Ammonia production in poultry houses can affect health of humans, birds, and the environment-techniques for its reduction during poultry production

Chicken metabolism, immobilization, and post-industrial production

Chickens have become emblematic of the Anthropocene: They embody the age of acceleration, (post-) industrial value, and intensification in scientific and technological knowledge and practice. Contemporary chickens are the bearers of significant genetic and nutritional knowledge, experimented upon and 'tweaked' so much so that some have denied that contemporary commercial chickens are chickens at all. This article reconsiders chickens through a metabolic lens, and the notion of metabolism through chickens, arguing that attending to chickens opens up new conceptualizations of life and labour in the metabosphere. The article tells a metabolic history of chickens from ornament to enclosed monocrop, by way of the laboratory and nutritional experiments. Then, it looks at chicken metabolism in three conceptual modes: first, as a conduit for value, metabolizing and enhancing human life for the past century; second, through technological innovations extending the gut outside chickens' immobilized bodies; and third, through the planetary impacts of metabolic porosity in geological manifestations, toxic atmospheres, and viral overflow. Ultimately, this article shows how techno-scientific production of chickens has taken place in and created the metabosphere as a site of experimentation and exploitation.

Atmospheric reduced nitrogen: Sources, transformations, effects, and management

Human activities have increased atmospheric emissions and deposition of oxidized and reduced forms of nitrogen, but emission control programs have largely focused on oxidized nitrogen. As a result, in many regions of the world emissions of oxidized nitrogen are decreasing while emissions of reduced nitrogen are increasing. Emissions of reduced nitrogen largely originate from livestock waste and fertilizer application, with contributions from transportation sources in urban areas. Observations suggest a discrepancy between trends in emissions and deposition of reduced nitrogen in the U.S., likely due to an underestimate in emissions. In the atmosphere, ammonia reacts with oxides of sulfur and nitrogen to form fine particulate matter that impairs health and visibility and affects climate forcings. Recent reductions in emissions of sulfur and nitrogen oxides have limited partitioning with ammonia, decreasing long-range transport. Continuing research is needed to improve understanding of how shifting emissions alter formation of secondary particulates and patterns of transport and deposition of reactive nitrogen. Satellite remote sensing has potential for monitoring atmospheric concentrations and emissions of ammonia, but there remains a need to maintain and strengthen ground-based measurements and continue development of chemical transport models. Elevated nitrogen deposition has decreased plant and soil microbial biodiversity and altered the biogeochemical function of terrestrial, freshwater, and coastal ecosystems. Further study is needed on differential effects of oxidized versus reduced nitrogen and pathways and timescales of ecosystem recovery from elevated nitrogen deposition. Decreases in deposition of reduced nitrogen could alleviate exceedances of critical loads for terrestrial and freshwater indicators in many U.S. areas. The U.S. Environmental Protection Agency should consider using critical loads as a basis for setting standards to protect public welfare and ecosystems. The U.S. and other countries might look to European experience for approaches to control emissions of reduced nitrogen from agricultural and transportation sectors.Implications: In this Critical Review we synthesize research on effects, air emissions, environmental transformations, and management of reduced forms of nitrogen. Emissions of reduced nitrogen affect human health, the structure and function of ecosystems, and climatic forcings. While emissions of oxidized forms of nitrogen are regulated in the U.S., controls on reduced forms are largely absent. Decreases in emissions of sulfur and nitrogen oxides coupled with increases in ammonia are shifting the gas-particle partitioning of ammonia and decreasing long-range atmospheric transport of reduced nitrogen. Effort is needed to understand, monitor, and manage emissions of reduced nitrogen in a changing environment.

Impact of dietary digestible aromatic amino acid levels and stachyose on growth, nutrient utilization, and cecal odorous compounds in broiler chickens

This study evaluated the impact of dietary digestible aromatic amino acid (DAAA) levels and stachyose on growth, nutrient utilization and cecal odorous compounds in broiler chickens. A 3×2 two-factor factorial design: Three dietary DAAA levels (1.40, 1.54, 1.68%) supplemented with either 5 g/kg of stachyose or without any stachyose were used to create 6 experimental diets. Each diet was fed to 6 replicates of 10 birds from d 22 to 42. Findings revealed that broilers receiving a diet with 1.54% DAAA levels supplemented with 5 g/kg stachyose exhibited a significant boost in average daily gain and improved utilization of crude protein, ether extract, tryptophan, and methionine compared to other diet treatments (P < 0.05). As the dietary DAAA levels increased, there was a significant rise in the concentrations of indole, skatole, p-methylphenol, and butyric acid in the cecum of broilers (P < 0.05). The addition of stachyose to diets reduced concentrations of indole, skatole, phenol, p-methylphenol, acetic acid and propionic acid in the cecum (P < 0.05). The lowest concentrations of indole, phenol, p-methylphenol, volatile fatty acids and pH in cecum of broilers were observed in the treatment which diet DAAA level was 1.40% with stachyose (P < 0.05). In conclusion, dietary DAAA levels and stachyose had significant interactions on the growth, main nutrient utilization and cecal odorous compounds in broilers. The dietary DAAA level was 1.54% with 5 g/kg of stachyose can improve the growth performance, nutrient utilization. However, the dietary DAAA level was 1.40% with stachyose was more beneficial to decrease the cecal odor compound composition in broilers.

Growth performance, carcass, and meat quality traits in broiler chickens reared on plastic-grid flooring, wood shavings, and zeolite-supplemented wood shavings

This study aimed to assess the growth performance, carcass characteristics, and meat quality traits of broiler chickens raised on plastic-grid floors, traditional wood shavings, and wood shavings enriched with zeolite. The experimental design included the allocation of 504-day-old chicks to three different bedding materials, namely wood shavings, plastic-grid floors, and zeolite litter, each with four replications (42 birds per replicate). The chicks were individually weighed at birth and grouped according to their average body weights. An experiment involving 504 chicks was conducted, with each replicate consisting of 42 male chicks of similar body weight. At the end of the experiment, a total of 120 chickens were slaughtered with 10 chickens selected from each replicate for processing carcass and meat quality traits. The effects of different bedding materials on mortality (P = 0.812), body weight (P = 0.565), and body weight gain (P = 0.569) were not significant. The ANOVA test was conducted to compare the main effects of performance, carcass, and meat quality characteristics. The feed intake was significantly affected in the 2nd, and 3rd weeks (P = 0.001; 0.023); in addition, the feed conversion ratio was significant in the 2nd, 4th, and overall period (P = 0.003; P = 0.026; P = 0.038) by the bedding materials. The breast yield (P = 0.001), thigh yield (P = 0.028), and wing yield (P = 0.023) were significant. The type of bedding material used in broiler production significantly influenced the pH24 (P = 0.030), L* (P = 0.037), a* (P = 0.000), and CL (P = 0.028). It was concluded that both a plastic-grid floor and zeolite supplementation to wood shaving litter did not significantly affect overall growth performance in broiler chickens. However, the plastic-grid floor showed superior effects on breast meat yield and quality characteristics, particularly reducing cooking loss, when compared to zeolite supplementation in wood shaving litter. The plastic-grid floor led to a slight increase in the feed conversion ratio. Consequently, adopting a plastic grid floor emerges as a viable alternative to traditional wood shavings in broiler farming.

A critical assessment of the cellular defences of the avian respiratory system: are birds in general and poultry in particular relatively more susceptible to pulmonary infections/afflictions?

In commercial poultry farming, respiratory diseases cause high morbidities and mortalities, begetting colossal economic losses. Without empirical evidence, early observations led to the supposition that birds in general, and poultry in particular, have weak innate and adaptive pulmonary defences and are therefore highly susceptible to injury by pathogens. Recent findings have, however, shown that birds possess notably efficient pulmonary defences that include: (i) a structurally complex three-tiered airway arrangement with aerodynamically intricate air-flow dynamics that provide efficient filtration of inhaled air; (ii) a specialised airway mucosal lining that comprises air-filtering (ciliated) cells and various resident phagocytic cells such as surface and tissue macrophages, dendritic cells and lymphocytes; (iii) an exceptionally efficient mucociliary escalator system that efficiently removes trapped foreign agents; (iv) phagocytotic atrial and infundibular epithelial cells; (v) phagocytically competent surface macrophages that destroy pathogens and injurious particulates; (vi) pulmonary intravascular macrophages that protect the lung from the vascular side; and (vii) proficiently phagocytic pulmonary extravasated erythrocytes. Additionally, the avian respiratory system rapidly translocates phagocytic cells onto the respiratory surface, ostensibly from the subepithelial space and the circulatory system: the mobilised cells complement the surface macrophages in destroying foreign agents. Further studies are needed to determine whether the posited weak defence of the avian respiratory system is a global avian feature or is exclusive to poultry. This review argues that any inadequacies of pulmonary defences in poultry may have derived from exacting genetic manipulation(s) for traits such as rapid weight gain from efficient conversion of food into meat and eggs and the harsh environmental conditions and severe husbandry operations in modern poultry farming. To reduce pulmonary diseases and their severity, greater effort must be directed at establishment of optimal poultry housing conditions and use of more humane husbandry practices.

