Using Natural Zeolite as a Feed Additive in Broilers' Diets for Enhancing Growth Performance, Carcass Characteristics, and Meat Quality Traits

BACKGROUND

Using natural zeolites as a food additive in poultry diets offers an intriguing perspective. The objective of this study was to investigate the effects of zeolite addition and particle size on broiler performance, carcass characteristics, meat quality, moisture of excreta and litter, and intestinal measurements during 35 days.

METHODS

A total of 560 1-day-old female Ross-308 broilers were divided into five treatment levels (0, 5, 10, 15, and 20 g zeolite/kg diet) (n = 16 replicates/treatment, n = 8 replicates /particle size of each treatment). Performance was calculated weekly. Carcass characteristics, meat quality, small intestine (SI) measurements, litter pH, and moisture content were determined on day 35.

RESULTS

Litter pH, breast redness, cooking loss, chewiness, total weight, and SI length were all affected by zeolite treatments (p < 0.05). Particle size had an impact on the gastric pH and texture analysis. Their interaction had an effect on color redness, litter pH, and cooking loss. Performance was unaffected by either the main or interaction effects.

CONCLUSION

Zeolite as a feed additive may be useful in broiler diets, particularly large particles. The performance and production efficiency factor improved numerically (p > 0.05) with increasing zeolite doses up to 10 g zeolite/kg diet.

Effects of Functionalized Materials and Bacterial Metabolites on Quality Indicators in Composts

The addition of functionalized materials (biochar, zeolite, and diatomite) and lyophilized metabolic products of Pseudomonas sp. and Bacillus subtilis to composted biomass may bring many technological and environmental benefits. In this study, we verify the effects of biochar, zeolite Na-P1 (Na6Si10Al6O32·12 H2O), diatomite (SiO2_nH2O), and bacterial metabolites on the composting of biomass prepared from poultry litter, corn straw, grass, leonardite, and brown coal. The experimental design included the following treatments: C-biomass without the addition of functionalized materials and bacterial metabolites, CB-biomass with the addition of biochar, CBM-biomass with the addition of biochar and bacterial metabolites, CZ-biomass with the addition of zeolite, CZM-biomass with the addition of zeolite and bacterial metabolites, CD-biomass with the addition of diatomite, and CDM-biomass with the addition of diatomite and bacterial metabolites. Composts were analyzed for enzymatic and respiratory activities, mobility of heavy metals, and the presence of parasites. The results of this study revealed that, among the analyzed functionalized materials, the addition of diatomite to the composted biomass (CD and CDM) resulted in the most effective immobilization of Cd, Zn, Pb, and Cu. Zinc immobilization factors (IFHM) for diatomite-amended composts averaged 30%. For copper, each functionalized material was found to enhance mobilization of the element in bioavailable forms; similar observations were made for lead, except for the compost to which biochar and bacterial metabolites were added (CBM). The determined values of biochemical indicators proved the different effects of the applied functionalized materials and bacterial metabolites on the microbial communities colonizing individual composts. The dehydrogenase activity (DhA) was lower in all combinations as compared with the control, indicating an intensification of the rate of processes in the studied composts. The highest basal respiration (BR) and substrate-induced respiration (SIR) activities were determined in composts with the addition of bacterial metabolites (CBM, CZM, and CDM). The addition of functionalized materials completely inactivated Eimeria sp. in all combinations. In the case of Capillaria sp., complete inactivation was recorded for the combination with zeolite as well as biochar and diatomite without bacterial metabolites (CB, CZ, and CD).

Isolation and Characterization of Effective Bacteria That Reduce Ammonia Emission from Livestock Manure

Ammonia from livestock manure reacts with chemical components discharged from various emission sources to produce airborne particulate matter. This study aimed to investigate a novel effective microbial agent to suppress ammonia gas emitted from manure. Both isolated L12I and 12III strains, identified as Pediococcus acidilactici (PA), were selected for their superior activity in assays performed with the evaluation criteria such as acid production, ammonia decomposition, and urease inhibition, which are key factors influencing ammonia excretion. The survivability of PA strains was confirmed by an increase in DNA abundance in the manure. PA strains lowered the pH of manure and suppressed the growth of hyper-ammonia-producing bacteria (HAB) possessing urease activity. The L12I and 12III treatment groups showed 23.58% and 38.00% emission reductions, respectively. Especially, the 12III strain was proven to be the more effective strain for reducing ammonia gas emission, with the best ability to reduce pH and inhibit HAB. The strains could have an additive effect in improving the manure quality as a nitrogen fertilizer by preserving the total nitrogen and urea content. These results suggest that PA strains can be used as unprecedented microbial agents to improve manure-derived environmental pollution and improve fertilizer quality.

