Microbial Community and Chemical Characteristics of Swine Manure during Maturation

Abstract

Swine diet formulations have the potential to lower animal emissions, including odor and ammonia (NH3). The purpose of this study was to determine the impact of manure storage duration on manure chemical and microbial properties in swine feeding trials. Three groups of 12 pigs were fed a standard corn–soybean meal diet over a 13‐wk period. Urine and feces were collected at each feeding and transferred to 12 manure storage tanks. Manure chemical characteristics and headspace gas concentrations were monitored for NH3, hydrogen sulfide (H2S), volatile fatty acids, phenols, and indoles. Microbial analysis of the stored manure included plate counts, community structure (denaturing gradient gel electrophoresis), and metabolic function (Biolog). All odorants in manure and headspace gas concentrations were significantly (p < 0.01) correlated for length of storage using quadratic equations, peaking after Week 5 for all headspace gases and most manure chemical characteristics. Microbial community structure and metabolic utilization patterns showed continued change throughout the 13‐wk trial. Denaturing gradient gel electrophoresis species diversity patterns declined significantly (p < 0.01) with time as substrate utilization declined for sugars and certain amino acids, but functionality increased in the utilization of short chain fatty acids as levels of these compounds increased in manure. Studies to assess the effect of swine diet formulations on manure emissions for odor need to be conducted for a minimum of 5 wk. Efforts to determine the impact of diets on greenhouse gas emissions will require longer periods of study (>13 wk). Core Ideas Emissions of odorants from manure stabilized after 5 wk in a swine feeding trial. Microbial numbers and species diversity declined significantly with manure storage. Manure chemical properties influence the microbial community metabolic functions. Emissions of GHG from manure never stabilized throughout the 13‐wk feeding trial.

Assessment of the Short-Term Fertilizer Potential of Mealworm Frass Using a Pot Experiment

“…It is noteworthy to mention that frass also stimulated significantly the substrate utilization of carboxylic acids compared with the NPK control. As observed for other organic amendments (Trabue et al, 2016), this likely reflects the fast decomposition of easily degradable organic compounds added by frass but also of more complex compounds, possibly originated from the soil organic matter (Kolton et al, 2017). According to Lazcano et al (2013) who reported similar findings for rabbit manure and vermicompost, frass might thus increase N availability not only by supplying N but also by promoting N turnover from organic matter through increased microbial activity.…”

Dietary composition and particle size effects on swine manure characteristics and gas emissions

“…Using manure storage model systems, it has been concluded that the diet type fed to the pigs and the age of the manure affects microbial ecology (Kerr et al., 2011, 2018; Trabue et al., 2016a; Van Weelden et al., 2016b; Ziemer et al., 2009). In manure samples obtained from this experiment, the microbial community was distinctly different among manure samples obtained from pigs fed CSBM, DDGS, and SH diets, with the assumption that this was due to the amount of C and N deposited into the manure due to the type (cellulose vs. hemicellulose) and amount (low vs. high) of dietary fiber the pigs consumed (Van Weelden et al., 2016a).…”

“…These undigested feed components are excreted as feces and urine and are allowed to accumulate in manure storage systems (Kerr, 2003; Le, Aarnink, Ogink, Becker, & Verstegen, 2005). Within manure storage structures, undigested feed components undergo microbial degradation, which may be aerobic (mineralization) or anaerobic (fermentation), depending on the manure storage conditions, which results in emission of numerous gases over time (Trabue et al., 2016a). These gases include greenhouse gases (GHGs) (e.g., methane [CH 4 ], nitrous oxide [N 2 O], ammonia [NH 3 ], and hydrogen sulfide [H 2 S]) and volatile organic compounds (VOCs) that cause malodor.…”

Strategies for reducing noxious gas emissions in pig production: a comprehensive review on the role of feed additives

“…In pigs, the primary cause of noxious gas emissions is the fermentation of undigested feed components in the large intestine, specifically non-starch polysaccharides found in plant-based feeds like soybean meal, corn, and wheat. These complex carbohydrates pose a digestive challenge as pigs inherently lack the enzymes necessary for their breakdown, leading to fermentation and gas production [ 49 , 50 ]. Zhang et al [ 51 ] further explain that microbial fermentation of these undigested proteins and amino acids in the hindgut contributes significantly to ammonia production, a major component of the overall ammonia emission in manure.…”

“…Zhang et al [ 51 ] further explain that microbial fermentation of these undigested proteins and amino acids in the hindgut contributes significantly to ammonia production, a major component of the overall ammonia emission in manure. The beneficial impact on nutrient digestion and gas emission reduction [ 49 , 50 ]. Moreover, the incorporation of these enzymes into pig diets has also been linked to improved pig performance [ 52 - 54 ].…”