed supplements in animal studies as the 'proof is in the pudding'. We hope to demonstrate that this approach can enhance the growth of swine whose diets are supplemented with select probiotic bacteria that target the breakdown of specific components in animal feed.
Project Methods
Methods.This project involves a variety of methods to result in itseventual completion.Bacterial isolation.We will employ bacterial isolation from samples from various sources (swine environment, slaughtered animal intestinal tract, swine feces) utilizing traditional microbiological agars with the addition of specific substrates (protein, lipid, starch, cellulose) to identify biochemical activities among bacteria that can utilize these components found in animal feedstuffs.Fermenter studies. Perhaps a novel approach we will use is to combine swine intestinal/stomach fluids with concentrated minimal media containing individual substrates mentioned above. The animal intestinal fluids will be clarified by centrifugation and crude filtration to remove particulates; any bacteria would be reduced but not eliminated. The addition of substrates plus minimal media will allow for the growth of those bacteria that can thrive on those substrates. A similar approach will be performed to examine prebiotics that can boost the growth of the selected probiotic bacteria.Molecular identification of bacteria. Efforts will be extended to use 16S rRNA PCR of extracted DNA from our various isolates that will then be submitted to our DNA Core Facility for DNA sequencing. We will obtain the information from the disclosed DNA sequences of the amplified DNA and search the NCBI Database using 'nucleotide Blast' with the identified sequences. This information will help us to discover the identities of the bacteria we isolated.Evaluation of Probiotic Bacteria in Live Animal Studies. This last method will help us define or measure the success of our approach to identify probiotic bacteria that could be useful in enhancing the weight gain (and profitability) of swine. Proper controls to normal feed or other supplements will identify the uniqueness of the results obtained in this study. Any semblance of success could be useful as 'seed data' to justify a more involved approach to using probiotic bacteria in swine to enhance weight gain, industry profitability, and reduce the use of traditional growth promotants in swine.