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ARS Home » Southeast Area » Mississippi State, Mississippi » Poultry Research » Research » Research Project #437259

Research Project: Environmental Management Strategies for Improving Production Efficiency in Poultry Production

Location: Poultry Research

Project Number: 6064-13000-013-008-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jul 31, 2019
End Date: Jul 30, 2024

The objective of this research is to assess effects of Escherichia (E.) coli mitigation in commercial poultry production as affected by rearing practices, litter management practices, and differing environmental management strategies on production efficiency and resource use.

Litter samples will be inoculated with non-pathogenic Escherichia (E.) coli and amended with 10, 20, 30, 40, and 50% by mass of biochar. As a comparison, treatments consisting of inoculated litter and 10, 20, 30, 40, and 50% by mass of poultry litter treatment (PLT) will also be examined. Final concentrations of E. coli in the treatments will be assessed using the methodology described below. Litter Moisture Content & Inoculation: Litter from a commercial poultry farm will be collected and autoclaved. Subsamples of the dried litter will be weighed and rewetted with distilled water to 30% dry-basis moisture content. Litter moisture contents of 30% are common in commercial broiler houses. Rewetted litter samples will be inoculated with 1,000 Colony forming units/meter cubed (CFU/ft3) of non-pathogenic E. coli and used as the base litter material for the study. System Set Up and Sampling: Samples (50 g) of the inoculated litter will be placed into flasks and placed in an incubator at 26°C for one week. After the first week, the litter will be treated with biochar and PLT at mixtures of 10, 20, 30, 40, and 50% by mass and the mixture placed back into the incubator at 26°C. A control will consist of inoculated litter only. Each treatment will have three replicates, resulting in 33 total samples. Treated litter samples will be removed from the incubator after one week and prepared for microbial analysis. Assessment of E. coli in the treated litter: Litter samples for microbiological analysis will be obtained immediately prior to the addition of biochar and PLT to the inoculated litter, and one week after adding biochar and PLT. Samples will be stored on ice or at 4°C through analysis. Ten gram subsamples of litter will then be placed into sterile bags containing 20 mL of sterile phosphate buffered saline (PBS) and will be mixed in a stomacher. Large debris will be removed by low-speed centrifugation (50 x g, 5 min, 4°C). The resulting suspension will be tested via the 2 following methods: a. To assess E. coli and treatment-related microbiomes. Bacteria will be pelleted at high-speed centrifugation (3,650 x g, 15 min, 4°C) and will be resuspended in 1 mL of Phosphate buffered saline (PBS). Bacterial DNA will be isolated and quantified using spectrophotometer and subject to PCR optimization and pyrosequencing analyses. Bacterial tag-encoded FLX amplicon pyrosequencing will be performed and will provide data on sample-associated microbial populations. b. Microbiological analyses of litter-associated E. coli. Dilutions will be prepared in 0.1% peptone water and plated. Plates will be incubated at 35-37°C for 24 hr and E. coli will be enumerated.