Manure Removal Research Articles

Effects of alkaline thermal hydrolysis on the formation of refractory compounds and energy balance of anaerobic digestion of cattle manure

Anaerobic digestion (AD) coupled with thermal hydrolysis pretreatment (THP) is appealing because it enhances the energy conversion rate of organic wastes. Here, cattle manure, the most abundant organic waste, was thermally hydrolyzed as a pretreatment of AD. In order to increase the process efficiency, a NaOH solution was introduced. Increasing the amount of NaOH addition during the THP enhances lignin removal and solubilization of cattle manure. The thermally hydrolyzed cattle manure (at 160 °C with 2 % (dry wt.) NaOH addition) showed a significantly higher biochemical methane potential of 227.0 ± 11.0 mL-CH4/g-volatile solid compared to that of intact cattle manure (182.2 ± 2.5 mL-CH4/g-volatile solid). Refractory compounds (humic acid-like substances and furfural) were identified at THP temperatures above 180 °C without NaOH addition, and it was enhanced by increasing NaOH addition. Energy balance analysis showed that additional 161.4 ± 39.3 MJ of energy can be gained per ton of cattle manure by applying THP (at 160 °C without NaOH addition). This study provides insights into the changes in the physicochemical and biochemical properties of cattle manure caused by alkaline THP.

Impact of Farm-Scale on Animal Management Practices in Pırlak Sheep Enterprises

This research aims to determine the effect of the farm-scale on the management practices applied in Pırlak sheep farms in the Emirdağ District of Afyonkarahisar province. The study was carried out in 56 Pırlak sheep farms, determined by a simple random cluster sampling method. Pırlak farms were assigned to small (101 heads) farms scale groups, taking into account the total number of sheep and rams. Management practices related to farm inputs, storage, animal feeding and grazing, milking, shearing, breeding, lamb care, marketing, animal health, and welfare were determined by creating measurements and observations in the farms and interviewing the farmers face to face. In general, animal feeding management in Pırlak farms, where traditional sheep farming was carried out, was mainly based on the common village pasture, and various amounts of concentrated feed were supplemented without determining the animals' real needs. The barns were soil, and air quality and dry litter were poor in this sheep with standard construction features. There were no rams, lambs, or maternity pens in the barns, and very few farms had maternity pens. It has been determined that performance records, animal diseases, and treatments were not kept, and the frequency of cleaning sheep equipment and manure removal was insufficient. Grazing, milking, lamb care, breeding, and shearing methods were accomplished mainly with traditional methods and manual. it has been understood that there are essential structural and managerial deficiencies in animal care and management in Pırlak farms, and the effect of farm scale is generally insignificant. In addition, it has been determined that Pırlak sheep farmers need to be trained in animal health, welfare, and business economics in order to support these family-type farms.

Biosecurity practices on commercial layer farms in Abyek county, Qazvin, Iran: A cross-sectional study

Objective: To investigate the biosecurity measures practiced at commercial layer chicken farms in Abyek country, Qazvin, Iran.. Methods: In this cross-sectional study, all licensed and active commercial layer chicken farms in Abyek county, Qazvin province, Iran in 2019 were recruited. We used a risk-based weighted scoring system (Biocheck.UGent) to assess the level of biosecurity according to internal and external classification. Biosecurity was quantified by converting the answers to 169 questions into score from 0 to 100. The minimum score, “0,” represents total absence of any biosecurity measure on the farm, whereas the maximum score, “100,” means full application of all investigated biosecurity measures. Results: The mean score of overall biosecurity in the commercial layer chicken farms in Abyek county, Qazvin province was 72.7. The mean score of internal and external biosecurity measures were 77.1 and 72.2, respectively. The lowest mean score was due to “Disease management” (69.7) among internal biosecurity measures and the lowest mean scores were for "Location of farm” (39.0) and “Removal of manure and dead animals” (42.6) among external biosecurity measures. The highest mean score was for “Transport of the eggs level” (91.0) for external biosecurity measures. Conclusions: This study showed the biosecurity status of commercial layer chicken farms in Abyek county, Qazvin, Iran and revealed some weaknesses in the implementation of these measures at the internal and external levels. It showed the biosecurity measures of these farms, especially at the external levels need to be improved. This information can aid decision-making on efforts used to improve disease control and prevention strategies in poultry farms.

