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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Biosciences & Biotechnology Laboratory » Research » Research Project #442615

Research Project: Nutritional Strategies to Improve Production Efficiencies in Broiler Chickens

Location: Animal Biosciences & Biotechnology Laboratory

2023 Annual Report

Objective 1: Assess, develop, and apply microbiome- and metagenomic-based strategies to define the development and function of the microbiota and to characterize manipulation of microbiota to improve nutrient uptake and utilization in the gastrointestinal tract of broilers. Sub-objective 1A: Using metagenomics, metatranscriptomics, and metabolomics to define the biological function of the chicken microbiota during PH growth. Sub-objective 1B: Determine the effect of in ovo delivery of nutrients, probiotics, prebiotics and synbiotics on microbiota development, gut health, and broiler performance. Sub-objective 1C: Assess early-life-intervention strategies including microbiota manipulation to improve gut health, nutrient digestibility and availability, growth performance and well-being of broilers. Objective 2: Evaluate the dosage and the mechanism of short-chain fatty acid (SCFA) supplementation as an alternative to chemotherapeutic and antimicrobial agents. Sub-objective 2A: Determine the dosage of SCFAs in Eimeria infected broiler chickens that is effective in decreasing FCR and increasing BWG while being readily ingested. Sub-objective 2B: Determine the effect of SCFA and coccidiosis on the GIT integrity and transport of nutrients. Sub-objective 2.C: Examine the anti-microbial and anti-inflammatory properties of SCFAs in coccidia infected birds. Objective 3: Reevaluate nutrient digestibility and utilization in the absence of antibiotic growth promoters (AGPs) and determine the potential of antibiotic alternatives (ATAs) for improving intestinal health, nutrient utilization, and maintaining production performance. Sub-objective 3A: Conduct further investigation of the mechanisms of action of different antimicrobial alternatives and antibiotic growth promoters on intestinal digestive and barrier function, nutrient utilization, and correlate changes with intestinal microbiota profile in broilers. Sub-objective 3B: Evaluate the effects of ATAs on nutrient digestibility and intestinal oxidative status and absorptive capacities in broilers fed mycotoxin-contaminated corn and/or soybean meal or other inducers of oxidative stress (such as oxidized dietary oil or deoxynivalenol). Sub-objective 3C: Evaluate and determine the optimal dose of Euglena gracilis containing ß-1,3-glucan as a potential ATA on gut health and growth performance of broilers.

Feed accounts for 70% of the total cost of poultry production. Improving feed efficiency (FE) is crucial to increase profitability and sustainability in animal production. Over the years, improvement in performance and FE (measured as a feed conversion ratio, FCR) has been achieved through genetic selection and the use of antibiotic growth promoters (AGPs). The recent ban on antibiotics as AGPs requires research to discover suitable alternatives to antibiotics (ATAs) that will sustain or improve FE, animal health, and chicken productivity. The project’s overall goal is to identify novel nutritional strategies to improve FE and growth parameters in broiler chickens in the absence of AGPs. First, the role of gastrointestinal microbiota in FE and poultry production will be assessed by a comprehensive experiment to determine microbiota function. Second, the project will investigate early-life-intervention to improve FE and broiler production, by defining the effects of microbiota manipulation through in ovo deliveries or early feeding of nutrients, probiotics, and synbiotics. Third, it will address the role and mechanism of action of short-chain fatty acids (SCFAs) as an alternative to chemotherapeutics and antimicrobial agents. Finally, the project will determine the effects of the absence of AGPs and the presence of ATAs on nutrient digestibility and utilization. Outcomes of the research directly benefit producers and consumers in terms of economic return and confidence in food security.

