S<span>everal challenges are associated </span></span><span style="font-family:"">with</span><span style="font-family:""> the development, adoption and...S<span>everal challenges are associated </span></span><span style="font-family:"">with</span><span style="font-family:""> the development, adoption and de</span><span style="font-family:"">ployment of biogas digesters in developing countries. Amongst these challenges is a comprehensive and systematic procedure for the design of digesters suitable for rural communities. This paper proposes the Flexible Biogas Digester System (FBDS) as a viable option for rural communities in developing countries and provide</span><span style="font-family:"">s</span><span style="font-family:""> a detailed step-by-step procedure for it</span><span style="font-family:"">s</span><span style="font-family:""> design. The biogas production process is a function of the digester operating factors which may be grouped into physical, process and performance parameters. The physical design parameters include</span><span style="font-family:""> </span><span style="font-family:"">the digester volume, the volume of the biogas storage tank, and the volume of the installation pit. The process parameters include total solid content of the slurry (TS), organic loading rate (OLR), digester operating temperatures, pH of the slurry inside the digester. The performance parameters include</span><span style="font-family:""> </span><span style="font-family:"">biogas production rate, biogas productivity and biogas quality. The Net Present Value and the Levelised Cost of Energy are presented for simple economic evaluation of the FBDS.展开更多
Pulping production process produces a large amount of wastewater and pollutant emitted, which has become one of the main pollution sources in pulp and paper industry. To solve this problem, it is necessary to implemen...Pulping production process produces a large amount of wastewater and pollutant emitted, which has become one of the main pollution sources in pulp and paper industry. To solve this problem, it is necessary to implement cleaner production by using modeling and optimization technology. This paper studies the modeling and multi\|objective genetic algorithms for continuous digester process. First, model is established, in which environmental pollution and saving energy factors are considered. Then hybrid genetic algorithm based on Pareto stratum\|niche count is designed for finding near\|Pareto or Pareto optimal solutions in the problem and a new genetic evaluation and selection mechanism is proposed. Finally using the real data from a pulp mill shows the results of computer simulation. Through comparing with the practical curve of digester,this method can reduce the pollutant effectively and increase the profit while keeping the pulp quality unchanged.展开更多
Biogas from livestock waste is considered as clean and renewable energy in Vietnam. In the last 20 years, in rural and remote areas of Vietnam, there has been a significant increase of small-scale household biogas dig...Biogas from livestock waste is considered as clean and renewable energy in Vietnam. In the last 20 years, in rural and remote areas of Vietnam, there has been a significant increase of small-scale household biogas digesters. Biogas digesters create the benefits of replacing energy and mitigation of climate change caused by greenhouse gas （GHG） emission and deforestation for firewood and charcoal. Livestock waste produces approximately 85 million tonnes every year and continues to increase, meaning there are huge feedstocks for biogas digesters to meet the energy demands in households. However, there are also many constraints on the development programme for small-scale household biogas digester. In Vietnam, the socio-economic situation and the lack of a sustainable energy policy for biogas from livestock sector are hindering the growth of the biogas digester industry. Government subsidies are needed to encourage farmers to participate. This paper will be helpful not only for the sustainable development of household biogas in Vietnam, but also for the developing program of biogas generation in developing countries with similar agricultural economies to Vietnam.展开更多
A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this ...A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this equipment, which could be used to test different materials and be able to apply these results to the possible scaling to bio-digesters installed in the field. The experiments were carried out in a hybrid system bio-digester photovoltaic cells. The bio-digester is made of stainless steel with dimensions to treat an average of 10 kg of raw material and produce biogas from different organic materials. The reactor has been conditioned with temperature sensors, pressure and methane gas that allow monitoring the concentration of the gas and the conditions of operation during the time of digestion. The system has a photovoltaic array to provide the energy required to keep the temperature constant, The experiment was conducted using materials such as goat manure mixed with household waste, and various formulations of these materials were prepared. The experimental results were used to test the mathematical model.展开更多
This study allowed us to highlight the level of pollution of a BAYA River water near several poultry farms and the sizing of an anaerobic digester that will be able to treat chicken manure from a poultry farm (BRIN FO...This study allowed us to highlight the level of pollution of a BAYA River water near several poultry farms and the sizing of an anaerobic digester that will be able to treat chicken manure from a poultry farm (BRIN FOUNDATION). To evaluate this pollution, the parameters such as ammonium (NH<sub>4</sub><sup>+</sup>), Phosphate (PO<sub>4</sub><sup>3-</sup>), Biochemical Oxygen Demand (DBO<sub>5</sub>) and Nitrate (NO<sub>3</sub><sup>-</sup>) were determined. For sampling point P1, the concentrations in mg/L of these parameters are (25.00 ± 4.25), (0.40 ± 0.20), (98.00 ± 6.35) and (96.00 ± 5.35), respectively. On the other hand, for sampling point P2, the concentrations in mg/L of these parameters are respectively (33.00 ± 9.05), (0.70 ± 0.12), (123 ± 7.13) and (93 ± 7.10). These values indicate a strong organic pollution of the BAYA River. The determination of the different concentrations of the organic pollution parameters allowed us to evaluate the degradation and the quality of the water of the BAYA River water, by the poultry activity. However, considering the physicochemical properties of the waste (chicken manure), which is the main source of organic pollution, we have considered an energy recovery through the production of biogas. This requires the design, sizing, and implementation of an anaerobic digester in a poultry farm. Therefore, the project would require the construction of an adapted masonry type anaerobic digester with a capacity of 10 m<sup>3</sup>.展开更多
The quality of the resulting pulping continuous digesters is monitored by measuring the Kappa number, which is a reference of residual lignin. The control of the kappa number is carried out mainly in the top of the di...The quality of the resulting pulping continuous digesters is monitored by measuring the Kappa number, which is a reference of residual lignin. The control of the kappa number is carried out mainly in the top of the digester, therefore it is important to get some indication of this analysis beforehand. In this context, the aim of this work was to obtain a prediction model of the kappa number in advance to the laboratory results. This paper proposes a new approach using the Box & Jenkins methodology to develop a dynamic model for predicting the kappa number from a Kamyr continuous digester from an eucalyptus Kraft pulp mill in Brazil. With a database of 1500 observations over a period of 30 days of operation, some ARMA models were studied, leading to the choice of ARMA (1, 2) as the best forecasting model. After fitting the model, we performed validation with a new set of data from 30 days of operation, achieving a model of 2.7% mean absolute percent error.展开更多
