In-house ammonia induced lung impairment and oxidative stress of ducks

Ammonia (NH3) is a toxic gas that in intensive poultry houses, damages the poultry health and induces various diseases. This study investigated the effects of NH3 exposure (0, 15, 30, and 45 ppm) on growth performance, serum biochemical indexes, antioxidative indicators, tracheal and lung impairments in Pekin ducks. A total of 288 one-day-old Pekin male ducks were randomly allocated to 4 groups with 6 replicates and slaughtered after the 21-d test period. Our results showed that 45 ppm NH3 significantly reduced the average daily feed intake (ADFI) of Pekin ducks. Ammonia exposure significantly reduced liver, lung, kidney, and heart indexes, and lowered the relative weight of the ileum. With the increasing of in-house NH3, serum NH3 and uric acid (UA) concentrations of ducks were significantly increased, as well as liver malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPX-Px) contents. High NH3 also induced trachea and lung injury, thereby increasing levels of tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4) in the lung, and decreasing the mRNA expressions of zonula occludens 1 (ZO-1) and claudin 3 (CLDN3) in the lung. In conclusion, in-house NH3 decrease the growth performance in ducks, induce trachea and lung injuries and meanwhile increase the compensatory antioxidant activity for host protection.

The Effects of Housing on Growth, Immune Function and Antioxidant Status of Young Female Lambs in Cold Conditions

Cold conditions in northern China during winter may reduce sheep growth and affect their health, especially if they are young, unless housing is provided. We allocated 45 two-month-old female lambs to be housed in an enclosed building, a polytunnel, or kept outdoors, for 28 days. The daily weight gain and scalp and ear skin temperature of outdoor lambs were less than those of lambs that were housed in either a house or polytunnel; however, rectal temperature was unaffected by treatment. There was a progressive change in blood composition over time, and by the end of the experiment, outdoor lambs had reduced total antioxidant capacity (T-AOC), catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) and increased malondialdehyde compared to those in the house or polytunnel. In relation to immune responses in the lambs' serum, in the polytunnel, immunoglobulin A (IgA), tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4) were higher and immunoglobulin G (IgG) lower compared with the concentrations in lambs that were outdoors. Over the course of the experiment, genes expressing heat shock proteins and antioxidant enzymes increased in lambs in the outdoor treatment, whereas they decreased in lambs in the indoor treatments. It is concluded that although there were no treatment effects on core body temperature, the trends for progressive changes in blood composition and gene expression indicate that the outdoor lambs were not physiologically stable; hence, they should not be kept outdoors in these environmental conditions for long periods.

Ammonia emissions, impacts, and mitigation strategies for poultry production: A critical review

Confined animal feeding operations (CAFOs) are the main sources of air pollutants such as ammonia (NH₃) and greenhouse gases. Among air pollutants, NH₃ is one of the most concerned gasses in terms of air quality, environmental impacts, and manure nutrient losses. It is recommended that NH₃ concentrations in the poultry house should be controlled below 25 ppm. Otherwise, the poor air quality will impair the health and welfare of animals and their caretakers. After releasing from poultry houses, NH₃ contributes to the form of fine particulate matters in the air and acidify soil and water bodies after deposition. Therefore, understanding the emission influential factors and impacts is critical for developing mitigation strategies to protect animals' welfare and health, environment, and ecosystems. This review paper summarized the primary NH₃ emission influential factors, such as how poultry housing systems, seasonal changes, feed management, bedding materials, animal densities, and animals' activities can impact indoor air quality and emissions. A higher level of NH₃ (e.g., >25 ppm) results in lower production efficiency and poor welfare and health, e.g., respiratory disorder, less feed intake, lower growth rates or egg production, poor feed use efficiency, increased susceptibility to infectious diseases, and mortality. In addition, the egg quality (e.g., albumen height, pH, and condensation) was reduced after laying hens chronically exposed to high NH₃ levels. High NH₃ levels have detrimental effects on farm workers' health as it is a corrosive substance to eyes, skin, and respiratory tract, and thus may cause blindness, irritation (throat, nose, eyes), and lung illness. For controlling poultry house NH₃ levels and emissions, we analyzed various mitigation strategies such as litter additives, biofiltration, acid scrubber, dietary manipulation, and bedding materials. Litter additives were tested with 50% efficiency in broiler houses and 80-90% mitigation efficiency for cage-free hen litter at a higher application rate (0.9 kg m^-2). Filtration systems such as multi-stage acid scrubbers have up to 95% efficiency on NH₃ mitigation. However, cautions should be paid as mitigation strategies could be cost prohibitive for farmers, which needs assistances or subsidies from governments.

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.

Genetic Comparisons of Body Weight, Average Daily Gain, and Breast Circumference between Slow-Growing Thai Native Chickens (Pradu Hang dum) Raised On-Site Farm and On-Station

To ensure that any new technology developed within an experimental station is appropriate to the community’s needs and compatible with the existing systems, on-site farm research is an important component in examining the effectiveness of agricultural research. The present study examined the growth performance and genetics of Thai native chickens under conditions typically experienced by farmers on smallholder farms (on-site farms) compared with at an experimental unit (on-station). There were 1694 Thai native chickens (Pradu Hang dum) used in this experiment, and they were divided into 613 chickens for the on-station and 1081 chickens for the on-site farm experiments. The individual chicken data included the birth weight (BW0) and body weight at 4, 8, 12, and 16 weeks of age (BW4, BW8, BW12, and BW16, respectively), ADG from 0−4, 4−8, 8−12, 12−16 weeks of age (ADG0−4, ADG4−8, ADG8−12, ADG12−16, respectively), and breast circumference at 8, 12, and 16 weeks of age (BrC8, BrC12, BrC16, respectively). A multiple traits animal model and a selection index were used to estimate the variance components, genetic parameters, and breeding values of growth traits. The results showed that the body weight, average daily gain, and breast circumference at 8, 12, and 16 weeks of age of Thai native chickens raised on-station were higher than those raised on-site at the farm among mixed-sex and sex-segregated chickens, while the birth weight and body weight at four weeks of age (BW0 and BW4) and ADG from 0−4 weeks of age (ADG0−4) were not significantly different (p > 0.05). The heritability estimates of body weight, average daily gain, and breast circumference in the chickens raised at the on-site farm and on-station were moderate to high, with on-station values slightly higher than on-site farm values. The heritability estimates of body weight were 0.236 to 0.499 for the on-site farm, and 0.291 to 0.499 for on-station. For average daily gain, the heritability estimates were 0.274 to 0.283 for the on-site farm and 0.298 to 0.313 for on-station; meanwhile, and for breast circumference, the heritability estimates were 0.204 to 0.268 for the on-site farm and 0.278 to 0.296 for on-station. Both phenotypic and genetic correlations among and between growth traits were positive and ranged from low to high values. The top 20% of the estimated breeding values and selection indices in the on-site farm and on-station experiments showed that the body weight at eight weeks of age (BW8), ADG from 4−8 weeks of age (ADG4−8), and breast circumference at eight weeks of age (BrC8) should be used as selection criteria for Thai native chicken breeding programs. In conclusion, the genetic parameters and breeding values in on-station experiments showed that the breeding program by selection index for improving growth performance is valid. Therefore, to implement such a breeding program in an on-site farm, an intensive or semi-intensive farm system should be considered to minimize the effect of genotype-environment interaction.

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.

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.