COMPARATIVE ASSESSMENT OF SANITARY AND HYGIENIC NORMS OF HOUSING PIGS ACCORDING TO DIFFERENT PARATYPICAL FACTORS

Introduction. The relevance of the work is determined by the implementation of the method of multi-parametric assessment of the microclimate of premises for pigs by the method of continuous automatic registration. The purpose o f the research was to conduct a comparative assessment of indoor pollution with carbon dioxide, ammonia, hydrogen sulfide, methane, and fine dust based on various paratypical factors. Research methods. Analytical, zootechnical, physical, ethological and biometric research methods are applied. Research results. A comparative assessment of the sanitary and hygienic norms for housing pigs in brick premises on concrete and slotted floors in machines was carried out. It was determined that during the periods of the year, the average daily CO2 and NH3 air pollution in pig houses with concrete and slotted floors in the machines were close to the normative values of MPC. The volume concentration of methane was 1.9-3.4 times higher in the premise with a slotted floor in the machines, which is associated with the features of the technology of the self-alloying system of manure removal. According to the calculations of the correlation between the temperature and the relative humidity of the air outside and inside the premises, a probable mostly positive connection was determined. The locomotor activity indices of young pigs were 9.6-12.4 % higher on the slatted floor, but they were inferior in the food activity index by 6.4-16.2 % to peers kept on the concrete floor. The variance analysis determined the probable influence fi=0.784) of the method of housing pigs on solid concrete and slotted floors in machines on the variability of the volume concentration of methane. It was also found out that the period of the year likely influenced the variability of air temperature, volume concentration of carbon dioxide, ammonia and mass concentration of fine dust in the room fi= 0.799; 0.794; 0.352 and 0.439, respectively). Conclusions. The average daily volume concentration in the air of carbon dioxide and ammonia in pig houses by periods of the year approached the normative values of the MPC. The volume concentration of methane was higher in the premise with a slotted floor, which is related to the features of the technology of the self-alloying manure removal system. The probable influence of the method of housing pigs on the variability of indicators of relative air humidity and volume concentration of methane wasdetermined. The probable influence of the period of the year on the variability of air temperature indicators, volume concentration of carbon dioxide, ammonia and mass concentration of fine dust has also been proven. Key words: measuring and computing complex, microclimate parameters, comparative assessment, premise for pigs, paratypic factor

Застосування мехатронних систем в системі машин для тваринництва

The purpose of this work is the systematization of research and implementation of mechatronic systems in the system of machines for keeping, caring for and obtaining the primary products of animal husbandry. The use of mechatronic systems in keeping animals and poultry, providing a microclimate, watering, feeding, removing manure and obtaining products is considered. The development of mechatronic systems in the animal husbandry system involves controlling the movement of animals through the farm, which is mainly provided by pre-selection gates. Unmanned aerial vehicles can also be used for animal monitoring when animals are kept out on pasture. To ensure the proper microclimate in modern ventilation systems, programmable multi-stage controllers are used to control the ventilation equipment. Introduction of elements of mechatronic systems into animal watering, there was a means of controlling the consumption of water individually by each animal. The application of mechatronic systems is also in stationary feed distribution systems, in mobile systems such as self-propelled or coordinate mixer dispensers, feed pushers, as well as in systems for recognizing the weight and size of animals to automatically change the amount of feed given to individual animals. The implementation of mechatronic systems in manure removal systems is realized in automated scraper systems and in mobile manure cleaning robots. There are also machines for milking and collecting eggs equipped by mechatronic systems. Conducted research shows that almost all mechanized processes of keeping, care and obtaining products in livestock and poultry farming use mechatronic systems, which already either have specific design solutions and are used on farms or are still at the stages of development and research. The main driving force behind the introduction of mechatronic systems in animal husbandry is the reduction of labor costs, improved control over mechanized processes on the farm, improvement of the performance of mechanized technological processes and ensuring the welfare of animals.