Internet of Things-based sustainable environment management for large indoor facilities

Due to global warming and climate change, the poultry industry is heavily impacted, especially the broiler industry, due to the sensitive immune system of broiler chickens. However, the continuous monitoring and controlling of the farm's environmental parameters can help to curtail the negative impacts of the environment on chickens' health, leading to increased meat production. This article presents smart solutions to such issues, which are practically implemented, and have low production and operational costs. In this article, an Internet of Things (IoT) based environmental parameters monitoring has been demonstrated for the poultry farmhouse. This system enables the collection and visualization of crucially sensed data automatically and reliably, and at a low cost to efficiently manage and operate a poultry farm. The proposed IoT-based remote monitoring system collects and visualizes environmental parameters, such as air temperature, relative humidity (RH), oxygen level (O2), carbon dioxide (CO2), carbon monoxide (CO), and ammonia (NH3) gas concentrations. The wireless sensor nodes have been designed and deployed for efficient data collection of the essential environmental parameters that are key for monitoring and decision-making process. The hardware is implemented and deployed successfully at a site within the control shed of the poultry farmhouse. The results revealed important findings related to the environmental conditions within the poultry farm. The temperature inside the control sheds remained within the desired range throughout the monitoring period, with daily average values ranging from 32 °C to 34 °C. The RH showed slight variations monitoring period, ranging from 65% to 75%, with a daily average of 70%. The O2 concentration exhibited an average value of 17% to 18.5% throughout the monitoring period. The CO2 levels showed occasional increases, reaching a maximum value of 1,100 ppm. However, this value was below the maximum permissible level of 2,500 ppm, indicating that the ventilation system was effective in maintaining acceptable CO2 levels within the control sheds. The NH3 gas concentration remained consistently low throughout the duration, with an average value of 50 parts per million (ppm).

Effect of Hardwood Dust and Ammonia Gas on the Respiratory Integrity of Broiler Chickens

Dust and ammonia gas (NH3) are two of the most abundant pollutants suspended in the air of poultry houses. Chronic inhalation of poultry dust and NH3 causes damage to the airways and reduces performance in broilers. Poultry dust is a mixture of organic and inorganic matter from feed, bedding material, manure, feathers, skin debris, and microorganisms. Thus, the composition and concentration of poultry dust vary among farms. This study proposes a model to assess the individual effect of a defined fraction of poultry dust derived from bedding material (wood dust) and its effects, alone or combined with NH3, on the performance and respiratory integrity of broilers. Ninety-six, 1-day-old broilers were randomly divided into groups of 24 and placed into four controlled environment chambers to continuously receive one of four treatments: 1) negative control; 2) exposure to airborne red oak wood dust at a concentration of 7.5 × 106 particles/m3 (particulate matter5.0); 3) exposure to 50 parts per million (ppm) of NH3; and 4) exposure to airborne red oak wood dust and 50 ppm of NH3. On day 43, all birds were weighed and euthanized. Performance data were recorded. Tissue samples were collected from six birds per treatment. Histologic evaluations of the nasal turbinates, trachea, and lungs were conducted. Histologic lesion scores (0 to 3) were assigned, and tracheal mucosal thickness was measured. No significant differences among treatments were found in body weight (P = 0.066), tracheal mucosal thickness (P = 0.593), or tracheal lesion score (P = 0.07). The average nasal turbinate lesion scores were higher in the wood and wood + ammonia treatments compared with the control (P = 0.015). The lung lesion scores were higher (P = 0.004) in all treatment groups compared with the control. In conclusion, chronic exposure to red oak wood dust, alone or in combination with NH3, induced important inflammatory damage to portions of the respiratory system of broilers; however, no significant effects on performance were observed.

Moisture-Resistant and Highly Selective NH3 Sensor Based on CdS/WS2 Composite Heterojunction

This study reports the synthesis of CdS/WS2 composites via a green and ultra-low-cost hydrothermal method. By controlling the relative mass ratio between WS2 and CdS, an n-n type CdS/WS2 heterostructure, with excellent NH3 gas-sensitive properties, was developed and investigated at room temperature. Compared with pristine WS2 and CdS, the CdS/WS2-40%wt composite exhibited excellent selectivity of more than 4 orders of magnitude for sensing NH3, a very short recovery time of 3 s, and ultrahigh selectivity at room temperature. The large specific surface area of the CdS/WS2 composite increased the active sites for the gas-sensitive reaction. Additionally, the 2D morphology of CdS/WS2 and the heterojunction formed between WS2 and CdS contributed to the improved performance. Anti-humidity interference tests showed that the CdS/WS2 sample remained stable under real-time monitoring of NH3 at different ambient humidity values. This study paves the way for designing high-performance gas sensors operating at room temperature.

Chemiresistive gas sensor based on Mo0.5W0.5S2 alloy nanoparticles with good selectivity and ppb-level limit of detection to ammonia

Transition metal dichalcogenides (TMDs) are promising materials for chemiresistive gas sensor, while TMD alloys (two chalcogenide or/and metal elements) with tunable electronic structures have drawn little attention in gas sensing. Herein, Mo_0.5W_0.5S₂ alloy nanoparticles (NPs) were prepared by a facile sonication exfoliation method and then tested for ammonia sensing. The crystal structure, geometric morphology, and elemental composition of Mo_0.5W_0.5S₂ NPs were investigated. The gas sensing measurements demonstrated Mo_0.5W_0.5S₂ NPs with good response to ammonia at 80 °C with a limit of detection down to 500 part per billion (ppb). The sensor also displayed good stability as well as superb selectivity to ammonia in the presence of interferences, such as methanol, acetone, benzene, and cyclohexane. The theoretical calculations revealed Mo and W atoms at edges (such as Mo_0.5W_0.5S₂ (010)) of sheet-like NPs as the active sites for ammonia adsorption. Electrons donated by the adsorbed ammonia were combined with holes in p-type Mo_0.5W_0.5S₂ NPs, and the concentration of the main charge carrier was reduced, resulting in resistance enhancement.

Effects of tea residues-fermented feed on production performance, egg quality, antioxidant capacity, caecal microbiota, and ammonia emissions of laying hens

This study was to assess the effects of tea residues-fermented feed (TR-fermented feed) on production performance, egg quality, serum antioxidant capacity, caecal microbiota, and ammonia emissions of laying hens. A total of 1,296 Lohmann laying hens have randomly distributed four groups with six parallels and fed with diets TR-fermented feed at the rates of 0 (control), 1, 3, and 5%. The inclusion of 1% (TR)-fermented feed resulted in a significant increase in egg-laying rate and average egg weight of birds, and a reduction in the feed-to-egg ratio when compared to the control group (p < 0.05). The addition of 1 and 3% of (TR)-fermented feed significantly improved the Haugh unit of eggs (p < 0.05). The eggshell thickness was observed to increase by almost one-fold upon the inclusion of 3 and 5% (TR)-fermented feed in the basal diet (p < 0.05). The supplementation of 3% (TR)-fermented feed significantly increased the content of methionine, tyrosine, proline, essential amino acids (EAA), alpha linoleic acid (C18:3n6), docosanoic acid (C22:0), docosahexaenoic acid (C22:6n3), twenty-three carbonic acids (C23:0), ditetradecenoic acid (C24:1) and total omega-3 polyunsaturated fatty acids (∑ω-3 PUFA) in the eggs (p < 0.05). The addition of a certain amount of (TR)-fermented feed can enhance the activity of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) in chicken serum, and reduce the level of malondialdehyde (MDA) (p < 0.05). The ammonia concentration in the hen house of laying hens in the treatment groups decreased significantly (p < 0.05). Bacteroidetes and Firmicutes, the main phyla in the cecal bacterial community, were differentially abundant in each group, comprising greater than 55 and 33%, respectively. Collectively, this research indicates that (TR)-fermented feed supplementation improves the performance of laying hens and reduces ammonia emissions and can be used in industry-scale layer production.