Progress Report
This is the report for the first year of project #8042-31000-114-000D. Relative to Objective 1, Sub-objective 1a, a study was carried out to determine the function and role of gastrointestinal tract microbiota in broiler chickens using metatranscriptomics and metabolomic approaches. In a floor-pen setting, newly hatched chicks were fed standard, commercial-type corn-soybean meal diet formulated for starter, grower, and finisher phase of broiler grow-out period of 6 weeks. Body weight, feed intake, and gastrointestinal samples were collected throughout the 6 weeks to determine the performance parameters, and composition and function of gastrointestinal microbiota, respectively. Currently, data are being analyzed and samples are being processed for DNA isolation. Relative to Objective 2, Sub-objective 2a, an experiment will be conducted where three doses of tributyrin (0.25%, 0.15% and 0.05%) will be tested for their activity against coccidia infection (1,000 oocysts of Eimeria maxima). Chickens will be fed either a normal corn-soybean diet, three doses of tributyrin, or an anti-coccidial and at 21 days of age will be infected with E. maxima. One week after infection performance parameters (weight gain, feed intake, feed conversion ratio) will be measured, and tissues will be taken for further analysis such as gene expression, microbiota analysis, SCFA concentration in plasma, and microscopic analysis. The animal care and use protocol has been approved for this experiment. The SCFAs which will be mixed into diets have been obtained and an experiment is scheduled to start in July 2023. Relative to Objective 3, Sub-objective 3b, an experiment was designed to study the effects of Lactobacillus acidophilus and FloraMax-B11 (made of Lactobacillus acidophilus and Pediococcus parvulus) on mycotoxin-induced intestinal oxidative stress in broiler chickens. Chickens will be fed diets containing either Lactobacillus acidophilus or FloraMax-B11 and contaminated with deoxynivalenol for 21 days. Different parameters including production performance, nutrient digestibility, intestinal oxidative status and barrier function, and intestinal microbiota profile will be assessed. The IACUC and the biosafety protocols have been approved, and the experiment is scheduled to start in August 2023. Additional studies: 1. As part of a continuing collaboration with Penn State University, Department of Animal Science, an analysis of the microbiota was conducted on intestinal samples (jejunum, ileum, ceca) from broiler chickens that were co-infected with Eimeria maxima and Clostridium perfringens to produce necrotic enteritis. The birds were fed either a commercial corn diet or a diet made with a corn variety which is high in flavonoid compounds (PennHFD1). Flavonoids have natural anti-inflammatory and anti-bacterial activity. Feeding the PennHFD1 diet to birds with necrotic enteritis resulted in improved performance parameters (weight gain, feed conversion ratio, decreased mortality). Analysis of the microbiota was carried out to determine whether the beneficial activity PennHFD1 is mediated through changes of the microbiota. Luminal as well as mucosal populations of the microbiota were analyzed separately since they are distinct in function and composition. Sequencing and analysis of a portion of the 16s rRNA revealed most of the significant changes occurred in the ileum and the ceca. In the ileum a decrease in C. perfringens was observed in infected animals consuming PennHFD1. Additionally, infection impacted the diversity of the microbiota, with the populations from infected chickens being distinct from non-infected chickens. In the ceca an increase in Enterococcus cecorum (which is responsible for a disease called kinky back) was observed in infected animals. Changes in the microbiota in infected birds consuming PennHFD1 indicate that flavonoid compounds may affect the intestinal microbiota by decreasing bacteria associated with necrotic enteritis. In addition, we are in the process of determining changes in expression of genes associated with gut health in infected birds consuming either commercial corn or PennHFD1. 2. In collaboration with University of Kentucky, Department of Animal and Food Sciences, a study was conducted to determine the effects of mycotoxin-contaminated corn and oxidized oil on intestinal microbiota in broiler chickens. Chickens were fed a diet made using corn contaminated with deoxynivalenol or using oxidized oil for 21 days post-hatch. Ileal and cecal contents and scrapings were collected for DNA extraction and microbiota diversity and taxonomic determination. The DNA has been extracted and the sequencing is being carried out. Deoxynivalenol contaminates most cereals used for chicken feed. In addition, high levels of unsaturated fatty acids make soybean oil more prone to oxidation. Therefore, broiler chickens may be subjected to cumulative effects of oxidative stress from deoxynivalenol-contaminated corn and oxidized oil, and this may reduce intestinal health and functions. Because intestinal microbiota plays a key role in intestinal development and functions, we expect to determine if the use of deoxynivalenol-contaminated corn and oxidized oil has introduced changes in ileal and cecal microbiota composition. 3. In collaboration with Agricultural Research Service, Food Science and Market Quality and Handling Research Unit, and North Carolina State University, a study was carried out to estimate the changes in gastrointestinal microbiota in broiler chickens fed diet supplemented with waste by-product of the peanut industry (peanut skin) and exposed to Salmonella. After hatch, chicks were fed diet supplemented with peanut skin or control diet and were inoculated with Salmonella Enteritidis. Twenty-four days after Salmonella inoculation, gastrointestinal samples (ileum and ceca) were collected for bacterial DNA isolation and microbiota determination through 16S rRNA sequencing. Salmonella infection and peanut skin feed additive affected the alpha and beta diversity of cecal microbiota only. Ileal microbiota was not affected. Taxonomic composition and predicted function of microbiota of ileum and cecum was affected by infection and the feed additive. The results indicate that the peanut skin may have potential application as antimicrobial and microbiota modulator. 4. In collaboration with North Carolina State University, Department of Food, Bioprocessing and Nutrition Sciences, a study was conducted to determine the effect of waste by-product of the peanut industry (peanut skin) on turkey growth performance, meat quality and gastrointestinal microbiota. Turkeys were raised according to industry standards and fed diet supplemented with peanut skin from hatch. At 5 and 19 weeks of age, samples of duodenal, jejunal, ileal and cecal content and epithelial scrapings were collected for microbiota analysis. Currently, samples are being processed for bacterial DNA isolation and microbiota composition determination via 16S rRNA sequencing. 5. In collaboration with University of Arkansas, Department of Poultry Science, a study was carried out to determine the effect of phytase and stimbiotic inclusion, and environmental challenge on microbiome cultivation and bone quality in reducing susceptibility to bacterial chondronecrosis with osteomyelitis/lameness. A stimbiotic is defined as a nondigestible, fermentable nonstarch polysaccharide source that stimulates fiber fermentation, resulting in increased volatile fatty acid production broiler chickens were raised according to industry standards (litter) or were challenged with wire-speed bump, and their diets were supplemented with phytase and stimbiotic. At the end of the grow out period (56 days), samples of the gastrointestinal tract, bones and blood were collected for microbiota analysis. Currently, microbiota analysis is being performed on the gastrointestinal samples. 6. In collaboration with University of Delaware, Department of Animal and Food Sciences, a study was carried out to determine the effect of different water treatments (normal water vs. filtered water vs. oxygenated water) on gastrointestinal microbiota. Broiler chickens were fed standard commercial type corn-soybean meal diet and had ad libitum access to three different types of water for 28 days. Samples of ileum and cecum digesta as well as epithelial scrapings were collected for bacterial DNA isolation and microbiota determination through 16S rRNA sequencing. Currently, bioinformatic analysis of the sequencing data are being performed to determine if the water treatment has ability to alter the microbiota composition.


