Landscape genomics reveals regions associated with adaptive phenotypic and genetic variation in Ethiopian indigenous chickens.

Climate change is a threat to sustainable livestock production and livelihoods in the tropics. It has adverse impacts on feed and water availability, disease prevalence, production, environmental temperature, and biodiversity. Unravelling the drivers of local adaptation and understanding the underlying genetic variation in random mating indigenous livestock populations informs the design of genetic improvement programmes that aim to increase productivity and resilience. In the present study, we combined environmental, genomic, and phenotypic information of Ethiopian indigenous chickens to investigate their environmental adaptability. Through a hybrid sampling strategy, we captured wide biological and ecological variabilities across the country. Our environmental dataset comprised mean values of 34 climatic, vegetation and soil variables collected over a thirty-year period for 260 geolocations. Our biological dataset included whole genome sequences and quantitative measurements (on eight traits) from 513 individuals, representing 26 chicken populations spread along 4 elevational gradients (6-7 populations per gradient). We performed signatures of selection analyses ([Formula: see text] and XP-EHH) to detect footprints of natural selection, and redundancy analyses (RDA) to determine genotype-environment and genotype-phenotype-associations. RDA identified 1909 outlier SNPs linked with six environmental predictors, which have the highest contributions as ecological drivers of adaptive phenotypic variation. The same method detected 2430 outlier SNPs that are associated with five traits. A large overlap has been observed between signatures of selection identified by[Formula: see text]and XP-EHH showing that both methods target similar selective sweep regions. Average genetic differences measured by [Formula: see text] are low between gradients, but XP-EHH signals are the strongest between agroecologies. Genes in the calcium signalling pathway, those associated with the hypoxia-inducible factor (HIF) transcription factors, and sports performance (GALNTL6) are under selection in high-altitude populations. Our study underscores the relevance of landscape genomics as a powerful interdisciplinary approach to dissect adaptive phenotypic and genetic variation in random mating indigenous livestock populations.

Preliminary snapshot reveals a relationship between multidrug-resistance and biofilm production among enterobacteriaceae isolated from fecal samples of farm-raised poultry in ceará, Brazil.

Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for ß-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of ß-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC ß-lactamase and extended-spectrum ß-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer.

Effects of in ovo injection of bacterial peptides and CpG-ODN on Salmonella enterica serovar Heidelberg infection in specific pathogen-free (SPF) chicks.

RESEARCH HIGHLIGHTS: Peptides + CpG-ODN reduced SH in caeca at the first week post-infection.Administered formulations did not reduce SH-faecal excretion.Levels of intestinal IgA were similar between all groups.CpG-ODN improved some parameters associated with chick intestinal health.

Exploratory study for implementing a Global Burden of Animal Diseases case study in Senegal. / Etude exploratoire pour la mise en oeuvre d'une étude de cas du programme " Impact mondial des maladies animales " au Sénégal.

Senegal is a West African country with both extensive animal production systems, representative of the environmental, economic and animal health constraints specific to the Sahel region, and thriving commercial poultry and dairy production. An exploratory study was conducted in Senegal between 2021 and 2022 as a prelude to a case study of the Global Burden of Animal Diseases (GBADs) programme. An overview of existing animal production systems as well as the main priorities and issues in animal health on a national level was developed. A national workshop gathering representatives from the livestock production and academic sectors took place in Dakar in June 2022 with the objective of jointly developing a case study. The participants prioritised pastoralist production systems for cattle and agropastoral systems for small ruminants for the application of the GBADs programme. Through a series of activities, the participants highlighted the health, environmental, economic and socio-political challenges surrounding these systems, all of which limit their contribution to the well-being of pastoralist households, consumers and other stakeholders. While Senegal has in the past hosted a large number of research and cooperative projects on these two livestock systems, participants noted difficulties in obtaining, centralising and harmonising the existing data. This exploratory study led to the funding of a focused case study of the agropastoral small-ruminant sector that was carried out in 2023 in partnership with national and international organisations.