Effects of Atmospheric Ammonia on Skeletal Muscle Growth in Broilers

Ammonia, one of the most polluted gases in poultry houses, has always been an urgent problem to solve. Exposure to ammonia can threaten the respiratory tract, induce inflammation, and decrease growth performance. To date, there are few studies investigating the effects of ammonia on skeletal muscle growth. In this experiment, a total of 144 broilers were randomly divided into two groups, and 0 ppm and 35 ppm atmospheric ammonia were administered in the chambers. The trial lasted for 21 days. The breast muscle, thigh muscle, dressed weight, and serum biochemical indexes were measured. The skeletal muscle fibre morphology was observed using light microscopy, and the expressions of genes associated with skeletal muscle development and myosin heavy chain genes were assessed. After 7 days of ammonia exposure, the broilers' weight in the ammonia group decreased. On the 21st day of the experiment, in the ammonia group, the breast muscle weight, thigh muscle weight, and dressed weight decreased, the blood urea nitrogen content increased, skeletal muscle fibre diameter shortened, the expression of myostatin increased, and the expression of myosin heavy chain-FWM and myosin heavy chain-FRM decreased significantly. This article suggests that 35 ppm atmospheric ammonia seriously affects the skeletal muscle gain rate of broilers, and the myostatin pathway could be a potential regulation of the growth rate of muscle fibre under ammonia exposure.

Real-time monitoring of atmospheric ammonia based on modifier-enhanced vacuum ultraviolet photoionization ion mobility spectrometry

Ammonia (NH₃) plays an important role in the atmospheric environment such as the formation of PM_2.5, the concentration monitoring of which could hence help in the air quality assessment. In this study, a method for quantitative monitoring of atmospheric NH₃ was developed based on modifier-enhanced selectivity detection using a homemade vacuum ultraviolet photoionization ion mobility spectrometry (VUV-PI-IMS). To enhance the resolution and sensitivity of measuring NH₃, 2-butanone as the gas modifier was introduced into the drift tube with the drift gas. Atmospheric NH₃ can be selectively detected, where the peak-to-peak resolution (R_P-P) of 7.69 was obtained. The product ions were identified to be [C₄H₈O]₂NH₄⁺ by using a homemade time-of-flight mass spectrometer. The calculated limit of detection (LOD) was 0.39 ppbv improving about 10 times. For the most common concentration variation of atmospheric NH₃ in the range of 10-100 ppbv, the linear curve was obtained with R² of 0.997. Lastly, the VUV-PI-IMS was used to monitor the evolution of atmospheric NH₃ near our laboratory and mounted on a car for monitoring the regional distribution of atmospheric NH₃ in Dalian, China. The results also showed that VUV-PI-IMS has a promising application prospect in monitoring the concentration of atmospheric NH₃ and supporting the air quality assessment.

Lignin from sugarcane bagasse as a prebiotic additive for poultry feed

Diet is a crucial factor on health and well-being of livestock animals. Nutritional strengthening with diet formulations is essential to the livestock industry and animal perfor-mance. Searching for valuable feed additives among by-products may promote not only circular economy, but also functional diets. Lignin from sugarcane bagasse was proposed as a potential prebiotic additive for chickens and incorporated at 1 % (w/w) in commercial chicken feed, tested in two feed forms, namely, mash and pellets. Physico-chemical characterization of both feed types with and without lignin was performed. Also, the prebiotic potential for feeds with lignin was assessed by in vitro gastrointestinal model and evaluated the impact on chicken cecal Lactobacillus and Bifidobacterium. As for the pellet's physical quality, there was a higher cohesion of the pellets with lignin, indicating a higher resistance to breakout and lignin decreases the tendency of the pellets for microbial contamination. Regarding the prebiotic potential, mash feed with lignin showed higher promotion of Bifidobacterium in comparison with mash feed without lignin and to pellet feed with lignin. Lignin from sugarcane bagasse has prebiotic potential as additive to chicken feed when supplemented in mash feed diets, presenting itself as a sustainable and eco-friendly alternative to chicken feed additives supplementation.

Particulate matter in poultry house on poultry respiratory disease: a systematic review

Particulate matter (PM) is one of the essential environmental stressors for the poultry industry in the world. Given its large specific surface area, PM can adsorb and carry a variety of pollutants, including heavy metal ions, ammonia, and persistent organic pollutants such as pathogenic microorganisms. High concentrations of PM induce poultry respiratory inflammation and trigger various diseases. However, the pathogenic mechanism of PM in poultry houses on respiratory diseases has not been clarified due to its complexity and lack of accurate assays. In terms of pathogenesis, there are 3 ways to explain this phenomenon: Inhaled PM irritates the respiratory tract, decreases immune resistance, and causes a respiratory disease; respiratory tract irritation by compounds presents in PM; infections with pathogenic and non-pathogenic microorganisms attached to PM. The latter 2 modes of influence are more harmful. Specifically, PM can induce the respiratory disease through several toxic mechanisms, including ammonia ingestion and bioaccumulation, lung flora dysbiosis, oxidative stress, and metabolic disorders. Therefore, this review summarizes the characteristics of PM in the poultry house and the impact of poultry PM on respiratory disease and proposes potential pathogenic mechanisms.

Intensive poultry farming: A review of the impact on the environment and human health

Poultry farming is one of the most efficient animal husbandry methods and it provides nutritional security to a significant number of the world population. Using modern intensive farming techniques, global production has reached 133.4 mil. t in 2020, with a steady growth each year. Such intensive growth methods however lead to a significant environmental footprint. Waste materials such as poultry litter and manure can pose a serious threat to environmental and human health, and need to be managed properly. Poultry production and waste by-products are linked to NH₃, N₂O and CH₄ emissions, and have an impact on global greenhouse gas emissions, as well as animal and human health. Litter and manure can contain pesticide residues, microorganisms, pathogens, pharmaceuticals (antibiotics), hormones, metals, macronutrients (at improper ratios) and other pollutants which can lead to air, soil and water contamination as well as formation of antimicrobial/multidrug resistant strains of pathogens. Dust emitted from intensive poultry production operations contains feather and skin fragments, faeces, feed particles, microorganisms and other pollutants, which can adversely impact poultry health as well as the health of farm workers and nearby inhabitants. Fastidious odours are another problem that can have an adverse impact on health and quality of life of workers and surrounding population. This study discusses the current knowledge on the impact of intensive poultry farming on environmental and human health, as well as taking a look at solutions for a sustainable future.

Lactobacillus (L. plantarum & L. rhamnosus) and Saccharomyces (S. cerevisiae): effects on performance, biochemical parameters, ammonium ion in manure, and digestibility of broiler chickens

Two strains of Lactobacillus combined with Baker's yeast (Saccharomyces cerevisiae) used as probiotics were evaluated to replace antibiotics in poultry flocks by reducing ammonia emissions in manure of broilers without comprising performance or health. One-day-old Cobb 500 broilers (600) were fed starter, grower, and finisher diets as control (CON); probiotic S. cerevisiae, inclusion rate at 4.26 × 10⁶ CFU/kg of feed (SCY); probiotic L. plantarum and L. rhamnosus, inclusion rate at 4.35 × 10⁸ CFU/kg of feed (LPR) for each; and a combination of Lactobacillus plantarum and L. rhamnosus at 4.35 × 10⁸ CFU/kg of feed for each plus Saccharomyces cerevisiae and 4.26 × 10⁶ CFU/kg of feed (SWL). The 4 treatments had 5 replicates (pens), each with 30 broilers. Performance was measured weekly as feed consumption, weight gain, BW, and feed conversion ratio (FCR) over a 6-wk grow-out period. Accompanying biochemical analyses included lipase activity of the pancreas, liver weight, and uric acid (UA) concentration in liver. Albumin, total protein, UA, ammonia, and blood urea nitrogen (BUN) were measured in serum. Ammonium (NH₄⁺) in manure and apparent ileal digestibility from digesta were also measured. Significance was determined at P ≤ 0.05. Results showed that biochemical analyses had no significant treatment effect; however, there were significant temporal changes in performance measures for individual treatments. Feed consumption increased over time for all treatments (P = 2.00 × 10^-16). CON had lower weight gain in wk 2 (P = 0.013) compared to all treatment and the lowest BW in wk 5 (P = 0.0008) and wk 6 (P = 0.0124) compared to SWL. Specific probiotic strains, with well-defined inclusion rates, and surrounding environmental analyses of present microbes are needed to ascertain effects of probiotics. Other important areas for investigation include 1) confirmation of probiotics present in the digesta/ceca and how they alter the microbiota within the gastrointestinal (GI) tract and 2) the serum heterophil:lymphocyte ratio to further examine potential immune responses to the probiotics.

