Brazilian Poultry Production Research Articles

Avian influenza and the Brazilian poultry production: Current situation and prevention strategies

Highly Pathogenic Avian Influenza (HPAI) presents a significant threat to global poultry, affecting trade and consumer trust. This analysis focuses on Brazil's preventive measures against HPAI to uphold its disease-free status recognized by the World Organization for Animal Health (WOAH). As of September 19th, 2023, Brazil confirmed 106 HPAI outbreaks, primarily in wild birds, with a few in backyard chickens. Despite most incidents occurring along the coast, a notable outbreak in Bonito-MS underlines the necessity for ongoing vigilance in key poultry regions. Brazil's HPAI prevention framework, initiated with the 1994 National Poultry Health Plan, has continually evolved. High biosecurity measures are emphasized in stringent regulations, surveillance, and rapid response strategies. The nation's vertically integrated poultry model supports centralized control, traceability, and consistent quality, fostering swift corrective actions and biosecurity guidelines. The private sector's commitment complements these efforts, often exceeding government regulations with rigorous biosecurity practices, highlighting Brazil's holistic approach to safeguarding its poultry sector from HPAI threats.

Avian influenza and Brazilian poultry production – Current situation and prevention strategies. Proceeding of The First International Avian Influenza Summit, University of Arkansas- October 16-17, 2023"

Highly Pathogenic Avian Influenza (HPAI), particularly caused by the influenza virus A genus, is a paramount concern for global poultry health. The strains associated with HPAI are known to precipitate mortality rates exceeding 90\%. Beyond the immediate and catastrophic impact on poultry, the emergence of HPAI strains disrupts international poultry trade, leading countries to impose trade bans and shake consumer confidence. By September 19th, 2023, Brazil had reported 106 confirmed outbreaks of HPAI. Most of these incidents were linked to wild birds, totaling 103 cases, while backyard chickens accounted for the remaining three. Notably, most of these outbreaks are situated in coastal regions. However, an exception that demanded attention was the HPAI detection in backyard chickens in Bonito, Mato Grosso do Sul. State-wise analysis reveals differential prevalence patterns. São Paulo and Rio Grande do Sul have documented cases far from their primary poultry hubs. In juxtaposition, Espírito Santo's proximity to the outbreak areas heightens its risk profile. The southern broiler-producing regions, which account for a significant 64\% of Brazil's total production and a whopping 79\% of exports, currently face diminished immediate threats due to their inland geographies. Nevertheless, the episode in Bonito-MS underscores the escalating risks even in regions previously considered low-threat and amplifies the call for perpetual vigilance. Brazil's approach to HPAI defense is structured and well-planned, not a result of hasty improvisation or last-minute measures. It's a result of a long-standing commitment and rigorous planning. The country's legal framework for HPAI prevention has evolved since the 1994 introduction of the National Poultry Health Plan. Successive years saw further tightening of regulations, climaxing with the 2013 National Contingency Plan for Avian Influenza, which underwent revision in 2023. Brazil’s strategy to ward off HPAI is deeply rooted in stringent biosecurity measures. Farms are mandated to erect physical barriers, strictly regulate vehicular and human movement, and uphold rigorous cleaning and disinfection standards. Farm personnel are also trained in and adhere to meticulous personal hygiene protocols. Simultaneously, comprehensive waste management practices are firmly in place. Additionally, the Brazilian government plays a proactive role. Border surveillance, active monitoring of avian populations, and the deployment of passive surveillance within commercial flocks manifest the government's unwavering dedication to the poultry sector. One of Brazil's trump cards against diseases like HPAI is its vertically integrated poultry production model. This modus operandi permits companies and cooperatives to oversee every production stage. Such centralized oversight minimizes financial risks, guarantees consistent quality, and facilitates the swift roll-out of biosecurity directives. Traceability, a cornerstone for rapid disease containment, is inherently assured in this system. The private sector in Brazil not only meets governmental biosecurity standards but frequently surpasses them. It's common to see the integration of extended quarantine durations, intensified disinfection routines, and stringent farm access controls. The commitment to a tiered biosecurity mechanism across diverse poultry production stages is a testament to the industry's intent to ensure a holistic health foundation. Brazil's comprehensive and adaptive approach to HPAI is commendable. The country's strategic alignment between governmental regulations and private sector commitment, especially in the face of recent outbreaks, underscores Brazil's unwavering focus on safeguarding its poultry industry. While the road ahead demands continuous vigilance, Brazil's current strategies and learnings provide valuable insights for global stakeholders.