Reduction of dietary crude protein and feed form: Impact on broiler litter quality, ammonia concentrations, excreta composition, performance, welfare, and meat quality

Nitrogen (N) excreted by poultry is converted to ammonia (NH₃), presenting an environmental risk and a health risk to the farmer and animals. A study was performed to investigate the effect of reduced CP and feed form on broiler performance and welfare, meat and litter quality, N utilization, and NH₃ concentrations at litter level. A total of 2,232 Ross 308 male broilers was divided into 6 treatments and 6 replicates, which was fed diets in both pellet and mash forms with different CP levels of 205.0 g/kg (H, high), 187.5 g/kg (M, intermediate) and 175.0 g/kg (L, low) in the grower phase and 195.0 g/kg (H), 180.0 g/kg (M) and 165.6 g/kg (L) in the finisher phase. Individual amino acids (AA) were supplemented to maintain digestible AA-to-digestible lysine ratios. Decreasing dietary CP content to 187.5 g/kg in the grower phase and 180.0 g/kg in the finisher phase reduced NH₃ concentrations at litter level (P < 0.001), but a further reduction in dietary CP had no additional effect. Mash treatments had better litter qualities and lower incidences of foot and hock lesions than pellet treatments at d 38 (P < 0.001). In addition, treatments with reduced CP had lower incidence of foot lesions at d 38 (P < 0.001). Broilers fed pelleted diets had higher ADFI, ADG, and final BW, improved feed conversion ratio (FCR), and heavier carcasses (P < 0.001) than those fed mash diets over a production period of 39 d. Performance could not be maintained when birds were fed L CP pelleted diets. This study demonstrated that, with the supplementation of AA to meet requirements, the concentration of dietary CP can be reduced to 187.5 and 180.0 g/kg in the grower and finisher phases respectively, without impairing broiler performance, meat yield and quality. Mash diets were favorable when considering the overall litter quality and welfare of the birds. However, they could not maintain the same broiler performance and slaughter yield as pelleted diets. Results from the present study may assist the poultry sector towards a socially acceptable low-emission farming system.

Assessment of Husbandry Practices That Can Reduce the Negative Effects of Exposure to Low Ammonia Concentrations in Broiler Houses

Simple Summary

We used two commercial breeds, differing in growth rate: Fast-growing breed and slow-growing breed. We stocked these birds in two different densities. The slow-growing birds was stocked at a high density and the fast-growing birds at a high density and low density. These birds were reared under two different environmental conditions: A control room with a low concentration of ammonia and a second room with a higher concentration. We analyzed management practices such as the effect of ventilation, animal density and growth rate as management possibilities to reduce the negative effect of ammonia on production parameters.

Abstract

Ammonia is an important pollutant emitted by broiler litter that can accumulate inside farms, impairing animal health and welfare productivity. An experiment was designed to evaluate of precision husbandry practices such as the effect of ventilation, animal density and growth rate as management options to reduce the adverse effects of ammonia exposure on productive parameters in broiler houses. Two identical experimental rooms were used in this study. They were programmed to differ in ammonia concentration from day 32 of the growing period (10 and 20 ppm in Room 1 and Room 2, respectively). Three treatments were tested in each room: slow growth in high stocking density (SHD), fast growth in low density (FLD) and fast growth in high density (FHD). Animal weight, feed intake and feed conversion ratio were determined weekly. In addition, the immune status of animals was assessed by weighing the organs related to immune response as stress indicators. Increasing ventilation was effective to control ammonia concentrations. Exposure to ammonia caused no significant effect on productive parameters. However, lowering stocking density improved response to higher ammonia concentrations by lowering the feed conversion ratio. No other relevant effects of differential exposure to ammonia were found in fast-growing animals, either at high or low stocking density. The use of slow-growing breeds had no effect on production parameters. Despite having a slower growth rate, their feed conversion ratio was not different from that of fast-growing breeds. The productive performance of slow-growing animals was not affected by the differential exposure to ammonia, but the reduced spleen size would suggest an impairment of the immune system.

Reducing ammonia emission by aluminum sulfate addition in litter and its influence on productive, reproductive, and physiological parameters of dual-purpose breeding hens

This research investigated the impact of aluminum sulfate (AS) as amendment to different types of litter (new, reused, and mixed litters) for reducing ammonia emission and improving productive performance of local dual-purpose breeding hens. A total of 450 hens and 60 cocks from the Inshas strain were randomly assigned to six groups (five replicates each of 15 hens + 2 cocks) raised in pen floor furnished with a wheat straw litter. The groups included: (1) new, (2) reused, (3) mixed (50% new + 50% reused) litter; the other groups (4, 5 and 6) were respectively housed on the same litter as groups 1, 2 and 3 but with the addition of 495 g of AS/m² litter. The feed conversion ratio was better for layers raised on new litter with or without AS than other groups. Different kinds of litter had different moisture (p < 0.05) and pH (p < 0.05) values. Birds raised on litter types treated with AS significantly (p < 0.05) decreased intestinal pH and decreased total bacterial count compared to the same litter types without AS at the end of the experiment. Birds raised on new litter supplemented with AS had the highest plasma T3, total protein, globulin, Hgb, and PCV% and the lowest levels of uric acid and cholesterol at the end of the experimental period. Therefore, litter amendment with AS, also the mixed or reused one, could be recommended to reduce ammonia and, in turn, increasing plasma T3 and decreasing total bacterial count, leading to increasing bird's performance.

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.

TBHQ alleviates pyroptosis and necroptosis in chicken alveolar epithelial cells induced by fine particulate matter from broiler houses

Fine particulate matter (PM2.5) from poultry houses has adverse effects on the health of animals and workers. Tert-butylhydroquinone (TBHQ), an antioxidant, is widely used in feed additives. The present study investigated the effects of TBHQ on broiler house PM2.5-induced damage in chicken primary alveolar epithelial cells (AECII) extracted from 16-day-old chicken embryos using the method of differential adhesion. AECII were exposed to PM2.5 and TBHQ alone or in combination, and then, cell membrane integrity, pyroptosis, and necroptosis were detected. Our results showed that PM2.5 from broiler houses caused cell rupture and loss of cell membrane integrity. This result was confirmed by the obvious increases in lactate dehydrogenase (LDH) release and propidium iodide (PI)-positive cells compared to the control group. In addition, the intracellular reactive oxygen species (ROS) levels and the expression levels of pyroptosis-related genes (NLRP3, IL-18, IL-1β) and necroptosis-related genes (RIPK3) were also significantly enhanced. However, TBHQ significantly inhibited intracellular ROS, improved cell viability, and reduced the release of LDH and the number of PI-positive cells compared to those in the PM2.5 group. The expression levels of pyroptosis-related genes (Caspase-1, NLRP3, IL-18, IL-1β) and necroptosis-related genes (RIPK3) were also significantly decreased in the co-treatment group. In summary, these results indicated that TBHQ can alleviate PM2.5-mediated cell pyroptosis and necroptosis in chicken AECII and provide a basis for overcoming the danger that air pollutants from broiler houses pose to the health of chickens.