Ascophyllum nodosum polysaccharide regulates gut microbiota metabolites to protect against colonic inflammation in mice

Ascophyllum nodosum polysaccharide (ANP) can protect against colonic inflammation but the underlying mechanism is still unclear. This study has determined the metabolites of gut microbiota regulated by ANP to reveal the mechanism of the anti-inflammation effect of ANP. Using an in vitro colonic fermentation model, the results indicate that gut microbiota could utilize a proportion of ANP to increase the concentrations of short-chain fatty acids (SCFAs) and decrease ammonia content. Metabolomics revealed that 46 differential metabolites, such as betaine, L-carnitine, and aminoimidazole carboxamide ribonucleotide (AICAR), could be altered by ANP. Metabolic pathway analysis showed that ANP mainly up-regulated the phenylalanine, tyrosine, and tryptophan biosynthesis and aminoacyl-tRNA biosynthesis, which were negatively correlated with inflammation progression. Interestingly, these metabolites associated with inflammation were also up-regulated by ANP in colitis mice, including betaine, L-carnitine, AICAR, N-acetyl-glutamine, tryptophan, and valine, which were mainly associated with amino acid metabolism and aminoacyl-tRNA biosynthesis. Furthermore, the metabolites modulated by ANP were associated with the relative abundances of Akkermansia, Bacteroides, Blautia, Coprobacillus, Enterobacter, and Klebsiella. Additionally, based on VIP values, betaine is a key metabolite after the ANP supplement in vitro and in vivo. As indicated by these findings, ANP can up-regulate the production of SCFAs, betaine, L-carnitine, and AICAR and aminoacyl-tRNA biosynthesis to protect against colonic inflammation and maintain intestinal health.

Dietary and phytogenic inclusion effects on the broiler chicken cecal ecosystem

Dietary modulation in broilers is crucial for the establishment of beneficial microbiota and, subsequently, the promotion of intestinal health. In this trial, a 2 × 2 factorial design was used with two different specifications with respect to dietary metabolizable energy (ME) and crude protein (CP) levels (i.e., 95% and 100% of recommendations) and phytogenic levels (0 and 150 mg/kg). Levels of total bacteria, Bacteroides spp., Lactobacillus spp., and Clostridium cluster XIVa attached to the cecal mucosa and in the cecal digesta were lower in broilers fed the 95% ME and CP specification diets, as was the molar ratio of butyric acid. In addition, the relative activity of autoinducers-2 (AI-2) and the expression levels of TLR4 and AvBD6 were increased. Phytogenic supplementation reduced cecal digesta levels of Escherichia coli and Clostridium cluster I levels, and increased Clostridium cluster IV levels. Moreover, the butyric acid molar ratio and the relative activity of AI-2 were increased, whereas the concentration of branched VFAs and the expression of AvBD6 and LEAP2 were reduced by phytogenic administration. Dietary specifications and phytogenic interactions were shown for the cecal-attached microbiota composition, metabolic activity of digesta microbiota, relative expression of autoinducers-2, and relative expression of toll-like signaling molecules and host antimicrobial peptides. In conclusion, it has been shown that ME and CP dietary specifications, combined or not with phytogenics, modulate multilevel gut biomarkers ranging from microbiota composition and metabolic activity to microbial communications and host signaling, inflammation, and defense.

Volatile organic compound emissions in free-range chicken production: Impacts on environment, welfare and sustainability

<abstract> <p>The increasing demand for free-range poultry products has led to a surge in their availability in the market, prompting a potential decline in premium prices associated with these products. This shift places considerable pressure on upstream costs in chicken production. A comprehensive under-standing of its impact on the environment is essential to ensure the success of commercial and industrial free-range chicken production. However, there exists a significant knowledge gap concerning the emission and concentrations of volatile organic compounds (VOCs) from organic-free range chicken, and their environmental implications have yet to be understood. We aim to address this critical knowledge gap by elucidating the role of VOC emissions in chicken production and assessing their impact on human and animal health, as well as environmental challenges. Understanding the implications of VOC emissions is essential for promoting sustainable and responsible free-range chicken farming practices. By identifying the sources of VOC emissions and their impacts, stakeholders can implement appropriate measures to optimize air quality and enhance the well-being of chickens and workers. Ultimately, this review highlights the role of VOCs in animal production, providing valuable insights for improving the efficiency, environmental sustainability and welfare aspects of free-range chicken farming.</p> </abstract>

Effects of tannic acid supplementation on growth performance, gut health, and meat production and quality of broiler chickens raised in floor pens for 42 days

A study was conducted to investigate the effects of tannic acid (TA) supplementation on growth performance, gut health, antioxidant capacity, gut microbiota, and meat yield and quality in broilers raised for 42 days. A total of 700 one-day-old male broiler chickens (Cobb500) were allocated into 5 treatments with 7 replicates of 20 birds per pen. There were five treatments: 1) tannic acid 0 (TA0: basal diet without TA); 2) tannic acid 0.25 (TA0.25: basal diet+0.25 g/kg TA); 3) tannic acid 0.5 (TA0.5: basal diet+0.5 g/kg TA); 4) tannic acid 1 (TA1: basal diet+1 g/kg TA); and 5) tannic acid 2 (TA2: basal diet+2 g/kg TA). The dietary phases included starter (D 0 to 18; crumble feed), grower (D 18 to 28; pellet feed), and finisher (D 28 to 42; pellet feed). On D 18, the supplementation of TA linearly reduced body weight (BW) and average daily feed intake (ADFI) (p < 0.05), and on D 28, the supplementation of TA linearly reduced BW, average daily gain (ADG), and feed conversion ratio (FCR) (p < 0.05). Relative mRNA expression of genes related to mucin production (MUC2), tight junction proteins (CLDN2 and JAM2), and nutrient transporters (B0AT1 and SGLT1) was linearly increased by the supplementation of TA (p < 0.05). The supplementation of TA tended to linearly increase the relative abundance of the family Enterobacteriaceae (p = 0.08) and quadratically increased the relative abundance of the families Lachnospiraceae and Ruminococcaceae in the cecal microbial communities (p < 0.05). On D 36, the ratio of the phyla Firmicutes and Bacteroidetes was quadratically reduced by the supplementation of TA (p < 0.05). On D 42, bone mineral density and the lean to fat ratio were linearly decreased by the supplementation of TA (p < 0.05). On D 43, total chilled carcass weight was linearly reduced (p < 0.05), and proportion of leg weight was increased by supplementation of TA (p < 0.05). The supplementation of TA linearly reduced pH of the breast meat (p < 0.05) and linearly increased redness (a*) (p < 0.05). Although the supplementation of TA positively influenced gut health and gut microbiota in the starter/grower phases, it negatively affected overall growth performance, bone health, and meat production in broilers on D 42.

Recent innovations in various methods of harmful gases conversion and its mechanism in poultry farms

Poultry breeding takes place in intensive, high-production systems characterized by high animal density, which is a source of harmful emission of odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S) and greenhouse gases, which in turn sustain animal welfare. This study identified and examined the characteristics of chemical compounds emitted in intensive poultry farming (laying hens, broilers) and their toxicity, which led to recommending methods of deodorization. Emphasis was placed on the law relative to air purification in poultry farms. Various methods of air treatment in poultry farms have been described: the modification of animal diet to improve nutrient retention and decrease the amount of their excrement; chemical oxidation technologies (ozonation, photocatalysis, Fenton reaction); various types/brands of biofilters, bioscrubbers and membrane reactors. Numerous studies show that biofilters can reduce ammonia emissions by 51%, hydrogen sulfide by 80%, odors by 67%, while scrubbers brings down ammonia emissions by 77% and odors by 42%, and the application of UV light lowers ammonia emissions by 28%, hydrogen sulfide by 55%, odors by 69% and VOCs by 52%. The paper presents both the solutions currently used in poultry farming and those which are currently in the research and development phase and, as innovative solutions, could be implemented in the near future.