Extraembryonic membrane morphology in greater rheas (Rhea americana americana Linnaeus, 1758).

The greater rhea, Rhea americana, is a wild ratite of high scientific importance and significant and zootechnical value, especially considering the current development state of Brazilian poultry production, where research aimed at increasing the productivity of these animals has become extremely relevant. Studies concerning fetal attachments and embryonic development are paramount, as they can provide essential information concerning reproductive and nutritional animal management. However, a lack of information on greater rhea fetal morphology is noted. Therefore, the aim of the present study was to establish a standard model for fetal attachments in this species. Greater rhea eggs were incubated from 0 to 36days, and macroscopic and microscopic embryonic attachment characterizations were performed. Histologically, all embryonic annexes exhibit germ layers, namely the ectoderm (outer layer), mesoderm (middle layer) and endoderm (inner layer). The findings indicate that greater rhea development patterns are similar to other birds.

High prevalence of intermediate resistance to ciprofloxacin in Salmonella enterica isolated from a Brazilian poultry production chain, located in Minas Gerais state

We characterized the distribution and diversity of antimicrobial-resistance Salmonella enterica isolated from a poultry production chain in Minas Gerais, Brazil, with special attention to ciprofloxacin and multidrug resistance (MDR). S. enterica (n = 96) of different serotypes and from different processing steps were subjected to broth dilution assay to estimate the minimum inhibitory concentration (MIC) for 12 antibiotics (8 classes) and screened using PCR for the presence of 17 antimicrobial-resistance genes. Isolates presented mainly resistance to ampicillin (11/96), and most presented intermediate resistance to ciprofloxacin (92/96). Roughly one-third (33/96) were resistant to streptomycin based on our interpretive criteria. Most strains resistant to streptomycin and ciprofloxacin were PCR-positive for aphA (51/96) and qnrB (94/96), respectively. Ciprofloxacin resistance was further investigated through high-resolution melting qPCR (HRM-qPCR) and sequencing of quinolone resistance-determining region (QRDR: gyrA, gyrB, parC, and parE). Minor differences were identified in melting temperatures (Tm), and a Thr57Sr mutation was observed in parC. MDR isolates harboring acrA and capable of expressing the AcrAB-TolC multidrug efflux pump were resistant to ethidium bromide at 0.4 mg/mL. The intermediate resistance to ciprofloxacin may be associated with qnrB, and the potential role of Thr57Ser mutation warrants further investigation. The high prevalence of antibiotic related genes and its association with the observed intermediary resistance to ciprofloxacin indicates the widespread of this hazard in the studied poultry production chain.

Effect of Ammonia Gas in Poultry Litter Contaminated with Salmonella Heidelberg

Salmonella Heidelberg is an emerging pathogen in Brazilian poultry production. The traditional methods (quicklime, windrowing and tarpaulin-on-surface) used for disinfecting reused poultry litter between flocks does not guarantee its elimination, thus allowing the transmission of this agent from one flock to another. The new tarpaulin-on-surface method with controlled injection of ammonia gas has proven to be effective in its control, however, it is still unknown what dose of ammonia gas is needed to eliminate Salmonella Heidelberg in reused poultry litter. The objective of this study was to evaluate the effect of ammonia gas at different concentrations in sterile poultry litter artificially contaminated with Salmonella Heidelberg. Then, ammonia gas was injected in concentrations of 0.25%, 0.5%, and 1%, and 48 hours later, a sample was collected from each repetition in an entirely randomized design, and bacterial isolation was performed. All treatments, including positive and negative controls, were tested in quadruplicate and the parameters temperature, humidity, pH and water activity were evaluated. In the 0.5% and 1% treated samples the pathogen was not isolated, while in the 0.25% concentration one of the four samples tested was positive. The study reveals that ammonia gas is efficient in killing Salmonella Heidelberg in poultry litter at concentrations of 0.5 % or more within a 48-hour period and that the litter treated with ammonia gas increases its pH and water activity.

