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

Nutrients excreted from animals affect the nutritive value of manure as a soil amendment as well as the composition of gases emitted from manure storage facilities. There is a dearth of information, however, on how diet type in combination with dietary particle size affects nutrients deposited into manure storage facilities, and how this subsequently affects manure composition and gas emissions. To fill this knowledge gap, an animal feeding trial was performed to evaluate potential interactive effects between feed particle size and diet composition on manure characteristics and manure‐derived gaseous emissions. Forty eight finishing pigs housed in individual metabolism crates which allowed for daily collection of urine and feces were fed diets differing in fiber content and particle size, with their urine and feces collected and stored in 446 L stainless steel containers over a period of 49 d. There were no interactive effects between diet composition and feed particle size on any manure or gas emission parameter measured. In general, diets higher in fiber content increased manure nitrogen (N), carbon (C), and total volatile fatty acid (VFA) concentrations, and increased manure VFA emissions, but decreased manure ammonia emissions. Decreasing the particle size of the diet lowered manure N, C, VFA, phenolics, and indole concentrations, and decreased manure emissions of total VFA. Neither diet composition nor particle size had an impact on manure greenhouse gas emissions (GHG)

An Evaluation of the Physicochemical and Biological Characteristics of Foaming Swine Manure

Foam accumulation in deep-pit manure storages is an increasing concern for swine producers because of the logistical and safety-related problems it creates. To investigate this phenomenon, samples of swine manure were collected over a 13-month period from 58 swine production facilities in Iowa with varying levels of foam accumulation. Samples were tested for a number of physical, chemical, and biological parameters including pH, total and volatile solids, volatile fatty acid concentration, long-chain free fatty acid concentration, biochemical methane potential, methane production rate, surface tension, foaming capacity, and foam stability. Statistical analysis indicated that manure collected from facilities with foam accumulation produced methane at significantly (p \u3c 0.05) faster rates than non-foaming manures (0.148 ±0.004 and 0.049 ±0.003 L CH4 L-1 slurry d-1, respectively) and consequently had significantly (p \u3c 0.05) greater fluxes of biogas moving through the manure. The biochemical methane production assay suggested that manure from foaming pits had less potential to generate methane (123 ±9 mL CH4 g-1 VS) than manure from non-foaming pits (150 ±9 mL CH4 g-1 VS), presumably because more of the methane potential had previously been consumed, as indicated by the higher methane production rates. Short-chain fatty acid concentrations were significantly lower in foaming manures (4200 ±570 mg kg-1) than non-foaming manures (9470 ±730 mg kg-1). The methane production rate, biochemical methane potential, and short-chain fatty acid assays suggest enhanced anaerobic digestion efficiency from foaming barns as compared to non-foaming barns. Other assays, such as surface tension and foaming capacity, indicated an accumulation of a surfactant at the manure-air interface of the foam, which may be capturing biogas bubbles generated within the manure. Most importantly, the foam layers exhibited a greatly enhanced ability to stabilize bubbles, which appeared to be correlated to the higher solids concentrations that stabilize the bubbles

Impact of Dietary Carbohydrate and Protein Source and Content on Swine Manure Foaming Properties

Diet ingredients are thought to contribute to foaming problems associated with swine manure stored in deep-pit systems. Two experiments explored the impact of protein and carbohydrate sources and levels in swine diets on the physicochemical properties, methane production potential, and foaming potential of swine manure. The first experiment was specific to protein and evaluated the impact of dietary protein level and source on manure properties, while the second experiment focused on evaluating the impact of different dietary carbohydrate sources on manure foaming properties. Manure from the animals was tested for total and volatile solids, methane production rate and biochemical methane potential, surface tension, foaming capacity and stability, and microbial community structure. No single diet yielded manure with all of the anticipated qualities associated with foaming manure. However, manure collected from pigs fed diets containing soy hulls and distillers dried grains with solubles (DDGS) exhibited higher methane production rates (0.95 ±0.20 and 0.96 ±0.20 L CH4 kg-1 VS, respectively) and biochemical methane potential (322 ±25 and 269 ±22 mL CH4 g-1 VS, respectively) when compared to manure obtained from pigs fed the other diets. Additionally, the results showed that both protein level and source exhibited greater influence over the microbial community than carbohydrate source, with manipulations in the protein diet leading to positive correlations with specific microbial community and higher methane production rates, foaming capacity, and foam stability. In this study, these parameters appeared to be tied to higher levels of corn, or corn protein, in the diet. Although some of the microbial community was explained by diet, this study also demonstrated that factors other than diet have significant influence on microbial community