DISPOSAL OF MANURE AT THE PIGGERY USING BIODESTRUCTORS OF DIFFERENT ORIGIN

The development of biotechnological methods of disposal of pig waste products is relevant at the current stage. However, the high cost of investment and operation of such technologies limits their application. Therefore, owners of pig farms are constantly looking for compromise solutions that would, on the one hand, ensure compliance with technological requirements for manure removal, and on the other hand, not pollute the environment. The purpose of the work is to improve existing technologies and develop innovative approaches to biotechnological methods of manure disposal. Scientific research was carried out at the piggery of Agroprime Holding LLC of the Odesa region with a capacity of 30,000 heads per year. The considered technology of using biological preparations De-Scentase and Complesin for descentization of manure in underground baths, manure storages, manure sites of the complex. The content of gases in the manure subfloor bath of the piggery due to the use of biological preparations was determined. The conducted monitoring of unpleasant scents and harmful gases confirmed the expediency of using new methods of neutralizing unpleasant scents. It was established that the reconstruction of the separator station by installing a metal hangar and a water-dispersion filtration chamber ensured the neutralization and release of scentous gases into the environment and did not affect the ecological state of the environment negatively. On the basis of the conducted research, the method of wide application of the biological preparation for the disposal of manure has been developed. The improved technology of manure disposal at the piggery, which involves the addition of the microbial destructor drug Complesin to underground baths, as well as to manure storages and manure sites, helps to reduce the release of harmful gases and accelerates the disposal of manure. The technology of utilization of liquid and solid fraction of manure by using biological preparation and vermiculture is highlighted. The experience of using equipment for underground application of liquid manure to fields is presented.

THE INFLUENCE OF VOLTAGE UNSYMMETRY ON THE ENERGY CHARACTERISTICS OF MANURE REMOVAL CONVEYORS

It was established that the greatest impact on electric drives of production machines and mechanisms has deviations and asymmetry of the voltage. Voltage asymmetry leads to losses that have an electromagnetic and technological component. Studies of the influence of voltage asymmetry on the technological characteristics of working machines and mechanisms have shown that their productivity decreases with voltage asymmetry. However, there are no studies on the influence of voltage asymmetry on the energy characteristics of working machines. The purpose of the study is to determine the influence of voltage asymmetry on the energy characteristics of manure removal conveyors. When the voltage is asymmetric, the constant and variable power losses in the asynchronous electric motor of manure removal conveyors change, which affects their energy characteristics. It is proposed to carry out an energy assessment of the electric drive of the manure removal conveyor based on the specific consumption of electricity. A study of the effect of voltage asymmetry on the energy characteristics of manure removal conveyors was conducted. The dependence of the specific power consumption on the change in stiffness of the mechanical characteristics of the electric motor, which is caused by voltage asymmetry, is obtained. Since the stiffness of the mechanical characteristics of the asynchronous motor decreases with voltage asymmetry, slippage and power losses increase. As a result, specific losses of electricity in the electric drive of manure removal conveyors increase.

PREVALENCE OF TICKS AND RISK FACTORS ASSOCIATED WITH THE INFESTATION OF SHEEP IN RIVER NILE STATE, SUDAN

A cross-sectional study was conducted in River Nile State, Sudan, between June to August 2018 to determine the prevalence of tick infestation on sheep and the potential risk factors associated with the infestation. A total of 135 sheep from five different localities (Shendi, Al Matamah, Ad-Damer, Atbara, and Berber) were examined and, of these, 90 were tick-infested (66.7%). A total of 340 ticks (male 185, female 155) were collected and identified using zoological taxonomic keys. The most dominant tick species collected in this survey were Rhipicephalus eversti Neumann, 1897 (38%), followed by Hyalomma anatolicum Koch, 1844 (23.8%), Rhipicephalus sanguineus Latreille, 1806 (20.6%), Rhipicephalus praetextatus Gerstacker, 1873 (16.4%), and Hyalomma dromedarii Koch, 1844 (1.2%). The chi-square analysis showed that there was a significant association (p ≤ 0.05) between tick infestation and localities, housing type, sex, control of ticks, and removal of manure. The highest prevalence rate was recorded in Atbara, in the open housing type, in females, in farms that did not use acaricides and did not remove the manure frequently. On the other hand, there was no significant association (p ˃ 0.05) between tick infestation and herd size, rearing system, breed, age and colour of coat (p=0.846). This study expanded the knowledge on tick fauna and associated risk factors in the River Nile State, and it demonstrated that multiple tick species are infesting sheep with the potential to transmit several tick-borne diseases.