Le Sénégal est un pays d'Afrique de l'Ouest comprenant à la fois des systèmes de production animale extensifs représentatifs des contraintes environnementales, économiques et sanitaires propres à la zone sahélienne, et un élevage commercial avicole et laitier en plein essor. Une étude exploratoire en prélude à une étude de cas du programme " Impact mondial des maladies animales " (GBADs) a été menée au Sénégal sur la période 2021-2022. Un état des lieux des systèmes de production animale existants, ainsi que des principales priorités et questions en termes de santé animale au niveau national, a été dressé. Un atelier national rassemblant des représentants de l'administration des productions animales et du secteur académique a eu lieu à Dakar en juin 2022 avec pour objectif de construire l'étude de cas de manière concertée. Les participants ont donné la priorité aux systèmes d'élevage bovins pastoral et petits ruminants agropastoral pour l'application du programme GBADs. Par une série d'activités, les participants ont mis en évidence les enjeux sanitaires, environnementaux, économiques et socio-politiques autour de ces systèmes qui limitent leur contribution au bien-être des ménages d'éleveurs, de consommateurs et autres acteurs de la société. Si le Sénégal a accueilli par le passé un grand nombre de projets de recherche et de coopération portant sur les deux systèmes d'élevage, les participants ont fait remonter les difficultés à obtenir, centraliser et harmoniser les données existantes. Cette étude exploratoire a débouché sur le financement d'une étude de cas focalisée sur le secteur agropastoral des petits ruminants, réalisée en 2023 en partenariat avec des organisations nationales et internationales.

Senegal es un país de África occidental con sistemas de producción animal extensivos, representativos de las limitaciones ambientales, económicas y zoosanitarias propias de la región del Sahel, y una próspera producción comercial avícola y lechera. Entre 2021 y 2022, se llevó a cabo en Senegal un estudio exploratorio como paso previo a la realización de un estudio de caso en el marco del programa sobre el impacto global de las enfermedades animales (GBADs). Se elaboró una reseña de los sistemas de producción animal existentes, así como de las principales prioridades y cuestiones en materia de sanidad animal a escala nacional. En junio de 2022, se celebró en Dakar un taller nacional que reunió a representantes del sector de la producción ganadera y el sector académico con el objetivo de elaborar conjuntamente un estudio de caso. Los participantes priorizaron los sistemas de producción pastoral de ganado vacuno y los sistemas agropastorales de pequeños rumiantes para la aplicación del programa GBADs. A través de una serie de actividades, los participantes pusieron de relieve los retos sanitarios, ambientales, económicos y sociopolíticos en torno a dichos sistemas, que limitan su contribución al bienestar de los hogares pastorales, los consumidores y otras partes interesadas. Aunque Senegal ha acogido en el pasado un gran número de proyectos de investigación y cooperación sobre estos dos sistemas ganaderos, los participantes señalaron las dificultades para obtener, centralizar y armonizar los datos existentes. Este estudio exploratorio condujo a la financiación de un estudio de caso centrado en el sector agropastoril de pequeños rumiantes que se llevó a cabo en 2023 en colaboración con organizaciones nacionales e internacionales.

Meta-analysis to predict the effects of probiotics on meat quality of broiler.

The demand for chicken meat has surged globally due to its status as a primary protein source in human diets. However, ensuring high-quality meat products has become an increasingly important subject to consumers. In this study, 21 articles from PubMed and Web of Science databases published between 2005 and 2023 were examined to assess the influence of probiotic supplementation on broiler meat quality. The meta-analysis revealed significant findings across various meat quality parameters. Specifically, probiotics were found to significantly affect meat colour parameters, including redness, yellowness, and lightness, in both breast and thigh meat samples. Moreover, significant differences were observed in parameters such as water-holding capacity (p < 0.001), cook loss (p = 0.047), and shear force (p = 0.025) between control and probiotic groups. However, it's essential to note the considerable heterogeneity among the studies, emphasising the need for a cautious interpretation of the results. Despite this variability, the study underscores the potential of probiotics to positively influence broiler meat quality, highlighting avenues for further research and standardisation in poultry production practices. These findings also contribute to a better understanding of probiotics' role in improving meat quality and meeting consumer preferences for nutritious and high-quality poultry products.

