Poultry Production Facilities Research Articles

Sublethal Effects of α-Cypermethrin on the Behavioral Asymmetries and Mating Success of Alphitobius diaperinus.

Sublethal exposure to insecticides can adversely impact various biological and behavioral characteristics of insects. Although α-cypermethrin has been previously tested for its effects on control of Alphitobius diaperinus, there is no knowledge about the effect of this insecticide on its behavioral asymmetries and mating success. Μales at all exposures (control, LC10, and LC30), that first approached their mate, showed right-biased tendency (approached their mate from their right side) in mate recognition. Females, however, showed variation in this behavior between the three exposures. Right-biased tendency of males in all treatment scenarios led to a higher percentage of successful copulations compared to the three other directions. For males that first approached their mate, the insecticide did not affect their lateralization of the first approach but did affect their copulation success. The duration of copulation time was reduced after the exposure to the insecticide, with the longest duration noted in the control females (63.0 s) and the lowest in the α-cypermethrin LC30 females (46.9 s). Moreover, at the α-cypermethrin LC10 exposure, mate recognition time was reduced, as opposed to α-cypermethrin LC30 exposure where mate recognition time was increased. These results can be further utilized to uncover the behavioral impacts of insecticides, enhancing the effectiveness of pest management in warehouses and poultry production facilities.

Emergence of Poultry-Associated Human Salmonella enterica Serovar Abortusovis Infections, New South Wales, Australia.

Salmonella enterica serovar Abortusovis is a ovine-adapted pathogen that causes spontaneous abortion. Salmonella Abortusovis was reported in poultry in 2009 and has since been reported in human infections in New South Wales, Australia. Phylogenomic analysis revealed a clade of 51 closely related isolates from Australia originating in 2004. That clade was genetically distinct from ovine-associated isolates. The clade was widespread in New South Wales poultry production facilities but was only responsible for sporadic human infections. Some known virulence factors associated with human infections were only found in the poultry-associated clade, some of which were acquired through prophages and plasmids. Furthermore, the ovine-associated clade showed signs of genome decay, but the poultry-associated clade did not. Those genomic changes most likely led to differences in host range and disease type. Surveillance using the newly identified genetic markers will be vital for tracking Salmonella Abortusovis transmission in animals and to humans and preventing future outbreaks.

Targeted Next-Generation Sequencing Assay for Direct Detection and Serotyping of Salmonella from Enrichment

In this study, an automated, targeted next-generation sequencing (tNGS) assay to detect and serotype Salmonella from sample enrichments was evaluated. The assay generates millions of reads to detect multiple Salmonella-specific genes and serotype-specific alleles, detecting all Salmonella spp. tested to date, and serotyping 62 common Salmonella serotypes. Accuracy was tested on 291 pure reference cultures (251 Salmonella, 40 non-Salmonella), 21 artificially contaminated poultry carcass rinse samples, and 363 naturally contaminated poultry environmental samples. Among the 291 pure reference cultures, the automated tNGS assay resulted in 100% detection accuracy, 100% serotyping accuracy for the claimed serotypes, and 0% false positives. The limit of detection was estimated at 5 × 104 CFU/mL by testing enumerated cultures of strains representative of six serotypes. In cocontamination studies with mixtures of two serotypes (Enteritidis, Typhimurium, Kentucky, Infantis, and Newport) at a 1:1 ratio, tNGS detected both serotypes with 100% accuracy. The assay demonstrated 100% accuracy in artificially contaminated poultry carcass rinse sample enrichments. Targeted NGS was highly effective in detecting Salmonella in samples collected from poultry production facilities. Results demonstrated that tNGS could detect Salmonella and provide accurate serotyping information consistent with conventional serology. These findings highlight the reliable and efficient performance of a fully automated tNGS Salmonella assay in detecting and identifying Salmonella strains in complex matrices, reducing the time to results from 4 to 5 days required by the traditional isolation and serotyping to 10–12 h for tNGS after primary enrichment.