Practical Application of the Five Domains Animal Welfare Framework for Supply Food Animal Chain Managers

The author has worked as a consultant with global commercial supply managers for over 20 years. The focus of this commentary will be practical application of The Five Domains Model in commercial systems. Commercial buyers of meat need simple easy-to-use guidelines. They have to use auditors that can be trained in a workshop that lasts for only a few days. Auditing of slaughter plants by major buyers has resulted in great improvements. Supply chain managers need clear guidance on conditions that would result in a failed audit. Animal based outcome measures that can be easily assessed should be emphasized in commercial systems. Some examples of these key animal welfare indicators are: percentage of animals stunned effectively with a single application of the stunner, percentage of lame animals, foot pad lesions on poultry, and body condition scoring. A farm that supplies a buyer must also comply with housing specifications. The farm either has the specified housing or does not have it. It will be removed from the approved supplier list if housing does not comply. These types of easy to assess indicators can be easily evaluated within the four domains of nutrition, environment, health and behavioral interactions. The Five Domains Framework can also be used in a program for continuous improvement of animal welfare.

High ambient humidity aggravates ammonia-induced respiratory mucosal inflammation by eliciting Th1/Th2 imbalance and NF-κB pathway activation in laying hens

Ammonia (NH3) is an irritant and harmful gas. Its accumulation in the poultry house poses detrimental effects on the respiratory mucosal system of birds. In this process, the relative humidity of the poultry house also plays an important role in potentiating the adverse effects of NH3 on the respiratory status of birds, causing severe physiological consequences. In this study, the combined effects of NH3 and humidity on the respiratory mucosal barrier of laying hens was studied. The gene expression of tight junction proteins, mucin, inflammatory cytokines secreted by Th1/Th2 cells, and proteins related to the Nuclear factor-κB (NF-κB) signaling pathway were detected by qRT-PCR. In addition, the contents of mucin and secretory immunoglobulin A (SIgA) in bronchoalveolar lavage fluid (BALF) were determined. The results showed that treatment with NH3 alone or NH3 and humidity led to morphological changes in the respiratory tract, decreased the gene expressions of tight junction protein, and increased the expression of mucin. Also, the expression of interleukin-4 (IL-4) and IL-10 were increased, whereas, the expression of interferon-γ (IFN-γ) and IL-2 was decreased in laying hens treated with NH3 and humidity. Furthermore, the activation of inhibitor kappa B kinase β (I-KK-β) and the degradation of inhibitor of NF-κB α (I-κB-α) contributed to the activation of the NF-κB pathway, such that the downstream genes, cycooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS) were significantly increased. In conclusion, NH3 damaged the mucosal barrier and induced an imbalance in the mucosal immunity, leading to respiratory tract inflammation. Thus, the relative humidity of the environment aggravates the adverse effects of NH3 in poultry.

Effects of Feed-Through Sulfur on Growth Performance, Atmospheric Ammonia Levels, and Footpad Lesions in Broilers Raised Beginning with Built-Up Litter

To the poultry industry, ammonia accumulation within poultry houses can be a costly issue, as this can lead to problems with bird performance, damage to economically important parts such as paws, and customer disapproval due to animal welfare concerns. Common management practices for ammonia control can be quite effective; however, these methods are used variably from farm to farm, which necessitates ammonia control measures that poultry companies can more uniformly implement across all contract growers. One possible measure is ammonia control through feed additives, which would allow poultry companies more direct control over the treatment. This project explored the efficacy of elemental sulfur added directly to the feed (feed-through sulfur) in controlling litter ammonia levels, live performance, and paw quality of broilers raised on built-up litter over three successive flocks. Feed-through sulfur on its own showed inconsistent effects on performance or footpad lesions after 38 days of production compared to sodium bisulfate or control treatments. However, combination of feed-through sulfur and sodium bisulfate showed a potential synergistic effect on ammonia levels and litter pH, although there were few differences between treatments and controls; therefore, additional research must be explored to confirm these observations.

Ammonia concentrations, litter quality, performance and some welfare parameters of broilers kept on different bedding materials

1. Litter quality has been related to broiler performance, behaviour, welfare, dust and ammonia (NH₃) emissions. Drier litter leads to a reduction in NH₃ emissions and reduces the formation of foot- and hock lesions. However, maintaining good litter quality is often challenging. This study investigated the effects of different bedding materials on litter quality and NH₃ concentrations at litter level, broiler performance, foot- and hock lesions, plumage cleanliness and breast skin irritation.2. A total of 2160 Ross 308 male broilers were randomly assigned to 36 floor pens. There were six replications for each of the following six litter treatments: wood shavings, flax, peat, corn silage, chopped wheat straw and flax pellets.3. For the total period, the highest feed intake and body weight was obtained for broilers housed on peat. The NH₃ concentrations measured at litter level was highest for peat and chopped wheat straw at 36 d of age and numerically the lowest for flax at 30 and 36 d of age. Corn silage remained friable, but did not result in lower NH₃ concentrations compared to wood shavings. Chopped wheat straw and wood shavings gave rise to the highest incidence of foot lesions at 38 d of age, while broilers kept on flax, peat, corn silage and flax pellets had the lowest incidence of foot lesions at the end of the rearing period.4. The results of the current study suggest a complicated relationship between the type of bedding material, litter conditions and NH₃ volatilized from the litter.

Liver transcriptome analysis reveals biological pathways and transcription factors in response to high ammonia exposure

Aim: Ammonia is a toxic gas that not only causes environmental pollution, but also is harmful to human health after inhalation. Liver is an important detoxification organ that can convert external or metabolized toxic substances into nontoxic substances. However, the toxic effects of ammonia exposure on livers have not been well studied.Method: In this study, pigs were used as an animal model and were exposed to 80 ppm ammonia (8 h during 12 days), and then, RNA-seq were conducted to explore the key genes in response to high ammonia exposure in livers.Result: Gene set enrichment analysis (GSEA) showed that the genes associated with hypoxia, inflammatory response, and apoptosis were up-regulated in the ammonia group, but the genes associated with DNA replication, linoleic acid metabolism, and glycolysis were down-regulated. Totally, 556 differentially expressed genes (DEGs) including 54 genes that encode the transcription factors (TFs) were identified between the exposure and control groups. GO and KEGG pathway analysis suggested that these DEGs were involved in inflammatory response, oxidative stress, apoptosis, immune, and cell cycle. Furthermore, the TF-target interaction analysis showed that FOS, HIF-1α, JUNB, ATF3, REL, and KLF4 were important TFs in regulating the hepatic gene expression in response to high ammonia exposure.Conclusion: Altogether, our findings not only presented a comprehensive mRNA transcriptome profile of liver after high ammonia exposure, but also found some key genes and TFs that could be used to investigate the toxicity mechanism of high ammonia on livers.

Monitoring of ammonia concentrations from coir-husk litter of Brazilian poultry house using diode laser photoacoustic spectroscopy

Ammonia (NH[Formula: see text]) from manure is a concern in raising broiler due to possible damages to production and the environment. Brazil is the main exporter of chicken meat in the world and is also responsible for large waste of poultry litter. The country, likewise, figures as top 5 producers of green coconut, which results in considerable volumes of waste, since 80%-85% of the fruit is unusable. This work analyzes the ammonia concentration profile of two bedding substrates for raising broiler, to know, coir-husk fiber and a commonly used pine wood shavings in a Brazilian climate. A differential home-made photoacoustic cell combined with a diode laser was employed for sensing ammonia at trace levels. Such combination confers selectivity as well as lower limits of detection to the system. The chemical compositions pH, N, C, Ca, Mg, P[Formula: see text]O[Formula: see text] and K[Formula: see text]O were also determined, in addition to the moisture, dry matter and mineral content of substrates and litters. NH[Formula: see text] concentrations varied from (0.9 ± 0.3) ppmv to (19 ± 3) ppmv and from (2.1 ± 0.5) ppmv to (21 ± 3) ppmv for the coir-husk fiber and wood shavings substrates, respectively. Results showed the feasibility of using coconut fiber as poultry litter in regions where this material is a common waste. Moreover, as NH[Formula: see text] concentrations were lower for coconut fiber bedding compared to shavings, this coir-husk fiber is a potential residue to guarantee the environmental sustainability by Brazilian poultry farming. Coir-husk fibers presented significantly higher amounts of P and K in comparison to pine wood. NH[Formula: see text] profiles revealed that coir-husk fiber emitted lower quantities than wood shavings. Besides, a delay on the NH[Formula: see text] emission pattern was clearly seen when the coconut waste was the bedding material. Such a tendency was confirmed by the logistic model. Our findings, in turn, make the coir-husk an environmentally friendly alternative low-cost product for poultry litter as well as its potential use as natural fertilizer. The later deserves attention since there is a need to accurately assess the emissions of methane, nitrous oxide, and carbon dioxide during the composting process. In Brazil, the waste generated by the high production of green coconut is an environmental liability. The cost of poultry production has been high, reducing the profit of producers, who seek to make production cheaper. Measuring NH[Formula: see text] from poultry activity in Brazil, a tropical country, aims to control management and reduce production losses, since NH[Formula: see text] is a harmful gas to birds. The measurement of NH[Formula: see text] concentrations at trace levels from raising broilers by photoacoustic diode laser spectroscopy, to the best of our knowledge, has been reported for the very first time.