Solid-phase denitrification and denitritation of swine manure-contaminated waters: Bioreactor performance and microbial community profiles

Waste streams from livestock facilities contribute to water contamination by nitrogenous compounds and a feasible approach for their treatment is needed. In this work, a microbial culture, originally developed for anoxic biodegradation of naphthenic acids, was used in woodchip bioreactors to evaluate denitrification and denitritation in medium simulating livestock wastewaters. Effects of nitrate and nitrite concentrations (10–150 mg L−1), loading rate (0.8–2000.2 mg L−1 day−1), manure content (0–10%), and residence time (0.04–11.26 day) on the performance of bioreactors operated with nitrate, nitrite or their mixture were investigated. The highest nitrate removal rates for nitrate alone were achieved at loading rates of 1000–1500 mg L−1 day−1 and 9–10% manure (removal rate ≥ 400 mg L−1 day−1), and for nitrate in mixture at 775–1150 mg L−1 day−1 and 7–10% manure (removal rate ≥ 350 mg L−1 day−1). For nitrite alone, these were 1000–1500 mg L−1 day−1 and 0–2% manure (removal rate ≥500 mg L−1 day−1) and 600–850 mg L−1 day−1 and 5–10% manure (removal rate ≥ 300 mg L−1 day−1) for nitrite in mixture. High nitrite concentration (75–100 mg L−1) negatively impacted its removal rate in mixture with nitrate or alone. Bioreactors microbial profiles were different from each other and from the stock cultures. Cloacimonetes, Firmicutes, and Proteobacteria phyla were prevalent in all bioreactors, but Bacteroidetes was seen only in the nitrate and nitrite bioreactors. At the class level, Candidatus cloacamonas, Thiomicrospira and Pseudomonas were seen in all bioreactors but Acidovorax and Comamonas were significant only in the nitrite bioreactor.

Calculation methods of a combined resourcesaving system of manure removal on pig-rearing complexes

Relevance. The use of liquid fraction of pig manure as technical water for manure removal is a resourcesaving solution. Applying this solution in designing combined resource-saving manure removal systems requires calculation and accounting methods for the manure nutrients and suspended matter, which pass into the solid and liquid fractions during manure separation. The study aimed to develop a methodology for calculating the quantity and quality of manure fractions for the case when a part of the liquid fraction would be used in the manure removal system.Methods. Calculations were based on the data from a pig rearing complex located in the Leningrad region, with 65,100 heads on the complex at any one time. The calculation results were compared with the actual values from the protocols of laboratory analyses.Results. The developed methodology will allow the farm to make a more efficient accounting plan for nutrients passing into organic fertilisers. It will also save up to 47 450 tons of clean water for the manure removal system per year.

REDUCED THE CONSUMPTION OF PROCESS WATER FOR GROWING-FINISHING YOUNG PIGS

The production of meat products requires significant direct and indirect water expenditures. Our research was aimed at improving technological methods to reduce the consumption of process water during the growing-finishing phase in young pigs. It was found that the use of technological method to reduce the consumption of process water for manure removal, which consists in reducing the level of filling baths with water in the first growing-finishing phase to 0.05 m, in the second phase - to 0.07 m, allowed to reduce the average daily water consumption by 36.8% compared to the normal operation of a self-alloying intermittent manure removal system. At the same time, the temperature-humidity conditions and gas composition of indoor air corresponded to the normative requirements.

Losses of phosphorus, potassium and nitrogen from horse manure left on the ground

ABSTRACT In this five-month Swedish field study, we examined losses of nutrients from horse manure over time, in order to examine how regularly manure should be cleared from paddocks in order to minimise the risk of nutrient leaching. Small heaps of manure (400 g) were placed in open cylinders outdoors and samples (five replicates) were taken on 12 occasions from December 2020 to May 2021. The samples were analysed for weight, dry matter content and concentrations of total nitrogen (N), ammonium N, total phosphorus (P), water-extractable P (WEP), potassium (K) and carbon (C). There was a fast decline in P and K concentrations and a strong correlation between accumulated precipitation and losses from the manure into the soil. The mean reduction in total-P was 11 mg P kg−1 manure dry weight per mm accumulated precipitation. Manure N was retained in the manure over the five-month period. In conclusion, this study demonstrated high mobility of P and K, indicating a need for strategies for rapid removal of manure from paddocks. Daily removal of manure from paddocks used year-round would, approximately, save 1.7 kg P and 5.5 kg K per horse per year, which could be recycled to replace non-renewable mineral fertilisers.