Research on automatic classification and detection of chicken parts based on deep learning algorithm.

Accurate classification and identification of chicken parts are critical to improve the productivity and processing speed in poultry processing plants. However, the overlapping of chicken parts has an impact on the effectiveness of the identification process. To solve this issue, this study proposed a real-time classification and detection method for chicken parts, utilizing YOLOV4 deep learning. The method can identify segmented chicken parts on the assembly line in real time and accurately, thus improving the efficiency of poultry processing. First, 600 images containing multiple chicken part samples were collected to build a chicken part dataset after using the image broadening technique, and then the dataset was divided according to the 6:2:2 division principle, with 1200 images as the training set, 400 images as the test set, and 400 images as the validation set. Second, we utilized the single-stage target detector YOLO to predict and calculate the chicken part images, obtaining the categories and positions of the chicken leg, chicken wing, and chicken breast in the image. This allowed us to achieve real-time classification and detection of chicken parts. This approach enabled real-time and efficient classification and detection of chicken parts. Finally, the mean average precision (mAP) and the processing time per image were utilized as key metrics to evaluate the effectiveness of the model. In addition, four other target detection algorithms were introduced for comparison with YOLOV4-CSPDarknet53 in this study, which include YOLOV3-Darknet53, YOLOV3-MobileNetv3, SSD-MobileNetv3, and SSD-VGG16. A comprehensive comparison test was conducted to assess the classification and detection performance of these models for chicken parts. Finally, for the chicken part dataset, the mAP of the YOLOV4-CSPDarknet53 model was 98.86% on a single image with an inference speed of 22.2 ms, which was higher than the other four models of YOLOV3-Darknet53, YOLOV3-MobileNetv3, SSD-MobileNetv3, and SSD-VGG16 mAP by 3.27%, 3.78%, 6.91%, and 6.13%, respectively. The average detection time was reduced by 13, 1.9, 6.2, and 20.3 ms, respectively. In summary, the chicken part classification and detection method proposed in this study offers numerous benefits, including the ability to detect multiple chicken parts simultaneously, as well as delivering high levels of accuracy and speed. Furthermore, this approach effectively addresses the issue of accurately identifying individual chicken parts in the presence of occlusion, thereby reducing waste on the assembly line. PRACTICAL APPLICATION: The aim of this study is to offer visual technical assistance in minimizing wastage and resource depletion during the sorting and cutting of chicken parts in poultry production and processing facilities. Furthermore, considering the diverse demands and preferences regarding chicken parts, this research can facilitate product processing that caters specifically to consumer preferences.

Antimicrobial susceptibility, plasmid replicon typing, phylogenetic grouping, and virulence potential of avian pathogenic and faecal Escherichia coli isolated from meat chickens in Australia

ABSTRACT Globally, avian colibacillosis is a leading cause of morbidity and mortality in poultry, associated with economic losses and welfare problems. Here, clinical avian pathogenic E. coli isolates (CEC; n = 50) and faecal E. coli isolates from healthy (FEC; n = 187) Australian meat chickens collected between 2006 and 2014 were subjected to antimicrobial susceptibility testing, phylogenetic grouping, plasmid replicon (PR) typing, multilocus sequence typing, and virulence gene (VG) profiling. Extended-spectrum cephalosporin (ESC)- and fluoroquinolone (FQ)-resistant E. coli isolates underwent further genetic characterization. Significant proportions of CEC and FEC were, respectively, susceptible (13/50; 48/187) or MDR (9/50; 26/187) to 20 tested antimicrobials. Phylogenetic groups A and C, and PR types IncFIB and IncFrep were most represented. Five tested CEC-associated VGs were more prevalent in CEC (≥ 90%) than FEC (≤ 58%). Some isolates (CEC n = 3; FEC n = 7) were resistant to ESCs and/or FQs and possessed signature mutations in chromosomal FQ target genes and plasmid-mediated qnrS, bla CMY-2, and bla DHA-1 genes. Sequence type 354 (n = 4), associated with extraintestinal infections in a broad range of hosts, was prevalent among ESC- and/or FQ-resistant FEC. This study confirmed existence of a small reservoir of ESC- and FQ-resistant E. coli in Australian commercial meat chickens despite absence of use in the industry of these drugs. Otherwise, diversity of VGs and PR types in both FEC and CEC populations was identified. We hypothesize that the source of ESC- and FQ-resistant E. coli is external to poultry production facilities. RESEARCH HIGHLIGHTS Low-level resistance to older and newer generation antimicrobial drugs detected. The most common sequence type (ST) associated with FQ resistance was ST354 (4/10). A small proportion of CEC (n = 3) and FEC (n = 7) were resistant to ESCs and/or FQs.