Strategies to combat heat stress in poultry production-A review.

The effects of heat stress (HS) caused by high temperatures continue to be a global concern in poultry production. Poultry birds are homoeothermic, however, modern-day chickens are highly susceptible to HS due to their inefficiency in dissipating heat from their body due to the lack of sweat glands. During HS, the heat load is higher than the chickens' ability to regulate it. This can disturb normal physiological functioning, affect metabolism and cause behavioural changes, respiratory alkalosis and immune dysregulation in birds. These adverse effects cause gut dysbiosis and, therefore, reduce nutrient absorption and energy metabolism. This consequently reduces production performances and causes economic losses. Several strategies have been explored to combat the effects of HS. These include environmentally controlled houses, provision of clean cold water, low stocking density, supplementation of appropriate feed additives, dual and restricted feeding regimes, early heat conditioning and genetic selection of poultry lines to produce heat-resistant birds. Despite all these efforts, HS still remains a challenge in the poultry sector. Therefore, there is a need to explore effective strategies to address this long-lasting problem. The most recent strategy to ameliorate HS in poultry is early perinatal programming using the in ovo technology. Such an approach seems particularly justified in broilers because chick embryo development (21 days) equals half of the chickens' posthatch lifespan (42 days). As such, this strategy is expected to be more efficient and cost-effective to mitigate the effects of HS on poultry and improve the performance and health of birds. Therefore, this review discusses the impact of HS on poultry, the advantages and limitations of the different strategies. Finally recommend a promising strategy that could be efficient in ameliorating the adverse effects of HS in poultry.

Chicken Production and Human Clinical Escherichia coli Isolates Differ in Their Carriage of Antimicrobial Resistance and Virulence Factors.

Contamination of food animal products by Escherichia coli is a leading cause of foodborne disease outbreaks, hospitalizations, and deaths in humans. Chicken is the most consumed meat both in the United States and across the globe according to the U.S. Department of Agriculture. Although E. coli is a ubiquitous commensal bacterium of the guts of humans and animals, its ability to acquire antimicrobial resistance (AMR) genes and virulence factors (VFs) can lead to the emergence of pathogenic strains that are resistant to critically important antibiotics. Thus, it is important to identify the genetic factors that contribute to the virulence and AMR of E. coli. In this study, we performed in-depth genomic evaluation of AMR genes and VFs of E. coli genomes available through the National Antimicrobial Resistance Monitoring System GenomeTrackr database. Our objective was to determine the genetic relatedness of chicken production isolates and human clinical isolates. To achieve this aim, we first developed a massively parallel analytical pipeline (Reads2Resistome) to accurately characterize the resistome of each E. coli genome, including the AMR genes and VFs harbored. We used random forests and hierarchical clustering to show that AMR genes and VFs are sufficient to classify isolates into different pathogenic phylogroups and host origin. We found that the presence of key type III secretion system and AMR genes differentiated human clinical isolates from chicken production isolates. These results further improve our understanding of the interconnected role AMR genes and VFs play in shaping the evolution of pathogenic E. coli strains. IMPORTANCE Pathogenic Escherichia coli causes disease in both humans and food-producing animals. E. coli pathogenesis is dependent on a repertoire of virulence factors and antimicrobial resistance genes. Food-borne outbreaks are highly associated with the consumption of undercooked and contaminated food products. This association highlights the need to understand the genetic factors that make E. coli virulent and pathogenic in humans and poultry. This research shows that E. coli isolates originating from human clinical settings and chicken production harbor different antimicrobial resistance genes and virulence factors that can be used to classify them into phylogroups and host origins. In addition, to aid in the repeatability and reproducibility of the results presented in this study, we have made a public repository of the Reads2Resistome pipeline and have provided the accession numbers associated with the E. coli genomes analyzed.

Quantitative assessment of Campylobacter spp. levels with real-time PCR methods at different stages of the broiler food chain.