Emergence, Dissemination and Antimicrobial Resistance of the Main Poultry-Associated Salmonella Serovars in Brazil.

Simple SummarySalmonellosis is a human and animal disease caused by Salmonella, a bacterial genus classified into different species, subspecies, and serological variants (serovars) according to adaptation to one or more different hosts (animals and humans), pathogenicity profiles, and antigenic properties. Some specific Salmonella serovars can spread more easily in the enteric microbiota of avian species, often causing disease in birds and/or being transmitted to humans through food (such as chicken and eggs). Antimicrobial resistance (AMR) has also been reported in poultry-associated Salmonella isolates due to the widespread use of antimicrobials on farms. The availability of comprehensive data on the emergence and spread of Salmonella serovars, as well as their AMR profiles in farms and food products in Brazil (a major producer of poultry in the World), is necessary to understand their relevance in all avian production chains and also occurrence in poultry-derived foods. This article aims to provide an overview of the genus Salmonella and the main serovars that emerged in Brazilian poultry over time (Gallinarum, Typhimurium, Enteritidis, Heidelberg, and Minnesota), reviewing the scientific literature and suggesting more effective prevention and control for the future.Salmonella infects poultry, and it is also a human foodborne pathogen. This bacterial genus is classified into several serovars/lineages, some of them showing high antimicrobial resistance (AMR). The ease of Salmonella transmission in farms, slaughterhouses, and eggs industries has made controlling it a real challenge in the poultry-production chains. This review describes the emergence, dissemination, and AMR of the main Salmonella serovars and lineages detected in Brazilian poultry. It is reported that few serovars emerged and have been more widely disseminated in breeders, broilers, and layers in the last 70 years. Salmonella Gallinarum was the first to spread on the farms, remaining as a concerning poultry pathogen. Salmonella Typhimurium and Enteritidis were also largely detected in poultry and foods (eggs, chicken, turkey), being associated with several human foodborne outbreaks. Salmonella Heidelberg and Minnesota have been more widely spread in recent years, resulting in frequent chicken/turkey meat contamination. A few more serovars (Infantis, Newport, Hadar, Senftenberg, Schwarzengrund, and Mbandaka, among others) were also detected, but less frequently and usually in specific poultry-production regions. AMR has been identified in most isolates, highlighting multi-drug resistance in specific poultry lineages from the serovars Typhimurium, Heidelberg, and Minnesota. Epidemiological studies are necessary to trace and control this pathogen in Brazilian commercial poultry production chains.

Direct Detection and Quantification of Bacterial Pathogens from Broiler Cecal Samples in the Slaughter Line by Real-Time PCR

Chicken meat is an important source of foodborne pathogens, including Salmonella, Campylobacter, and Clostridium perfringens. These bacteria can occur in the intestinal microbiota of broilers and contaminate chicken carcasses in industrial meat processing. This study aimed to develop and evaluate a procedure based on real-time PCRs for the direct detection and quantification of these three bacteria in broilers’ ceca collected in poultry slaughter houses and demonstrate the occurrence of these important foodborne pathogens in Brazilian poultry production flocks. Cecal contents were collected from 45 different broiler flocks in three different slaughterhouses in the state of Paraná, Brazil, totaling 45 samples (in pools of 10 different ceca/chickens per broiler flock). Then, these samples were tested for the detection and quantification of Salmonella, Campylobacter, and Clostridium perfringens by real-time PCRs. The results demonstrated the occurrence of three (6.7%) positive pools for Salmonella, 20 (44.4%) for Campylobacter, and 32 (71.1%) for C. perfringens. Mean bacterial concentrations in the positive samples were 4.3log10 cells/g for Salmonella, 6.4 log10 cells/g for Campylobacter, and 5.5 log10 cells/g for C. perfringens. In conclusion, Salmonella, Campylobacter, and C. perfringens could be detected and quantified directly from the broilers cecal contents collected in the slaughter line. This procedure will be certainly useful to more quickly detect these foodborne pathogens and prevent their occurrence in chicken meat and other poultry food products.