A domestic balloon-type digester with 1200 liters of substrate and a 700-litre gas reserve was installed at the Université Gaston Berger pilot farm, which has 4 cows. After an initial load of 1000 L of water, 90 ...A domestic balloon-type digester with 1200 liters of substrate and a 700-litre gas reserve was installed at the Université Gaston Berger pilot farm, which has 4 cows. After an initial load of 1000 L of water, 90 L of bovine rumen and 145 L of cow dung, the functional parameters of the reaction medium, i.e., temperature, pH, salinity and conductimetry, were regularly monitored at a rate of 3 tests per day until the thirtieth day, corresponding to the flame test and the start of analysis and daily loading of the biodigester. The analysis of the biogas obtained after the flame test showed us the considerable contribution of bovine hindquarters to the CH4 fraction, which reached 72.2% from the start of the production phase. As anaerobic digestion is both a complex and multiparametric process, microbiological analysis revealed the presence of several strains of bacteria in the substrate used. Among the most abundant were Escherichia coli, Klebsiella spp, non-fermentative Gram-negative bacilli and Enterococcus sp. However, the bacterial strain that interests us most in anaerobic digestion is the non-fermentative Gram-negative family. We see the identification and temporal monitoring of these families of bacteria as a major step forward in the control of anaerobic fermentation processes in the Sahelian context and in Senegal in particular.展开更多
Anaerobic digestion （AD） is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Des...Anaerobic digestion （AD） is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Despite extensive efforts, AD microbial ecology is still limitedly understood, especially due to the lack of quantitative information on the structures and dynamics of AD microbial communities. Such knowledge gap is particularly pronounced in sewage sludge AD processes although treating sewage sludge is among the major practical applications of AD. Therefore, we examined the microbial communities in three full-scale sewage sludge digesters using qualitative and quantitative molecular techniques in combination： denaturing gradient gel electrophoresis （DGGE） and real-time polymerase chain reaction （PCR）. Eight out of eleven bacterial sequences retrieved from the DGGE analysis were not affiliated to any known species while all eleven archaeal sequences were assigned to known methanogen species. Quantitative real-time PCR analysis revealed that, based on the 16S rRNA gene abundance, the hydrogenotrophic order Methanomicrobiales is the most dominant methanogen group （〉 94% of the total methanogen population） in all digesters. This corresponds well to the prevailing occurrence of the DGGE bands related to Methanolinea and Methanospirillum, both belonging to the order Methanomicrobiales, in all sludge samples. It is therefore suggested that hydrogenotrophic methanogens, especially Methanomicrobiales strains, are likely the major players responsible for biogas production in the digesters studied. Our observation is contrary to the conventional understanding that aceticlastic methanogens generally dominate methanogen communities in stable AD environments, suggesting the need for further studies on the dominance relationship in various AD systems.展开更多
This Anaerobic Digestion of Sisal decortication residue (SDR) from sisal decorication unit at Hale biogas plant in Tanga (Tanzania) is presented. The study was done to address the challenges facing Katani limited at H...This Anaerobic Digestion of Sisal decortication residue (SDR) from sisal decorication unit at Hale biogas plant in Tanga (Tanzania) is presented. The study was done to address the challenges facing Katani limited at Hale biogas plant. This plant was built as pilot before building other biogas plants. These challenges were like high retention time of substrate which was SDR, low biogas productivity, high investment costs due to large tanks sizes and low plant availability. From the study, it was discovered that, when particle size was reduced biogas production increased, degradation of SDR also increased and no significant change in biogas composition. Increase in biogas yield of 30% and 129% were recorded for reduced SDR compared to raw size SDR digested at atmospheric condition and 40°C respectivelly. SDR degradation measured in TS and VS removal efficiency, showed increase in degradation of about 5% for the reduced particle size compared to raw size particle. The study concluded that SDR was good raw material for biogas production when 90% of the particles reduced to less than 2 mm. To maximize production, digestion must be conducted at high temperature around 40°C with constant monitoring and control of all para-meters. This will increase plant availability by increasing efficiency and life span of the pumps and stirrers.展开更多
The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digesti...The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digestion reactors were carried out to investigate the effect of ammonia/sulfate concentrations on the methane production.Experimental results manifested that the anaerobic digesters with an ammonia concentration of 3500 mg/L or sulfate of 1600 mg/L showed the best performance of methane production,with an average methane yield of 0.32 and 0.33 L (g VS)^(-1)d^(-1),respectively.Specifically,a higher ammonia (6500 mg/L) or sulfate (1600-3500 mg/L) level hindered the bioconversion of C from liquid to gas phase (2.68%or 1.73%CH_(4)-Gas,respectively),while insignificantly for the hydrolyzation of C and N from solid to liquid phase.Similar to sulfate,high ammonia nitrogen seriously inhibited the methanation process,leading to a significant carbon accumulation in the anaerobic reactor,especially for propionic acid.The predominant archaea Methanosarcina at genus level indicated that aceticlastic methanogenesis was the major methanogenic pathway.Meanwhile,high ammonia level suppressed the activity of Methanosarcina,while modest sulfate improved H_(2)-consuming methanogens activity.A large fraction of unclassified bacteria within the Firmicutes (43.78%-63.17%) and Bacteroidetes (24.20%-33.30%) phylum played an important role in substrates hydrolysis.展开更多
The present paper assessed a feasibility study to build a small-size anaerobic digester, where a forage legume, （Alfalfa, IVledicago sativa L.）, together with other crops, such as sorghum, could be used. Alfalfa is ...The present paper assessed a feasibility study to build a small-size anaerobic digester, where a forage legume, （Alfalfa, IVledicago sativa L.）, together with other crops, such as sorghum, could be used. Alfalfa is a highly sustainable crop, since it can fix nitrogen, with the benefit of avoiding underground water pollution by nitrates, its residual products are rich with nitrogen, thus improving soil structure and fertility more than popular graminaceous crops such as corn, and it needs little irrigation. All these characteristics make it one of the vegetable species with the lowest energy and water needs for growing. The aims of this feasibility study are： （1） optimization of feedstock in the bio-digester; （2） typology of bio-digester; （3） size of bio-digester in relation with land availability for growing the energy crops; （4） the utilization of bio-gas produced by bio-digester as fuel in combined heat and power systems; （5） disposal of waste-water according to regional and national laws. The final aim of this study is to verify the possibility to develop an alternative economical use of marginal soils in relatively dry areas of central Italy that could be applied in other areas with similar climatic conditions.展开更多