Modelling and optimisation of a wire-plate ESP for mitigation of poultry PM emission using COMSOL

Particulate matter (PM) emissions constitute a major air pollution concern for commercial poultry production facilities. Recently, the electrostatic precipitator (ESP) has emerged as a promising technology for mitigation of poultry PM. However, further optimisation of ESP design, operation scale, and operating parameters is necessary for improved PM removal efficiencies and practical applications in poultry facilities. In this study, a comprehensive model of the poultry PM collection process in a simulated ESP module was developed using COMSOL software. The model simulated airflow characteristics, electric field and space charge development, particle charging, and particle trajectory tracking of both PM10 and PM2.5. Wire-plate ESP configurations with varying design parameters, such as number of wire electrodes and plate separation distance, were simulated using the COMSOL model at an inlet air velocity of 2.0 m s−1 to identify the optimal configuration for development of ESP physical prototypes. The model was validated by laboratory testing of a prototype ESP within a wind tunnel under three sets of ventilation conditions representing hot, warm, and cold weather, respectively. The prototype ESP exhibited PM10 collection efficiencies of 90.8%, 97.1%, and 99.0% in hot, warm, and cold weather conditions, respectively. The observed PM2.5 collection efficiencies under these respective conditions were 86.9%, 94.4%, and 97.8%. This COMSOL model can be used as an inexpensive alternative to developing physical prototypes when evaluating ESP designs for PM mitigation in poultry facilities.

Influence of Different Light Spectrums on Behaviour and Welfare in Laying Hens.

Simple SummaryThis study investigated how different types of lighting affect laying hen behaviour and welfare. Amount and quality of light are important for birds to perform their natural behaviours, e.g., find food and water, recognise conspecifics and safely navigate their environment. The lighting used in poultry production facilities differs considerably from light conditions in the natural environment in which domestic fowl have evolved, which might have negative consequences for their welfare. This study examined whether light closely resembling natural daylight and light found in forest understory in Southeast Asia (ancestral habitat of jungle fowl) affected the behaviour of laying hens. The results revealed that birds had a preference for natural lighting in some situations. It is likely that these effects were due to the presence of ultraviolet light, which is known to be important for visual performance in birds. However, the differences were rather small, indicating that sufficient light intensity and other quality factors in the housing environment are more important in maintaining high welfare than the specific spectral composition of the light. This new knowledge can be used to improve the housing environment of domestic fowl by supplying artificial spectrums replicating natural lighting.Artificial commercial lighting used in animal production facilities can have negative influences on visual abilities, behaviour and welfare of domestic fowl. This study examined the effects of natural-derived light spectrums on behaviour, production and welfare of laying hens reared from hatching into adulthood. Comparisons were made of frequency of a range of behaviours associated with activity, aggression and comfort in birds kept in control light (commercial standard), daylight (full spectrum, including ultraviolet (UV) wavelengths and forest light (forest understorey, including UV). In addition, bird preferences for different lights, feather damage and egg production were monitored. The results showed that the behavioural repertoire of birds changed with age, while the effects of light treatment were subtle. Some evidence was found that birds preferred either daylight or forest light to control light, suggesting that inclusion of UV contributed to the preference. Daylight and forest light were associated with more active behaviours, and daylight with better plumage and later start of lay. Thus natural-like light may have beneficial effects on domestic fowl, but the differences between broad-spectrum light sources are rather small.