Working Mechanism and Parameter Optimization of a Crushing and Impurity Removal Device for Liquid Manure

Aiming to solve the problems of easy clogging and high energy consumption of multi-way fertilization devices for liquid manure, a crushing and impurity removal device for liquid manure was designed by combining the physical characteristics of liquid manure and impurities, and building the corresponding test bench. The proposed device could crush flexible impurities such as straw and filoplume and intercept hard impurities with high density. The main structural parameters of the device were determined according to the survey analysis and the theoretical design. The influences of cutter head shape, cutter edge angle, cutter shaft speed, and cutting clearance on the disqualification rate and energy consumption of straw crushing were obtained by a single-factor experiment. Furthermore, the Box–Behnken central composite design method of the response surface was employed to investigate the effects of the cutter shaft speed, cutting clearance, and cutter edge angle on the disqualification rate and energy consumption of straw crushing. In addition, the working parameters of the device were optimized by employing the response surface method. On this basis, the mathematical relationship model among the disqualification rate, energy consumption, and all influencing factors was established. The results show that the optimal combination of working parameters includes a cutter shaft speed of 312 r/min, a cutting clearance of 1.4 mm, and a cutter edge angle of 45°. From the prediction model, the predicted failure rate was 4.15%, and the predicted energy consumption was 47.53 J. The verification experiment was then performed under the optimal combination of working parameters. The obtained disqualification rate was 4.08% and the energy consumption was 47.56 J, which met the design and work requirements.

Effects of Manure Removal Frequencies and Deodorants on Ammonia and GHG Concentrations in Livestock House

In order to mitigate the concentration of NH3 and greenhouse gases (GHGs: CO2, N2O, CH4) in livestock houses, two experiments, one determining the ideal manure removal frequency by cleaning the feces from a livestock house once, twice, three, and four times a day, and one in which microbial deodorant and VenaZn deodorant were sprayed, were conducted in a rabbit breeding house. The NH3, CO2, N2O, and CH4 concentrations were monitored continuously with an Innova 1512 photoacoustic gas monitor during the experiments. The results were as follows: the manure removal frequency had a significant impact on the average concentrations of NH3, CO2, and CH4 in the rabbit house. Cleaning the feces in the rabbit breeding house two to three times a day significantly reduced the NH3 concentration, and, on the contrary, cleaning the feces four times a day increased the NH3 concentration in rabbit house; increasing the manure removal frequency significantly reduced the concentrations of CO2 and CH4 in the rabbit house. Considering the average concentrations of NH3, CO2, N2O, and CH4 in the rabbit house and economic cost, it was better to remove feces twice a day. The average NH3 and CO2 concentration declined significantly within 3 days in the summer and winter; the N2O concentration declined within 3 days in the summer but did not decline in the winter; and there was no effect on the CH4 concentration in the summer and in the winter after spraying the rabbit house with microbial deodorant. Therefore, it was better to spray microbial deodorant twice a week on Monday and Thursday to reduce the NH3, CO2, and N2O concentrations in rabbit houses. The NH3, CO2, N2O, and CH4 concentrations first showed a decreasing trend and then an increasing trend over 5 days in the summer and 7 days in the winter after VenaZn deodorant was sprayed in the rabbit house, and the NH3, CO2, N2O, and CH4 concentrations on day 3 and day 4 were significantly lower than they were on the other days.

Impact of slurry removal frequency on CH4 emission and subsequent biogas production; a one-year case study

Anaerobic digestion of animal slurry to produce biogas is the dominated treatment approach and a storage period is normally applied prior to digestion. Pre-storage, however, contributes to CH4 emissions and results in loss of biogas potential. Manure management was found to be an efficient approach to reduce not only the on-site CH4 emission but may also have extended influence on CH4 emission/losses for storage and subsequent biogas process, while the connection remains unclear. The objective of this study was therefore to evaluate the impact of slurry management (e.g. removal frequency) on CH4 emission (both on-site and storage process prior to biogas) and biogas yield. An experimental pig house for growing-finishing pigs (30–110 kg) and the relevant CH4 emission was monitored for one year. In addition, the specific CH4 activity (SMA) test was conducted and used as an alternative indicator to reflect the impact. Results showed that the manure management affected both on-site and subsequent methane emission; with increased manure removal frequencies, the methane emission became less dependent on variation of temperatures and the specific methanogenesis activity was significantly lower. The highest SMA (100 mL CH4 gVS-1), for instance, was observed from the slurries with limited emptied times, which was 10 times of that from the slurries being emptied three times a week. These findings could enlighten the development of environmentally friendly strategies for animal slurry management and biogas production.

