Manure Piles Research Articles

Fasting horses perioperatively decreases manure production and increases time to manure output postoperatively: a controlled randomized trial.

To compare 3 perioperative feeding regimens and their effect on anesthetic complications, manure output, and colic proportion in healthy horses. 45 horses presenting for elective orthopedic procedures were randomly assigned to 1 of 3 groups: not fasted (NF; continuous access to hay perioperatively), fasted muzzled (FM; 10-hour preoperative fast with slow refeeding postoperatively and muzzle placement), or fasted not muzzled (FNM; same as FM without muzzle placement). Anesthetic protocol was standardized. Outcomes compared between groups included anesthesia time, arterial oxygenation, duration of hypotension, perioperative manure output, time to first passage of manure postoperatively, pain scores, and colic proportion. Comparisons were made with a mixed model and Fisher exact test with statistical significance considered at P ≤ .05. No differences were seen in pain scores, oxygenation, hypotension, or colic between groups. Groups FM and FNM had a significantly greater mean reduction in postoperative manure weight (-81% and -70%; P = .003) and number of manure piles (-63% and -55%; P = .005) compared to group NF (-39% and -22%; P < .001; weight and piles, respectively). Mean ± SD minutes to passage of manure postoperatively was significantly shorter in group NF (238 ± 13 minutes) than groups FM (502 ± 174 minutes; P < .001) and FNM (444 ± 171 minutes; P = .003). Horses with continuous access to hay prior to and following recovery from anesthesia passed more manure and passed manure sooner after surgery than their fasted counterparts without detrimental effect on anesthetic parameters and postoperative complications. Continuous access to hay perioperatively supports manure production in healthy horses without increase in anesthetic complications.

Effectiveness of the Sustainable Manure Pile Model for Ammonia Emission and Soil

In order to reduce odor emissions and surface water pollution while storing manure in field heaps near a barn, there is a challenge in properly designing manure-storage areas. Therefore, it is important to assess what solutions and conditions, considering environmental requirements, should be considered when storing manure in field heaps. The goal of the research is to determine the impact of various factors on the risk of nutrient leaching, soil, and gas emissions from solid manure heaps, considering climatic factors in the environment. Through various scientific studies, a manure pile model has been developed and evaluated for its impact on the risk of potential leaching and odor emissions (using hyperspectral gas emission analysis mass flow method) from manure and the dynamics of the 0–80 cm soil layer properties (nitrate (N-NO3) and nitrite (N-NO2), ammonia (NH3), mineral, and total N). Based on the research results, requirements for manure management and storage during the prohibited fertilization period were established, considering the requirements for nitrates from agricultural sources in Lithuania. An optimal new manure heap model has been identified—a layer of not less than 20 cm of compacted straw (density 150–200 kg m−3) or a 10 cm layer of peat for absorbing manure slurries is formed on the soil surface, the manure heap is surrounded by an earth embankment not less than 30 cm high, the manure heap is covered with a layer of finely chopped straw not less than 10 cm thick, or 5 cm of sawdust, or 5 cm of peat. The manure is stored in the heap for 6–12 months. Following the research results, requirements for manure management and storage during the prohibited fertilization period were established, considering the requirements for nitrates from agricultural sources in Lithuania, applicable to the northern part of the temperate climate zone and applying similar requirements to the relevant countries.

Changes in Metabolism and Content of Chlorophyll in Common Duckweed (Lemna minor L.) Caused by Environmental Contamination with Fluorides.