The Influence of Different Types of Environmental Enrichment on the Performance and Welfare of Broiler Chickens and the Possibilities of Real-Time Monitoring via a Farmer-Assistant System

The aim of this study is to evaluate the influence of environmental enrichment on the growth performance, litter and/or air quality as well as animal welfare indicators of broilers. Control groups (CG) and trial groups (TG) were housed under identical conditions during six fattening runs, with the TG having three types of environmental enrichment and a Farmer-Assistant System (FAS). A representative number of 50 birds were weighed and litter samples were taken at d 14, 21 and 28. Additionally, the same broilers were examined for foot pad dermatitis (FPD) on those days. The average bodyweight of the birds in the CG was significantly lower (1671 g) only at d 28 compared to TG (1704 g); at d 14, d 21 and d 33 at the slaughterhouse, no significant differences were observed. The dry matter content in the litter did not significantly differ between CG and TG. Birds housed in CG had significantly higher FPD scores at d 14 (1.24) and d 21 (2.19) compared to those housed in TG (0.73 and 1.52, respectively). No effects on air quality parameters, such as CO2 and NH3, were seen between the groups. Overall, our study shows no negative influences of environmental enrichment on growth performance, litter and air quality.

Effect of Zeolite Supplementation on Gene Expression in the Intestinal Mucosa in the Context of Immunosafety Support in Poultry

Zeolite is an effective and non-toxic silicate mineral. Its properties are widely used in industry due to its sorption and ion exchange properties. Due to its excellent chemical properties, it has also great potential in poultry production as a food additive or supplement to bedding. This is of great importance for the biosafety and hygiene of production. The study aimed to analyse the effects of simultaneous application of zeolite to feed and bedding on production parameters and expression of genes related to intestinal tightness, organism defence, and immune response. Male Ross 308 broiler chickens were used in the experiment. In the experimental group, an external factor in the form of a powdery zeolite was used for feed and pelleted bedding. On the day of slaughter, the caecal mucosa was collected for gene expression analysis. We showed no significant changes in the tissue composition of the carcasses, but zeolite had a beneficial effect on the carcass yield. The analysis of the immune gene panel showed a significant increase in the expression of the interleukins and interferons genes. We have demonstrated the effect of zeolite on the improvement of the intestinal barrier and increasing the tightness of the intestines. There were no changes in gene expression related to the host’s defence against infections; therefore, based on the obtained results, it was concluded that zeolite can be considered an immunomodulating factor of the immune system.

Factors Influencing Soil Nitrification Process and the Effect on Environment and Health

To meet the global demand for food, several factors have been deployed by agriculturists to supply plants with nitrogen. These factors have been observed to influence the soil nitrification process. Understanding the aftermath effect on the environment and health would provoke efficient management. We review literature on these factors, their aftermath effect on the environment and suggest strategies for better management. Synthetic fertilizers and chemical nitrification inhibitors are the most emphasized factors that influence the nitrification process. The process ceases when pH is &lt;5.0. The range of temperature suitable for the proliferation of ammonia oxidizing archaea is within 30 to 37oC while that of ammonia oxidizing bacteria is within 16 to 23oC. Some of the influencing factors excessively speed up the rate of the nitrification process. This leads to excess production of nitrate, accumulation of nitrite as a result of decoupling between nitritation process and nitratation process. The inhibition mechanism of chemical nitrification inhibitors either causes a reduction in the nitrifying micro-organisms or impedes the amoA gene's function. The effects on the environment are soil acidification, global warming, and eutrophication. Some of the health effects attributed to the influence are methemoglobinemia, neurotoxicity, phytotoxicity and cancer. Biomagnification of the chemicals along the food chain is also a major concern. The use of well-researched and scientifically formulated organic fertilizers consisting of microbial inoculum, well-treated organic manure and good soil conditioner are eco-friendly. They are encouraged to be used to efficiently manage the process. Urban agriculture could promote food production, but environmental sustainability should be ensured.

Atmospheric Ammonia Causes Histopathological Lesions, Cell Cycle Blockage and Apoptosis of Spleen in Chickens

The experiment was conducted to investigate the effect of atmospheric ammonia (NH3) on histological changes, cell cycle distribution, and apoptosis of spleen in chickens. 240 chickens were randomly allocated to control group (without NH3 challenge) and NH3 group (70±5 ppm NH3). The experiment lasted for eight days. The results showed that NH3 exposure caused the decreased relative weight (P<0.05), dysplasia of lymphatic follicle, up-regulation of G0G1 phase cells, excessive apoptosis, and increase of reactive oxygen spcecies (ROS) activated cells (P<0.05) in the spleen. The mechanisms of cell cycle blockage were closely related to the upregulation of p53, p21 gene (P<0.05), the downregulation of cyclinD1, cdk6 gene (P<0.05), and the decrease of Proliferating Cell Nuclear Antigen (PCNA) protein (P<0.05). The activated apoptosis could resulted from the increased gene and protein expressions of bax and caspase-3 (P<0.05), and the decreased gene and protein expressions of bcl-2 (P<0.05). The results suggested that 70±5 ppm NH3 caused the spleen dysplasia, which were closely related to the cell cycle arrest and mitochondria apoptotic pathway activation.

Potential Application of Urease and Nitrification Inhibitors to Mitigate Emissions from the Livestock Sector: A Review

Human activities have caused an increase in greenhouse gas emissions, resulting in climate change that affects many factors of human life including its effect on water and food quality in certain areas with implications for human health. CH₄ and N₂O are known as potent non-CO₂ GHGs. The livestock industry contributes to direct emissions of CH₄ (38.24%) and N₂O (6.70%) through enteric fermentation and manure treatment, as well as indirect N₂O emissions via NH₃ volatilization. NH₃ is also a secondary precursor of particulate matter. Several approaches have been proposed to address this issue, including dietary management, manure treatment, and the possibility of inhibitor usage. Inhibitors, including urease and nitrification inhibitors, are widely used in agricultural fields. The use of urease and nitrification inhibitors is known to be effective in reducing nitrogen loss from agricultural soil in the form of NH₃ and N₂O and can further reduce CH₄ as a side effect. However, the effectiveness of inhibitors in livestock manure systems has not yet been explored. This review discusses the potential of inhibitor usage, specifically of N-(n-butyl) thiophosphoric triamide, dicyandiamide, and 3,4-dimethylpyrazole phosphate, to reduce emissions from livestock manure. This review focuses on the application of inhibitors to manure, as well as the association of these inhibitors with health, toxicity, and economic benefits.

Emissions of Gaseous Pollutants from Pig Farms and Methods for their Reduction – A Review

Agriculture contributes significantly to anthropogenic emissions of greenhouse gases (GHG). Livestock production, including pig production, is associated with several gaseous pollutants released into the atmosphere, including carbon dioxide (CO2), methane (CH4), ammonia (NH3) and nitrous oxide (N2O). Emissions of volatile organic compounds (VOCs), including alcohols, aldehydes, and aromatic and aliphatic hydrocarbons, as well as typically odorous pollutants, are an inseparable element of raising and breeding farm animals. These emissions can degrade local and regional air quality, contribute to surface water eutrophication and acid rain, and increase the greenhouse gas footprint of the production sector. The paper is organized as follows. First, the sources and factors influencing the level of emissions from pig houses are described. Next, the effects of dietary methods (optimization of animal diets), hygienic methods (including microclimate optimization) and technological methods (application of technological solutions) for mitigating emissions from pigs are discussed.