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

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

Nutrients excreted from animals affect the nutritive value of manure as a soil amendment as well as the composition of gases emitted from manure storage facilities. There is a dearth of information, however, on how diet type in combination with dietary particle size affects nutrients deposited into manure storage facilities, and how this subsequently affects manure composition and gas emissions. To fill this knowledge gap, an animal feeding trial was performed to evaluate potential interactive effects between feed particle size and diet composition on manure characteristics and manure‐derived gaseous emissions. Forty eight finishing pigs housed in individual metabolism crates which allowed for daily collection of urine and feces were fed diets differing in fiber content and particle size, with their urine and feces collected and stored in 446 L stainless steel containers over a period of 49 d. There were no interactive effects between diet composition and feed particle size on any manure or gas emission parameter measured. In general, diets higher in fiber content increased manure nitrogen (N), carbon (C), and total volatile fatty acid (VFA) concentrations, and increased manure VFA emissions, but decreased manure ammonia emissions. Decreasing the particle size of the diet lowered manure N, C, VFA, phenolics, and indole concentrations, and decreased manure emissions of total VFA. Neither diet composition nor particle size had an impact on manure greenhouse gas emissions (GHG).This is a manuscript of an article published as Kerr, Brian J., Steven L. Trabue, Daniel S. Andersen, Mark B. Van Weelden, and Laura M. Pepple. "Dietary composition and particle size effects on swine manure characteristics and gas emissions." Journal of Environmental Quality (2020). DOI: 10.1002/jeq2.20112. Posted with permission.</p

An Evaluation of the Physicochemical and Biological Characteristics of Foaming Swine Manure

Foam accumulation in deep-pit manure storages is an increasing concern for swine producers because of the logistical and safety-related problems it creates. To investigate this phenomenon, samples of swine manure were collected over a 13-month period from 58 swine production facilities in Iowa with varying levels of foam accumulation. Samples were tested for a number of physical, chemical, and biological parameters including pH, total and volatile solids, volatile fatty acid concentration, long-chain free fatty acid concentration, biochemical methane potential, methane production rate, surface tension, foaming capacity, and foam stability. Statistical analysis indicated that manure collected from facilities with foam accumulation produced methane at significantly (p 4 L-1 slurry d-1, respectively) and consequently had significantly (p 4 g-1 VS) than manure from non-foaming pits (150 ±9 mL CH4 g-1 VS), presumably because more of the methane potential had previously been consumed, as indicated by the higher methane production rates. Short-chain fatty acid concentrations were significantly lower in foaming manures (4200 ±570 mg kg-1) than non-foaming manures (9470 ±730 mg kg-1). The methane production rate, biochemical methane potential, and short-chain fatty acid assays suggest enhanced anaerobic digestion efficiency from foaming barns as compared to non-foaming barns. Other assays, such as surface tension and foaming capacity, indicated an accumulation of a surfactant at the manure-air interface of the foam, which may be capturing biogas bubbles generated within the manure. Most importantly, the foam layers exhibited a greatly enhanced ability to stabilize bubbles, which appeared to be correlated to the higher solids concentrations that stabilize the bubbles.This article was published in Transactions of the ASABE 58(5): 1299-1307 (doi: 10.13031/trans.58.11119). Copyright 2015 American Society of Agricultural and Biological Engineers.</p

Impact of Dietary Carbohydrate and Protein Source and Content on Swine Manure Foaming Properties

Diet ingredients are thought to contribute to foaming problems associated with swine manure stored in deep-pit systems. Two experiments explored the impact of protein and carbohydrate sources and levels in swine diets on the physicochemical properties, methane production potential, and foaming potential of swine manure. The first experiment was specific to protein and evaluated the impact of dietary protein level and source on manure properties, while the second experiment focused on evaluating the impact of different dietary carbohydrate sources on manure foaming properties. Manure from the animals was tested for total and volatile solids, methane production rate and biochemical methane potential, surface tension, foaming capacity and stability, and microbial community structure. No single diet yielded manure with all of the anticipated qualities associated with foaming manure. However, manure collected from pigs fed diets containing soy hulls and distillers dried grains with solubles (DDGS) exhibited higher methane production rates (0.95 ±0.20 and 0.96 ±0.20 L CH4 kg-1 VS, respectively) and biochemical methane potential (322 ±25 and 269 ±22 mL CH4 g-1 VS, respectively) when compared to manure obtained from pigs fed the other diets. Additionally, the results showed that both protein level and source exhibited greater influence over the microbial community than carbohydrate source, with manipulations in the protein diet leading to positive correlations with specific microbial community and higher methane production rates, foaming capacity, and foam stability. In this study, these parameters appeared to be tied to higher levels of corn, or corn protein, in the diet. Although some of the microbial community was explained by diet, this study also demonstrated that factors other than diet have significant influence on microbial community.This article is from Transctions of the ASABE, 59(4): 923-932 (doi: 10.13031/trans.59.11470).</p