The</span><span style="font-family:""><span style="font-family:Verdana;"> Anaerobic digestion in Senegal is of particular interest to the scientific com</span><span ...The</span><span style="font-family:""><span style="font-family:Verdana;"> Anaerobic digestion in Senegal is of particular interest to the scientific com</span><span style="font-family:Verdana;">munity given the availability of substrates and their distributio</span><span style="font-family:Verdana;">n throughout the country. However, from a technological point of view, the existing installations seem to be obsolete, which does not allow to reproduce the results of the laboratory tests. Thus, the present study aims to take stock of the situation in relation to the studies carried out in laboratories and those concerning the actual monitoring of the bio-digesters </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">situ</span></i><span style="font-family:Verdana;">. In fact, most experimental bio-digesters operate under optimal implementation conditions with strict control of input and output parameters. However, this is not the case for reactors installed in the field, as these so-called bio-digesters are exposed to r</span><span style="font-family:Verdana;">eal environmental conditions with a periodic variation of the phy</span><span style="font-family:Verdana;">sic-chemical parameters in the reactors throughout the day. This leads to a differential behavior of the micro-organisms, thus affecting their performance. This results in lower yields for those digesters operating under real environmental conditions.展开更多
To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subseq...To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.展开更多
Ammonia recovery from wastewater is crucial,yet technology of low carbon emission and high ammonia perm-selectivity against complex stream compositions is urgently needed.Herein,a membrane-based hybrid process of the ...Ammonia recovery from wastewater is crucial,yet technology of low carbon emission and high ammonia perm-selectivity against complex stream compositions is urgently needed.Herein,a membrane-based hybrid process of the Donnan dialysiseelectrodialysis process(DDeED)was proposed for sustainable and efficient ammonia recovery.In principle,DD removes the majority of ammonia in wastewater by exploring the concentration gradient of NH4 t and driven cation(Nat)across the cation exchange membrane,given industrial sodium salt as a driving chemical.An additional ED stage driven by solar energy realizes a further removal of ammonia,recovery of driven cation,and replenishment of OHtoward ammonia stripping.Our results demonstrated that the hybrid DDeED process achieved ammonia removal efficiency>95%,driving cation(Nat)recovery efficiency>87.1%for synthetic streams,and reduced the OH-loss by up to 78%compared to a standalone DD case.Ammonia fluxes of 98.2 gN m^(-2)d^(-1)with the real anaerobic digestion effluent were observed using only solar energy input at 3.8 kWh kgN^(-1).With verified mass transfer modeling,reasonably controlled operation,and beneficial recovery performance,the hybrid process can be a promising candidate for future nutrient recovery from wastewater in a rural,remote area.展开更多
Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitig...Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitigate CH_(4)production and improve digestibility in cattle,we incubated substrate with rumen inoculum from yak(YRI)and cattle(CRI)in vitro in five ratios(YRI:CRI):(1)0:100(control),(2)25:75,(3)50:50,(4)75:25 and(5)100:0 for 72 h.The YRI:CRI ratios of 50:50,75:25 and 100:0 produced less total gas and CH_(4)and accumulated less hydrogen(H_(2))than0:100(control)at most time points.From 12 h onwards,there was a linear decrease(P<0.05)in carbon dioxide(CO_(2))production with increasing YRI:CRI ratio.At 72 h,the ratios of 50:50 and 75:25 had higher dry matter(+7.71%and+4.11%,respectively),as well as higher acid detergent fiber digestibility(+15.5%and+7.61%,respectively),when compared to the 0:100 ratio(P<0.05).Increasing the proportion of YRI generally increased total VFA concentrations,and,concomitantly,decreased the proportion of metabolic hydrogen([2H])incorporated into CH_(4),and decreased the recovery of[2H].The lower[2H]recovery indicates unknown[2H]sinks in the culture.Estimated Gibbs free energy changes(ΔG)for reductive acetogenesis were negative,indicating the thermodynamic feasibility of this process.It would be beneficial to identify:1)the alternative[2H]sinks,which could help mitigate CH_(4)emission,and 2)core microbes involved in fiber digestion.This experiment supported lower CH_(4)emission and greater nutrient digestibility of yaks compared to cattle.Multi-omics combined with microbial culture technologies developed in recent years could help to better understand fermentation differences among species.展开更多
Household biodigesters are self-mixing anaerobic digesters used mostly in rural areas of developing countries as a reliable source of clean cooking energy.For an efficient anaerobic digestion process,the mixing of slu...Household biodigesters are self-mixing anaerobic digesters used mostly in rural areas of developing countries as a reliable source of clean cooking energy.For an efficient anaerobic digestion process,the mixing of slurry inside the digester is regarded as one of the most important parameters.In this study,the mixing of slurry in three different designs of household digesters,namely the fixed-dome digester(GGC 2047 model),plug-flow digester and prefabricated plastic digester,are investigated and compared using compu-tational fluid dynamics.A 3D transient simulation is performed using a multiphase volume of fluid(VOF)model in Ansys^(■)Fluent release 16.0.The rheological properties of the feedstock are considered identical for all three digesters.The volume of the plug-flow and prefabricated plastic digesters is designed to be 1 m^(3) while the volume of the GGC 2047 digester was 6 m^(3) as the standard size of the household digester.The regions inside the digester where the velocity of slurry is<0.02 m/s are regarded as dead zones and the obtained results were analysed and compared using velocity patterns and dead-zone formation.It is found that the prefabricated plastic digester model has a relatively higher percentage of dead volume(74.6%)and the plug-flow digester has the lowest per-centage(54%)of dead volume among digesters that were compared in this study.The study will serve as the basis for designers and researchers to improve the design of household digesters for better mixing performances.展开更多