The importance of thermotolerant Campylobacter spp. as a food-borne pathogen continues to increase and there is a great need for rapid quantitative results in routine diagnostics. However, currently, only the culture-based ISO method is authorized for use in the context of official food control. The present study therefore aimed to assess the suitability of a qPCR method for a rapid quantitative determination of Campylobacter spp. at different stages in the poultry production chain and its equivalence with the culture-based method. Samples from two processors were collected and evaluated both separately and together. Censored regression (Tobit) models have been used to establish a relationship between Campylobacter qPCR counts on the carcasses and explanatory variables of processor and meat counts. Further, correlations of qPCR Campylobacter spp. counts at the different stages of production were calculated. In addition, the comparative data between microbiological enumeration and qPCR results were statistically analyzed. In the correlation calculation of the qPCR results, a highly significant relationship between the Campylobacter spp. counts of the neck skin samples to breast fillet and leg samples could be calculated, indicating a good prediction of Campylobacter spp. loads in these samples. The intercalating dye ethidium monoazide (EMA) was used to see whether the correlations between microbiological counts and qPCR results were improved by pretreating fecal and cecal samples before qPCR analysis. It was shown that the observed values of scatter plots between the qPCR-based and the culture-based methods were strongly correlated. However, on average, the qPCR results were two log10 CFU/mL levels higher than the microbiological counts. However, the classical culture-based method for food hygiene risk assessment cannot be replaced one-to-one by the qPCR or EMA-qPCR. The qPCR method can rather be used for the rapid identification of particularly highly contaminated flocks.

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.

Impact of a Homestead Food Production program on poultry rearing and egg consumption: A cluster-randomized controlled trial in Bangladesh.

Women and children in Bangladesh face high levels of micronutrient deficiencies from inadequate diets. We evaluated the impact of a Homestead Food Production (HFP) intervention on poultry production, as a pathway outcome, and women's and children's egg consumption, as secondary outcomes, as part of the Food and Agricultural Approaches to Reducing Malnutrition cluster-randomized trial in Sylhet division, Bangladesh. The 3-year intervention (2015-2018) promoted home gardening, poultry rearing, and nutrition counseling. We randomly allocated 96 clusters to intervention (48 clusters; 1337 women) or control (48 clusters; 1368 women). Children < 3 years old born to participants were enrolled during the trial. We analyzed poultry production indicators, measured annually, and any egg consumption (24-h recall), measured every 2-6 months for women and their children. We conducted intention-to-treat analyses using mixed-effects logistic regression models with repeat measures, with minimal adjustment to increase precision. Poultry ownership increased by 16% points (pp) and egg production by 13 pp in the final intervention year. The intervention doubled women's odds of egg consumption in the final year (Odds Ratio [OR]: 2.31, 95% CI: 1.68-3.18), with positive effects sustained 1-year post-intervention (OR: 1.58, 95% CI: 1.16-2.15). Children's odds of egg consumption were increased in the final year (OR: 3.04, 95% CI: 1.87-4.95). Poultry ownership was associated with women's egg consumption, accounting for 12% of the total intervention effect, but not with children's egg consumption. Our findings demonstrate that an HFP program can have longer-term positive effects on poultry production and women's and children's diets.

Increased Microbial Diversity and Decreased Prevalence of Common Pathogens in the Gut Microbiomes of Wild Turkeys Compared to Domestic Turkeys.