Comprehensive characterization reveals antimicrobial-resistant and potentially virulent Campylobacter isolates from poultry meat products in Southern Brazil

The aim of this study was to perform a comprehensive characterization of 48 Campylobacter isolates obtained from broiler meat products in Southern Brazil, which had been previously typed by pulsed-field gel electrophoresis (PFGE). The antimicrobial resistance (AMR) profile and the presence of 30 virulence-associated genes (VAGs) were investigated. Six AMR patterns and 26 VAG patterns were found, indicating a great genetic diversity among the isolates. It is noteworthy that 79.2% of Campylobacter isolates were resistant to one or more antimicrobial agents, and MDR was found in 35.4%, being more prevalent in C. jejuni isolates. Data analysis for the combination of AMR and VAG profiles indicated that the antimicrobial resistance and virulence profile were not related to a particular species. The combination of the PFGE, AMR and VAG sets of data improved the discrimination power. In addition, the presence of antimicrobial-resistant Campylobacter isolates carrying virulence genes such as hcp (T6SS marker), cgtB and wlaN (LOS biosynthesis markers), among others, represents a potential emerging threat to public health. The findings also demonstrate the need for more rigorous control measures for Campylobacter in the Brazilian poultry production chain to avoid the dissemination of antimicrobial resistant and virulent Campylobacter isolates through the poultry meat.

Gastrointestinal Parasites in Free-Range Chicken Raised under Extensive System from the Northeast of Brazil

ABSTRACT Brazilian poultry production is growing, mainly due to the cost and benefit that chicken meat provides. The importance of free-range chickens and the susceptibility, to which they are exposed, makes it necessary to know about gastrointestinal parasites and the consequences that large infections can cause for them as such as weight loss. The present study aimed to determine the occurrence of gastrointestinal parasites in free-range hens raised in an extensive regime in the municipality of Santa Rita, state of Maranhao, Brazil. The studied population was composed of adult chickens (Gallus gallus domesticus) acquired from slaughterhouses in the region. The gastrointestinal organs of each chicken were separated and subsequently conditioned in flasks containing Railliet and Henry’s solution and sent to the laboratory, to be analyzed and processed. Of the 100 chickens examined, 227 specimens of helminthes were identified, with a frequency of 32.6% for nematodes and 67.4% for cestodes. Among the nematode the following parasites were identified: Ascaridia galli (27.03%); Heterakis gallinarum (48.65%) and Subulura spp. (24, 32%). Raillietina echinobothrida (100%) was the only cestoda identified. The average infection rate by species of parasite was 1.18 for A. galli, 2.22 for H. gallinarum, 1.06 for Subulura spp. and 9.00 for R. echinobothrida. It is concluded that free-range chickens are parasitized by nematodes and cestoda.

Genetic Similarities of Escherichia Coli Isolated from Different Substrates of the Broiler Production Chain

ABSTRACT Brazil is the largest exporter of chicken meat and poultry farming is one of the most important productive segments, despite major losses due to the bacterium Escherichia coli, which is also a zoonotic microorganism. The objetive of this study was to isolate E. coli and to evaluate its transmissibility potential from the field to chicken meat using the Pulsed Field Gel Electrophoresis (PFGE) technique. Environmental samples (poultry litter, soil and water) were collected from broiler farms located in the South of Brazil where the majority of the Brazilian poultry production occurs. In addition, chicken meat (gizzard, heart, drumette and tulip) samples were collected from local supermarkets. As results, 47.36% of the samples were positives for E. coli. Furthermore, 10 pairs of clones of E. coli were found always in the same substrate (two water-water pairs; three soil-soil pairs and five meat-meat pairs) using PFGE. These findings suggest that certain strains of E. coli may have habitat preferences, making the transfer from one substrate type to another more difficult to occur. Moreover, since no clones were found between environmental samples and chicken meat, it is possible to imply a low risk of E. coli transmissibility throughout the chicken meat production chain.