The impact of fluorine on plants remains poorly understood. We examined duckweed growth in extracts of soil contaminated with fluorine leached from chicken manure. Additionally, fluorine levels were analyzed in fresh manure, outdoor-stored manure, and soil samples at varying distances from the manure pile. Fresh manure contained 37-48 mg F- × kg-1, while soil extracts contained 2.1 to 4.9 mg F- × kg-1. We evaluated the physiological effects of fluorine on duckweed cultured on soil extracts or in 50% Murashige-Skoog (MS) medium supplemented with fluorine concentrations matching those in soil samples (2.1 to 4.9 mg F- × L-1), as well as at 0, 4, and 210 mg × L-1. Duckweed exposed to fluorine displayed similar toxicity symptoms whether in soil extracts or supplemented medium. Fluoride at concentrations of 2.1 to 4.9 mg F- × L-1 reduced the intact chlorophyll content, binding the porphyrin ring at position 32 without affecting Mg2+. This reaction resulted in chlorophyll a absorption peak shifted towards shorter wavelengths and formation of a new band of the F--chlorophyll a complex at λ = 421 nm. Moreover, plants exposed to low concentrations of fluorine exhibited increased activities of aminolevulinic acid dehydratase and chlorophyllase, whereas the activities of both enzymes sharply declined when the fluoride concentration exceeded 4.9 mg × L-1. Consequently, fluorine damages chlorophyll a, disrupts the activity of chlorophyll-metabolizing enzymes, and diminishes the plant growth rate, even when the effects of these disruptions are too subtle to be discerned by the naked human eye.

Devitalization of Bacteria in Composted Cattle Manure with Natural Additives and Risk for Environment.

Nowadays, there is an effort to improve the effectiveness of the composting process, supported by the addition of various supplements to reduce soil nutrition losses and increase soil remediation. The aim of this study was to examine the devitalization effect of natural additives like zeolite-clinoptilolite and its combination with hydrated lime in composted cattle manure on indicator and pathogen bacteria. The composting process was running in three static piles of cattle manure mixed with wheat straw (control, zeolite-lime, and zeolite) for 126 days. Composted manure substrates were determined for physicochemical (temperature, pH, nitrogen and phosphorus content, C/N, organic matter, and moisture) and microbiological analyses (Salmonella spp., indicator bacteria). The effects of additives were reflected in changes in physicochemical factors, e.g., an increase in temperature (<53 °C) or pH (<9.3). According to Pearson correlation, these changes (pH, Nt, Pt) resulted in a significant decrease (p < 0.001) of indicator bacteria (two or three orders) in zeolite pile or zeolite-lime pile. Die-off of Salmonella spp. in the zeolite-lime pile was indicated within 41 days; in other piles, this occurred on day 63. Our results can aid in further optimizing the composting of cattle manure in order to lower environmental pollution and the risk of human infection.

Field application of bio-foam spray to reduce ammonia emission from ammonia-rich swine manure piles

In this study, the first field-scale application of a bio-foam spray (a mixture of microbes and a surfactant) for the reduction of ammonia emitted from manure was investigated on six field swine manure piles. The objective of this study was to evaluate the odor suppression ability of bio-foam and odor degradation ability of odor-degrading bacteria loaded in the surfactant foam after covering manure piles. The size of field manure piles tested in this study ranged from 27 to 300 m3. Bio-foam spraying completely suppressed the release of the major odor component, ammonia (NH3), and odor-degrading bacteria in the bio-foam aided in the degradation of NH3 in field swine manure piles. On average, 85.7–100% of NH3 was reduced after 24–48 h of serial bio-foam spray application on the swine manure surface, while the control showed 25–42%. The reduction efficiency of NH3 by the bio-foam application was affected by the bio-foam spray frequency, ambient temperature, ventilation of the field facility, and upward airflow to the pile. The reduction in surface emission of NH3 also reduced the ambient air concentration of NH3 at the gate of the compost facility. NH3 gas measurements at a depth of 50 cm indicated that NH3-degrading bacteria infiltrated the manure and were active in biodegradation. Finally, the measured effectiveness of bio-foam application as shown by this study indicates that sprinkling bio-foam via specialized rotating sprinklers may be an efficient and uniform method for the delivery of bio-foam to wide field areas within composting facilities.