Turkeys (Meleagris gallopavo) provide a globally important source of protein and constitute the second most important source of poultry meat in the world. Bacterial diseases are common in commercial poultry production, causing significant production losses for farmers. Due to the increasingly recognized problems associated with large-scale/indiscriminate antibiotic use in agricultural settings, poultry producers need alternative methods to control common bacterial pathogens. In this study, we compared the cecal microbiota of wild and domestic turkeys, hypothesizing that environmental pressures faced by wild birds may select for a disease-resistant microbial community. Sequence analyses of 16S rRNA genes amplified from cecal samples indicate that free-roaming wild turkeys carry a rich and variable microbiota compared to domestic turkeys raised on large-scale poultry farms. Wild turkeys also had very low levels of Staphylococcus, Salmonella, and Escherichia coli compared to domestic turkeys. E. coli strains isolated from wild and domestic turkey cecal samples also belong to distinct phylogenetic backgrounds and differ in their propensity to carry virulence genes. E. coli strains isolated from factory-raised turkeys were far more likely to carry genes for capsule (kpsII and kpsIII) or siderophore (iroN and fyuA) synthesis than were those isolated from wild turkeys. These results suggest that the microbiota of wild turkeys may provide colonization resistance against common poultry pathogens. IMPORTANCE Due to the increasingly recognized problems associated with antibiotic use in agricultural settings, poultry producers need alternative methods to control common bacterial pathogens. In this study, we compare the microbiota of wild and domestic turkeys. The results suggest that free-ranging wild turkeys carry a distinct microbiome compared to farm-raised turkeys. The microbiome of wild birds contains very low levels of poultry pathogens compared to that of farm-raised birds. The microbiomes of wild turkeys may be used to guide the development of new ways to control disease in large-scale poultry production.

Fast and Non-Destructive Quail Egg Freshness Assessment Using a Thermal Camera and Deep Learning-Based Air Cell Detection Algorithms for the Revalidation of the Expiration Date of Eggs.

Freshness is one of the most important parameters for assessing the quality of avian eggs. Available techniques to estimate the degradation of albumen and enlargement of the air cell are either destructive or not suitable for high-throughput applications. The aim of this research was to introduce a new approach to evaluate the air cell of quail eggs for freshness assessment as a fast, noninvasive, and nondestructive method. A new methodology was proposed by using a thermal microcamera and deep learning object detection algorithms. To evaluate the new method, we stored 174 quail eggs and collected thermal images 30, 50, and 60 days after the labeled expiration date. These data, 522 in total, were expanded to 3610 by image augmentation techniques and then split into training and validation samples to produce models of the deep learning algorithms, referred to as "You Only Look Once" version 4 and 5 (YOLOv4 and YOLOv5) and EfficientDet. We tested the models in a new dataset composed of 60 eggs that were kept for 15 days after the labeled expiration label date. The validation of our methodology was performed by measuring the air cell area highlighted in the thermal images at the pixel level; thus, we compared the difference in the weight of eggs between the first day of storage and after 10 days under accelerated aging conditions. The statistical significance showed that the two variables (air cell and weight) were negatively correlated (R2 = 0.676). The deep learning models could predict freshness with F1 scores of 0.69, 0.89, and 0.86 for the YOLOv4, YOLOv5, and EfficientDet models, respectively. The new methodology for freshness assessment demonstrated that the best model reclassified 48.33% of our testing dataset. Therefore, those expired eggs could have their expiration date extended for another 2 weeks from the original label date.

Performance evaluation of the parents of the improved backyard poultry germplasm in sub-tropical condition of North Eastern Hill Region of India.

Productivity of traditional backyard poultry in developing countries can be enhanced by introduction of improved germplasm of backyard chicken which is adaptable to diverse ago-climatic condition. The growth and reproductive performance of parents of improved backyard chicken (Vanaraja and Srinidhi) were evaluated under intensive production system in humid sub-tropical region of North East India. We also evaluated the growth performance and mortality in terminal crosses of above parents until 6 weeks of age. At day 0 and at 25 weeks of age, body weight of Srinidhi male parent was significantly (P<0.05) higher than Vanaraja male parent. During brooding stage, mortality was 15.7% in Srinidhi male parent, 14.5% in Vanaraja male parent, 13.9% in Srinidhi female parent, and 8% in Vanaraja female parent. Hen-day egg production (HDEP) of Vanaraja female parent varied from 0.2 at 25 weeks to 54.9% at 54th weeks of age. In Srinidhi female parent, HDEP reached 60% at 35 weeks and peaked 63.9% at 39 weeks of age. Srinidhi female parent has significantly (P<0.05) lower age at first lay. Average annual egg production was significantly (P<0.05) higher in Srinidhi female parent (202 eggs vs. 137 eggs). Egg weight at 25, 30, 35, 40, 45, and 50 week of age was significantly (P<0.05) higher in Vanaraja female parent. Egg shape index and yolk index at 40 weeks of age were significantly (P<0.05) higher in Srinidhi female parent. Fertility of Vanaraja female parent was significantly (P<0.05) lower in winter. In case of Srinidhi female parent, fertility was significantly higher (P<0.05) in winter as compared to summer. In case of terminal crosses, body weight at 6 weeks of age was significantly (P<0.05) higher in Vanaraja as compared to Srinidhi. Cumulative mortality during brooding phase was 9.2 per cent in Vanaraja and 9.6 per cent in Srinidhi. In conclusion, parents of Vanaraja and Srinidhi are suitable and well-adapted birds in humid sub-tropical condition of North East India. These birds could be introduced in the region on large scale for up-scaling of traditional backyard poultry.