Evaluation of a Precision Biotic on the Growth Performance, Welfare Indicators, Ammonia Output, and Litter Quality of Broiler Chickens

A dietary glycan-based precision biotic (Glycan PB) was evaluated on the performance, welfare indicators, and litter characteristics of broiler chickens. In Trial 1, the main effects of Glycan PB dose (0, 250 and 500 g/metric ton (MT)) and xylanase supplementation (0 or 100 g/MT) were tested, as was their interaction. In Trial 2, pens located inside a commercial house were used to test the effect of Glycan PB supplementation (500 g/MT) versus a control diet. In Trial 1, Glycan PB supplementation at 250 and 500 g/MT improved feed conversion ratio (FCR) by 7 and 11 points when compared to diets without Glycan PB (p < 0.001). At 35 d, Glycan PB reduced the pH and ammonia concentration in diets with xylanase. In Trial 1, the supplementation with 500 g of Glycan PB/MT of feed reduced litter scores (p < 0.05). In both trials, 500 g of Glycan PB/MT of feed increased the proportions of birds without footpad lesions (Trial 1: 72.2% vs. 82.7%; p < 0.001; Trial 2: 14 to 27.3% (p = 0.05) or gait defects (Trial 1: 96.1% vs. 98.4%; p < 0.001) and decreased the proportion of birds with footpad lesions (Trial 2: 86% vs. 72.7%; p = 0.05).

Recovery of E. coli From Liver and Spleen of Broiler Birds and the Effects of Induced High Ammonia Level on Haematobiochemical Parameters and Its Amelioration by Different Modifiers

The poultry sector is one of the most vibrant segments of the agriculture industry of Pakistan. In addition to different infections, ammonia (NH₃) production from litter material of broiler is the most harmful pollutant and causes serious threats for the environment. To overcome this problem, different methods are proposed assuring poultry bird’s health and production. This study was carried out to evaluate the effect of toxic levels of NH₃ on the haematology and serum proteins of broiler birds and its amelioration by using different modifiers. The recovery of Escherichia coli (E. coli) from liver and spleen of broiler birds was also carried out. A total of 100 birds were divided into 5 separate groups (groups A–D). The groups C, D and E were treated with potassium aluminium sulphate, aluminium silicate and Yucca schidigera plant extract, respectively. Blood and tissue samples were collected after slaughtering the birds at 42 days of age. This study revealed increased RBC, total leucocyte count, Hb and heterophils percentage. Serum proteins were decreased in Yucca-treated and potassium aluminium sulphate–treated groups. This study concluded that NH₃ production was reduced by the application of different modifiers, and these modifiers also neutralized the changes in blood parameters induced by NH₃.

Effects of dietary inclusion of Radix Bupleuri extract on the growth performance, and ultrastructural changes and apoptosis of lung epithelial cells in broilers exposed to atmospheric ammonia

To explore whether Radix Bupleuri extract (RBE) could protect lung injury of broilers under ammonia (NH3) exposure, 360 one-d-old male broilers were randomly allocated to four groups of six replicates each in a 2 × 2 factorial design with two diets (the basal diet [control; CON] and the basal diet supplemented with RBE [RB]) and two air conditions (normal condition [<2 ppm of NH3; NOR] and NH3 exposure [70 ppm of NH3; NH70]). The RB diet contained 80 mg saikosaponins/kg diet. On day 7, the lung tissues were collected and the lung epithelial cells (LEC) were isolated. Our experimental results showed that the NH3 exposure decreased body weight gain and feed intake irrespective of dietary treatments during days 1 to 7. However, the RBE addition decreased feed consumption to body weight gain ratio in broilers under NH70 conditions. In the LEC of CON-fed broilers under NH70 conditions, Golgi stacks showed the dilation of cisternaes and reduced secretory vesicles, mitochondria enlarged, the inner membrane of mitochondria became obscure, and the cristae of mitochondria ruptured, whereas only a mild enlargement of Golgi cisternaes and the part rupture of mitochondrial cristaes occurred in the LEC of RB-fed broilers under NH70 conditions. The NH3 exposure increased malondialdehyde (MDA) level, but decreased total antioxidant capacity (T-AOC) in the lungs of CON-fed broilers. However, the RBE addition decreased MDA level and increased T-AOC in the lungs of broilers under NH70 conditions. Simultaneously, the NH3 exposure increased apoptotic rate (AR), mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) level in the isolated LEC of CON-fed broilers. The RBE addition decreased AR, MMP, and ROS in the isolated LEC of broilers under NH70 condition. Besides, the NH3 exposure increased mRNA expression of B-cell lymphoma-2 associated X protein (BAX), caspase-3, and tumor necrosis factor α (TNF-α), but increased interferon γ (IFN-γ) mRNA abundance in the lungs of CON-fed broilers. The RBE supplement decreased mRNA levels of BAX, caspase-3, and TNF-α, but increased IFN-γ, interleukin (IL)-4, and IL-17 mRNA levels in the lungs of broilers under NH70 conditions. These results indicated that dietary RBE addition alleviated NH3 exposure-induced intercellular ultrastructural damage via mitochondrial apoptotic pathway, possibly due to RBE-induced increase of antioxidant capacity and immunomodulatory function in the lungs of broilers under NH3 exposure.

The Effect of Dietary Halloysite Supplementation on the Performance of Broiler Chickens and Broiler House Environmental Parameters

The aim of the study was to determine the effect of supplementing broiler chickens' diets with halloysite on daily body weight gain (BWG), feed conversion ratio (FCR), daily water consumption (DWC), and some broiler house hygiene parameters. The trial was conducted on 18,000 broiler chickens divided into two groups throughout the 42-day (D) rearing period. The birds were fed complete diets without (group C) or with halloysite addition (1%, group E) from D8 of rearing. No difference in the mortality rate was observed between groups C and E. Birds from group E had a tendency (0.05 < p < 0.10) towards a higher body weight at D32 and D42, a higher BWG, and a lower FCR compared to group C during the entire rearing period. Average DWC differed only in the finisher period, with a tendency towards lower overall DWC in group E. The concentration of ammonia in the air from D21 to D35 was increased more than 5-fold in group C but only 1.5-fold in group E. In conclusion, the use of halloysite as a feed additive in the diet of broiler chickens resulted in a reduction in feed consumption per unit of BWG and higher utilisation of crude protein, which led to improved environmental conditions.

Energy metabolism disorder mediated ammonia gas-induced autophagy via AMPK/mTOR/ULK1-Beclin1 pathway in chicken livers

Ammonia gas is a well-known environmental pollution gas, threatening human health. Ammonia gas is also one of the most harmful gases to livestock and poultry for many years. Many studies have demonstrated toxic effect of ammonia gas on animal health, such as eyes, respiratory system, and digestive system. However, the effect of ammonia gas toxicity on chicken livers and underlying molecular mechanism remains unclear. In this study, we selected chicken liver as research object and duplicated successfully ammonia gas poisoning model of chickens. 1-day-old Ross-308 broilers were randomly divided into the control group (the low ammonia gas group), and two treatment groups (the middle ammonia gas group and the high ammonia gas group) (3 replicates per group and 12 chickens per replicate). Ammonia gas concentration in the low ammonia gas group was ≤5 mg/m³ during day 1-42. Ammonia gas concentration in the middle group was set as 10 ± 0.5 mg/m³ during day 1-21, and 15 ± 0.5 mg/m³ during day 22-42). Ammonia gas concentration in the high ammonia gas group was set as 20 ± 0.5 mg/m³ during day 1-21, and 45 ± 0.5 mg/m³ during day 22-42. The ultrastructure of chicken livers was observed. The activities of four ATPases (Na⁺K⁺-ATPase, Mg⁺⁺-ATPase, Ca⁺⁺-ATPase, and Ca⁺⁺Mg⁺⁺-ATPase), the expression of twelve energy metabolism-related genes (HK1, HK2, PK, PFK, PDHX, CS, LDHA, LDHB, SDHA, SDHB, avUCP, and AMPK), as well as the expression of ten autophagy-related genes (PI3K, LC3I, LC3II, Beclin1, SQSTM1, mTOR, ULK1, ATG5, ATG12, and ATG13) were measured to explore the effect of ammonia gas on energy metabolism and autophagy in chicken livers. Our results showed that excess ammonia gas induced mitochondrial and autophagic damage in chicken liver tissue cells. Meanwhile, ATPases activities were inhibited and the expression of energy metabolism-related genes changed during ammonia gas treatment, meaning that excess ammonia gas caused energy metabolism disorder. Furthermore, ammonia gas exposure altered the expression of autophagy-related genes, suggesting that ammonia gas treatment caused autophagy in chicken livers. Moreover, ammonia gas-induced AMPK compensatory up-regulation activated autophagy process through inhibiting mTOR and promoting ULK1. In addition. there were dose-dependent and time-dependent effects on all detected indexes in ammonia gas-caused chicken liver cell damage. Taken together, AMPK/mTOR/ULK1-Beclin1 pathway participated in energy metabolism disorder-mediated autophagic injury caused by ammonia gas exposure in chicken livers.