Evolution of humus dynamics in composting of swine manure combined with wood vinegar

Aerobic composting was carried out in a greenhouse using home-made compost bins, and the changes in humus(HS) composition of composted manure with different proportions of wood vinegar(WV) added to pig manure and rice straw as raw materials were studied. Since the temperature, water content and pH were very different from those of the summer compost, they were used as basic evaluation indices of compost maturity. Rice straw(RS) and Swine manure (SM) were used as test materials, and the water-soluble carbon (CWSS), extractable humic carbon (CHE), humic carbon (CHA), humic carbon (CFA) and humic carbon (CHU) of the materials were investigated, and the humus decomposition coefficients were dynamically analyzed. The findings demonstrated that 1.25% and 1.75% wood vinegar affect humification. Meanwhile, the results of Ratio of absorbance of water-soluble organic substances at 465 and 665 under UV spectrophotometer (E4/E6) indicated that the aromatic ring of 1.75% WV solution was more stable after condensation, and the decomposition of hominin as a HS stabilizing component was more complete at the concentration of 1.75%. Consequently, this study revealed that WV at a concentration of 1.75% was more efficient in stimulating pile decomposition in cold conditions.

Optimization of growth conditions and biological cementation effect of Sporosarcina pasteurii

Microbially induced carbonate precipitation (MICP) has been widely used in soil reinforcement and other fields. Aiming at the problems of accumulation and resource utilization of tailings sand, which is a special kind of sand, we enriched the urease-producing microorganism Sporosarcina pasteurii (S. pasteurii) from soil and applied it to the field of tailings solidification in this study. Based on single-factor experiments and response surface methodology (RSM), the effects of temperature, pH and urea concentration on the growth of S. pasteurii were investigated and the optimum growth conditions of S. pasteurii were determined. CaCl2·2H2O and Ca(CH3COO)2·H2O were used as calcium sources, combined with SEM-EDS, XRD, FTIR and XPS detection, the effect and mechanism of Ca2+ bio-cementation by S. pasteurii was investigated. By comparing the effect of bio-cemented tailings sand by soaking method, stirring method and stratification method, we optimized the method of S. pasteurii bio-cemented tailings. The results indicated that the activity of S. pasteurii mixed bacteria enriched in soil was significantly better than that of single S. pasteurii standard strain. In particular, the S. pasteurii mixed bacteria (1# bacteria) enriched from the soil around the pig manure pile had the strongest activity. The results of RSM showed that the optimum growth conditions of 1# bacteria were: at 31°C culturing temperature, pH = 9.07, which urea concentration was 0.5 mol/L. Compared with temperature and pH value, urea concentration had the most obvious effect on the activity of 1# bacteria. Compared with the soaking method and the stirring method, the layered solidification method using Ca(CH3COO)2·H2O as the bio-cemented calcium source was more suitable for S. pasteurii mixed bacteria (1# bacteria) enriched from soil bio-cementing tailings. This bio-cementing technology provides a theoretical basis for the efficient MICP engineering application of tailings in the field of alternative building materials.

Bacterial community dynamics and co-occurrence network patterns during different stages of biochar-driven composting

Bacterial communities were dynamically tracked at four stages of biochar-driven sheep manure pile composting, and the co-occurrence networks with keystone taxa were established. The succession of bacterial community obvious varied during the composting process, Proteobacteria predominant in initial stage (39%) then shifted into Firmicutes in thermophilic (41%) and mesophilic (27%) stages, finally the maturation stage dominant by Bacteroidota (26%). Visualizations of bacterial co-occurrence networks demonstrate more cooperative mutualism and complex interactions in the thermophilic and mesophilic phases. Noticeably, the 7.5 and 10% biochar amended composts shown highest connections (736 and 663 total links) and positive cooperation (97.37 and 97.13% positive link) as well as higher closeness centrality and betweenness centrality of keystone taxa. Overall, appropriate biochar addition alters bacterial community succession and strengthens connection between keystone taxa and other bacteria, with 7.5 and 10% biochar amended composts has intense mutualistic symbiosis among bacterial communities.