A retrospective study of Newcastle disease in Kenya.

Newcastle disease (ND) is a major constraint to Kenya's poultry production, which is comprised of approximately 80% indigenous chickens (ICs; caged and free-range system) and 20% exotic chickens (intensive system). This study analyzed cases reported as suspected ND in Kenya between 2005 and 2015. Of the suspected 332 ND reported cases from the three production systems in 27 locations within six Kenyan Agro-Ecological Zones (AEZs), 140 diagnosed as infected with avian orthoavulavirus 1 (AOaV-1; formerly Newcastle disease virus) were present in every year in all AEZs. The numbers of AOaV-1-positive cases differed significantly (p < 0.05) between the production systems across the years depending on the season, climate, and location. In the free-range system, both ambient temperatures and season associated significantly (p = 0.001 and 0.02, respectively) with the number of cases, while in the intensive and caged systems, the positive cases correlated significantly with season and relative humidity, respectively (p = 0.05). Regardless of the production systems, the numbers of clinically sick birds positively correlated with the ambient temperatures (r = 0.6; p < 0.05). Failure to detect AOaV-1 in 58% of the ND cases reported, and mortalities exceeding the observed numbers of clinically sick birds suggest deficiencies in the current ND reporting and diagnostic system. Intensive farmers were the slowest in reporting the cases and diagnostic deficiencies were most evident by failure to test the exposure of ICs to natural infection with AOaV-1 and for the AOaV-1-negative cases lack of testing for other pathogens and/or AOaV-1 variants. This study indicates a need for improved surveillance and diagnostics in Kenyan domestic poultry.

Poultry population dynamics and mortality risks in smallholder farms of the Mekong river delta region.

BACKGROUND: Poultry farming is widely practiced by rural households in Vietnam and the vast majority of domestic birds are kept on small household farms. However, smallholder poultry production is constrained by several issues such as infectious diseases, including avian influenza viruses whose circulation remains a threat to public health. This observational study describes the demographic structure and dynamics of small-scale poultry farms of the Mekong river delta region. METHOD: Fifty three farms were monitored over a 20-month period, with farm sizes, species, age, arrival/departure of poultry, and farm management practices recorded monthly. RESULTS: Median flock population sizes were 16 for chickens (IQR: 10-40), 32 for ducks (IQR: 18-101) and 11 for Muscovy ducks (IQR: 7-18); farm size distributions for the three species were heavily right-skewed. Muscovy ducks were kept for long periods and outdoors, while chickens and ducks were farmed indoors or in pens. Ducks had a markedly higher removal rate (broilers: 0.14/week; layer/breeders: 0.05/week) than chickens and Muscovy ducks (broilers: 0.07/week; layer/breeders: 0.01-0.02/week) and a higher degree of specialization resulting in a substantially shorter life span. The rate of mortality due to disease did not differ much among species, with birds being less likely to die from disease at older ages, but frequency of disease symptoms differed by species. Time series of disease-associated mortality were correlated with population size for Muscovy ducks (Kendall's coefficient τ = 0.49, p-value < 0.01) and with frequency of outdoor grazing for ducks (τ = 0.33, p-value = 0.05). CONCLUSION: The study highlights some challenges to disease control in small-scale multispecies poultry farms. The rate of interspecific contact and overlap between flocks of different ages is high, making small-scale farms a suitable environment for pathogens circulation. Muscovy ducks are farmed outdoors with little investment in biosecurity and few inter-farm movements. Ducks and chickens are more at-risk of introduction of pathogens through movements of birds from one farm to another. Ducks are farmed in large flocks with high turnover and, as a result, are more vulnerable to disease spread and require a higher vaccination coverage to maintain herd immunity.