In this editorial,we comment on the article by Qin et al,recently published in the World Journal of Gastrointestinal Oncology.Malignant tumors of the digestive tract represent a significant health threat.Kinesin famil...In this editorial,we comment on the article by Qin et al,recently published in the World Journal of Gastrointestinal Oncology.Malignant tumors of the digestive tract represent a significant health threat.Kinesin family member 14(KIF14),a critical kinesin,is pivotal in the proliferation,migration,and invasion of tumor cells.It has emerged as a focal point in recent studies of malignant tumors in the digestive tract.This article reviews the current research on KIF14 within these tumors and details its significant role in tumor cell behaviors,including proliferation,apo-ptosis,migration,invasion,and angiogenesis,alongside the regulatory mechanisms of the associated intracellular signaling pathways.Additionally,it explores the clinical value of KIF14 as a potential biomarker for early diagnosis,disease monitoring,and prognostic evaluation in malignant tumors of the digestive tract.The article concludes by introducing the potential regulatory role of traditional Chinese medicine,aiming to combine the strengths of both modern and traditional medical approaches to enhance treatment outcomes and prognosis for patients with these tumors.展开更多
Gene expression and the content of hormones regulating feed intake and digestion are crucial for understanding gastric evacuation(GE)and feeding frequency in fish.This study assessed the effects of temperature and siz...Gene expression and the content of hormones regulating feed intake and digestion are crucial for understanding gastric evacuation(GE)and feeding frequency in fish.This study assessed the effects of temperature and size on these parameters by examining the domestication of steelhead trout(Oncorhynchus mykiss)at four temperatures(8℃,12℃,16℃,and 20℃)and with two sizes(75.99 g±10.48 g and 140.21 g±22.08 g)over two weeks.The trout were fasted for 72 h before the GE trial to ensure complete gastric emptying.In each GE trial,the expressions of peptide tyrosine(PYY),cholecystokinin(CCK),and ghrelin genes,along with corresponding serum hormone levels,were measured before feeding and at 0 h and 24 h after feeding,in conjunction with feed intake and 24-h gastric content mass.Results revealed significant effects of temperature on the expression of the three gastric genes.CCK expression increased at 8℃,correlating with reduced feed intake,while PYY and CCK increased at 20℃,correlating with accelerated gastric evacuation.Size significantly influenced serum levels of all three hormones,but the interaction between temperature and size did not affect PYY and ghrelin expression or their serum contents.This study provides molecular insights into how temperature and size regulate the digestion of steelhead trout,offering a theoretical framework for optimizing feeding frequency in aquaculture practices.展开更多
As a new type of pollutant,the harm caused by microplastics(MPs)to organisms has been the research focus.Recently,the proportion of MPs ingested through the digestive tract has gradually increased with the popularity ...As a new type of pollutant,the harm caused by microplastics(MPs)to organisms has been the research focus.Recently,the proportion of MPs ingested through the digestive tract has gradually increased with the popularity of fast-food products,such as takeout.The damage to the digestive system has attracted increasing attention.We reviewed the literature regarding toxicity of MPs and observed that they have different effects on multiple organs of the digestive system.The mechanism may be related to the toxic effects of MPs themselves,interactions with various substances in the biological body,and participation in various signaling pathways to induce adverse reactions as a carrier of toxins to increase the time and amount of body absorption.Based on the toxicity mechanism of MPs,we propose specific suggestions to provide a theoretical reference for the government and relevant departments.展开更多
Background Exogenous xylanase can increase utilization of fiber and energy when included in diets for pigs,and xylo-oligosaccharides(XOS)may improve growth performance of pigs by modulating intestinal fermentation.How...Background Exogenous xylanase can increase utilization of fiber and energy when included in diets for pigs,and xylo-oligosaccharides(XOS)may improve growth performance of pigs by modulating intestinal fermentation.However,it is unclear if a stimbiotic(i.e.,a combination of xylanase and XOS)has superior effects compared with a xylanase alone,and there is a lack of data demonstrating if xylanase fed to lactating sows influences growth performance of weanling pigs.Therefore,two hypotheses were tested:1)xylanase and stimbiotic improve growth performance,apparent total tract digestibility(ATTD)of gross energy(GE)and total dietary fiber(TDF),digestible energy(DE),and intestinal health of weanling pigs and 2)offspring of sows fed xylanase in lactation have greater growth performance after weaning than offspring of sows fed no xylanase during lactation.Methods One hundred and twenty pigs were weaned from sows fed a diet without xylanase,and 120 pigs were weaned from sows fed a lactation diet containing 16,000 beechwood xylanase units per kg(initial weight:5.81±0.50 kg).Pigs were allotted to a 2×3 factorial with two sow groups(lactation diet without or with xylanase)and three dietary treatments(i.e.,control,control plus xylanase,or control plus stimbiotic).Results There were no interactions between sow treatment and post-weaning pig treatment,and sow treatment did not impact post-weaning growth or ATTD of GE and TDF in weaned pigs.From d 15 to 28 post-weaning,the ADG,G:F,ATTD of GE and TDF,and concentration of DE were greater(P<0.05)for pigs fed the diet with stimbiotic than if fed the xylanase diet or the control diet,and pigs fed the xylanase diet had greater(P<0.05)ADG,G:F,ATTD of GE and TDF,and concentration of DE than pigs fed the control diet.From d 29 to 42 post-weaning,pigs fed the diets with xylanase or stimbiotic had greater(P<0.05)ADG,ATTD of GE and TDF,and DE than pigs fed the control diet.Conclusions Pigs fed xylanase or stimbiotic had greater ATTD of GE and TDF,greater DE,and greater overall ADG,G:F,and final body weight on d 42 post-weaning than pigs fed the control diet,but feeding sows xylanase in lactation did not influence post-weaning growth performance.展开更多
文摘S<span>everal challenges are associated </span></span><span style="font-family:"">with</span><span style="font-family:""> the development, adoption and de</span><span style="font-family:"">ployment of biogas digesters in developing countries. Amongst these challenges is a comprehensive and systematic procedure for the design of digesters suitable for rural communities. This paper proposes the Flexible Biogas Digester System (FBDS) as a viable option for rural communities in developing countries and provide</span><span style="font-family:"">s</span><span style="font-family:""> a detailed step-by-step procedure for it</span><span style="font-family:"">s</span><span style="font-family:""> design. The biogas production process is a function of the digester operating factors which may be grouped into physical, process and performance parameters. The physical design parameters include</span><span style="font-family:""> </span><span style="font-family:"">the digester volume, the volume of the biogas storage tank, and the volume of the installation pit. The process parameters include total solid content of the slurry (TS), organic loading rate (OLR), digester operating temperatures, pH of the slurry inside the digester. The performance parameters include</span><span style="font-family:""> </span><span style="font-family:"">biogas production rate, biogas productivity and biogas quality. The Net Present Value and the Levelised Cost of Energy are presented for simple economic evaluation of the FBDS.