Compaction effects on greenhouse gas and ammonia emissions from solid dairy manure

Waste management practices of solid dairy manures were evaluated under controlled conditions to study gas transport and emission inside manure piles. Three applied stresses and three moisture contents were tested to represent manure conditions managed at various pile depths. A Fourier-transform infrared spectroscopy monitor measured concentrations of greenhouses gases [methane, carbon dioxide, and nitrous oxide] and ammonia as part of gas flux rate calculations. Results showed that carbon dioxide dominated the greenhouse gas emissions under all test conditions. Gas transfer, primarily diffusion, was facilitated by manure with high mechanical strength and high permeability. Gas emission rates reduced dramatically when moisture content increased in manure with high water holding capacity, while compaction treatments did not as strongly affect the gas emission rates. Results provide fundamental insights into management strategies for reducing gas emissions from solid dairy manure.

TEMPERATURE AND MICROBIOLOGICAL PARAMETERS OF POULTRY MANURE UNDER DIFFERENT FERMENTATION MODES

To meet food needs both in Ukraine and globally, the production of affordable and relatively cheap poultry meat will increase. At the same time, the problem of increasing poultry waste accumulation, including manure with and without bedding, is becoming more acute. Large volumes of broiler manure in limited areas due to different storage conditions have a negative impact on the environment. The study of the conditions and modes of composting broiler manure as an effective way of its utilisation is of scientific and economic importance. The aim of the study is to determine the temperature and microbiological parameters of broiler manure composting using different modes of its aeration. To achieve this goal, fresh broiler manure was composted in the conditions of the scientific and educational research centre of the Bila Tserkva National Agrarian University using a mixture of biodestructors and different aeration regimes. In the control group, the piles were formed on a concrete platform without the use of a tubular frame of the barbital type, and aeration was carried out by mechanical mixing of broiler manure once every 10 days. In the experimental groups, piles of broiler manure were formed on tubular frames through which air was injected by a compressor. In the first experimental group, air injection was carried out for 15 minutes in the first half of the day. In the second experimental group, air was injected into the broiler manure twice for 15 minutes in the morning and in the evening. It was experimentally established that the composting temperature of broiler manure depended on the intensity of aeration of the latter. With daily aeration twice a day, the temperature of the manure biomass (6th day of composting) was the highest and exceeded the control values by 87.8 %. In experimental groups I and II, with one and two daily enrichment of broiler manure, the period of fermentation in the thermophilic mode was the same. Comparing the groups where poultry manure was enriched once and twice a day, it was found that double aeration did not lead to a statistically significant increase in the temperature of composted biomass. It was proved that active air enrichment of poultry manure (experimental group II) increased the QMAFAnM index and the number of Bacillus spp. bacteria by 7.6 and 24.0%, respectively, compared to the control group. The study of a number of chemical parameters of broiler chickens' manure composted by the accelerated method under different aeration regimes is promising.

Comprehensive analysis of the fates and risks of veterinary antibiotics in a small ecosystem comprising a pig farm and its surroundings in Northeast China

This study investigated the behavior of veterinary antibiotics (VAs) in a small farm ecosystem. Manure and environmental samples were collected around a large pig farm in northeast China. Thirty-four VAs in six categories were analyzed. Then, a multimedia fugacity model was used to estimate the fates of VAs in the environment. The results showed that VAs were prevalent in manure, soil, water, and sediment, but not in crops. Compared with fresh manure, VA levels were significantly lower in surface manure piles left in the open air for 3–6 months. The main VAs, tetracyclines and quinolones, decreased by 427.12 and 158.45 µg/kg, respectively. VAs from manure piles were transported to the surroundings and migrated vertically into deep soil. The concentrations of ∑VAs detected in agricultural soils were 0.03–4.60 µg/kg; > 94% of the mass inventory of the VAs was retained in soil organic matter (SOM), suggesting that SOM is the main reservoir for antibiotics in soil. Risk assessment and model analysis indicated that the negative impact of mixed antibiotics at low concentrations in farmland on crops may be mediated by indirect effects, rather than direct effects. Our findings highlight the environmental fates and risks of antibiotics from livestock farms.