Impact of exposure time to harsh environments on physiology, mortality, and thermal comfort of day-old chickens in a simulated condition of transport.

The aim of this study was to assess the variation of physiological responses and mortality of day-old chicks subjected to different thermal conditions and exposure times during simulated transport. For this purpose, day-old chicks (n = 900) were used and subjected to simulated conditions of transport in a climate chamber. The experimental design was a completely randomized block design, with the structure of the treatments in a 3 × 3 factorial scheme (thermal ranges and time intervals) and each level of containers considered a block. The physiological variables used in this trial were body weight, respiratory rate, cloacal temperature, average surface temperature, and gene expression of heat shock protein (HSP70). Regarding body weight, a small variation was observed between treatments (P > 0.05). The animals subjected to the heat treatment exhibited respiratory rates above 100 movements per minute (P < 0.05), average cloacal temperatures above 44.7 °C, surface temperatures above the comfort zone (greater than 39.6 °C; P < 0.05), and increased gene expression of HSP70 (P < 0.001), especially after 3 initial hours of exposure. In addition, the heat treatment lead to increased mortality of the animals (over 6%). Also in the cold treatment, despite the absence of mortality, the animals showed hypothermia from 3 h of exposure, based on the results of the average surface (28 °C) and cloacal temperatures (39.6 °C; P < 0.05). In this way, the results imply that the effects of thermal stress caused by heat as well as by cold in a simulated transport condition are increased when traveling for more than 3 h, indicating a trend of rising mortality after long-term transportation of day-old chickens.

Relation between changes in organic matter structure of poultry litter and heavy metals solubility during composting.

Poultry litter (PL) is widely used as fertilizer because of its rich N, P and Ca content. When PL is applied to previously untreated soil, it is a potential contaminant. Composting is an alternative for stabilizing organic and mineral components. This study aimed to elucidate the structural changes and its influence on the solubility of heavy metals in poultry litter during the first 30 d of composting, which is the period when the most intense transformations occur. For this analysis, the transformation dynamics of the organic structures and the availability of mineral elements were studied via spectroscopic characterization, total heavy metal content determination and chemical fractionation at three composting times (0, 15, and 30 d). During composting, the material's aromaticity increased, while its aliphaticity decreased, and the hydrophobicity index increased as the polarity decreased. These results indicate that during the first 30 d, PL composting occurs via transformation of the most labile structures (carbohydrate, peptide and fatty acid fragments), thereby preserving the most stable and least functionalized structures. Composting increased the concentrations of Cu, Cr, Pb and Zn and the transformation of CAlk-O and CAlk-di-O associated with peptides and carbohydrates and favored solubilizing and leaching a water-soluble fraction rich in these compounds. The labile fractions of Fe and the humified organic matter fractions of Cu, Fe, Mn, Zn, and Al increased. The structural changes reduced heavy metal solubility, thus indicating that after 30 d of composting, the heavy metal contamination risk is low.

Impact of Prebiotics on Poultry Production and Food Safety.