Lignite, dewatered lignite and modified subbituminous coal reduce nitrogen loss from broiler litter

Broiler litter is generated in large quantities as a waste by-product of chicken meat production. N may be lost from the litter and emitted from bird housing as gaseous NH₃, which can be damaging to the environment and limit the recycling of a valuable nutrient. This study investigated the effect of lignite application rate (0, 5, 10, 15, 20%) on N loss from broiler litter in a static chamber laboratory incubation. Lignite was subsequently dewatered and subbituminous coal modified by aerobic thermal oxidation and their ammoniacal N adsorption potentials were characterised. In a second static chamber incubation, the capacity of these materials (applied at 20%) to reduce N loss from litter was investigated. Finally, their potential to directly reduce NH₃ emissions was examined using a chamber acid trap system. This study showed that lignite reduced N loss when applied to litter at a rate ≥ 5%, with the amount of N retained increasing with increasing lignite application rate. Litter treated with 20% lignite retained 24% more N than untreated litter. Following aerobic thermal treatment, maximum ammoniacal N adsorption capacities of the materials were as follows: lignite > dewatered lignite > modified subbituminous coal > subbituminous coal. Despite inequalities in adsorption capacity, lignite, dewatered lignite and modified subbituminous coal reduced total N loss by 17.3, 18.2 and 18.4% and NH₃ emissions by 41.6, 49.1 and 29.8%, respectively. This study demonstrates the potential of coal-based materials to reduce NH₃ emissions from broiler litter and increase the nutrient value of waste by reducing N loss.

Impact of fiber on growth, plasma, gastrointestinal and excreta attributes in broiler chickens and turkey poults fed corn- or wheat-based diets with or without multienzyme supplement

Effects of fiber on growth performance, gizzard attributes, ileal digesta viscosity, plasma uric acid (PUA) and excreta characteristics were investigated in broiler chickens (experiment 1) and turkey poults (experiment 2) fed corn or wheat-based diets with or without multienzyme supplement (MES). Fibrous diets were created by adding 10% corn distillers dried grains with solubles or wheat middlings in corn or wheat-based diets, respectively. The MES had main activities of xylanase and β-glucanase. A total of 960-d old Ross x Ross 708 male chicks and 720-d old male Hybrid toms were allocated to eight grain, fiber and MES combinations to give 6 replicates per combination. In each experiment, birds had free access to feed and water for 28 days. Excreta samples were collected for 3-d prior to the end and on d 28, body weight and feed intake were recorded, birds bled and subsequently necropsied for gastrointestinal samples. There was an interaction (P ≤ 0.036) between grain, fiber and MES in broilers final body weight (FBW) and BW gain (BWG). In this context, high fiber corn diets reduced FBW and BWG and supplementation of MES improved these parameters. Broilers fed corn had a higher (P < 0.05) FBW (1,462 vs. 1,424 g) and BWG (1,416 vs. 1,378 g) than birds fed wheat diets. Broilers fed corn-based diets without fiber diets had a higher ileal viscosity and excreta moisture compared to birds fed wheat-based and high fiber diets. Broilers fed low fiber wheat diets without MES had higher (P < 0.05) PUA concentration compared to birds fed low fiber corn diets without MES. Poults fed wheat diets had a higher (P < 0.05) FBW (1,441 vs. 1,408 g) and BWG (1,376 vs. 1,343 g) than poults fed corn diet. The MES supplementation in corn-based diets rich in fiber increased (P = 0.03) gizzard weight in poults. In conclusion, there were varied growth and physiological responses in broilers and turkey suggesting the need for refining enzyme application for different poultry species.

Dietary fiber in poultry nutrition and their effects on nutrient utilization, performance, gut health, and on the environment: a review

Dietary fiber (DF) was considered an antinutritional factor due to its adverse effects on feed intake and nutrient digestibility. However, with increasing evidence, scientists have found that DF has enormous impacts on the gastrointestinal tract (GIT) development, digestive physiology, including nutrient digestion, fermentation, and absorption processes of poultry. It may help maintain the small and large intestine's integrity by strengthening mucosal structure and functions and increasing the population and diversity of commensal bacteria in the GIT. Increasing DF content benefits digestive physiology by stimulating GIT development and enzyme production. And the inclusion of fiber at a moderate level in diets also alters poultry growth performance. It improves gut health by modulating beneficial microbiota in the large intestine and enhancing immune functions. However, determining the source, type, form, and level of DF inclusion is of utmost importance to achieve the above-noted benefits. This paper critically reviews the available information on dietary fibers used in poultry and their effects on nutrient utilization, GIT development, gut health, and poultry performance. Understanding these functions will help develop nutrition programs using proper DF at an appropriate inclusion level that will ultimately lead to enhanced DF utilization, overall health, and improved poultry growth performance. Thus, this review will help researchers and industry identify the sources, type, form, and amount of DF to be used in poultry nutrition for healthy, cost-effective, and eco-friendly poultry production.