Nitrogen Losses and Enrichment of Soil and Sawdust Coverings during Composting of Poultry Manure

Aims: Composting poultry manure is an effective way of enhancing its nutrient content and reduce nutrient losses. There is the need to reduce gaseous nutrient losses during composting through the use of covering materials. Assess the level of chemical enrichment of soil and sawdust used as covering materials; and identify the most suitable medium that can best perform as a covering material during composting of poultry manure.&#x0D; Materials and Methods: Experiments were set up to examine the changes in the chemical properties of soil and sawdust used as covering material for composted poultry manure. Five treatments – no covering, layers of 2.8 kg soil, 5.6 kg soil, 0.9 kg sawdust, and black polythene sheet on 5.28 kg broiler and layer manure heaps with four replications were arranged in a completely randomized design. Samples were taken from the manure piles and the soil and sawdust covering materials for chemical analysis at 3, 6 and 9 weeks after composting.&#x0D; Results: The pH, N, P, K, Na and Ca, in both soil covers increased as time elapsed, whereas the Mg and C/N ratios of the soil coverings decreased with time. With regards to the broiler manure, however, the pH and the nutrient content of the two levels of soils used as cover increased at all the stages of composting. Composting of both poultry manures resulted in the improvement of the chemical properties of both sawdust and soil coverings. The enrichment ratio of N was greater in the 5.6 kg soil than the 2.8 kg soil covering. Additionally, the 5.6 kg soil covering was highly efficient (P = .05) in reducing N losses by 57 and 83.85% from the broiler and layer piles, respectively. In general, the 5.6 kg soil was the most effective covering material.

Development of an integrated hydrochemical index for delineating livestock manure-derived groundwater plumes in agro-livestock farming areas

To delineate a livestock manure-derived groundwater plume (LDGP) in agro-livestock farming areas with the extensive use of chemical fertilizers, multilevel monitoring wells (MLWs) were installed for depth-specific sampling of groundwater, and then hydrochemical, nitrate N-O isotopic and microbiological data of shallow groundwater collected from the MLWs were evaluated with the help of multivariate statistical tools. The LDGP was distinguished from the pervasive agricultural contamination based on δ15Nnitrate (10‰). Fecal coliforms and Escherichia coli were not observed in the LDGP, whereas bovine enterovirus type 2 was detected at a sample collected at a depth of 18 m below ground level (bgl) downgradient manure piles, indicating a potential virus risk. Among hydrochemical parameters, Ca2+, Mg2+, Na+, Cl- and SiO2(aq) were shown to be effective indicators to trace the LDGP. On the other hand, nitrate was not effective to discriminate the LDGP because of denitrification in deep parts (>6 m bgl) within the LDGP, although nitrate contamination was serious at shallow parts (≤6 m bgl; 62.4 to 119.1 mg/L, median 97.9 mg/L). Thus, an integrated hydrochemical index consisting of Ca2+, Mg2+, Na+, Cl- and SiO2(aq) was suggested based on the result of principal component analysis with isometric log-ratio transformed data to delineate the LDGP in shallow unconsolidated aquifers overlying silicate bedrocks, and a threshold of the index was determined to be 1.17. The application of the index to three other agro-livestock farming areas with prevalent agricultural contamination successfully distinguished the groundwater samples within the LDGP (11 of 40 samples) that showed the index values exceeding the threshold and a median δ15Nnitrate of 12.5 ‰. The study results show that the hydrochemical index can be used for the quick evaluation of a LDGP in agro-livestock farming areas given its cost efficiency and easily accessible analysis devices for water chemistry compared to isotopes, although the broad use of the index to determine LDGPs needs to be further verified by application to various geology and land uses. Livestock manures should be carefully managed to protect groundwater resources, including impermeable covers above or beneath the manure piles, given the potential risk of virus at deep parts and nitrate at shallow parts within the LDGP. The methodology to select hydrochemical indicators for distinguishing a LDGP and the combination of the indicators to develop an index suggested in this study will be useful to build new indices adapted to local conditions.