With the phasing out of routine use of antibiotics in animal agriculture, interest has grown for the need to develop feed supplements that augment commercial poultry performance and provide food safety benefits. From a food safety perspective, alternative feed supplements can be broadly categorized as either agents which reduce or eliminate already colonized foodborne pathogens or prevent colonization of incoming pathogens. Prebiotics are considered preventative agents since they select for gastrointestinal microbiota which not only benefits the host but can serve as a barrier to pathogen colonization. In poultry, prebiotics can elicit both indirect effects on the bird by shifting the composition and fermentation patterns of the gastrointestinal microbiota or directly by influencing host systems such as immune responses. Generation of short chain fatty acids is believed to be a primary inhibitory mechanism against pathogens when prebiotics are fermented by gastrointestinal bacteria, but other mechanisms such as interference with attachment can occur as well. While most of the impact of the prebiotic is believed to occur in the lower parts of the bird gastrointestinal tract, particularly the ceca, it is possible that some microbial hydrolysis could occur in upper sections such as the crop. Development of next generation sequencing has increased the resolution of identifying gastrointestinal organisms that are involved in metabolism of prebiotics either directly or indirectly. Novel sources of non-digestible oligosaccharides such as cereal grain brans are being explored for potential use in poultry to limit Salmonella establishment. This review will cover the current applications and prospects for use of prebiotics in poultry to improve performance and limit pathogens in the gastrointestinal tract.

Implementing small-scale poultry-for-nutrition projects: Successes and lessons learned.

This paper examines Helen Keller International's model for nutrition-sensitive poultry production using a programme implemented in four diverse African contexts-three rural and one urban. Consecutive cross-sectional surveys conducted every 5 months among ~15% of participating households show that despite project-provided training and inputs, there was only limited uptake of many "best practices." Few households constructed improved henhouses; vaccination rates varied and were highest when support was provided. Poultry mortality was high. Egg productivity remained average for village poultry systems, and egg consumption remained low (two to six eggs consumed per household per fortnight). However, children whose mothers were exposed to project messages on nutrition were more likely to eat eggs, and consumption was consistently higher among households with chickens. Women's involvement in chicken rearing was widespread, but their control over revenues from the sale of poultry products was limited. Key lessons learned from implementation were as follows: (a) strong behaviour change communication is needed to encourage egg consumption, (b) nutrition-sensitive village poultry programmes should often focus more on improved practices than improved breeds, (c) supporting women's chicken production is not a route to empowerment without complementary activities that directly support women's ownership and decision making. There is also a need for rigorous research on the role of village poultry in livelihoods, food systems, and consumption as well as the structure of poultry and egg markets in low-resource areas.

Altered development, oxidative stress and DNA damage in Leptodactylus chaquensis (Anura: Leptodactylidae) larvae exposed to poultry litter.

Poultry litter (PL), which is usually used as organic fertilizer, is a source of nutrients, metals, veterinary pharmaceuticals and bacterial pathogens, which, through runoff, may end up in the nearest aquatic ecosystems. In this study, Leptodactylus chaquensis at different development stages (eggs, larval stages 28 and 31 here referred to as stages I, II and III respectively) were exposed to PL test sediments as follows: 6.25% (T1), 12.5% (T2); 25% (T3); 50% (T4); 75% (T5); 100% PL (T6) and to dechlorinated water as control. Larval survival, development endpoints (growth rate -GR-, development rate -DR-, abnormalities), antioxidant enzyme activities (Catalase -CAT- and Glutathione-S-Transferase -GST-), and genotoxic effect (DNA damage index by the Comet assay) were analyzed at different times. In stage I, no egg eclosion was observed in treatments T3-T6, and 50% of embryo mortality was recorded after 24h of exposure to T2. In stages II and III, mortality in treatments T3-T6 reached 100% between 24 and 48h. In the three development stages evaluated, the DR and GR were higher in controls than in PL treatments (T1, T2), except for those T1-treated larvae of stage II. Larvae of stage I showed five types of morphological abnormalities, being diamond body shape and lateral displacement of the intestine the most prevalent in T1, whereas larvae of stages II and III presented lower prevalence of abnormalities. In stage I, CAT activity was similar to that of control (p>0.05), whereas it was higher in T1- and T2- treated larvae of stages II and III than controls (p<0.05). In stages I and III, GST activity was similar to that of controls (p>0.05), whereas it was inhibited in T1-treated larvae of stage II (p<0.05). T1- and T2-treated larvae of stages II and III caused higher DNA damage respect to controls (p<0.05), varying from medium to severe damage (comet types II, III and IV). These results showed that PL treatments altered development and growth and induced oxidative stress and DNA damage, resulting ecotoxic for L. chaquensis larvae.