基金TheNationNaturalScienceFoundationofChina (No .6 9974 0 34)
文摘Pulping production process produces a large amount of wastewater and pollutant emitted, which has become one of the main pollution sources in pulp and paper industry. To solve this problem, it is necessary to implement cleaner production by using modeling and optimization technology. This paper studies the modeling and multi\|objective genetic algorithms for continuous digester process. First, model is established, in which environmental pollution and saving energy factors are considered. Then hybrid genetic algorithm based on Pareto stratum\|niche count is designed for finding near\|Pareto or Pareto optimal solutions in the problem and a new genetic evaluation and selection mechanism is proposed. Finally using the real data from a pulp mill shows the results of computer simulation. Through comparing with the practical curve of digester,this method can reduce the pollutant effectively and increase the profit while keeping the pulp quality unchanged.
文摘Biogas from livestock waste is considered as clean and renewable energy in Vietnam. In the last 20 years, in rural and remote areas of Vietnam, there has been a significant increase of small-scale household biogas digesters. Biogas digesters create the benefits of replacing energy and mitigation of climate change caused by greenhouse gas （GHG） emission and deforestation for firewood and charcoal. Livestock waste produces approximately 85 million tonnes every year and continues to increase, meaning there are huge feedstocks for biogas digesters to meet the energy demands in households. However, there are also many constraints on the development programme for small-scale household biogas digester. In Vietnam, the socio-economic situation and the lack of a sustainable energy policy for biogas from livestock sector are hindering the growth of the biogas digester industry. Government subsidies are needed to encourage farmers to participate. This paper will be helpful not only for the sustainable development of household biogas in Vietnam, but also for the developing program of biogas generation in developing countries with similar agricultural economies to Vietnam.
文摘A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this equipment, which could be used to test different materials and be able to apply these results to the possible scaling to bio-digesters installed in the field. The experiments were carried out in a hybrid system bio-digester photovoltaic cells. The bio-digester is made of stainless steel with dimensions to treat an average of 10 kg of raw material and produce biogas from different organic materials. The reactor has been conditioned with temperature sensors, pressure and methane gas that allow monitoring the concentration of the gas and the conditions of operation during the time of digestion. The system has a photovoltaic array to provide the energy required to keep the temperature constant, The experiment was conducted using materials such as goat manure mixed with household waste, and various formulations of these materials were prepared. The experimental results were used to test the mathematical model.
文摘This study allowed us to highlight the level of pollution of a BAYA River water near several poultry farms and the sizing of an anaerobic digester that will be able to treat chicken manure from a poultry farm (BRIN FOUNDATION). To evaluate this pollution, the parameters such as ammonium (NH<sub>4</sub><sup>+</sup>), Phosphate (PO<sub>4</sub><sup>3-</sup>), Biochemical Oxygen Demand (DBO<sub>5</sub>) and Nitrate (NO<sub>3</sub><sup>-</sup>) were determined. For sampling point P1, the concentrations in mg/L of these parameters are (25.00 ± 4.25), (0.40 ± 0.20), (98.00 ± 6.35) and (96.00 ± 5.35), respectively. On the other hand, for sampling point P2, the concentrations in mg/L of these parameters are respectively (33.00 ± 9.05), (0.70 ± 0.12), (123 ± 7.13) and (93 ± 7.10). These values indicate a strong organic pollution of the BAYA River. The determination of the different concentrations of the organic pollution parameters allowed us to evaluate the degradation and the quality of the water of the BAYA River water, by the poultry activity. However, considering the physicochemical properties of the waste (chicken manure), which is the main source of organic pollution, we have considered an energy recovery through the production of biogas. This requires the design, sizing, and implementation of an anaerobic digester in a poultry farm. Therefore, the project would require the construction of an adapted masonry type anaerobic digester with a capacity of 10 m<sup>3</sup>.
文摘The quality of the resulting pulping continuous digesters is monitored by measuring the Kappa number, which is a reference of residual lignin. The control of the kappa number is carried out mainly in the top of the digester, therefore it is important to get some indication of this analysis beforehand. In this context, the aim of this work was to obtain a prediction model of the kappa number in advance to the laboratory results. This paper proposes a new approach using the Box & Jenkins methodology to develop a dynamic model for predicting the kappa number from a Kamyr continuous digester from an eucalyptus Kraft pulp mill in Brazil. With a database of 1500 observations over a period of 30 days of operation, some ARMA models were studied, leading to the choice of ARMA (1, 2) as the best forecasting model. After fitting the model, we performed validation with a new set of data from 30 days of operation, achieving a model of 2.7% mean absolute percent error.