Thermochemical Analysis of Ammonia Gas Sorption by Struvite from Livestock Wastes and Comparison with Biochar and Metal-Organic Framework Sorbents

Struvite-bearing solids from swine (S) and dairy (D) wastewater, heat-treated to 150-300 °C, were evaluated as ammonia gas (NH₃(g)) sorbents and compared to biochar (BC) and a metal-organic framework (MOF). Simultaneous thermal analysis-pulse thermal analysis-Fourier-transform infrared spectroscopy (STA-PTA-FTIR) was used to determine sorption capacity, reversibility, thermodynamics, and kinetics. For wastewater-derived sorbents, S solids heated to 150 °C (S-150) had the highest NH₃(g) sorption capacity (47.2-49.9 mg g^-1), comparable to BC (50.8 mg g^-1). Enthalpies increased with sorption capacity, and the energy released per mole sorbed NH₃(g) indicated stronger bonds formed with S sorbents than BC. After desorption, S-150 retained more NH₃(g) (48-51%) than BC (39%). The MOF had the highest sorption capacity (289.7 mg g^-1) and irreversibly bound NH₃(g) (81%) but similar sorption activation energy (Ea) as S-150. The rates (k) of NH₃(g) sorption and desorption were fastest for S-150. Overall, S-150 sorbents performed similarly to BC but were less effective than MOF for NH₃(g) sequestration. However, advantages of S-150 for NH₃(g) mitigation include wastewater valorization, minimal synthesis, low heat treatment, and potential use in agricultural applications. Evaluation of struvite-based wastewater-derived sorbents, comparison with commonly used sorbents, and the implementation of thermochemical analysis for this purpose are all novel aspects of this study.

Influence of bamboo biochar on mitigating greenhouse gas emissions and nitrogen loss during poultry manure composting

The effectiveness of specific concentrations of bamboo biochar (BB) on nutrient conservation based on gaseous emissions during poultry manure composting was investigated. The results indicate that the total carbon and nitrogen losses were significantly reduced with elevated of biochar from 542.8 to 148.9% and 53.5 to 12.6% (correspondingly with an additive of 0%, 2%, 4%, 6% and 8% to 10% BB dry weight based). The primary contributor was CO₂ and NH₃ losses (542.3-148.8% and 47.8-10.81%). The enzyme activities related to carbon and nitrogen metabolism indicated a positive and significantly enhanced with high concentration biochar amended composting. Simultaneously, the alteration of total organic carbon and total Kjeldahl nitrogen as well as maturity indexes during ultimate compost also confirmed a high quality product under higher content biochar amended composting. Carbon and nitrogen were best preserved with 10%BB and produced a superior final product. The analysis of a network and heat map illustrated the correlation of gaseous and physicochemical elements as well as enzyme activities, with an intersection of 68.81%.

Indústria do Ovo: qual é o significado e uso dessa expressão?

Resumo No início dos anos 2000, ovos foram reabilitados como saudáveis, sendo alimento nutritivo e economicamente acessível, de uma rica fonte de proteína animal e uma alternativa à carne vermelha. O presente trabalho objetivou identificar se a expressão “Indústria do Ovo” é utilizada em publicações acadêmicas e, se confirmada sua utilização, a que produção se refere frequentemente, bem como em que contexto é utilizada quanto à temática dos artigos científicos. Para tanto, realizou-se uma revisão sistemática da literatura, considerando investigações publicadas nas bases de dados Scopus e Web of Science. Os resultados obtidos demonstraram que a utilização da expressão “Indústria do Ovo” em artigos científicos ocorre desde 1947, sendo empregada para designar, principalmente, a produção comercial de ovos de galinha, cujo uso apresenta linha de tendência crescente. Os artigos com foco em administração, economia, mercados e certificações foram predominantes no emprego da expressão “Indústria do Ovo” no decorrer do período analisado.