Concentration and size distribution of particulate matter in a new aviary system for laying hens in China

ABSTRACTParticulate matter (PM) from poultry production facilities may strongly affect the health of animals and workers in the houses, and PM emitted to the ambient air is an important pollution source to the surrounding areas. Aviary system is considered as a welfare friendly production system for laying hens. However, its air quality is typically worse as compared with conventional cage systems, because of the higher PM concentration of indoor air and other airborne contaminants. Furthermore, PM’s physical property, which has a direct impact on the penetration depth into the lungs of the birds and humans, is largely unknown for the aviary system. Therefore, a systematic method was utilized to investigate the characteristics of particles in the aviary house with large cage aviary unit system (LCAU) in Beijing, China. For the field measurements, three measuring locations were selected with two inside and one outside the house with LCAU to continuously monitor PM concentrations and collect the samples for particle size distribution (PSD) analysis. Results showed that PM2.5, PM10, and total suspended particulate (TSP) concentrations averaged at 0.037 ± 0.025 mg/m3, 0.42 ± 0.10 mg/m3, and 1.92 ± 1.91 mg/m3, respectively. Particle concentrations increased from October to December due to less ventilation as the weather got colder, and were generally affected by stocking density, ventilation rate, birds’ activities, and housing system. Meanwhile, indoor PM2.5 concentration was easily impacted by the ambient air quality. Mass median diameter (MMD) and mass geometric standard deviation (MGSD) of the TSP during the measurement were 18.92 ± 7.08 μm and 3.11 ± 0.31, respectively. Count median diameter (CMD) and count geometric standard deviation (CGSD) were 1.94 ± 0.14 μm and 1.48 ± 0.08, respectively. Results indicated that the aviary system can attain a good indoor condition by suitable system design and environment control strategy.Implications: Indoor PM2.5 concentration of the layer house can be significantly affected by ambient air quality when the air quality index (AQI) was larger than 100. PM2.5 and PM10 concentrations of the layer house with a LCAU system were comparable to the cage system. TSP concentration was higher, and PM size was larger than most of the cage system. System design, larger space volume, and higher ventilation rate were the main influence factors. Good indoor environment of the aviary system can be achieved through the reasonable design of the production system and appropriate environment control strategy.

Plant-based vaccine candidate against Infectious bursal disease: An alternative to inactivated vaccines for breeder hens

Infectious bursal disease (IBD) is an acute, highly contagious immunosuppressive disease that affects young birds causing important economic losses in the poultry industry worldwide. Strict hygiene management together with effective vaccination programs are the most important strategies to prevent Infectious bursal disease virus entry in poultry production facilities. Hyperimmunisation of dams with inactivated vaccines just before the laying period provides passive immunity to the progeny that protects them during the critical first few weeks after hatching before vaccination with live attenuated virus takes place. In the present study, a safe and economic plant-based vaccine candidate against IBD intended for breeder hens was evaluated. We demonstrated that the recombinant immunogen is effective as booster for previously primed hens since it increases specific antibodies against VP2 that are transmitted to the offspring with titres and decay rate similar to those achieved by inactivated vaccine. Moreover, these maternally derived antibodies have virus neutralising activity and are able to confer protection against challenge in progeny, as evidenced by absence of bursal damage and low viral titres in this organ. Taking into account the disadvantages of inactivated vaccines as well as the benefits of plants as expression systems, such as time and cost efficiency, lower risk of contamination from animal pathogens and nearly unlimited scalability, a plant-based subunit IBD vaccine represents a viable alternative in the veterinary field.