文摘A domestic balloon-type digester with 1200 liters of substrate and a 700-litre gas reserve was installed at the Université Gaston Berger pilot farm, which has 4 cows. After an initial load of 1000 L of water, 90 L of bovine rumen and 145 L of cow dung, the functional parameters of the reaction medium, i.e., temperature, pH, salinity and conductimetry, were regularly monitored at a rate of 3 tests per day until the thirtieth day, corresponding to the flame test and the start of analysis and daily loading of the biodigester. The analysis of the biogas obtained after the flame test showed us the considerable contribution of bovine hindquarters to the CH4 fraction, which reached 72.2% from the start of the production phase. As anaerobic digestion is both a complex and multiparametric process, microbiological analysis revealed the presence of several strains of bacteria in the substrate used. Among the most abundant were Escherichia coli, Klebsiella spp, non-fermentative Gram-negative bacilli and Enterococcus sp. However, the bacterial strain that interests us most in anaerobic digestion is the non-fermentative Gram-negative family. We see the identification and temporal monitoring of these families of bacteria as a major step forward in the control of anaerobic fermentation processes in the Sahelian context and in Senegal in particular.
基金supported by the 2013 Research Fund of Ulsan National Institute of Science and Technology through a Future Challenge Project
文摘Anaerobic digestion （AD） is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Despite extensive efforts, AD microbial ecology is still limitedly understood, especially due to the lack of quantitative information on the structures and dynamics of AD microbial communities. Such knowledge gap is particularly pronounced in sewage sludge AD processes although treating sewage sludge is among the major practical applications of AD. Therefore, we examined the microbial communities in three full-scale sewage sludge digesters using qualitative and quantitative molecular techniques in combination： denaturing gradient gel electrophoresis （DGGE） and real-time polymerase chain reaction （PCR）. Eight out of eleven bacterial sequences retrieved from the DGGE analysis were not affiliated to any known species while all eleven archaeal sequences were assigned to known methanogen species. Quantitative real-time PCR analysis revealed that, based on the 16S rRNA gene abundance, the hydrogenotrophic order Methanomicrobiales is the most dominant methanogen group （〉 94% of the total methanogen population） in all digesters. This corresponds well to the prevailing occurrence of the DGGE bands related to Methanolinea and Methanospirillum, both belonging to the order Methanomicrobiales, in all sludge samples. It is therefore suggested that hydrogenotrophic methanogens, especially Methanomicrobiales strains, are likely the major players responsible for biogas production in the digesters studied. Our observation is contrary to the conventional understanding that aceticlastic methanogens generally dominate methanogen communities in stable AD environments, suggesting the need for further studies on the dominance relationship in various AD systems.
文摘This Anaerobic Digestion of Sisal decortication residue (SDR) from sisal decorication unit at Hale biogas plant in Tanga (Tanzania) is presented. The study was done to address the challenges facing Katani limited at Hale biogas plant. This plant was built as pilot before building other biogas plants. These challenges were like high retention time of substrate which was SDR, low biogas productivity, high investment costs due to large tanks sizes and low plant availability. From the study, it was discovered that, when particle size was reduced biogas production increased, degradation of SDR also increased and no significant change in biogas composition. Increase in biogas yield of 30% and 129% were recorded for reduced SDR compared to raw size SDR digested at atmospheric condition and 40°C respectivelly. SDR degradation measured in TS and VS removal efficiency, showed increase in degradation of about 5% for the reduced particle size compared to raw size particle. The study concluded that SDR was good raw material for biogas production when 90% of the particles reduced to less than 2 mm. To maximize production, digestion must be conducted at high temperature around 40°C with constant monitoring and control of all para-meters. This will increase plant availability by increasing efficiency and life span of the pumps and stirrers.
基金financed by the National Key Research and Development Program of China (No. 2018YFC1900902)the State Key Laboratory of Urban Water Resource and Environment (No. 2020TS01)+1 种基金the Heilongjiang Nature Science Foundation (No. YQ2020E022)the National Nature Science Foundation of China (No. 51878213)。
文摘The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digestion reactors were carried out to investigate the effect of ammonia/sulfate concentrations on the methane production.Experimental results manifested that the anaerobic digesters with an ammonia concentration of 3500 mg/L or sulfate of 1600 mg/L showed the best performance of methane production,with an average methane yield of 0.32 and 0.33 L (g VS)^(-1)d^(-1),respectively.Specifically,a higher ammonia (6500 mg/L) or sulfate (1600-3500 mg/L) level hindered the bioconversion of C from liquid to gas phase (2.68%or 1.73%CH_(4)-Gas,respectively),while insignificantly for the hydrolyzation of C and N from solid to liquid phase.Similar to sulfate,high ammonia nitrogen seriously inhibited the methanation process,leading to a significant carbon accumulation in the anaerobic reactor,especially for propionic acid.The predominant archaea Methanosarcina at genus level indicated that aceticlastic methanogenesis was the major methanogenic pathway.Meanwhile,high ammonia level suppressed the activity of Methanosarcina,while modest sulfate improved H_(2)-consuming methanogens activity.A large fraction of unclassified bacteria within the Firmicutes (43.78%-63.17%) and Bacteroidetes (24.20%-33.30%) phylum played an important role in substrates hydrolysis.
文摘The present paper assessed a feasibility study to build a small-size anaerobic digester, where a forage legume, （Alfalfa, IVledicago sativa L.）, together with other crops, such as sorghum, could be used. Alfalfa is a highly sustainable crop, since it can fix nitrogen, with the benefit of avoiding underground water pollution by nitrates, its residual products are rich with nitrogen, thus improving soil structure and fertility more than popular graminaceous crops such as corn, and it needs little irrigation. All these characteristics make it one of the vegetable species with the lowest energy and water needs for growing. The aims of this feasibility study are： （1） optimization of feedstock in the bio-digester; （2） typology of bio-digester; （3） size of bio-digester in relation with land availability for growing the energy crops; （4） the utilization of bio-gas produced by bio-digester as fuel in combined heat and power systems; （5） disposal of waste-water according to regional and national laws. The final aim of this study is to verify the possibility to develop an alternative economical use of marginal soils in relatively dry areas of central Italy that could be applied in other areas with similar climatic conditions.
