Plant-Scale Validation of Physical Heat Treatment of Poultry Litter Composts Using Surrogate and Indicator Microorganisms for Salmonella

This study selected and used indicator and surrogate microorganisms for Salmonella to validate the processes for physically heat-treated poultry litter compost in litter processing plants. Initially laboratory validation studies indicated that 1.2- to 2.7-log or more reductions of desiccation-adapted Enterococcus faecium NRRL B-2354 were equivalent to > 5-log reductions of desiccation-adapted Salmonella Senftenberg 775/W in poultry litter compost, depending on treatment conditions and compost types. Plant validation studies were performed in one turkey litter compost processor and one laying hen litter compost processor. E. faecium was inoculated at ca.7 log CFU g−1 into the turkey litter compost and at ca. 5 log CFU g−1 into laying hen litter compost with respectively targeted moisture contents. The thermal processes in the two plants yielded 2.8 - > 6.4 log CFU g−1 (> 99.86%) reductions E. faecium of the inoculated. Similarly, for the processing control samples, reductions of presumptive indigenous enterococci were in the order of 1.8-3.7 log CFU g−1 (98.22% to 99.98%) of the total naturally present. In contrast, there were less reductions of indigenous mesophiles (1.7-2.9 log CFU) and thermophiles (0.4-3.2 log CFU g−1). More indigenous enterococci were inactivated in the presence of higher moisture in the poultry litter compost. Based on the data collected under the laboratory conditions, the processing conditions in both plants were adequate to reduce any potential Salmonella contamination of processed poultry litter compost by at least 5 logs, even though the processing conditions varied among trials and plants.IMPORTANCE Poultry litter compost, commonly used as a biological soil amendment, is subjected to a physical heat-treatment in industry setting to reduce pathogenic bacteria such as Salmonella and produce a dry product. According to the FDA Food Safety Modernization Act (FSMA) Produce Safety Rule, the thermal process for poultry litter compost should be scientifically validated to satisfy the microbial standard requirement. To the best of our knowledge, this is the first validation study in commercial poultry litter compost processing plants, and our results indicated that Salmonella levels, if present, could be reduced by at least 5 logs based on the reductions of surrogate and indicator microorganisms, even though the processing conditions in these commercial plants varied greatly. Furthermore, both indicator and surrogate microorganisms along with the custom-designed sampler can serve as practical tools for poultry litter compost processors to routinely monitor or validate their thermal processes without introducing pathogens into the industrial environments.

Broiler house litter processing by anaerobic digestion using enzymes

Sawdust is used as litter for broiler chickens. Mostly they are taken from the treatment of low-value deciduous trees. Keeping broilers for 40-50 days on a litter of sawdust, all the time, absorbs moisture well and mixes with bird droppings. When the broilers are moved to the slaughterhouse, these littered manures are removed from the barn and stored in stacks. They can be used to fertilize fields but only once or twice a year when the fields are fertilized, so they need to be spread over large areas and must be covered due to unpleasant odors. The other alternative is to use this manure with litter to produce energy, preferably biomethane. Sawdust is rich in lignin, cellulose and hemicellulose and is therefore slowly and incompletely broken down by bacteria. This study investigated the effects of the use of the enzymes alpha amylase and xylanase as well as the biocatalyst Metaferm on the mixture of bird droppings and sawdust actually produced in broiler houses. The 14 bioreactors of the laboratory were filled with raw materials and the appropriate additives were added. An average of 0.349 Lg-1dom methane was obtained from bioreactors where alpha amylase was added, but 0.368 Lg-1dom methane was added to xylanase. From the bioreactors where the biocatalyst Metaferm was added average yield was 0.329 Lg-1dom of methane. Addition of enzymes improved methane production, but the addition of biocatalyst Metaferm showed no improvement compared to control bioreactors.