71 Overview of arthropod pests of typical livestock production systems.

An overview of insect and acari pests of typical livestock production systems will be presented. Pests of livestock are often specific to the individual production system, and are responsible for decreases in production of meat, milk, wool, and work in addition to vectoring disease-causing pathogens to both livestock and people. Mismanagement or lack of management for common pests causes many species of flies to increase past the economic threshold levels. The horn fly, Haematobia irritans, is a pest of pastured beef and dairy cattle. The rapid lifecycle and blood-feeding nature of this fly causes large populations to quickly develop which alter the normal behavior of cattle, causing loss in production (weight gain, calf weight, milk production, and mastitis). Stable flies, Stomoxys calcitrans, are associated with humans and numerous livestock production types as they feed on blood and develop in various decomposing environments, including fouled hay around feeders and rotting vegetable matter. Stable flies are known to blood-feed on several hosts, including cattle, pigs, dogs, and people. Other flies (house fly Musca domestica, little house fly Fannia canicularis, and other fly species) are associated with manure pits common to pork and poultry production facilities. Management practices alone are often unable to prevent pests from reaching economic threshold levels. Speculative guesses will be made for common production systems, as current livestock production methods change, for future pests and their potential impact on livestock, husbandry techniques, and their economic impact for producers. Concluding remarks will highlight the current research needs in livestock-arthropod interactions.

Effects of light-emitting diode light v. fluorescent light on growing performance, activity levels and well-being of non-beak-trimmed W-36 pullets

More energy-efficient, readily dimmable, long-lasting and more affordable light-emitting diode (LED) lights are increasingly finding applications in poultry production facilities. Despite anecdotal evidence about the benefits of such lighting on bird performance and behavior, concrete research data were lacking. In this study, a commercial poultry-specific LED light (dim-to-blue, controllable correlated color temperature (CCT) from 4500 to 5300 K) and a typical compact fluorescent light (CFL) (soft white, CCT=2700 K) were compared with regards to their effects on growing performance, activity levels, and feather and comb conditions of non-beak-trimmed W-36 pullets during a 14-week rearing period. A total of 1280-day-old pullets in two successive batches, 640 birds each, were used in the study. For each batch, pullets were randomly assigned to four identical litter-floor rooms equipped with perches, two rooms per light regimen, 160 birds per room. Body weight, BW uniformity (BWU), BW gain (BWG) and cumulative mortality rate (CMR) of the pullets were determined every 2 weeks from day-old to 14 weeks of age (WOA). Activity levels of the pullets at 5 to 14 WOA were delineated by movement index. Results revealed that pullets under the LED and CFL lights had comparable BW (1140±5 g v. 1135±5 g, P=0.41), BWU (90.8±1.0% v. 91.9±1.0%, P=0.48) and CMR (1.3±0.6% v. 2.7±0.6%, P=0.18) at 14 WOA despite some varying BWG during the rearing. Circadian activity levels of the pullets were higher under the LED light than under the CFL light, possibly resulting from differences in spectrum and/or perceived light intensity between the two lights. No feather damage or comb wound was apparent in either light regimen at the end of the rearing period. The results contribute to understanding the impact of emerging LED lights on pullets rearing which is a critical component of egg production.

1291 Measurement and mitigation of reactive nitrogen species from swine and poultry production facilities

1291 Measurement and mitigation of reactive nitrogen species from swine and poultry production facilities

Influence of biotic and abiotic factors on the persistence of a Beauveria bassiana biopesticide in laboratory and high-rise poultry house settings