Suitability of litter amendments for the Australian chicken meat industry

The Australian chicken meat indutstry is rapidly expanding due to the increasing consumption of chicken meat. As a result, the industry has growing issues of sourcing new bedding materials and disposing of spent litter, which can be attributed, in part, to a lack of widespread litter re-use for rearing chickens. According to insights and perspectives recently gathered from industry stakeholders, it is believed that re-using litter will become more common in the future, so as to reduce production costs and ease pressures on both the supply of new bedding materials and disposal of spent litter. However, there are potential risks that need to be addressed if litter re-use increases, particularly with regard to the production and mitigation of ammonia, which can negatively affect chicken health if not managed correctly. The present review discusses the potential benefits reported for different types of litter amendments, which have the primary goal of reducing ammonia volatilisation, but may also contribute to improvements in bird performance, welfare, pathogen loads, fertiliser value of spent litter, and reduced costs associated with purchasing new bedding materials. Acidifiers have been shown to be the most effective of all amendment types, with sodium bisulfate or alum being among the most commonly tested products mentioned in research literature. Litter amendments are currently rarely used in Australia, but it is hoped that the information provided in the present review, based mostly on overseas usage and research, will help inform future decision-making on the use of these products in Australian poultry production systems.

Mitigating ammonia emissions from typical broiler and layer manure management - A system analysis

Broiler and layer productions are important ammonia (NH₃) emission sources in the livestock industry. Here, we present the first meta-analysis and integrated assessment of NH₃ emissions and mitigation potentials for typical broiler litter manure management system (MMS) and layer manure belt MMS based on data from 96 studies. A total of 10 integrated NH₃ emission factors (EFs) and the NH₃ mitigation efficiencies (MEs) of 14 available options were provided. The estimated NH₃ emissions from the baseline scenarios of the broiler litter MMS and the layer manure belt MMS were 84.1 ± 5.9 kg AU^-1 yr^-1 and 53.5 ± 15.8 kg AU^-1 yr^-1, respectively. The NH₃ mitigation for the broiler litter MMS should be focused on the in-house stage, while the mitigation in the layer manure belt MMS should be focused on the outdoor and land application stages. The recommended NH₃ mitigation options for the in-house stage, the outdoor stage and the land application stage were acid scrubber (-92.5%), compost biofilter (-71.9%) and changing the manure surface application to incorporation (-83.0%), respectively. The recommended mitigation combinations of low crude protein (LCP) diet, acid scrubber, compost biofilter and manure incorporation achieved the highest NH₃ mitigation efficiency from both broiler litter MMS and layer manure belt MMS, by 89.3% and 84.8%, respectively. The results of this study have important implications for developing sustainable poultry production systems from the viewpoint of NH₃ mitigation. The environment issues such as the other reactive nitrogen emissions and the greenhouse gas (GHG) emissions should also be considered in the future.

Decreased enzyme activities, ammonification rate and ammonifiers contribute to higher nitrogen retention in hyperthermophilic pretreatment composting

Hyperthermophilic pretreatment composting (HPC) is superior to traditional composting (TC) with shortened maturity period and increased nitrogen (N) retention. However, the mechanism associated with N retention in HPC remains unclear. In this study, we compared the impact of HPC and TC on N retention, and found the proportion of N retained in the final compost was 83.3% and 67.2% for HPC and TC, respectively. Decreased ammonification rate, urease and protease activities together with an elevated temperature were found in HPC. Illumina amplicon sequencing showed that HPC caused a major decline in microbial community richness and diversity in the thermophilic phase. Notably, bacterial (Pseudomonas and Bacillus) and fungal ammonifiers (Acremonium, Alternaria and Penicillium) decreased remarkably in HPC during this phase. Changes in the microbial community could be related to unfavorable modifications of environment from HPC, and which resulted in decreased ammonification and enzyme activities and improved N retention.

Biochar lowers ammonia emission and improves nitrogen retention in poultry litter composting

The poultry industry produces abundant quantities of nutrient-rich litter, much of which is composted before use as a soil amendment. However, a large proportion of nitrogen (N) in poultry litter is lost via volatilisation during composting, with negative environmental and economic consequences. This study examined the effect of incorporating biochar during composting of poultry litter on ammonia (NH₃) volatilisation and N retention. Biochars produced at 550°C from greenwaste (GWB) and poultry litter (PLB) feedstocks were co-composted with a mixture of raw poultry litter and sugarcane straw [carbon (C):N ratio 10:1] in compost bins. Ammonia emissions accounted for 17% of the total N (TN) lost from the control and 12-14% from the biochar-amended compost. The TN emitted as NH₃, as a percentage of initial TN, was significantly lower (P<0.05) i.e. by 60% and 55% in the compost amended with GWB and PLB, respectively, relative to the control. The proportion of N retained in the finished compost, as a percentage of initial TN, was 84%, 78% and 67% for the GWB, PLB and nil biochar control, respectively. Lower concentration of dissolved organic C (DOC) together with higher activity of beta-glucosidase and leucine-aminopeptidase were found in the GWB-amended compost (cf. control). It is hypothesized that lower NH₃ emission in the GWB-amended compost was caused not just by the higher surface area of this biochar but could also be related to greater incorporation of ammonium (NH₄⁺) in organic compounds during microbial utilisation of DOC. Furthermore, the GWB-amended compost retained more NH₄⁺ at the end of composting than the PLB-amended compost. Results showed that addition of biochar, especially GWB, generated multiple benefits in composting of poultry litter: decrease of NH₃ volatilisation, decrease in NH₃ toxicity towards microorganisms, and improved N retention, thus enhancing the fertiliser value of the composted litter. It is suggested that the latter benefit is linked to a beneficial modification of the microbial environment.