Effects of Different Ammonia Concentrations on Pulmonary Microbial Flora, Lung Tissue Mucosal Morphology, Inflammatory Cytokines, and Neurotransmitters of Broilers

Atmospheric ammonia is one of the main environmental stressors affecting the performance of broilers. Previous studies demonstrated that high levels of ammonia altered pulmonary microbiota and induced inflammation. Research into the lung-brain axis has been increasing in recent years. However, the molecular mechanisms in pulmonary microbiota altered by ambient ammonia exposure on broilers and the relationship between microflora, inflammation, and neurotransmitters are still unknown. In this study, a total of 264 Arbor Acres commercial meal broilers (21 days old) were divided into 4 treatment groups (0, 15, 25, and 35 ppm group) with 6 replicates of 11 chickens for 21 days. At 7 and 21 D during the trial period, the lung tissue microflora was evaluated by 16S rDNA sequencing, and the content of cytokines (IL-1β, IL-6, and IL-10) and norepinephrine (NE), 5-hydroxytryptamine (5-HT) in lung tissue were measured. Correlation analysis was established among lung tissue microflora diversity, inflammatory cytokines, and neurotransmitters. Results showed that the broilers were not influenced after exposure to 15 ppm ammonia, while underexposure of 25 and 35 ppm ammonia resulted in significant effects on pulmonary microflora, inflammatory cytokines, and neurotransmitters. After exposure to ammonia for 7 and 21 days, both increased the proportion of Proteobacteria phylum and the contents of IL-1β and decreased the content of 5-HT. After exposure to ammonia for 7 days, the increase in Proteobacteria in lung tissue was accompanied by a decrease in 5-HT and an increase in IL-1β. In conclusion, the microflora disturbance caused by the increase in Proteobacteria in lung tissue may be the main cause of the changes in inflammatory cytokines (IL-1β) and neurotransmitters (5-HT), and the damage caused by ammonia to broiler lungs may be mediated by the lung-brain axis.

Ammonia Generation System for Poultry Health Research Using Arduino

An ammonia gas (NH₃) generator was developed to maintain a set concentration of ammonia gas in a controlled environment chamber to study poultry physiological responses to sustained elevated levels of ammonia gas. The goal was to maintain 50 parts per million (ppm) of ammonia gas in a 3.7 m × 4.3 m × 2.4 m (12 ft × 14 ft × 8 ft) controlled environment chamber. The chamber had a 1.5 m³/s (3000 cfm) recirculation system that regulated indoor temperature and humidity levels and a 0.06 m³/s (130 cfm) exhaust fan that exchanged indoor air for fresh outdoor air. The ammonia generator was fabricated by coupling ultrasonic humidifiers with an Arduino-based microcontroller and a metallic oxide MQ-137 ammonia gas sensor. Preliminary evaluation under steady conditions showed the average MQ-137 gas sensor accuracy was within 1.4% of the 65.4 ppm concentration measured using a highly accurate infrared gas analyzer. Further evaluation was performed for a setpoint concentration of 50 ppm where ammonia generator reservoirs were filled with 2% or 10% ammonia liquid. For the system tested, it was found that two generators operating at the same time filled with 3.8 L (1.0 gallon) of 2% ammonia cleaning liquid each (7.6 L or 2.0 gallons total) could maintain a gas level of 49.45 ± 0.79 ppm in the chamber air for a duration of 30 h before refilling was required. One generator filled with 3.8 L of 10% ammonia cleaning liquid could maintain 51.24 ± 1.53 ppm for 195 h. Two ammonia generators were deployed for a six-week animal health experiment in two separate controlled environment chambers. The two ammonia generators maintained an average ammonia concentration of 46.42 ± 3.81 ppm and 45.63 ± 4.95 ppm for the duration of the experiment.

Research on the Correlation between Breeding Environment and Activity of Yellow Feather Broilers Based on the Multichromatic Aberration Model

Broiler behavior is closely related to the breeding environment. Therefore, studying broiler behavior helps breeding farm workers to better carry out welfare breeding. In the breeding environment of yellow feather broilers, temperature, humidity, and ammonia concentration are the main factors that affect the behavior of the broilers. This study used a multichromatic aberration model to process the color images of yellow feather broilers to extract the activity feature of the broilers at different periods, utilized the Cb component of YCbCr color model and the b component of Lab color model to remove background litter in images, and employed the Q component of YIQ color model to remove the feeders and the drinkers from the image. The segmented images were constructed into an accumulator to generate a heat map of yellow feather broilers' activity. Then, the correlation between the activity and the temperature and humidity index (THI) and the correlation between the activity and ammonia concentration were explored. The experiment found that the activity of the broilers was significantly positively correlated with ammonia concentration (P < 0.05), indicating that the activity of yellow feather broilers increased with ammonia concentration ascending. Besides, the THI in the broiler chamber had a significant positive correlation with the ammonia data (P < 0.01), indicating that when the THI in the broiler chamber increases, the ammonia concentration rises. The research provides a direction for exploring the impact of THI and ammonia concentration on the performance of yellow feather broilers. At the same time, it provides a theoretical basis for the early warning and judgment of broiler breeding by farm workers in the future.

Effect of a Mineral-Microbial Deodorizing Preparation on the Functions of Internal Organs and the Immune System in Commercial Poultry

Animal production is identified as one of the main sources of high concentrations of odours, which are related to air pollution, health problems of living organisms and indirect negative impact on production results. One common method for reducing emissions of ammonia is using preparations containing probiotics and hygroscopic or disinfecting compounds. This study was undertaken in order to determine the impact of innovative mineral-microbial deodorizing preparation, which reduces odorous gases, applying to the litter once a week in poultry houses on the physiological status of breeder chickens, broiler chickens and turkeys. Samples were collected after slaughter and analyzed using ELISA tests, flow cytometry and biochemical methods. Biochemical markers of the liver and kidney profile (ALT, AST, LDH, ALP, CK, TP, CALC, PHOS) and the titers of specific antibodies against AEV, aMPV, AAvV-1, IBDV, HEV, BA were analyzed in serum samples. The percentage contribution of T and B lymphocyte subpopulations was determined in the samples of tracheal mucosa, blood, and spleen. No significant differences were found between the control and experimental group with regard to all the analyzed parameters, with some exceptions for biochemistry. The results of our study indicated that mineral-microbial deodorizing preparation did not affect the physiological status of birds.

Molecular Evaluation of Traditional Chicken Farm-Associated Bioaerosols for Methicillin-Resistant Staphylococcus aureus Shedding

The outbreak of airborne pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) through bioaerosol, and their molecular characterization around domestic poultry farming areas, was not completely understood. This imposes risk of a MRSA-associated health threat for the relevant livestock food production units. To address this issue, the present study investigated the role of bioaerosol in transmitting MRSA strains in poultry house settings by combining molecular typing, phylogenetic classification, antibiotic susceptibility, and virulence gene distribution patterns. The present study highlights that all 18 bioaerosol and stool samples collected were MRSA positive, with a unique set of virulence factors. Out of 57 isolated MRSA isolates, 68.4% and 19.3% consisted of SCCmec I and IV elements, respectively, which are commonly linked with hospital-acquired and livestock-associated MRSA strains. It is worth noting that the exfoliative toxin eta and etb genes were carried by 100% and 70.2% of all isolates, respectively. Only 17.5% of strains showed the presence of enterotoxin entC. These MRSA isolates were resistant to chloramphenicol (C), ciprofloxacin (CIP), clindamycin (DA), erythromycin (E), and tetracycline (T), signifying their multi-drug resistance traits. A cluster of phylogenetic analysis described that 80.7% and 15.8% of total isolates belonged to Staphylococcus aureus protein A (spa) type t002 and t548. Whereas 3.5% were reflected as a new spa type. Additionally, as per the chi-squared test score value, these two spa types (t002 and t548) have a distribution correlation with HA-MRSA and LA-MRSA in all the samples (p < 0.005, chi-squared test; degree of freedom = 1). Ultimately, this study highlights the prevalence of MRSA colonization in the conventional poultry farm environment, showing the risk of bioaerosol transmission, which needs epidemiological attention and prevention strategies.