Recent studies suggest the potential for use of oil formulations of the entomopathogenic fungus, Beauveria bassiana, as residual sprays for control of house flies in poultry production facilities. The current study investigated the influence of biotic and abiotic factors on biopesticide persistence. We found that flies physically removed and deactivated conidia, with higher fly densities and greater cumulative exposure hastening the decline. Nonetheless, very low densities of viable conidia were still able to cause rapid mortality, suggesting the potential for relatively long re-treatment intervals as fly populations are controlled. Considering abiotic factors, we found that fungal spray treatments remained viable for up to 13 weeks under laboratory conditions. Periodic exposure of flies to the spray residue showed high levels of mortality, with very little decline in mortality rate over time. Equivalent treatments placed in a commercial poultry house showed much more rapid decline. One trial at the end of summer showed conidia to remain viable up to seven weeks. However, repeats during the winter months revealed decay in 1–2 weeks, with fly mortality rates influenced accordingly. The exact reasons for the more rapid decay remain unclear but could be linked to high concentrations of ammonia in the basement areas, especially during winter when ventilation is minimal. The combined data suggest the potential for adaptive treatment regimes with weekly spray intervals in conditions with very high fly populations and/or high ammonia levels, and potentially monthly spray intervals when fly populations and ammonia levels are reduced.

Persistence and efficacy of a Beauveria bassiana biopesticide against the house fly, Musca domestica, on typical structural substrates of poultry houses

Entomopathogenic fungi, such as Beauveria bassiana, offer potential for use as biopesticides for control of house flies in poultry production facilities. This study evaluates persistence and efficacy of oil-formulated B. bassiana conidia against adult house flies on a range of structural substrates commonly found in poultry houses. Exposure of flies to fungal-treated surfaces produced high levels of infection leading up to 100% mortality in 6–10 days. However, the infectivity of the spray residues declined rapidly within 1 or 2 weeks following repeated fly exposures. Investigations showed that, in the absence of flies, conidia remained viable on test surfaces for up to 3 months regardless of substrate type, application method or fungal production batch. Rather, it was the presence of flies themselves that was responsible for reducing persistence. The exact mechanisms remain unclear but involve a combination of physical removal and chemical deactivation, with decay rates increasing at higher fly densities. While the rapid decay could pose a challenge for operational use, the results suggest it might be possible to tailor treatment frequencies to fly densities with, for example, weekly applications at high fly densities and longer intervals when populations decline. Further research is needed to determine persistence in semifield and field settings and to quantify the influence of fly densities under natural exposure conditions.

Behavioral Responses of Lesser Mealworm Beetles, Alphitobius diaperinus, (Coleoptera: Tenebrionidae) to Pheromone Components Using a Wind Tunnel Dual Choice Walking Bioassay

The lesser mealworm beetle (LMW), Alphitobius diaperinus (Panzer), is a serious pest in poultry production facilities world-wide and is difficult to control by conventional means. Pheromone-based tools might become useful in the management of this species. Male LMW emit a five-component pheromone consisting of, (R)-(+)-limonene, (E)-β-ocimene, (S)-(+)-linalool, (R)-(+)-daucene, and 2-nonanone. Three of the five components ((E)-β-ocimene, (R)-(+)-daucene, and 2-nonanone) had shown behavioral activity, but it was not yet known if different blend combinations of the five components could modulate the beetle behavioral response. We developed a dual choice wind tunnel walking bioassay to test the attraction of male and female adult beetles to individual pheromone components and their blends. We tested hundreds of male and female adults at the same time to create a high throughput bioassay, which confirmed that only three compounds, (E)-β-ocimene, (R)-(+)-daucene, and 2-nonanone, are necessary to exhibit the pheromone behavioral activity of the naturally emitted blend. Randomly roaming males and females responded by forming lines while walking up to a source of attractive odor.