Review Publications
Campos, P.M., Miska, K.B., Jenkins, M.C., Yan, X., Proszkowiec-Wegla, M.K. 2023. Effects of Eimeria acervulina infection on the luminal and mucosal microbiota of the duodenum and jejunum in broiler chickens. Frontiers in Physiology. 14:1147579.
Proszkowiec-Wegla, M.K., Kpodo, K.R. 2023. Physiological effects of in ovo delivery of biological substances in broiler chickens. Frontiers in Veterinary Science. 10:1124007.
Proszkowiec-Wegla, M.K., Miska, K.B., Ellestad, L.E., Schreier, L.L., Kahl, S., Darwish, N., Campos, P.M., Shao, J.Y. 2022. Delayed access to feed early post-hatch affects the development and maturation of gastrointestinal tract microbiota in broiler chickens. BMC Microbiology. 22:206.
Kpodo, K.R., Schreier, L.L., Miska, K.B., Proszkowiec-Wegla, M.K., Chaudhari, A. 2022. The supplementation of FloraMax-B11 did not affect the bile acid neosynthesis and the enterohepatic circulation in broiler chickens. Animals.
Davies, C.L., Summers, K.L., Arfken, A., Darwish, N., Chaudharil, A., Foster Frey, J.A., Schreier, L.L., Proszkowiec-Wegla, M.K. 2022. Temporal dynamics of the chicken mycobiome. Frontiers in Physiology. 13:1057810.
Cloft, S.E., Miska, K.B., Jenkins, M.C., Kahl, S., Proszkowiec-Wegla, M.K., Wong, E.A. 2023. A temporal investigation of genes associated with intestinal homeostasis in broiler chickens following a single infection with Eimeria acervulina. Poultry Science. 102:102537.