The effect of an acidified-gypsum mixture on broiler litter urease-producing bacteria and nitrogen mineralization

Ammonia (NH₃ ) volatilization from broiler (Gallus gallus domesticus) litter is a microbially mediated process that can decrease bird productivity and serves as an environmental pollutant. The release of NH₃ is strongly influenced by the pH of litter. Flue-gas desulfurization gypsum (FGDG) has been suggested as a potential amendment to reduce NH₃ volatilization due to the pH buffering capacity of calcium carbonate (CaCO₃ ) precipitation. However, its effect on litter pH is not as pronounced as acidifying agents, such as aluminum sulfate (alum). The main objective of our study was to develop an acidified-FGDG amendment that has a more pronounced effect on litter pH and NH₃ volatilization than FGDG alone. We conducted a 33-d incubation in which litter pH, NH₃ volatilization, nitrogen mineralization, PLUP-ureC gene abundance, and CaCO₃ precipitation were measured. Treatments in the study included: broiler litter (BL), broiler litter + 20% FGDG (BL+FGDG), broiler litter + FGDG-alum mixture (BL+FGDG+A6), broiler litter + 6% alum (BL+A6), and broiler litter + 10% alum (BL+A10). Our FGDG+alum amendment decreased litter pH (0.68 pH units) and PLUP-ureC gene abundance (>1 log) compared with FGDG alone and the control (p < .05). This led to a 25% decrease in cumulative NH₃ loss after 33 d. The addition of FGDG alone did not have an effect on litter pH (p = .36) or cumulative NH₃ loss (p = .29) due to a lack of significant CaCO₃ precipitation. Treating litter with 6 and 10% alum was the most effective amendment for reducing pH and cumulative NH₃ loss.

Very virulent infectious bursal disease virus-induced immune injury is involved in inflammation, apoptosis, and inflammatory cytokines imbalance in the bursa of fabricius

Infectious bursal disease virus (IBDV) can cause a highly contagious disease in young chickens, resulting in bursal necrosis that causes severe damage to the immune system. The effects of various IBDV strains on the bursa of Fabricius (BF) have been extensively studied; however, few studies have investigated the effects of IBDV strain LJ-5, a newly discovered very virulent IBDV (vvIBDV), infection on young chicken BF. In this study, three-week-old specific pathogen-free (SPF) chickens were infected with vvIBDV for one to five days. LJ-5 decreased the bursa index, B lymphocyte viability and immunoglobulin (Ig) levels, including IgM and IgA in the bursa and IgY in the sera. Histopathological analysis revealed necrosis and depletion of the lymphoid cells and complete loss of bursal architecture in the BF, and transmission electron microscopy revealed mitochondrial vacuoles, cristae breaks, and nuclear damage in vvIBDV-infected bursa tissue. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-positive nuclei significantly increased following IBDV infection. Cytokine levels increased in the bursa after IBDV infection, promoting inflammation and causing an inflammatory imbalance. Apoptotic gene expression confirmed that vvIBDV infection promotes the apoptosis of bursal cells. These results suggest that vvIBDV infection attenuate immune responses by reducing B lymphocyte activity of secretion Ig in the bursa or sera and triggers inflammation, apoptosis, and an imbalance of inflammatory cytokines in the BF, resulting in immune injury in SPF chickens, which offered basic data for further study of vvIBDV pathogenesis.

Assessing Environmental Control Strategies in Cage-Free Egg Production Systems: Effect on Spatial Occupancy and Natural Behaviors

Simple Summary

An increment pattern in the worldwide egg production, as well as in the farm’s capacity in laying hen housing systems, have been observed for the last fifty years. Also, animal welfare has become a subject of interest due to consumer awareness. These issues have introduced new challenges to respond to international markets’ demands while ensuring animal welfare and environmental footprint. Cage-free systems have been alternative systems to ensure the well-being of laying hens. Likewise, environmental control strategies have been implemented to improve air quality since airborne contaminants’ concentration can be high inside these systems. Thus, the analysis of the effect of these strategies on natural behavior and flock distribution is essential to assess a comprehensive analysis. Four strategies and a control were tested in an experimental cage-free system. Spatial occupancy and animal behaviors were tracked using video recordings. Neither the four environmental strategies nor the control applied in this experiment affected the natural behaviors of hens. However, changes in flock distribution and stress patterns were identified in the treatment with a reduction in litter allowance. This study provides evidence that it is possible to implement strategies to improve air quality without disrupting natural animal behaviors in cage-free systems.

Abstract

Animal welfare concerns have been a challenging issue for producers and international marketing. In laying hen production, cage-free systems (CFS) have been identified as an alternative to ensure the laying hens’ well-being. Nevertheless, in CFS, important environmental issues have been reported, decreasing indoor air quality. Environmental control strategies (ECS) have been designed to enhance indoor air quality in CFSs. However, little information exists about the effect of these ECSs on natural animal behaviors. Four strategies and one control were tested in an experimental CFS, previously designed to track behavioral variables using video recordings over seven time-lapses of 1 hour per day. Spatial occupancy (SO) and laying hen behaviors (LHB) were registered. One statistical analysis was applied to evaluate the effect of ECS on SO and LHB using a multinomial response model. Results show lower chances to use litter area within the reduction of litter allowance treatment (T17) (p < 0.05). Neither the four ECSs nor the control implemented in this experiment affected the natural behaviors of the hens. However, stress patterns and high activity were reported in the T17 treatment. This study shows that it is possible to use these ECSs without disrupting laying hens’ natural behaviors.

The effect of ammonia exposure on energy metabolism and mitochondrial dynamic proteins in chicken thymus: Through oxidative stress, apoptosis, and autophagy

Ammonia (NH₃) gas is an atmospheric pollutant, produced from different sources. In poultry houses NH₃ is produced from the biological process of liter, manure, and protein composition. It has been well documented that NH₃ adversely effects the health of chickens. However, the underlying mechanism of NH₃ toxicity on chicken thymus is still unknown. Thymus is an important immune organ, which play a critical role in eliciting protective immune responses to ensure healing process and elimination of harmful stimuli. The results showed that NH₃ exposure reduced antioxidant activities and induced oxidative stress in thymus tissues. Histological observation showed normal morphology of chicken thymus in control group. In contrast, increased number of nuclear debris, vacuoles, and cristae break were seen in NH₃ affected chickens. Ultrastructural analysis indicated mitochondrial breakdown, disappearance, vacuoles, and chromatin condensation in NH₃ treated groups. The mRNA and protein expression of apoptosis related genes were significantly enhanced in the chicken thymus of NH₃ affected chickens compared to control group. Moreover, Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay results suggested that NH₃ exposure increased positive stained nuclei in the chicken thymus. Meanwhile, NH₃ exposure reduced the number of CD8⁺ T-lymphocytes, decreased the adenosine triphosphate (ATPase) activities. The mRNA and protein expression of autophagy, energy metabolism, and mitochondrial dynamics proteins were altered by NH₃ exposure. In summary, these results showed that NH₃ induced oxidative stress, apoptosis and autophagic cell death (ACD), which could be the possible causes of immune damage and structural impairment in chicken thymus.

Potential contaminants and hazards in alternative chicken bedding materials and proposed guidance levels: a review

Bedding material or litter is an important requirement of meat chicken production which can influence bird welfare, health, and food safety. A substantial increase in demand and cost of chicken bedding has stimulated interest in alternative bedding sources worldwide. However, risks arising from the use of alternative bedding materials for raising meat chickens are currently unknown. Organic chemicals, elemental, and biological contaminants, as well as physical and management hazards need to be managed in litter to protect the health of chickens and consequently that of human consumers. This requires access to information on the transfer of contaminants from litter to food to inform risk profiles and assessments to guide litter risk management. In this review, contaminants and hazards of known and potential concern in alternative bedding are described and compared with existing standards for feed. The contaminants considered in this review include organic chemical contaminants (e.g., pesticides), elemental contaminants (e.g., arsenic, cadmium, and lead), biological contaminants (phytotoxins, mycotoxins, and microorganisms), physical hazards, and management hazards. Reference is made to scientific literature for acceptable levels of the above contaminants in chicken feed that can be used for guidance by those involved in selecting and using bedding materials.