Natural zeolites in diet or litter of broilers

This study aims to analyse the influence of adding natural zeolites (clinoptilolite) to the diet or litter of broilers and their effects on growth performance, carcass yield and litter quality. Three consecutive flocks of broilers were raised on the same sawdust litter, from d 1 to d 42 of age, and distributed in three treatments (control with no added zeolites, addition of 5 g/kg zeolite to diet and addition of 100 g/kg zeolites to litter). The addition of zeolites to the diet or litter did not affect growth performance or carcass yield. The addition of zeolites to the diet did not influence moisture content of the litter, ammonia volatilisation was reduced only in the first flock and pH of litter was reduced in the second and third flock. However, the addition of zeolites to the litter reduced moisture content, litter pH and ammonia volatilisation in all flocks analysed. The addition of 5 g/kg zeolite to the diet in three consecutive flocks was not effective in maintaining litter quality, whereas the addition of 100 g/kg natural zeolites to sawdust litter reduced litter moisture and ammonia volatilisation in three consecutive flocks raised on the same litter.

Summary of performance data for technologies to control gaseous, odor, and particulate emissions from livestock operations: Air management practices assessment tool (AMPAT)

The livestock and poultry production industry, regulatory agencies, and researchers lack a current, science-based guide and data base for evaluation of air quality mitigation technologies. Data collected from science-based review of mitigation technologies using practical, stakeholders-oriented evaluation criteria to identify knowledge gaps/needs and focuses for future research efforts on technologies and areas with the greatest impact potential is presented in the Literature Database tab on the air management practices tool (AMPAT). The AMPAT is web-based (available at www.agronext.iastate.edu/ampat) and provides an objective overview of mitigation practices best suited to address odor, gaseous, and particulate matter (PM) emissions at livestock operations. The data was compiled into Excel spreadsheets from a literature review of 265 papers was performed to (1) evaluate mitigation technologies performance for emissions of odor, volatile organic compounds (VOCs), ammonia (NH₃), hydrogen sulfide (H₂S), particulate matter (PM), and greenhouse gases (GHGs) and to (2) inform future research needs.

Effect of straw size and microbial amendment of litter on certain litter quality parameters, ammonia emission, and footpad dermatitis in broilers

Abstract. This study was conducted to evaluate the impact of litter amendment (microbiological product – Micropan complex) and straw size (unchopped and chopped straw) on pH, moisture level, ammonia emission, and footpad dermatitis in broilers. A total of 1200 1-day-old Ross 308 broilers were randomly allocated to four treatments (2  ×  2 factorial arrangement), with four replicates per treatment. Each replicate consisted of 75 as-hatched birds per pen. The first factor consisted of wheat straw – chopped (C) or unchopped (U) – and the second factor was the litter amendment with (WM) or without (OM) Micropan® (enzymatic bacterial product – Eurovix, USA). At 4, 5, and 6 weeks of the trial, the levels of ammonia concentration, moisture content, and pH of litter in each pen were measured. The foot pad lesions were evaluated at 21, 35, and 42 days of age. Broilers reared on chopped straw had significantly better leg condition as expressed by a smaller incidence and severity of footpad dermatitis. The pH value of litter was decreased and footpad quality was significantly improved by Micropan application in broilers kept on chopped and unchopped straw in the sixth week of age. There was no significant effect of Micropan application and straw size on ammonia emission in broiler housing.