Potential for biocontrol of house flies, Musca domestica, using fungal biopesticides

Chemical control of house flies in poultry production facilities is becoming increasingly difficult due to insecticide resistance and regulatory constraints. Biopesticides based on entomopathogenic fungi could provide an alternative approach. Here we evaluated population control potential of two fungal pathogens, Beauveria bassiana and Metarhizium anisopliae. Cohorts of adult flies were established in large plastic boxes in the laboratory and were exposed to residues of oil-formulated fungal conidia sprayed on strips of plastic sheeting attached to the box walls. Exposure to the biopesticide barrier treatments caused 100% mortality in adult populations within 8–16 days, depending on the fungal species. In contrast, control flies survived until 96–110 days. Additionally, fungal infections caused 13–20% reduction in egg viability and >70% reduction in fecundity of flies prior to death. The combined lethal and pre-lethal impacts resulted in 21- to 26-fold reduction in basic reproductive rate in the fungus-exposed populations relative to controls. Based on these promising proof-of-principle results, further research is currently under way to determine the feasibility of developing a biopesticide product for operational use.

Identification of new sub-genotypes of virulent Newcastle disease virus with potential panzootic features

Virulent Newcastle disease virus (NDV) isolates from new sub-genotypes within genotype VII are rapidly spreading through Asia and the Middle East causing outbreaks of Newcastle disease (ND) characterized by significant illness and mortality in poultry, suggesting the existence of a fifth panzootic. These viruses, which belong to the new sub-genotypes VIIh and VIIi, have epizootic characteristics and do not appear to have originated directly from other genotype VII NDV isolates that are currently circulating elsewhere, but are related to the present and past Indonesian NDV viruses isolated from wild birds since the 80s. Viruses from sub-genotype VIIh were isolated in Indonesia (2009–2010), Malaysia (2011), China (2011), and Cambodia (2011–2012) and are closely related to the Indonesian NDV isolated in 2007, APMV1/Chicken/Karangasem, Indonesia (Bali-01)/2007. Since 2011 and during 2012 highly related NDV isolates from sub-genotype VIIi have been isolated from poultry production facilities and occasionally from pet birds, throughout Indonesia, Pakistan and Israel. In Pakistan, the viruses of sub-genotype VIIi have replaced NDV isolates of genotype XIII, which were commonly isolated in 2009–2011, and they have become the predominant sub-genotype causing ND outbreaks since 2012. In a similar fashion, the numbers of viruses of sub-genotype VIIi isolated in Israel increased in 2012, and isolates from this sub-genotype are now found more frequently than viruses from the previously predominant sub-genotypes VIId and VIIb, from 2009 to 2012. All NDV isolates of sub-genotype VIIi are approximately 99% identical to each other and are more closely related to Indonesian viruses isolated from 1983 through 1990 than to those of genotype VII, still circulating in the region. Similarly, in addition to the Pakistani NDV isolates of the original genotype XIII (now called sub-genotype XIIIa), there is an additional sub-genotype (XIIIb) that was initially detected in India and Iran. This sub-genotype also appears to have as an ancestor a NDV strain from an Indian cockatoo isolated in1982. These data suggest the existence of a new panzootic composed of viruses of subgenotype VIIi and support our previous findings of co-evolution of multiple virulent NDV genotypes in unknown reservoirs, e.g. as recorded with the virulent NDV identified in Dominican Republic in 2008. The co-evolution of at least three different sub-genotypes reported here and the apparent close relationship of some of those genotypes from ND viruses isolated from wild birds, suggests that identifying wild life reservoirs may help predict new panzootics.