Effects of Cold Stress and Ammonia Concentration on Productive Performance and Egg Quality Traits of Laying Hens

In a cold climate, ensuring indoor air quality and heat preservation simultaneously has always been a difficult problem in the poultry house. The current study was carried out in order to determine the effects of chronic low temperature and ammonia concentration on productive performance and egg quality of commercial laying hens. 576 18-week-old Hy-line Brown hens were used in this study. Birds were housed in cages and received for 20-week exposure to low temperature and ammonia in six artificial environmental chambers. Birds were randomly assigned into six treatments: treatment 1 (T1, 20 °C, ≤5 ppm, control group), treatment 2 (T2, 20 °C, 20 ppm), treatment 3 (T3, 20 °C, 45 ppm), treatment 4 (T4, 8 °C, ≤5 ppm), treatment 5 (T5, 8 °C, 20 ppm) and treatment 6 (T6, 8 °C, 45 ppm). Daily feed intake (DFI), feed efficiency (FE), egg production (EP) and body weight (BW) were recorded and calculated from 19 weeks of age. Egg samples were collected at 22, 26, 30, 34 and 38 weeks of age and egg weight (EW), shell breaking strength (SBS), albumen height (AH), yolk weight (YW), shell weight (SW), shell thickness (ST) and Haugh unit (HU) were measured. The results of the present study indicated that low temperature and excessive ammonia decreased the EP of hens compared with those of the T1 birds. Low temperature increased DFI of hens thereby FE showed significant differences among treatments. During the early period of the experiment, low temperature treatment increased the BW of laying hens, but this trend of increase was suppressed by the treatment of ammonia with the prolongation of the experimental period. Egg quality was also affected by low temperature and excessive ammonia. At different experimental periods, egg quality traits of hens exposed to the cold and ammonia stress presented significant differences compared to those of control birds. The present study indicated that the effect of ammonia was more pronounced on hens than that of low temperature at the early and peak laying period in terms of several main traits of productive performance and egg quality under long term hens breeding.

The inflammatory injury of heart caused by ammonia is realized by oxidative stress and abnormal energy metabolism activating inflammatory pathway

Inflammation is an essential biological process for maintaining homeostasis in the body. However, excessive inflammatory response is closely related to many chronic diseases. Ammonia is a known environmental pollutant and a main harmful gas in the environment of livestock house. It causes deterioration of air quality and poses a threat to human and animal health. Chickens are very sensitive to ammonia. In order to assess the toxicity of ammonia to the heart, the pathology, ATPase activities, markers of oxidative stress, inflammatory pathways and inflammation markers were investigated in the hearts of chickens exposed to ammonia. The results showed that the cardiac pathological structure, oxidative stress index, and ATPase activity changed significantly in ammonia-treated chickens. In addition, the inflammation pathways (JAK/STAT and MAPK) were activated in the ammonia group, and the inflammatory markers (COX-2, TNF-α, NF-κB and PPAR-γ) were significantly altered at both mRNA and protein levels. In conclusion, excess ammonia can activate inflammatory pathways through oxidative stress and abnormal energy metabolism, and induce cardiac inflammatory injury. Our findings will provide a new insight for better assessing the toxicity mechanism of ammonia on the heart.

Encapsulated crystalline lysine and DL-methionine have higher efficiency than the crystalline form in broilers

Crystalline amino acids (AAs) exhibit high nutritional values when supplemented AA-deficient diets. However, the AAs in crystalline form in the diet are absorbed quickly than protein-bound AAs, which may take an effect on AA utilization efficiency. In this study, 2 experiments were conducted to investigate the effect of encapsulated lysine-HCl (Lys) and DL-methionine (DL-Met) on the growth performance of broiler chickens. In experiment 1, a total of 432 one-day-old male Arbor Acres broilers were subjected to 3 dietary treatments (27 pens; 16 birds per pen) for 42 d. The control group was basal diets supplemented with crystalline Lys and DL-Met, and treatment groups had basal diets supplemented with encapsulated Lys and DL-Met at the levels of 80% and 60% of control diets (80CLM, 60CLM), respectively. The growth performance, intestinal development, and transcription of AA transporters were determined. In experiment 2, 24 broiler chickens were subjected to the same treatments as in experiment 1. The plasma concentrations of free AAs were measured 0, 2, 4, and 6 h after feeding. The results showed that 80CLM treatment had no significant influence on production performance, carcass characteristics, and plasma free AAs content during the experiment compared with the control group (P > 0.05). In addition, the 80CLM group moderately enhanced gut morphology development and increased AAs' absorption capacity. However, broilers fed the 60CLM diet had lower production performance and breast muscle weight than the control group (P < 0.05), but increased villi height and B⁰AT mRNA expression level (P < 0.05). At h 4 after feeding, the 60CLM broilers exhibited higher concentration of Ala, Cys, and total dispensable AAs than the control group (P < 0.05). In conclusion, the result suggests that the supplemental levels of crystalline Lys and DL-Met can be effectively saved approximately for 20% by using the encapsulated form in broilers, with improvements to AAs utilization efficiency, while posing no detrimental effects on production performance. Encapsulated Lys and DL-Met would have greater potential for application when replacing crystalline AAs in broiler chickens.

Effects of chronic heat stress and ammonia concentration on blood parameters of laying hens

Less evidence is available currently to reveal whether the immune system and productivity of laying hens change under long periods of ammonia exposure in hot climate. The present study was conducted to determine the effects of chronic exposure to high temperature and ammonia concentrations on health, immune response, and reproductive hormones of commercial laying hens. A total of five hundred and seventy six 20-week-old laying hens (Hy-Line Brown) were used in this study. Birds were housed in cages (4 birds per cage) and received 16-wk treatments in 6 artificial environmental chambers. Hens were allocated to 6 treatments: treatment 1 (T1, 20°C, ≤5 ppm, control group), treatment 2 (T2, 20°C, 20 ppm), treatment 3 (T3, 20°C, 45 ppm), treatment 4 (T4, 35°C, ≤5 ppm), treatment 5 (T5, 35°C, 20 ppm), and treatment 6 (T6, 35°C, 45 ppm). Blood samples were collected at 22, 26, 30, 34, and 38 wk of age and plasma IgG, IgM, IgA, corticosterone (CORT), total antioxidant capacity (T-AOC), luteinizing hormone (LH), estradiol (E2), and follicular stimulating hormone (FSH) were measured. The results of this study showed that high ambient temperature and excessive ammonia increased the concentration of IgG but decreased the concentration of IgA, T-AOC, LH, FSH, and E2 of hens compared with those of the control birds. From the age of 34 wk, significantly increased concentrations of IgG were observed in hens exposed to moderate and high levels of ammonia. CORT level showed marked differences between the treatments only at the age of 26 wk. In addition, LH and E2 of hens demonstrated significant differences among the treatments in the middle and later stages of the experiment, while FSH levels of the control birds were significantly higher than the others at the age of 38 wk. Excessive ammonia in high temperature was a physiological stress factor that had a negative effect, which inhibited immune function and impacted the reproductive hormones.