文摘The</span><span style="font-family:""><span style="font-family:Verdana;"> Anaerobic digestion in Senegal is of particular interest to the scientific com</span><span style="font-family:Verdana;">munity given the availability of substrates and their distributio</span><span style="font-family:Verdana;">n throughout the country. However, from a technological point of view, the existing installations seem to be obsolete, which does not allow to reproduce the results of the laboratory tests. Thus, the present study aims to take stock of the situation in relation to the studies carried out in laboratories and those concerning the actual monitoring of the bio-digesters </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">situ</span></i><span style="font-family:Verdana;">. In fact, most experimental bio-digesters operate under optimal implementation conditions with strict control of input and output parameters. However, this is not the case for reactors installed in the field, as these so-called bio-digesters are exposed to r</span><span style="font-family:Verdana;">eal environmental conditions with a periodic variation of the phy</span><span style="font-family:Verdana;">sic-chemical parameters in the reactors throughout the day. This leads to a differential behavior of the micro-organisms, thus affecting their performance. This results in lower yields for those digesters operating under real environmental conditions.
文摘To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.
基金support provided by the National Natural Science Foundation of China(51908083,52270058)the Venture&Innovation Support Program for Chongqing Overseas Returnees(CX2021121)+1 种基金the National Key Research and Development Program of China(2022YFC3203402)the Graduate Research and Innovation Foundation of Chongqing,China(CYS22066)。
文摘Ammonia recovery from wastewater is crucial,yet technology of low carbon emission and high ammonia perm-selectivity against complex stream compositions is urgently needed.Herein,a membrane-based hybrid process of the Donnan dialysiseelectrodialysis process(DDeED)was proposed for sustainable and efficient ammonia recovery.In principle,DD removes the majority of ammonia in wastewater by exploring the concentration gradient of NH4 t and driven cation(Nat)across the cation exchange membrane,given industrial sodium salt as a driving chemical.An additional ED stage driven by solar energy realizes a further removal of ammonia,recovery of driven cation,and replenishment of OHtoward ammonia stripping.Our results demonstrated that the hybrid DDeED process achieved ammonia removal efficiency>95%,driving cation(Nat)recovery efficiency>87.1%for synthetic streams,and reduced the OH-loss by up to 78%compared to a standalone DD case.Ammonia fluxes of 98.2 gN m^(-2)d^(-1)with the real anaerobic digestion effluent were observed using only solar energy input at 3.8 kWh kgN^(-1).With verified mass transfer modeling,reasonably controlled operation,and beneficial recovery performance,the hybrid process can be a promising candidate for future nutrient recovery from wastewater in a rural,remote area.
基金supported by the National Natural Science Foundation of China(32072757 and U21A20250)。
文摘Yaks are well-adapted to the harsh environment of the Tibetan Plateau,and they emit less enteric methane(CH_(4))and digest poor-quality forage better than cattle.To examine the potential of yak rumen inoculum to mitigate CH_(4)production and improve digestibility in cattle,we incubated substrate with rumen inoculum from yak(YRI)and cattle(CRI)in vitro in five ratios(YRI:CRI):(1)0:100(control),(2)25:75,(3)50:50,(4)75:25 and(5)100:0 for 72 h.The YRI:CRI ratios of 50:50,75:25 and 100:0 produced less total gas and CH_(4)and accumulated less hydrogen(H_(2))than0:100(control)at most time points.From 12 h onwards,there was a linear decrease(P<0.05)in carbon dioxide(CO_(2))production with increasing YRI:CRI ratio.At 72 h,the ratios of 50:50 and 75:25 had higher dry matter(+7.71%and+4.11%,respectively),as well as higher acid detergent fiber digestibility(+15.5%and+7.61%,respectively),when compared to the 0:100 ratio(P<0.05).Increasing the proportion of YRI generally increased total VFA concentrations,and,concomitantly,decreased the proportion of metabolic hydrogen([2H])incorporated into CH_(4),and decreased the recovery of[2H].The lower[2H]recovery indicates unknown[2H]sinks in the culture.Estimated Gibbs free energy changes(ΔG)for reductive acetogenesis were negative,indicating the thermodynamic feasibility of this process.It would be beneficial to identify:1)the alternative[2H]sinks,which could help mitigate CH_(4)emission,and 2)core microbes involved in fiber digestion.This experiment supported lower CH_(4)emission and greater nutrient digestibility of yaks compared to cattle.Multi-omics combined with microbial culture technologies developed in recent years could help to better understand fermentation differences among species.
基金This study is supported by Energize Nepal and Renewable&Sustainable Energy Laboratory(RESL),Kathmandu University.
文摘Household biodigesters are self-mixing anaerobic digesters used mostly in rural areas of developing countries as a reliable source of clean cooking energy.For an efficient anaerobic digestion process,the mixing of slurry inside the digester is regarded as one of the most important parameters.In this study,the mixing of slurry in three different designs of household digesters,namely the fixed-dome digester(GGC 2047 model),plug-flow digester and prefabricated plastic digester,are investigated and compared using compu-tational fluid dynamics.A 3D transient simulation is performed using a multiphase volume of fluid(VOF)model in Ansys^(■)Fluent release 16.0.The rheological properties of the feedstock are considered identical for all three digesters.The volume of the plug-flow and prefabricated plastic digesters is designed to be 1 m^(3) while the volume of the GGC 2047 digester was 6 m^(3) as the standard size of the household digester.The regions inside the digester where the velocity of slurry is<0.02 m/s are regarded as dead zones and the obtained results were analysed and compared using velocity patterns and dead-zone formation.It is found that the prefabricated plastic digester model has a relatively higher percentage of dead volume(74.6%)and the plug-flow digester has the lowest per-centage(54%)of dead volume among digesters that were compared in this study.The study will serve as the basis for designers and researchers to improve the design of household digesters for better mixing performances.