Controlling phosphate releasing from poultry litter using stabilized Fe-Mn binary oxide nanoparticles

Animal wastes contain high concentrations of phosphorus (P), most of which is lost into the environment due to uncontrolled release rates. Polysaccharide stabilized Fe-Mn binary oxide nanoparticles were prepared and tested for phosphate adsorption from water and for controlling leachability of P from poultry litter. A water soluble starch and carboxymethyl cellulose (CMC) were used as a stabilizer. Both the Freundlich and Langmuir models were able to adequately interpret the isotherm data. The Langmuir maximum capacity was determined at 252, 298 and 313 mg-P/g for bare, CMC- and starch-stabilized nanoparticles, respectively. The presence of the stabilizers not only enhanced the sorption capacity, but facilitated delivery and dispersion of the nanoparticles in poultry litter (PL) and in soil. High phosphate sorption capacity was observed over a broad pH range of 4-9. FTIR analyses indicated that inner sphere surface complexation (Fe-O-P) was the key mechanism for the enhanced uptake of P. When applied to poultry litter, the stabilized nanoparticles reduced water leachable phosphate by >86% at a dose of 0.2 g/L as Fe, and simultaneously, water leachable arsenic by >87-95%. Under conditions of simulated land application of PL, the nanoparticle amendment of PL reduced the water soluble P from 66% (for untreated PL) to 4.4%, and lowered the peak soluble P concentration from 300 to <20 mg/L. By transferring the peak soluble P to the nanoparticle-bound P, the nanoparticles not only greatly reduce the potential runoff loss of P from PL, but also provide a long-term slow-releasing nutrient source. Fortuitously, the nanoparticle treatment was able to immobilize arsenic from PL. With excellent adsorption capacity, easy deliverability, low cost and environmental innocuousness, the stabilized Fe-Mn nanoparticles appear promising for controlling P releases from poultry litter or other animal wastes and for phosphate recovery from water.

Air Quality in Alternative Housing Systems may have an Impact on Laying Hen Welfare. Part II-Ammonia

The EU ban on conventional barren cages for laying hens from 2012 has improved many aspects of laying hen welfare. The new housing systems allow for the expression of highly-motivated behaviors. However, the systems available for intensive large-scale egg production (e.g., aviaries, floor housing systems, furnished cages) may cause other welfare challenges. We have reviewed the literature regarding the health, behavior, production characteristics, and welfare of laying hens when exposed to ammonia in their housing environment. Concentrations of ammonia gas are commonly high in aviaries and floor housing systems in which manure is not regularly removed, whereas they are usually lower in furnished cages. High levels are found during the cold season when ventilation flow is often reduced. Ammonia is a pungent gas, and behavioral studies indicate chickens are averse to the gas. High concentrations of gaseous ammonia can have adverse health effects and, when very high, even influence production performance. The most profound effects seen are the occurrence of lesions in the respiratory tract and keratoconjunctivitis. There is also evidence that high ammonia concentrations predispose poultry to respiratory disease and secondary infections. We conclude that there are animal welfare challenges related to high ammonia levels, and that immediate actions are needed. Development of improved systems and management routines for manure removal and ventilation will be important for the reduction of ammonia levels and hence will contribute to safeguarding hen welfare.

Effects of a silica-based feed supplement on performance, health, and litter quality of growing turkeys

Poor litter quality is a potential challenge to footpad health as well as the primary cause of ammonia volatilization. High ambient ammonia concentration is one of the most significant factors negatively affecting poultry production today. Some minerals have been reported to reduce ammonia release from poultry litter. Silicon dioxide, a highly pure and natural mineral, shows promise in decreasing ammonia volatilization and improving litter quality. The objective of the current study was to investigate the effects of feed-borne silicon dioxide on litter quality and how this impacts bird performance, general health and footpad health throughout a 12-wk posthatching turkey study. Supplementing the diet with silicon dioxide was found to significantly improve turkey BW gain and the efficiency of feed conversion. The severity of footpad dermatitis was monitored throughout the experimental period but no significant effect of diet was seen. The feeding of silicon dioxide reduced litter pH which decreased the conversion of NH4⁺ to NH3 thereby reducing nitrogen losses from litter. It was concluded that, under our study conditions, the feeding of 0.02% silicon dioxide offers potential economic benefits to turkey producers.

Gaseous emissions from management of solid waste: a systematic review

The establishment of sustainable soil waste management practices implies minimizing their environmental losses associated with climate change (greenhouse gases: GHGs) and ecosystems acidification (ammonia: NH3 ). Although a number of management strategies for solid waste management have been investigated to quantify nitrogen (N) and carbon (C) losses in relation to varied environmental and operational conditions, their overall effect is still uncertain. In this context, we have analyzed the current scientific information through a systematic review. We quantified the response of GHG emissions, NH3 emissions, and total N losses to different solid waste management strategies (conventional solid storage, turned composting, forced aerated composting, covering, compaction, addition/substitution of bulking agents and the use of additives). Our study is based on a meta-analysis of 50 research articles involving 304 observations. Our results indicated that improving the structure of the pile (waste or manure heap) via addition or substitution of certain bulking agents significantly reduced nitrous oxide (N2 O) and methane (CH4 ) emissions by 53% and 71%, respectively. Turned composting systems, unlike forced aerated composted systems, showed potential for reducing GHGs (N2 O: 50% and CH4 : 71%). Bulking agents and both composting systems involved a certain degree of pollution swapping as they significantly promoted NH3 emissions by 35%, 54%, and 121% for bulking agents, turned and forced aerated composting, respectively. Strategies based on the restriction of O2 supply, such as covering or compaction, did not show significant effects on reducing GHGs but substantially decreased NH3 emissions by 61% and 54% for covering and compaction, respectively. The use of specific additives significantly reduced NH3 losses by 69%. Our meta-analysis suggested that there is enough evidence to refine future Intergovernmental Panel on Climate Change (IPCC) methodologies from solid waste, especially for solid waste composting practices. More holistic and integrated approaches are therefore required to develop more sustainable solid waste management systems.