Skeletal Muscle and the Effects of Ammonia Toxicity in Fish, Mammalian, and Avian Species: A Comparative Review Based on Molecular Research

Typically, mammalian and avian models have been used to examine the effects of ammonia on skeletal muscle. Hyperammonemia causes sarcopenia or muscle wasting, in mammals and has been linked to sarcopenia in liver disease patients. Avian models of skeletal muscle have responded positively to hyperammonemia, differing from the mammalian response. Fish skeletal muscle has not been examined as extensively as mammalian and avian muscle. Fish skeletal muscle shares similarities with avian and mammalian muscle but has notable differences in growth, fiber distribution, and response to the environment. The wide array of body sizes and locomotion needs of fish also leads to greater diversity in muscle fiber distribution and growth between different fish species. The response of fish muscle to high levels of ammonia is important for aquaculture and quality food production but has not been extensively studied to date. Understanding the differences between fish, mammalian and avian species’ myogenic response to hyperammonemia could lead to new therapies for muscle wasting due to a greater understanding of the mechanisms behind skeletal muscle regulation and how ammonia effects these mechanisms. This paper provides an overview of fish skeletal muscle and ammonia excretion and toxicity in fish, as well as a comparison to avian and mammalian species.

Ammonia inhalation-induced inflammation and structural impairment in the bursa of fabricius and thymus of broilers through NF-κB signaling pathway

Ammonia (NH₃) is a toxic, environmental pollutant, and irritant gas. Previous studies reported the toxic effects of NH₃ which led to inflammation in various organs of chicken. However, the exact mechanism of NH₃-induced inflammation in chicken lymphoid organs bursa of fabricius (BF) and thymus is still elusive. Thus, this study was designed to investigate NH₃-induced inflammation in chicken BF and thymus. Experimental chickens were divided into low (5.0 mg/m³), middle (10.0-15.0 mg/m³), and high (20.0-45.0 mg/m³) NH₃-treated groups. To investigate NH₃-induced inflammation in chicken's BF and thymus, histological observation, NO content and iNOS activity, inflammatory cytokine contents, and mRNA levels were performed by light microscopy, microplate spectrophotometer, ELISA assay, and qRT-PCR. The finding of the present study showed that NH₃ exposure reduced BF and thymus index, increased nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity, inflammatory cytokine contents and mRNA levels of nuclear factor-kappa B (NF-κB), cyclooxygenase-2 (Cox-2), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), IL-10, IL-1β, IL-18, toll-like receptor 2A (TLR-2A), and iNOS. Histopathological examination revealed signs of inflammation including increased nuclear debris and vacuoles in the cortex and medulla of thymus and bursal follicles. Conclusively, our findings displayed that NH₃ exposure affects the normal function of BF and thymus and led inflammation. The data provided a new ground for NH₃-induced toxicity and risk assessment in chicken production.

Effects of ammonia exposure on growth performance and cytokines in the serum, trachea, and ileum of broilers

This study investigated the effects of ammonia (NH₃) exposure (0, 15, 25, and 35 ppm) on growth performance and cytokines in the serum, trachea, and ileum of broilers. A total of 288 22-day-old male broiler chickens were assigned to 4 treatment groups with 6 replicates of 12 chickens for a 21-D trial period. Growth performance and cytokines (IL-1β, IL-6, and IL-10) concentrations in the serum, trachea, and ileum were measured in response to 3, 7, 14, or 21 D of exposure to NH₃. Correlations between cytokines in the serum, trachea, and ileum and growth performance, and between tracheal and ileal cytokines, were also analyzed. Results showed that exposure to 15 ppm NH₃ did not influence the growth performance, but exposure to both 25 ppm and 35 ppm NH₃ decreased the growth performance compared to that of the control group. Exposure to 15 ppm NH₃ for 3 D increased IL-6 concentrations and induced an inflammatory response in the trachea and ileum, whereas exposure to 15 ppm NH₃ for 7 D increased IL-10 concentrations and induced an anti-inflammatory response in the ileum. Exposure to 25 ppm NH₃ induced an inflammatory response in the serum, trachea, and ileum after 3 D and induced an anti-inflammatory response in the ileum after 7 D. Exposure to 35 ppm NH₃ for 3 D induced both inflammatory and anti-inflammatory responses in the trachea and ileum. Furthermore, increases in cytokines in the serum, trachea, or ileum were accompanied by a decrease in BW, ADFI, ADG, and an increase of feed/gain (F/G) from 7 D to 21 D. In addition, tracheal cytokine, especially IL-1β, was positively correlated with ileal cytokine IL-1β. These results indicated that the low growth performance associated with NH₃ exposure may be due in part to an increase in cytokines, and the inflammatory response in the trachea and ileum may be related to cross-talk by cytokines such as IL-6, IL-10, and, in particular, IL-1β.

Effect of dietary coarse corn inclusion on broiler live performance, litter characteristics, and ammonia emission

Ammonia (NH3) emission from nondigested nutrients in poultry creates additional adverse environmental impacts on soil, water, air, and health. Mitigating NH3 emission has become vital for the poultry industry to remain sustainable. As the presence of large particles in the feed stimulates the broiler gizzard to retain ingesta in the gastrointestinal tract longer and improve digestive efficiency, the inclusion of large particles in feed may lead to less nitrogen (N) and moisture content (MC) in feces such that lower NH3 production would be expected. This chamber study investigated the effects of dietary coarse corn (CC) inclusion on broiler live performance, litter characteristics, and NH3 emission. One hundred eighty female broilers (Ross 344 × 708 strains) at day 21 were randomly placed in 6 chambers with 2 dietary treatments (0% CC and 50% CC), with 3 chambers per treatment and 30 birds per chamber for 3 wks. The results showed that the 50% CC inclusion (1) decreased broiler feed intake and BW without affecting mortality-adjusted feed conversion ratio from day 21 to 42; (2) increased gizzard weight and decreased proventriculus weight; (3) decreased N content and MC in litter; and (4) decreased NH3 concentrations in the chambers, as well as NH3 emission from the chambers. Dietary CC inclusion could be an effective way to mitigate broiler litter N content and MC as well as NH3 emission.

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.

miR-187-5p/apaf-1 axis was involved in oxidative stress-mediated apoptosis caused by ammonia via mitochondrial pathway in chicken livers

Ammonia (NH₃), a toxic gas, is an important cause of atmospheric haze and one of the main pollutants in air environment of poultry houses, threatening the health of human beings and poultry. However, little is known about the effect of NH₃ on liver apoptotic damage. This study aimed to investigate the mechanism of oxidative stress-mediated apoptosis caused by NH₃ in chicken livers and whether miR-187-5p/apaf-1 axis was involved in this mechanism. Here we duplicated NH₃ poisoning model of chickens for fattening to study the ultrastructure of chicken livers, apoptosis rate, oxidative stress indexes, miR-187-5p, and apoptosis-related genes. Obvious apoptotic characteristics of liver tissues exposed to excess NH₃ were observed, and the apoptosis rate increased. Excess NH₃ decreased the activities of catalase (CAT), superoxide dismutase (SOD), total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px), and increased the content of malondialdehyde (MDA), suggesting that oxidative stress occurred. miR-187-5p decreased, and apoptotic protease activating factor-1 (apaf-1) increased, indicating that excess NH₃ dysregulated miR-187-5p/apaf-1 axis. The expression of tumor protein p53 (p53), Bcl-2 associated X protein (Bax), Bcl-2 homologous antagonist/killer (Bak), Cytochrome-c (Cyt-c), Caspase-9, Caspase-8, and Caspase-3 was promoted, and the expression of B-cell lymphoma-2 (Bcl-2) was inhibited, resulting in apoptosis. Moreover, oxidative stress indexes, miR-187-5p, and apoptosis-related genes changed in dose- and time-dependent manner. Altogether, miR-187-5p/apaf-1 axis participated in oxidative stress-mediated apoptosis caused by NH₃ via mitochondrial pathway in the livers of chickens for fattening. This study may provide new ideas to study the mechanism of liver apoptotic damage induced by NH₃ exposure.