Correction to: Identification of Size-segregated Bioaerosol Community and Pathogenic Bacteria in a Tunnel-ventilated Layer House: Effect of Manure Removal

Correction to: Identification of Size-segregated Bioaerosol Community and Pathogenic Bacteria in a Tunnel-ventilated Layer House: Effect of Manure Removal

Characterizing manure drying practices in Iowa commercial egg production facilities

As laying hen housing styles change throughout Iowa to meet legislative and consumer demands, drying of manure can be economically expensive and energy intensive. With about 50% of total electricity consumption and about 60% of annual electricity costs attributed to manure drying, this represents an opportunity for producers to decrease production costs while reducing electrical grid strain. To understand current practices and potential opportunities, survey data were collected from 34 Iowa egg producers in fall 2020, representing egg-laying ( n = 50), breeding ( n = 30), and rearing ( n = 20) facilities. Average (± SD) reported number of weekly manure removal events was 2.2 ± 0.50 for all housing styles with 2.4 ± 0.09 for cage-free aviaries and 2.2 ± 0.58 for conventional cage. Reported daily manure blower operation was 14.2 ± 11.0 h/d for all facilities, with cage-free aviaries operating blowers for 10.0 ± 11.8 h/d while conventional cage houses operated blowers for 15.1 ±10.8 h/d. On a per thousand bird basis, reported overall energy usage was 10.1 kWh per day, 308 kWh per month, and 3.7 MWh per year. Energy costs per thousand birds were US$0.81 per day, US$25 per month, and US$296 per year. Respondents from 16 facilities reported their facility did not have smart meters (i.e., monitoring voltage, current, power factor, and energy consumption), while 10 reported smart meter usage and 5 reported they were unsure. Managers were no more likely to be aware of facility peak demand or track peak demand regardless of whether the facility had a smart meter (aware: P = 0.09; track: P = 0.26). Interestingly, all 21 respondents reported being aware of peak demand incentives; however, only 9 (43%) respondents indicated their facilities participate in these incentives. These results provide a characterization of manure drying practices and energy usage in Iowa egg production facilities. There are opportunities to impact the manure drying process through control strategies that optimize blower energy based on environmental conditions, target manure moisture content, and peak demand periods.

Evaluating the 2019 IPCC refinement for estimating methane conversion factors in Canada

Methane emissions from liquid manure management in Canada are an important greenhouse gas source. A wide range of seasonal temperatures, distribution of livestock farms, and various management practices in Canada means that regional methane conversion factors (MCF) that account for spatially discrete climate and management should be used. This study explores the impacts of using the 2019 IPCC Refinement methodology on estimates of MCFs across Canada. MCFs were calculated for 3403 locations across Canada using historical weather data, with varying management parameters at each location (emptying efficiency, timing, and frequency of manure removal). Sensitivity to two model parameters was also evaluated (minimum manure temperature, damping factor). Results showed the influence of climate, as average MCF in each ecozone ranged from 0.27 in the Mixedwood Plains to 0.15 in the Taiga. Further climate variation within ecozones was evident. For example, the MCF range within Mixedwood Plains was 0.17 to 0.33. The MCF reduction by improving management was evident as the average MCF in Canada was 0.15 for triannual removal, 0.21 for biannual removal, 0.28 for one-time removal in spring, and 0.32 for one-time removal in fall. Emptying efficiency was found to be critical; for example, the average MCF for triannual removal with 100% efficiency was 0.14 but increased to 0.15 at 95%, 0.17 at 85%, and 0.30 at 50% efficiency. The damping factor had higher sensitivity in terms of model parameters because it influences peak manure temperature in summer before manure removal. Our results suggest that the average MCF in Canada will be similar to the 2006 IPCC value, but that using the 2019 IPCC Refinement provides a greater ability to represent the variations in climate and management regionally across the country. This will improve accuracy and enable inventory practitioners to reflect regional farm management changes in national methane emission estimates.