Emission of Harmful Gases from Poultry Farms and Possibilities of Their Reduction

This review is devoted to methodology that can help to assess emission of gases from poultry housings and could be used to expand the knowledge base of researchers, policymakers and farmers to maintain sustainable environment conditions for farming systems. Concentration and emission of ammonia, methane, nitrous oxide and carbon dioxide in poultry barns are discussed in this paper. Surveys of ammonia and greenhouse gases mean concentrations and emission factors in different poultry systems are showed. This paper is also gives the findings in emission mitigation, especially to different manure handling practices, management schemes, housing and facility designs for broilers and laying hens. Finally this paper focused on investigating practical means to reduce air emissions from animal production facilities.

Effect of feeding a commercial ammonia binding product De-Odorase™ on broiler chicken performance

Ammonia production in commercial poultry sheds poses a problem for farmers as high levels can affect animal's respiratory health, resulting in hock and foot pad lesions and thereby affecting performance. A study was conducted to evaluate the suitability of whole, chopped and dried Yucca schidigera (De-Odorase™, Alltech Inc, USA) to reduce ammonia excretion from broilers and investigate the impact on broiler performance. Nine hundred and two, one-day-old Cobb broilers were randomly assigned to one of two diets, without (control) or supplemented with 500 g/t De-Odorase™. Birds fed the treatment diet had significantly higher body weight (P < 0.05) at 42 d and improved FCR (P < 0.05). Significant reductions in ammonia from litter were reported at 37 and 42 days old (P < 0.05 and P < 0.1, respectively). No significant differences were seen in foot pad, gait score, feather score or carcass data; although the birds fed De-Odorase™ had consistent numerical improvements in these parameters. The results of this study suggest that feeding whole, chopped and dried Yucca schidigera as a functional ingredient in the diet can be part of an ammonia management programme to improve broiler welfare and zootechnical performance.

A laboratory study of microalgae-based ammonia gas mitigation with potential application for improving air quality in animal production operations

Ammonia gas emission is a major concern in concentrated animal production operations. It not only reduces the manure value as fertilizer due to nitrogen loss, but also has considerable environmental consequences for both animals and ecosystem. In this work, a microalgae culture system was developed as an ammonia gas bioscrubber to reduce ammonia gas emission. The green algae Scenedesmus dimorphus was grown in a flat-panel photobioreactor aerated with ammonia-laden air. A continuous culture was performed at different operational conditions including dilution rate (D = 0.05, 0.1, 0.2, and 0.3 day(-1)), ammonia gas loading rate (9.4, 19.3, 28.9, 39.9, 55.6 mg/L-day), and medium pH (5, 6, 7, and 8). The alga culture at 0.1 day(-1) dilution rate, 39.9 mg/L-day ammonia gas loading rate, and pH 7 resulted in the highest cell density and biomass productivity. In order to provide a wide spectrum evaluation of the algae-based ammonia mitigation system, four parameters were determined, including ammonia removal rate, overall ammonia gas removal efficiency, cellular ammonia consumption rate, and cell yield based on ammonia input. Depending on the operational conditions used, the maximum values of those four evaluative parameters were 50.92 +/- 2.91 mg/L-day of ammonia removal rate, 94.90 +/- 1.87% of ammonia removal efficiency, 0.0597 +/- 0.0024 g NH3/g cell-day of cellular ammonia consumption rate, and 19.40 +/- 2.52 g cell/g NH3 of cell yield based on ammonia. It was also found that the majority of nitrogen in the ammonia gas was assimilated by the algal cells. At D = 0.1 day(-1), 39.9 mg/L-day of ammonia gas loading rate and pH 7, algal biomass assimilated 98.6% of nitrogen contained in the ammonia gas input, with less than 5% of inlet ammonia gas was exhausted after the algal treatment.