Methods for Solving Environmental Problems in Livestock and Poultry Farming

In the Northwestern Federal District, the main agricultural source of environmental pollution is the disposal of organic waste (manure and litter), which accounts for a risk of 85 percent. The problem of ensuring environmental safety requires appropriate solutions based on modern intelligent machine technologies, means of monitoring and controlling technological processes of organic waste disposal. (Research purpose) To provide rationale for combined methods of solving environmental problems in animal and poultry farming. (Materials and methods) The authors studied the environmental impact of machine technologies used in livestock and poultry farming. The studies were carried out by assessing environmental risks and the sustainability of agroecosystems, applying methods and techniques for assessing the best available technologies, and studying the main prospects of developing intelligent digital technologies. (Results and discussion) The authors have identified the main methods of solving the environmental problems associated with large farm enterprises, including the calculation, design and system operation of the best available technologies for agricultural production. They have proposed a technical tool in the form of a bioreactor for the disposal of organic waste, capable of reducing manure and litter processing period in 60 times and providing automated flow and process control with online registration of production and environmental indicators. They have described an intelligent system for monitoring and utilizing organic waste, including a conceptual framework for establishing modular centers for deep processing. (Conclusions) The authors have proved that the implementation of modern methods for ensuring effective and environmentally safe agricultural production requires the establishing of experimental plot sites for complex research and demonstration of a “machine technology – monitoring – management” system. It has been proposed that a site of the VIM agrobiotechnological cluster should be established at a pilot livestock complex enterprise in the Leningrad Region. The authors have identified promising areas of research to ensure the transition of agricultural production to a new technological structure that implements the principles of Smart Farming to provide for the disposal of at least 510 million tons of agricultural organic waste a year.

Timing and duration of phenological subsidies: toward a mechanistic understanding of impacts on community structure and ecosystem processes in stream food chains

ABSTRACTPhenological resources are common across many ecological communities, and can strongly affect community dynamics. Recent field manipulation experiments in stream food chains found that seasonal timing and duration of terrestrial prey inputs affected the feeding behavior, growth, and maturation of fish predators, caused predator-mediated indirect effects on aquatic prey, and modified trophic-cascading effects on litter processing. These experiments described impacts of resource phenological changes over a few month period, and long-term impacts of continued changes in resource phenology are unknown. Here we develop a mathematical model to extrapolate long-term predictions about the effects of changes in resource phenology from the results of field manipulation experiments. The model predicts that advanced timing generally decreases aquatic prey and litter processing and prolonged duration will either increase or decrease aquatic prey and litter processing depending on the total amount and pre-disturbed timing and duration of terrestrial prey inputs. Importantly, our modeling approach clarifies the mechanisms by which stage-specific responses of life history processes in fish, such as growth, maturation, and reproduction, respond to phenological changes in terrestrial prey inputs and mediate indirect effects on aquatic prey and litter processing. Stage-specific responses of life history processes are an integral part of the mechanisms with which to predict the consequences of phenological species interactions at the community and ecosystem levels.

Dispersal syndromes can impact ecosystem functioning in spatially structured freshwater populations

Dispersal can strongly influence ecological and evolutionary dynamics. Besides the direct contribution of dispersal to population dynamics, dispersers often differ in their phenotypic attributes from non-dispersers, which leads to dispersal syndromes. The consequences of such dispersal syndromes have been widely explored at the population and community level; however, to date, ecosystem-level effects remain unclear. Here, we examine whether dispersing and resident individuals of two different aquatic keystone invertebrate species have different contributions to detrital processing, a key function in freshwater ecosystems. Using experimental two-patch systems, we found no difference in leaf consumption rates with dispersal status of the common native species Gammarus fossarum . In Dikerogammarus villosus , however, a Ponto-Caspian species now expanding throughout Europe, dispersers consumed leaf litter at roughly three times the rate of non-dispersers. Furthermore, this put the contribution of dispersing D. villosus to leaf litter processing on par with native G. fossarum, after adjusting for differences in organismal size. Given that leaf litter decomposition is a key function in aquatic ecosystems, and the rapid species turnover in freshwater habitats with range expansions of non-native species, this finding suggests that dispersal syndromes may have important consequences for ecosystem functioning.