Effects of feeding a pine-based biochar to beef cattle on subsequent manure nutrients, organic matter composition and greenhouse gas emissions

Biochar in ruminant diets is being assessed as a method for simultaneously improving animal production and reducing enteric CH4 emissions, but little is known about subsequent biochar-manure interactions post-excretion. We examined chemical properties, greenhouse gas (GHG) emissions and organic matter (OM) composition during farm scale stockpiling (SP) or composting (CP) of manure from cattle that either received a pine-based biochar in their diet (BM) or did not (RM). Manure piles were monitored hourly for temperature and weekly for top surface CO2, N2O and CH4 fluxes over 90 d in a semiarid location near Lethbridge, AB, Canada. Results indicate that cumulative CO2, N2O and CH4 emissions were not affected by biochar, implying that BM was as labile as RM. The pH, total C (TC), NO3-N and Olsen P were also not influenced by biochar, although it was observed that NH4-N and OM extractability were both 13% lower in BM than RM. Solid-state 13C nuclear magnetic resonance (NMR) showed that biochar increased stockpile/compost aromaticity, yet it did not alter the bulk C speciation of manure OM. Further analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) revealed that dissolved OM was enriched by strongly reduced chemical constituents, with BM providing more humic-like OM precursors than RM. Inclusion of a pine-based biochar in cattle diets to generate BM is consistent with current trends in the circular economy, “closing the loop” in agricultural supply chains by returning C-rich organic amendments to croplands. Stockpiling/composting the resulting BM, however, may not provide a clear advantage over directly mixing low levels of biochar with manure. Further research is required to validate BM as a tool to reduce the C footprint of livestock waste management.

Increasing the Energy Supply of the Population of Remote Regions of the Republic of Kazakhstan with the Help of Compact Autonomous Bioenergy Plants

The economy of Kazakhstan is one of the largest agro-industrial economies in Central Asia with a developed cultivation of crops. For this reason, significant volumes of agricultural waste are generated. Currently, the resulting manure is not decontaminated and it is not processed: there are no systems for its disposal. Low temperatures contribute to the preservation of pathogenic microflora and weed seeds in manure piles, and in the spring with meltwater they fall into lakes and reservoirs. The lands of settlements and open water bodies are intensively polluted with organic and biogenic substances of animal manure. In addition, the population of the remote regions of the Republic of Kazakhstan needs energy supply (electricity, heat, and gas). In order to solve these problems, one of the promising options for the remaining and unused volumes of waste is to convert them into biogas. The article presents data of the developed autonomous biogas plant and the main results of biogas production in autonomous bioenergy plants for farms located in remote areas in a mesophilic regime.

Cost-Performance Evaluation of a Recognition Service of Livestock Activity Using Aerial Images

The recognition of livestock activity is essential to be eligible for subsides, to automatically supervise critical activities and to locate stray animals. In recent decades, research has been carried out into animal detection, but this paper also analyzes the detection of other key elements that can be used to verify the presence of livestock activity in a given terrain: manure piles, feeders, silage balls, silage storage areas, and slurry pits. In recent years, the trend is to apply Convolutional Neuronal Networks (CNN) as they offer significantly better results than those obtained by traditional techniques. To implement a livestock activity detection service, the following object detection algorithms have been evaluated: YOLOv2, YOLOv4, YOLOv5, SSD, and Azure Custom Vision. Since YOLOv5 offers the best results, producing a mean average precision (mAP) of 0.94, this detector is selected for the creation of a livestock activity recognition service. In order to deploy the service in the best infrastructure, the performance/cost ratio of various Azure cloud infrastructures are analyzed and compared with a local solution. The result is an efficient and accurate service that can help to identify the presence of livestock activity in a specified terrain.