IMPLICATIONS

This study demonstrated the effectiveness of using microalgae for mitigating ammonia gas emission from animal production operations. The results enabled us to better understand the mechanisms of ammonia assimilation by microalgae, the engineering design parameters for the process scale up, and the economic viability of the system. Eventually, it will lead to a novel, alternative method for mitigating ammonia gas emission from concentrated animal operations while producing biomass as high-quality feed ingredient.

Assessment of frequent litter amendment application on ammonia emission from broilers operations

Litter amendments have been used to control the ammonia (NH3) emission from the broiler litter during the brooding period. One of the commercially available litter amendments, sodium bisulfate, was frequently applied on the litter with two different rates on weekly basis in a laboratory setup and with a single rate on biweekly basis under field conditions. Repeated application ofsodium bisulfate led to significant reduction in NH3 emissions from broilers. The magnitude of NH3 emission reduction increases with the application rate of sodium bisulfate. The reduction rates of cumulative emissions with 366 g/wk-m2 (75 lb/wk-1000 ft) rate (from 14% to 64.5%) were higher than the reduction rate of 183 g/wk-m2 (37.5 lb/wk-1000 ft2) rate (from 0% to 55%) from 28 to 61 days of age. The cumulative NH3 emission was reduced by 51.7% with 244 g/2 wk-m2 (50 lb/2 wk-1000 ft2) rate over a three-flockperiod (8-wk average grow-out per flock) under field production conditions. Sodium bisulfate application showed no significant difference on body weight and feed conversion efficiency. However, footpad quality was significantly improved by sodium bisulfate application. Litter pH and ammonia nitrogen level of the litter were decreased by sodium bisulfate application with both rates. Organic and total nitrogen contents in the litter were higher, whereas less nitrogen was emitted as NH3. The laboratory-scale findings of emission reduction by the additives should be considered to be preliminary if the additives are to be applied under commercial production settings.

IMPLICATIONS

This work demonstrated that frequent litter amendment application can be used to reduce NH3 emissions from broiler houses, with no adverse effect on the animal production performances. The NH3 reduction rates could vary with different application frequencies and rates. Using litter amendment during broiler grow-out to lower NH3 emissions should be applicable to boiler production systems. The results of this study also contribute to the baseline data for improving the national air emissions inventory for livestock and poultry production facilities.

Bentonite can decrease ammonia volatilisation losses from poultry litter: laboratory studies

Ammonia volatilisation from manure materials within poultry sheds can adversely affect production, and also represents a loss of fertiliser value from the spent litter. This study sought to compare the ability of alum and bentonite to decrease volatilisation losses of ammonia from spent poultry litter. An in-vessel volatilisation trial with air flushing, ammonia collection, and ammonia analysis was conducted over 64 days to evaluate the mitigation potential of these two materials. Water-saturated spent litter was incubated at 25°C in untreated condition (control) or with three treatments: an industry-accepted rate of alum [4% Al2(SO4)3·18H2O by dry mass of litter dry mass; ALUM], air-dry bentonite (127% by dry mass; BENT), or water-saturated bentonite (once again at 127% by dry mass; SATBENT). A high proportion of the nitrogen contained in the untreated spent litter was volatilised (62%). Bentonite additions were superior to alum additions at retaining spent litter ammonia (nitrogen losses: 15%, SATBENT; 34%, BENT; 54%, ALUM). Where production considerations favour comparable high rates of bentonite addition (e.g. where the litter is to be re-formulated as a fertiliser), this clay has potential to decrease ammonia volatilisation either in-shed or in spent litter stockpiles or formulated products, without the associated detrimental effect of alum on phosphorus availability.

Effects of reed straw, zeolite, and superphosphate amendments on ammonia and greenhouse gas emissions from stored duck manure

Stored poultry manure can be a significant source of ammonia (NH) and greenhouse gases (GHGs), including nitrous oxide (NO), methane (CH), and carbon dioxide (CO) emissions. Amendments can be used to modify physiochemical properties of manure, thus having the potential to reduce gas emissions. Here, we lab-tested the single and combined effects of addition of reed straw, zeolite, and superphosphate on gas emissions from stored duck manure. We showed that, over a period of 46 d, cumulative NH emissions were reduced by 61 to 70% with superphosphate additions, whereas cumulative NO emissions were increased by up to 23% compared with the control treatment. Reed straw addition reduced cumulative NH, NO, and CH emissions relative to the control by 12, 27, and 47%, respectively, and zeolite addition reduced cumulative NH and NO emissions by 36 and 20%, respectively. Total GHG emissions (as CO-equivalents) were reduced by up to 27% with the additions of reed straw and/or zeolite. Our results indicate that reed straw or zeolite can be recommended as amendments to reduce GHG emissions from duck manure; however, superphosphate is more effective in reducing NH emissions.