Influence of bedding materials on organ weights, meat quality, breast and footpad dermatitis of broiler chickens under hot humid climate

Wood shavings is the most common material used as litter in commercial broiler production in many areas in Nigeria. It is, however, becoming scarce and expensive. Therefore this study was conducted to determine and compare the effects of other bedding materials on organ weights, meat quality, footpad and breast dermatitis of Marshall broiler chickens under hot humid climate. One hundred and eighty broiler chicks of mixed sexes (Marshal strain) were randomly assigned to three treatments of wood shavings (WS), maize cobs (MC) and chopped Panicum maximum (PM) as bedding materials replicated four times with 15 birds each in a Completely Randomized Design. Feed and water were provided to birds ad libitum throughout the study. Data were collected on the relative body and organ weights, meat quality, breast and footpad dermatitis. The results showed that footpad and breast lesion of the birds were not significantly influenced (P > 0.05) by different litter materials. Similarly, most of the organ weights, including spleen and bursa of Fabricius were not influenced by litter materials. However, the relative weight of thigh of the birds reared on PM and MC were similar but higher (P < 0.05) than those raised on WS. The intestinal weight of the birds raised on PM was significantly higher than those of the other treatment groups whose weights were similar. Birds reared on chopped PM had higher (P < 0.05) relative weight of liver than those reared on MC. There was no significant (P > 0.05) effect of bedding materials on meat quality. It was concluded that chopped PM could serve as a replacement for WS as a bedding material for broiler chickens under hot humid climate.

Optimization of a wet scrubber with electrolyzed water spray-Part I: Ammonia removal

Electrolyzed water (EW) is an effective disinfectant with a wide range of pH. EW in acid range was proved to be an ammonia absorbent which make it valuable for wet scrubbers used in animal feeding operations (AFOs). This study aimed to optimize the design and operating parameters of a wet scrubber with EW spray for ammonia removal, based on the size distribution of droplets, the property of EW and the reduction efficiency of ammonia. The optimized parameters included droplet size, nozzle flow rates, pH and available chlorine concentration (ACC) of EW, nozzle number at single stage, stage number, initial ammonia concentration and air speed in the duct. The ammonia removal efficiency increased with the decrease of droplet size and the increase of flow rate. The pH values of EW showed significant influence on ammonia removal efficiency (P ˂ 0.05), while ACC of the EW showed no significant influence (P > 0.05). For inlet ammonia concentration of 70 ppm with one and three spray stages, the wet scrubber with EW (pH = 1.35) spray was able to reduce 55.8 ± 4.3 % and 97.2 ± 3.0 % of ammonia, respectively, when the nozzles with 0.9 mm orifice diameter operated at a flow rate of 1.20 L min^-1. Response surface analysis showed that orifice diameter, nozzle flow rate, and their combination were all significant factors impacting ammonia removal efficiency for both pH =1.35 and 5.50 at a 95% confidence level. Optimal ammonia removal efficiency was obtained at orifice diameter 0.9 mm and flow rate 1.20 L min^-1 within the selected range. The results of this study demonstrated that wet scrubber with EW spray could be a very effective and feasible ammonia mitigation technology for animal feeding operation. Implications: It is difficult to effectively reduce ammonia emitted from the animal feeding operations (AFOs). Both the acidity and disinfection effects of electrolyzed water (EW) make it a potential absorbent used for spray in wet scrubber to reduce the ammonia and microorganisms. Based on some preliminary field test results, lab tests were conducted to optimize the design and operation parameters of a wet scrubber with EW spray to improve the ammonia removal efficiency. A better understanding of the application and influence factors of the wet scrubber with EW spray can contribute to effective mitigation of ammonia emission from animal houses and improve the atmosphere air quality.

Differential ammonia metabolism and toxicity between avian and mammalian species, and effect of ammonia on skeletal muscle: A comparative review

Comparative aspects of ammonia toxicity, specific to liver and skeletal muscle and skeletal muscle metabolism between avian and mammalian species are discussed in the context of models for liver disease and subsequent skeletal muscle wasting. The purpose of this review is to present species differences in ammonia metabolism and to specifically highlight observed differences in skeletal muscle response to excess ammonia in avian species. Ammonia, which is produced during protein catabolism and is an essential component of nucleic acid and protein biosynthesis, is detoxified mainly in the liver. While the liver is consistent as the main organ responsible for ammonia detoxification, there are evolutionary differences in ammonia metabolism and nitrogen excretory products between avian and mammalian species. In patients with liver disease and all mammalian models, inadequate ammonia detoxification and successive increased circulating ammonia concentration, termed hyperammonemia, leads to severe skeletal muscle atrophy, increased apoptosis and reduced protein synthesis, altogether having deleterious effects on muscle size and strength. Previously, an avian embryonic model, designed to determine the effects of increased circulating ammonia on muscle development, revealed that ammonia elicits a positive myogenic response. Specifically, induced hyperammonemia in avian embryos resulted in a reduction in myostatin, a well-known inhibitor of muscle growth, expression, whereas myostatin expression is significantly increased in mammalian models of hyperammonemia. These interesting findings imply that species differences in ammonia metabolism allow avians to utilize ammonia for growth. Understanding the intrinsic physiological mechanisms that allow for ammonia to be utilized for growth has potential to reveal novel approaches to muscle growth in avian species and will provide new targets for preventing muscle degeneration in mammalian species.

Hydrogen sulfide inhalation-induced immune damage is involved in oxidative stress, inflammation, apoptosis and the Th1/Th2 imbalance in broiler bursa of Fabricius

Hydrogen sulfide (H₂S) is widely accepted to be a signaling molecule that exhibits some potentially beneficial therapeutic effects at physiological concentrations. At elevated levels, H₂S is highly toxic and has a negative effect on human health and animal welfare. Studies have shown that H₂S exposure induces an immune function in mice, but there are few studies of the effect of continuous H₂S exposure on immune organs in poultry. In this study, one-day-old broilers were selected and exposed to 4 or 20 ppm of H₂S gas for 14, 28 and 42 days of age. After exposure, the bursa of Fabricius (BF) was harvested. The results showed that continuous H₂S exposure reduced the body weight, abdominal fat percentage, and antibody titer in broilers. H₂S exposure also decreased mRNA expression of IgA, IgM and IgG in the broiler BF. A histological study revealed obvious nuclear debris, and a few vacuoles in the BF, and an ultrastructural study revealed mitochondrial and nuclear damage to BF cells after H₂S exposure for 42 d. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay suggested H₂S exposure remarkably increased the number of TUNEL positive nuclei and significantly increased apoptotic index. The expression of apoptotic genes also confirmed that H₂S inhalation damaged the broiler BF. Increased cytokines and reduced antioxidant responses were detected in the BF after exposure to H₂S. Cytokines promoted inflammation and caused a Th1/Th2 imbalance. We suggest that continuous H₂S intoxication triggers oxidative stress, inflammation, apoptosis and a Th1/Th2 imbalance in the BF, leading to immune injury in broilers.