Effects of Ammonia on Gut Microbiota and Growth Performance of Broiler Chickens

Simple Summary

The composition and function of gut microbiota is crucial for the health of the host and closely related to animal growth performance. Factors that impact microbiota composition can also impact its productivity. Ammonia (NH3), one of the major contaminants in poultry houses, negatively affects poultry performance. However, the influence of ammonia on broiler intestinal microflora, and whether this influence is related to growth performance, has not been reported. Our results indicated that ammonia caused changes to cecal microflora of broilers, and these changes related to growth performance. Understanding the effects of ammonia on the intestinal microflora of broilers will be beneficial in making targeted decisions to minimize the negative effects of ammonia on broilers.

Abstract

In order to investigate the influence of ammonia on broiler intestinal microflora and growth performance of broiler chickens, 288 21-day-old male Arbor Acres broilers with a similar weight were randomly divided into four groups with different NH3 levels: 0 ppm, 15 ppm, 25 ppm, and 35 ppm. The growth performance of each group was recorded and analyzed. Additionally, 16s rRNA sequencing was performed on the cecal contents of the 0 ppm group and the 35 ppm group broilers. The results showed the following: a decrease in growth performance in broilers was observed after 35 ppm ammonia exposure for 7 days and 25 ppm ammonia exposure for 14 days. At phylum level, the relative abundance of Proteobacteria phylum was increased after 35 ppm ammonia exposure. At genus level, ammonia increased the relative abundance of Escherichia–Shigella and decreased the relative abundance of Butyricicoccus, Parasutterella, Lachnospiraceae_UCG-010, Ruminococcaceae_UCG-013 and Ruminococcaceae_UCG-004. Negative correlation between Escherichia–Shigella and growth performance, and positive correlation between bacteria genera (including Butyricicoccus, Parasutterella, Lachnospiraceae_UCG-010, Ruminococcaceae_UCG-013 and Ruminococcaceae_UCG-004) and growth performance was observed. In conclusion, ammonia exposure caused changes in the structure of cecal microflora, and several species were either positively or negatively correlated with growth performance. These findings will help enhance our understanding of the possible mechanism by which ammonia affect the growth of broilers.

Varying combinations of Lactobacillus species: impact on laying hens' performance, nitrogenous compounds in manure, serum profile, and uric acid in the liver

This study was conducted to evaluate the effects of various combinations of Lactobacillus species (L. rhamnosus, L. paracasei, and L. plantarum) on closely associated variables of production of laying hens, nitrogenous compounds in manure, the serum concentration of specific chemicals, and liver uric acid (UA) concentrations at peak lay. White Leghorns W-36 (32-week-old) were randomly assigned to five treatments for 8 weeks. Treatments were T1, the Control, a commercial feed; T2, the Control + L. paracasei + L. plantarum; T3, the Control + L. paracasei + L. rhamnosus; T4, the Control + L. plantarum + L. rhamnosus and T5, the Control + L. paracasei + L. plantarum + L. rhamnosus. Each bacterial species was included at 3.33 × 10¹¹cfu/kg feed for a total of 6.66 x 10¹¹ cfu/kg feed for T2–T4 and a total of 1.0 × 10¹² cfu/kg feed for T5. Major effects among combinations of probiotics on production were not noted. The interaction of Probiotics by Week (Probiotics*Time) affected feed intake (P = 0.0007) and feed conversion ratio (FCR, P = 0.0049) due to fluctuation by week. Significant effects of time were also recorded for a gradual increase in body weight (BW, P = 0.0007); lowest and greatest feed intake at weeks 2 and 7, respectively (P < 0.0001); an increase in egg production (P = 0.0007) and maximum FCR at week 7 (P < 0.0001). Ammonia (NH₃) concentration, ammonium nitrogen (NH₄–N), total Kjeldahl nitrogen (TKN), and total nitrogen remained unaffected at P < 0.05. Although there were fluctuations, a trend emerged for the reduction of TKN. Combinations of probiotics did not affect NH₃, UA, total protein (TP), albumin (ALB), creatine kinase (CK), and UA in the liver. Temporal (Time as a fixed effect) effects were noted for all nitrogenous compounds present in manure. For ammonia, temporal effects were significant due to fluctuation over time. Week 0 had the lowest value followed by weeks 4 and 8. Week 6 had the greatest value. For ammonium nitrogen, week 8 had the lowest value followed by week 0 and 4 with the next highest value. Week 6 had the greatest value. For TKN, week 4 had the lowest value followed by weeks 6 and 8. Week 0 had the greatest value. For TN, weeks 4, 6, and 8 had similar and lowest values followed by week 0 having the greatest value. However, an overall reduction in NH₄-N, TKN, and TN was noted. Fluctuations in NH₃ (P = 0.0033) and CK (P = 0.0085) were noted for Time. There was also a trend (P = 0.0706) for the increase of UA in serum. Two or more species of probiotics with yeast should be investigated. If the combination is applicable for increasing production measurements and reducing nitrogenous and serum compounds, the most appropriate time to feed the probiotics from day 1 to the end of production should be investigated.

Recent Progress of Toxic Gas Sensors Based on 3D Graphene Frameworks

Air pollution is becoming an increasingly important global issue. Toxic gases such as ammonia, nitrogen dioxide, and volatile organic compounds (VOCs) like phenol are very common air pollutants. To date, various sensing methods have been proposed to detect these toxic gases. Researchers are trying their best to build sensors with the lowest detection limit, the highest sensitivity, and the best selectivity. As a 2D material, graphene is very sensitive to many gases and so can be used for gas sensors. Recent studies have shown that graphene with a 3D structure can increase the gas sensitivity of the sensors. The limit of detection (LOD) of the sensors can be upgraded from ppm level to several ppb level. In this review, the recent progress of the gas sensors based on 3D graphene frameworks in the detection of harmful gases is summarized and discussed.

Welfare of broiler chickens reared in two different industrial house types during the winter season in Southern Brazil

1. The following trial compared broiler chicken welfare in closed-sided (CS) versus open-sided (OS) industrial house types during the winter season in the South of Brazil.2. Ten flocks in each house type were evaluated as follows: a) bird health: contact dermatitis on the breast and abdominal areas (CDE), bird soiling (BSO), footpad dermatitis (FPD), hock burn (HBU), lameness (LAM), fractures (FRA), bruising (BRU), scratches (SCR), dead on arrival (DOA), and diseases (DIS); b) house environmental measurements: relative humidity (RHU), temperature (TEM), air velocity (AVE), illuminance (ILL), ammonia concentration (NH₃), and carbon dioxide concentration (CO₂), and c) bird behaviour and affective states: bird behaviour (BBE), touch test (TTE), and qualitative behaviour assessment (QBA).3. Statistical analyses were based on regression models for CDE, BSO, FPD, HBU, LAM and generalised linear models for DOA, FRA, BRU, SCR, and DIS. The Mann-Whitney test was used for RHU, TEM, AVE, ILL, NH₃, CO₂, and the t-test for TTE and LMO, with a specific regression model for BBE data and Principal Component Analysis for QBA.4. According to odds ratio for worse scores for CS relative to OS, birds were less likely to have severe scores for CDE (P = 0.040 and P = 0.007), BSO (P = 0.031, P = 0.016, and P = 0.038), and HBU (P = 0.017), and had higher median values for AVE (2.3, 0.0-7.8 m s^-1 vs. 0.0, 0.0-4.3 m s^-1), lower NH₃ concentration (9.0, 0.0-64.0 ppm vs. 12.0, 0.0-60.0 ppm) and TTE scores (98, 96-100 vs. 67, 25-100). Worse results were observed in CS houses for higher stocking density (13.8 ± 0.2 birds/m² vs. 12.0 ± 0.2 birds/m²), RHU (74.5, 50.7-99.9% vs 72.3, 47.4-99.9%), and TEM (23.9, 14.6-29.2°C vs. 21.7, 12.9-30.1°C), lower ILL (16.0, 1.0-60.0 lx vs. 161.0, 8.0-2380.0 lx), less drinking (P = 0.007), more inactive behaviour (P < 0.001) and lower positive emotions, according to QBA (P = 0.028).5. In the studied region and season, CS houses seemed to offer fewer welfare problems in terms of the health indicators; however, OS houses showed fewer behavioural restrictions and higher positive emotional states.