68 Effect of a marine-sourced calcium on fecal pH in horses

Lithothamnium calcareum (LC) is a red, marine algae containing calcite in its cell walls. LC has been touted for its gastroprotective effects in horses attributed to the increased surface area of its honeycomb structure allowing greater acid-buffering capacity versus calcium carbonate. Effects on the equine hindgut have not been evaluated. This pilot study aimed to determine if LC (CalseaPowder, Nuwen, France) fed to horses at a rate of 4.6g/kg finished feed would alter fecal pH. Twelve mature horses (12.5 yrs ± 1.4, mean ± SEM, 6 mares, 6 geldings) in moderate exercise in the Ohio State ATI equine program participated in a randomized crossover study. Horses were maintained on 1.2-ha fields and brought into the barn for feeding and riding sessions. Horses transitioned onto the control feed over 2 wks (CON: SAFE ‘N EASY Performance, BUCKEYE Nutrition, Dalton, OH, 1.2% total Ca, 100% added was CaCO 3 ), formulated to meet or exceed NRC 2007 requirements for mature horses in light-moderate work. Horses were randomly assigned to receive either CON or CAL (CON + LC , 1.2% total Ca, added 74% CaCO 3 , 26% calcite) during the first test period then crossed over for the second. Horses acclimated to CON or CAL for 2 wks and were offered 0.5 kg feed per 100 kg bodyweight, divided into 2 feedings (0700 and 1600). Horses had access to mixed grass forage to supplement pasture, fresh water and salt ad libitum . At the end of the first 2-week trial period, horses were brought into stalls bedded with sawdust and observed. All fecal samples were collected immediately upon defecation (within 1–3 h post feeding) from the middle of the top of the manure pile to avoid bedding contamination and analyzed. Within 5 min, approximately 10 mL of fecal water was squeezed through cheesecloth from freshly defecated samples and stirred for 60s. Fecal water pH was then measured in duplicate with a calibrated pH meter. Diets were switched and the protocol repeated with 2 wk acclimation. Statistical analyses utilized R version 3.6.3, with significant differences declared when P ≤ 0.05. A linear mixed effect model was used with pH vs. diet and horse as a random effect. A Dunnett post-hoc comparison between the 2 diet groups was applied. There was no effect of period ( P = 0.66). There was an effect of diet ( P < 0.001). Horses consuming CAL had higher fecal water pH (6.87 ± 0.2; mean ± SD) compared with CON (6.69 ± 0.2). LC may be useful in supporting hindgut health in horses, especially when such changes in pH become clinically relevant (e.g., acidosis). Future work should examine the effects of different doses of LC on hindgut pH and its effects on the microbial population.

Methane emissions from cattle manure during short-term storage with and without a plastic cover in different seasons

AbstractManure is a primary source of methane (CH4) emissions into the atmosphere. A large proportion of CH4 from manure is emitted during storage, but this varies with storage methods. In this research, we tested whether covering a manure heap with plastic reduces CH4 emission during a short-term composting process. A static chamber method was used to detect the CH4 emission rate and the change of the physicochemical properties of cattle manure which was stored either uncovered (treatment UNCOVERED) or covered with plastic (treatment COVERED) for 30-day periods during the four seasons? The dry matter content of the COVERED treatment was significantly less than the UNCOVERED treatment (P &lt; 0.01), and the C/N ratio of the COVERED treatment significantly greater than the UNCOVERED treatment (P &gt; 0.05) under high temperature. In the UNCOVERED treatment, average daily methane (CH4) emissions were in the order summer &gt; spring &gt; autumn &gt; winter. CH4 emissions were positively correlated with the temperature (R2 = 0.52, P &lt; 0.01). Compared to the UNCOVERED treatment, the daily average CH4 emission rates from COVERED treatment manure were less in the first 19 days of spring, 13 days of summer, 10 days of autumn and 30 days of winter. In summary, covering the manure pile with plastic reduces the evaporation of water during storage; and in winter, long-term covering with plastic film reduces the CH4 emissions during the storage of manure.