Poultry rearing on perforated plastic floors and the effect on air quality, growth performance, and carcass injuries - Experiment 2: Heat stress situation

Previously, we reported the effect of rearing conditions (plastic floors and air quality) on carcass injury development of broiler chickens at thermal comfort. In this study, the same rearing conditions were tested at thermal stress. The birds were reared in 2 climatic chambers, and the experiment followed a completely randomized design with one factor, flooring material: wood shaving or perforated plastic. The birds were divided into 16 experimental pens, being 8 females and 8 males. The studied parameters were the same as the previous study (ammonia concentration, carbon dioxide, performance, carcass yield, and variability, and scores of hygiene, gait and chest, and hocks and footpad lesions). Higher ammonia (15 ppm vs. 4 ppm) and carbon dioxide (1,000 ppm vs. 850 ppm) concentration was seen at d 42 for the wood shavings floor as compared to the perforated plastic floor, respectively. Regarding gender, males had better performance than females at 42 d of age on both floor types. Males reared on wood shavings showed a higher meat production (29.049 kg/m2) than females (24.700 kg/m2). There were observed breast lesion incidences of 10.4% (score 1) in males reared on the plastic floor, as well higher incidence of hock injury and footpad dermatitis. Chickens reared on plastic flooring showed better hygiene than chickens reared on wood shavings. Our findings revealed that the use of perforated plastic flooring in a heat stress situation can improve the air quality (less CO2 and NH3 concentration) and bird cleanliness. On the other hand, chickens are more susceptible to develop lesions in the breast, hock, and footpad. We conclude that the use of plastic flooring in heat stress conditions needs more attention, since chickens are more susceptible to develop lesions on the carcass, being a source of pain, impairing bird wellbeing and causing losses in meat production.

Does supplemental zeolite (clinoptilolite) affect growth performance, meat texture, oxidative stress and production of polyunsaturated fatty acid of Turkey poults?

BACKGROUND

Following the ban on the use of growth factors, the use of zeolite in poultry feed could be a solution to obtain healthier food products that are more demanded by the consumer.

METHODS

Zeolite (Clinoptilolite) was added to turkey male and female feed at concentrations 1% or 2% and was evaluated for its effectiveness on performance of the production. The turkeys were given free and continuous access to a nutritionally non-limiting diet (in meal form) that was either a basal diet or a 'Zeolite supplemented-diet' (the basal diet supplemented with clinoptilolite at a level of 1% or 2%).

RESULTS

It was found that adding zeolite in the turkey diet had a positive effect on growth performance and increased weight gain compared to the control. In addition, zeolite treatment had a positive effect on oxidative stress and organoleptic parameters that were measured. It was found that adding zeolite in the turkey diet reduced the MDA level in the liver and in the meat, as compared to the control. Quality of meat was measured as a significantly increase (p < 0.05) in pH for male meat, indicated that the zeolite could maintain the quality of longer period. The adding of zeolite in the turkey diet increased level of polyunsaturated fatty acid.

CONCLUSION

This study showed the significance of using zeolite, as a feed additive for turkey, as part of a comprehensive program to improve growth performance and oxidative stress parameters and to increase level of polyunsaturated fatty acid on the turkey body.

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

Due to greater consumption of poultry products and an increase in exports, more poultry houses will be needed. Therefore, it is important to investigate ways that poultry facilities can coexist in close proximity to residential areas without odors and environmental challenges. Ammonia (NH₃) is the greatest concern for environmental pollution from poultry production. When birds consume protein, they produce uric acid, ultimately converted to NH₃ under favorable conditions. Factors that increase production include pH, temperature, moisture content, litter type, bird age, manure age, relative humidity, and ventilation rate (VR). NH₃ concentration and emissions in poultry houses depend on VR; seasons also have effects on NH₃ production. Modern ventilation systems can minimize NH₃ in enclosed production spaces quickly but increase its emissions to the environment. NH₃ adversely affects the ecosystem, environment, and health of birds and people. Less than 10 ppm is the ideal limit for exposure, but up to 25 ppm is also not harmful. NH₃ can be minimized by housing type, aerobic and anaerobic conditions, manure handling practices, litter amendment, and diet manipulation without affecting performance and production. Antibiotics can minimize NH₃, but consumers have concerns about health effects. Administration of probiotics seems to be a useful replacement for antibiotics. More studies have been conducted on broilers, necessitating the need to evaluate the effect of probiotics on NH₃ production in conjunction with laying hen performance and egg quality. This comprehensive review focuses on research from 1950 to 2018.

Poultry rearing on perforated plastic floors and the effect on air quality, growth performance, and carcass injuries-Experiment 1: Thermal Comfort

The present study investigated the use of perforated plastic floors in the rearing of male and female poultry under thermal comfort conditions. The study was conducted in 2 climate chambers, in one was conventional poultry litter (wood shavings) and in the other was a perforated plastic floor. The experimental design was a completely randomized design with the factors wood shavings and plastic floor. In each chamber, the animals were divided into 16 experimental pens (8 with males and 8 with females) with a density of 12 birds/m2. The poultry rearing effect was evaluated in terms of air quality (% concentration of ammonia [NH3] and carbon dioxide [CO2]); broiler performance, e.g., weight gain (kg), feed intake (kg), feed conversion, carcass yield and parts (%), meat production (kg/m2), and viability (% of live birds at d 42); scores of hygiene and mobility; and injuries in the chest, hocks, and footpads. Treatments affected air quality, with higher concentrations of NH3 on d 42 (25 ppm vs. 2 ppm) and CO2 (1,400 ppm vs. 1,000 ppm) for wood shavings than for perforated plastic floor, respectively. Males showed a better performance (weight gain, feed intake and feed conversion) than females on d 42 in both floor types (wood shavings and plastic floor). Males reared on wood shavings showed a higher meet production (35.992 kg/m2) than females (32.257 kg/m2). On the plastic floor, males showed a better viability (100%) than females (94.05%), as well better meet production for males (38.55 kg·m-2) than females (31.64 kg/m2). There was no incidence of breast lesions in any of the studied systems. The birds reared on the plastic floor had better hygiene scores and lower hock injury rates than birds reared in the wood shavings chambers. The results of the present study show that the use of perforated plastic floors in chicken farming is an efficient method, which promotes a better-quality environment, superior production rates, and reduced incidence of injuries.

Atmospheric ammonia alters lipid metabolism-related genes in the livers of broilers (Gallus gallus)

Atmospheric ammonia in animal housing is reported to have adverse effects on livestock performance and animal health. Previous experiments have found that 75 ppm ammonia reduced the production performance and altered body fat distribution quality of broilers. In this study, we examined the body fat distribution, serum metabolites and lipid metabolism gene expression of broiler exposed to ammonia. A total of 400 chickens were randomly allocated to four groups with four replicates and received ammonia treatments at 0, 25, 50 and 75 ppm, respectively, for 3 weeks. The average daily feed intake and weight gain were decreased when broiler was exposed to ammonia concentration exceeding 50 ppm (p < .05). The increased abdominal fat and reduced thickness of subcutaneous adipose were found in broilers of 75 ppm group (p < .05). When ammonia exceeded 50 ppm, the content of fat in breast muscle of broiler was increased, and when ammonia was higher than 25 ppm, the fat in liver was increased (p < .05). It showed that the fat content in liver was a sensitive index for broilers exposed to ammonia. Furthermore, ammonia exposure had no significant effect on total cholesterol and triglyceride in serum, but significantly increased the relative mRNA expression of acetyl-CoA carboxylase (p = .046) and malic enzyme in liver (p = .038), which indicated that ammonia exposure may increase the de novo fat synthesis in liver. In addition, ammonia increased the high-density lipoprotein cholesterol (p = .02) and activity of hepatic lipase in serum (p < .001), which indicated that ammonia exposure may improve the transportation of cholesterol to liver. To conclude, our results indicated that ammonia exposure might increase the de novo fat synthesis in liver and increased the transportation of cholesterol to liver. In addition, the concentration of ammonia in poultry house should be limited lower than 25 ppm based on the variation of hepatic fat content.