Spatiotemporal Distribution of Ammonia Emissions from Poultry Farming in the Yangtze River Delta Based on Online Monitoring Derived Local Emission Factors

In order to obtain the ammonia emission level and space-time distribution characteristics of the poultry production industry in the Yangtze River Delta, an online high-resolution monitoring system was used to continuously monitor the atmospheric ammonia concentration in the breeding house and compost shed in a typical large-scale layer farm. By obtaining the ammonia emission level and emission factor during each growth stage, we established the localized ammonia emission inventory for the poultry production industry in the Yangtze River Delta. The results showed that the average daily ρ(NH3) in the breeding house and compost shed for spring, summer, autumn, and winter were (1.85±0.38), (4.58±0.33), (3.87±0.12), and (2.83±0.47) mg·m-3 and (2.04±0.50), (4.04±1.04), (2.51±0.67), and (1.55±0.16) mg·m-3 respectively. Ammonia emissions showed a significant daily hourly change trend. The highest hourly ammonia concentration in the layer house appeared from 13:00-14:00 in the afternoon, and the minimum appeared from 01:00-03:00 in the morning. The highest hourly ammonia concentration in the compost shed occurred between 16:00-19:00 in summer and autumn, whereas the diurnal changes in spring and winter were not significant. Hourly changes in ammonia emissions during the day were mainly affected by daily temperature, poultry activities, and manure management. Ammonia concentrations at different growth stages of laying hens showed significant differences. ρ (NH3) from young chickens, laying hens, and pre-eliminated chickens were (1.85±0.38), (2.83±0.47), and (1.61±0.32) mg·m-3, respectively. The ammonia emission rate from laying hens reached 1.53 times and 1.65 times that of young chickens and pre-eliminated chickens, respectively. Metabolism levels and feed intake at different growth stages were the main reasons for the differences in ammonia emissions. Ammonia emission factors for the layer house and compost shed in spring, summer, autumn, and winter were (0.13±0.02), (0.54±0.01), (0.39±0.01), and (0.17±0.01) g·(bird·d)-1 and (0.07±0.01), (0.17±0.02), (0.08±0.01), and (0.04±0.01) g·(bird·d)-1, respectively. Annual ammonia emission factors reached (0.11±0.06) kg·(bird·a)-1 and (0.03±0.02) kg·(bird·a)-1, respectively. Our results suggest that ambient temperature, ventilation mode, chicken house type, and manure removal frequency were the main influencing factors of ammonia emissions from poultry production. The uncertainty ranges of the ammonia emission coefficients reached±122%,±79%, and±74%, and±56%, respectively. Great uncertainties were generated when empirical emission factors were used for emission inventory establishment. Based on the results of online monitoring, model simulation, and literature analysis, we established an ammonia emission inventory for the poultry production industry within the Yangtze River Delta region by adopting the emission factors of (0.16±0.08) kg·(bird·a)-1. In 2019, the total ammonia emission from poultry production was (108.81±54.41) kt. In terms of spatial distribution, ammonia emission intensities in the northern regions were significantly higher than those in the southern parts. The ammonia emission intensities during summer were 3.38-3.56 times higher than those in spring and winter.

Productive traits of calves depending on the method of their rearing

The rearing of young animals is an important and fundamental stage in obtaining highly productive animals. The traditional technology of calves rearing in typical heated rooms provides for significant costs for their heating, ventilation, manure removal and feeding. The purpose of the work was to study the productive traits of calves depending on the method of their rearing. Research has been carried out to study the influence of different conditions of housing calves during the preweaning period under conditions in the farm “Ershov” (Vykhodnyi village) in the Buguruslansky area in the Orenburg region. The influence of housing methods on the dynamics of live weight, morphological and biochemical parameters of blood, conformation characteristics and body type indices of replacement heifers has been established. During the entire study period the average daily gain in calves of the experimental group was higher by 66 g or 9,4 % (P < 0,05), live weight by 7,0 kg or 6,9 % (P < 0,05). There was no significant difference in the morphological and biochemical parameters of the blood of the experimental calves. At 3 months of age the animals of the experimental group had superiority in all the measurements taken: in height at the withers by 2,0 cm or 2,2 % (P < 0,05), height in the rump bone by 0,5 cm or 0,5 %, length of the body by 2,8 cm or 3,1 %, chest width by 0,9 cm or 3,6 %, chest depth by 1,5 cm or 3,9 %, chest circumference by 2,0 cm or 1,9 %, width in hook bones by 0,4 cm or 1,8 %, hip joint width by 1,1 cm or 5,4 % (P < 0,05), rump half–circumference by 1,0 cm or 2,2 %, pastern circumference by 0,1 cm, or 0,8 %, compared with the corresponding indicators of calves of the control group.. Similarly, the calves of the experimental group had superiority over the analogues of the control group in terms of body type indices. Thus, according to the thoracic index the calves of the experimental group outperformed their herdmates by 9,2 abs.% (P < 0,01) and according to the meatness index they outperformed the herdmates of the control group by 3,5 abs.% (P < 0,05).