A BIOPHYSIOCHEMICAL ANALYSIS OF SETTLED LIVESTOCK AND POULTRY HOUSING DUSTS

The levels and composition of agricultural dusts ar e influenced by animal species, production strategy , housing type and ventilation efficiency. Agricultural dust within animal houses is complex and consists of fee d particles, microbes and their products, dander, fecal matter, gases, metals and other organic and inorganic components. Livestock and poultry production facilities may be categorized as confinement, semi-confinement or pasturebased. Characterization of animal husbandry buildin g dust will provide insight into understanding expo sures experienced by animals, workers and farm visitors. The goal was to characterize biophysiochemical feat ures of livestock dusts from swine, small ruminant, equine, poultry and cattle husbandry units. Settled dust s amples were collected from livestock and poultry housing units at the University Farm and other livestock farms ac ross the state. Morphological features were determined by el ectron microscopy and gravimetry. Biochemical evaluation consisted of pH determination and trace metal detec tion via mass spectrometry. Biological assessment c entered on bacterial characterization via selective media, DNA analysis and endotoxin quantitation. Morphological analyses revealed higher levels of respirable and t horacic particles in poultry, swine, small ruminant and equine units compared to the dairy unit (p<0.01). Dusts we re slightly acidic with the exception of the NCAT s mall ruminant unit (p<0.05). Dust endotoxin levels were consistent and bacterial species detected include Listeria and Escherichia coli . These findings suggest animal husbandry buildings harbor higher levels of smaller respirable and thoracic dust particles compared to inhalable p articles. This information may be helpful in unders tanding dust exposures experienced by animals, farmers and agricultural workers.

Occupational exposure to aflatoxin B1: the case of poultry and swine production

Although there is an abundance of literature concerning the ingestion of food contaminated with aflatoxin B1 (AFB1), only a small number of studies explore mycotoxin exposure in occupational settings. Taking this into consideration, our study was developed with the intention of elucidating whether there is occupational exposure to AFB1 in Portuguese poultry and swine production facilities. A specific biomarker was used to assess exposure to AFB1. A total of 45 workers (34 from poultry farms; 11 from swine production facilities) participated in this study, providing blood samples. Additionally, a control group (n=30) composed of subjects without any type of contact with agricultural activity was considered. All participants signed a consent form and were provided with the study protocol. Eighteen poultry workers (58.6%) and six workers from the swine production facilities (54.5%) showed detectable levels of AFB1. In the control group, the AFB1 values were all below 1 ng/ml. No significant differences in AFB1 levels in serum between workers from poultry and swine farms were found. Poultry workers, however, showed the highest serum levels and a significant statistical difference between this group and the control group was found. Results suggest that exposure to AFB1 by inhalation occurs in both occupational settings representing an additional risk that needs to be recognised, assessed and prevented.

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

Litter amendments have been used to control the ammonia (NH3) emission from the broiler litter during the brooding period. One of the commercially available litter amendments, sodium bisulfate, was frequently applied on the litter with two different rates on weekly basis in a laboratory setup and with a single rate on biweekly basis under field conditions. Repeated application of sodium bisulfate led to significant reduction in NH3 emissions from broilers. The magnitude of NH3 emission reduction increases with the application rate of sodium bisulfate. The reduction rates of cumulative emissions with 366 g/wk-m2 (75 lb/wk-1000 ft2) rate (from 14% to 64.5%) were higher than the reduction rate of 183 g/wk-m2 (37.5 lb/wk-1000 ft2) rate (from 0% to 55%) from 28 to 61 days of age. The cumulative NH3 emission was reduced by 51.7% with 244 g/2 wk-m2 (50 lb/2 wk-1000 ft2) rate over a three-flock period (8-wk average grow-out per flock) under field production conditions. Sodium bisulfate application showed no significant difference on body weight and feed conversion efficiency. However, footpad quality was significantly improved by sodium bisulfate application. Litter pH and ammonia nitrogen level of the litter were decreased by sodium bisulfate application with both rates. Organic and total nitrogen contents in the litter were higher, whereas less nitrogen was emitted as NH3. The laboratory-scale findings of emission reduction by the additives should be considered to be preliminary if the additives are to be applied under commercial production settings. Implications This work demonstrated that frequent litter amendment application can be used to reduce NH3 emissions from broiler houses, with no adverse effect on the animal production performances. The NH3 reduction rates could vary with different application frequencies and rates. Using litter amendment during broiler grow-out to lower NH3 emissions should be applicable to boiler production systems. The results of this study also contribute to the baseline data for improving the national air emissions inventory for livestock and poultry production facilities.