Small things are important: the value of singular point elements for birds in agricultural landscapes.

Farmland birds belong to the most endangered group of vertebrates in Europe. They are an important component of farmland biodiversity considering the numerous functions they perform (e.g. seed dispersal, improving germination, increasing gene flow, nutrient recycling, and pest control). Therefore, their decline imposes substantial risks on agricultural ecosystems. In general, farmland bird conservation includes land-use and management alterations leading to less-intensive farming and land-sparing for breeding habitats (e.g. agri-environment-climate schemes, and organic farming). However, theoretical concepts describing farmland biodiversity maintenance and applied conservation measures usually ignore the role of singular, often very small, natural or man-made elements in an agricultural landscape. These elements play a role in the populations of certain species, their biology and in the general species richness of farmland. Furthermore, the importance of these elements has never been empirically tested, which means that conservationists and practitioners are not aware of their measurable value for birds. Herein, we define and identify singular point elements in the agricultural landscape (SPELs) which are potentially important for breeding farmland birds. We also describe each SPEL and evaluate its importance for birds in farmland based on a systematic review of the available literature. Using a horizon-scanning technique, we then polled field ornithologists about their personal observations of birds in relation to SPELs and the evaluation of the potential roles of such structures for birds. We identified 17 SPELs that vary in naturalness and age: singular trees, singular shrubs, erratic boulders, puddles, electricity pylons, wind turbines, spiritual sites, hunting platforms, fence and border posts, wells, road signs, scarecrows, piles of manure, piles of brushwood/branches, piles of stones/debris, piles of lime, and haystacks. Analysis of the literature revealed knowledge gaps, because some SPELs are frequently mentioned in ecological studies (e.g. trees, shrubs, pylons), but others such as spiritual sites, stones, hunting platforms, wells, road signs, or piles of lime are ignored. Despite the fact that some authors incorporate the effects of some SPELs in their studies, little research to date has aimed to assess the impact of various SPELs on farmland bird species numbers and distribution. Horizon scanning revealed that ornithologists often observe birds on various SPELs and thus, attribute to SPELs many functions that are important for maintaining bird populations. Horizon scanning also highlighted the importance of SPELs for many declining bird species and suggested possible mitigation of negative changes in the agricultural landscape by retaining SPELs within fields. We suggest that a better understanding of the role of SPELs for farmland birds is required. We also recommend that SPELs are considered as a potential tool for the conservation of birds, and existing conservation programs such as agri-environment-climate schemes and organic farming should be updated accordingly. Finally, we suggest that SPELs are included in predictive models that evaluate habitat suitability for farmland biodiversity.

Using the heat generated from electrically conductive concrete slabs to reduce antibiotic resistance in beef cattle manure

Proper treatment is necessary to reduce antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in livestock manure before land application. Conventional stockpiling suffers unreliable removal efficiency, while composting can be complicated and expensive. The objective of this study was to test the feasibility of a novel heat-based technology, i.e., stockpiling manure on conductive concrete slabs, to inactivate ARB and ARGs in beef cattle manure. In this study, two independent bench-scale trials were conducted. In both trials, samples were taken from manure piles on conductive concrete slabs and regular slabs (i.e., heated and unheated piles). In the heated pile of the first trial, 25.9% and 83.5% of the pile volume met the EPA Class A and Class B biosolids standards, respectively. For the heated pile of the second trial, the two values were 43.9% and 74.2%. In both trials, nearly all forms of the total and resistant Escherichia coli and enterococci were significantly lower in the heated piles than in the unheated piles. Besides, significant reduction of ARGs in heated piles was observed in the first trial. Through this proof-of-concept study, the new technology based on conductive concrete slabs offers an alternative manure storage method to conventional stockpiling and composting with respect to reduce ARB and ARGs in manure.