基金Supported by the 2023 Government-funded Project of the Outstanding Talents Training Program in Clinical Medicine,No.ZF2023165Key Research and Development Projects of Hebei Province,No.18277731D+1 种基金Natural Science Foundation of Hebei Province,No.H202423105Hebei Provincial Administration of Traditional Chinese Medicine,Scientific Research Project,No.2020014.
文摘In this editorial,we comment on the article by Qin et al,recently published in the World Journal of Gastrointestinal Oncology.Malignant tumors of the digestive tract represent a significant health threat.Kinesin family member 14(KIF14),a critical kinesin,is pivotal in the proliferation,migration,and invasion of tumor cells.It has emerged as a focal point in recent studies of malignant tumors in the digestive tract.This article reviews the current research on KIF14 within these tumors and details its significant role in tumor cell behaviors,including proliferation,apo-ptosis,migration,invasion,and angiogenesis,alongside the regulatory mechanisms of the associated intracellular signaling pathways.Additionally,it explores the clinical value of KIF14 as a potential biomarker for early diagnosis,disease monitoring,and prognostic evaluation in malignant tumors of the digestive tract.The article concludes by introducing the potential regulatory role of traditional Chinese medicine,aiming to combine the strengths of both modern and traditional medical approaches to enhance treatment outcomes and prognosis for patients with these tumors.
基金National Key Research and Development Program of China(Nos.2024YFD2400300 and 2019YFD0901000)the Natural National Science Foundation of China(No.32373104).
文摘Gene expression and the content of hormones regulating feed intake and digestion are crucial for understanding gastric evacuation(GE)and feeding frequency in fish.This study assessed the effects of temperature and size on these parameters by examining the domestication of steelhead trout(Oncorhynchus mykiss)at four temperatures(8℃,12℃,16℃,and 20℃)and with two sizes(75.99 g±10.48 g and 140.21 g±22.08 g)over two weeks.The trout were fasted for 72 h before the GE trial to ensure complete gastric emptying.In each GE trial,the expressions of peptide tyrosine(PYY),cholecystokinin(CCK),and ghrelin genes,along with corresponding serum hormone levels,were measured before feeding and at 0 h and 24 h after feeding,in conjunction with feed intake and 24-h gastric content mass.Results revealed significant effects of temperature on the expression of the three gastric genes.CCK expression increased at 8℃,correlating with reduced feed intake,while PYY and CCK increased at 20℃,correlating with accelerated gastric evacuation.Size significantly influenced serum levels of all three hormones,but the interaction between temperature and size did not affect PYY and ghrelin expression or their serum contents.This study provides molecular insights into how temperature and size regulate the digestion of steelhead trout,offering a theoretical framework for optimizing feeding frequency in aquaculture practices.
文摘As a new type of pollutant,the harm caused by microplastics(MPs)to organisms has been the research focus.Recently,the proportion of MPs ingested through the digestive tract has gradually increased with the popularity of fast-food products,such as takeout.The damage to the digestive system has attracted increasing attention.We reviewed the literature regarding toxicity of MPs and observed that they have different effects on multiple organs of the digestive system.The mechanism may be related to the toxic effects of MPs themselves,interactions with various substances in the biological body,and participation in various signaling pathways to induce adverse reactions as a carrier of toxins to increase the time and amount of body absorption.Based on the toxicity mechanism of MPs,we propose specific suggestions to provide a theoretical reference for the government and relevant departments.
基金financial support for this research by AB Vista,Marlborough,UK,is greatly appreciated.
文摘Background Exogenous xylanase can increase utilization of fiber and energy when included in diets for pigs,and xylo-oligosaccharides(XOS)may improve growth performance of pigs by modulating intestinal fermentation.However,it is unclear if a stimbiotic(i.e.,a combination of xylanase and XOS)has superior effects compared with a xylanase alone,and there is a lack of data demonstrating if xylanase fed to lactating sows influences growth performance of weanling pigs.Therefore,two hypotheses were tested:1)xylanase and stimbiotic improve growth performance,apparent total tract digestibility(ATTD)of gross energy(GE)and total dietary fiber(TDF),digestible energy(DE),and intestinal health of weanling pigs and 2)offspring of sows fed xylanase in lactation have greater growth performance after weaning than offspring of sows fed no xylanase during lactation.Methods One hundred and twenty pigs were weaned from sows fed a diet without xylanase,and 120 pigs were weaned from sows fed a lactation diet containing 16,000 beechwood xylanase units per kg(initial weight:5.81±0.50 kg).Pigs were allotted to a 2×3 factorial with two sow groups(lactation diet without or with xylanase)and three dietary treatments(i.e.,control,control plus xylanase,or control plus stimbiotic).Results There were no interactions between sow treatment and post-weaning pig treatment,and sow treatment did not impact post-weaning growth or ATTD of GE and TDF in weaned pigs.From d 15 to 28 post-weaning,the ADG,G:F,ATTD of GE and TDF,and concentration of DE were greater(P<0.05)for pigs fed the diet with stimbiotic than if fed the xylanase diet or the control diet,and pigs fed the xylanase diet had greater(P<0.05)ADG,G:F,ATTD of GE and TDF,and concentration of DE than pigs fed the control diet.From d 29 to 42 post-weaning,pigs fed the diets with xylanase or stimbiotic had greater(P<0.05)ADG,ATTD of GE and TDF,and DE than pigs fed the control diet.Conclusions Pigs fed xylanase or stimbiotic had greater ATTD of GE and TDF,greater DE,and greater overall ADG,G:F,and final body weight on d 42 post-weaning than pigs fed the control diet,but feeding sows xylanase in lactation did not influence post-weaning growth performance.