Characterization and control of biofilms of Salmonella Minnesota of poultry origin

Biofilms characterize sessile form that allows bacterial maintenance under hostile conditions. Salmonella represents an important foodborne zoonotic agent, capable of forming biofilms on diverse surfaces. The emergence of Salmonella Minnesota in the Brazilian poultry production expresses the need for more specific knowledge related to its maintenance in the environment and consequent food contamination, as well as control measures. Our approach combines the analysis of genetic determinants linked to biofilm formation and the phenotypic study of biomass on different surfaces, together with the determination of the effect of chemical agents on the control of sessile structure. It also evaluates the genetic similarity profile of 29 S. Minnesota strains isolated from food and environmental samples in two full-cycle poultry industries from 2009 to 2014. Genetic analysis showed low heterogeneity with the identification of six clonal groups, three clusters with homology greater than 80% and seven distinct genotypes. It was compatible with the presence of important genes in biofilm formation, with 28/29 (97.0%) presenting adrA and csgD and 27 (93.0%) presenting the luxS gene. Allied to this, 19/29 of the strains (66.0%) presented biomass that varied the intensity in weak (9/19–47.0%), moderate (6/19–32.0%) and strong (4/19–21.0%), with characteristic ultrastructure of a mature biofilm. Sodium hypochlorite showed greater efficiency in the control of sessile cells, even after incubation process. The study shows the presence of biofilm-producing S. Minnesota characterizing the problem of persistence in broiler slaughterhouses and indicates as a control strategy the use of sodium hypochlorite in an appropriate manner.

Identification of critical requirements for data recording of traceability in laying poultry: a study with farmers from the city of Bastos-SP

More demanding consumers pressure the food industry to attend the increasing demand for information. Traceability is a system that allows to gather information related to a product, from the beginning of its production chain to the moment of consumption. Data recording is the first stage of the Data Life Cycle, and supports the implementation of a system that is capable of tracking egg quality information. Egg is a widely consumed staple food and the Brazilian poultry production needs to be structured in order to attend quality and informational requirements. The aim of this paper is to identify the critical points of the traceability information gathering of eggs in commercial farms. The interviews carried for this paper allowed to validate the identified requirements, and to propose improvements in the process of collecting data of eggs. The steps of sanitary management in breeding and rearing, control of inputs, eggs collection, eggs classification and product identification were described as the critical steps for the implementation of traceability.

High occurrence of β-lactamase-producing Salmonella Heidelberg from poultry origin.

Salmonella Heidelberg is commonly reported in foodborne outbreaks around the world, and chickens and poultry products are known as important source of these pathogen. Multidrug-resistant S. Heidelberg strains are disseminated into poultry production chair, which can lead to severe clinical infections in humans and of difficult to treat. This study aimed at evaluating the β-lactam susceptibility and genotypic relatedness of Salmonella Heidelberg at Brazilian poultry production chain. Sixty-two S. Heidelberg strains from poultry production chain (poultry, poultry meat and poultry farm) were used. All strains were evaluated to antimicrobial susceptibility by diffusion disk test, as well as β-lactam resistance genes. Genotypic relatedness was assessed by Pulsed-Field Gel Eletrophoresis, using Xba1 restriction enzyme. Forty-one strains were characterized as multidrug-resistant according to phenotype characterization. The resistance susceptibility revealed 31 distinct profiles, with higher prevalence of streptomycin (61/62), nalidixic acid (50/62), tetracycline (43/62) and β-lactam drugs (37/62). blaCMY-2 was the more frequent β-lactamase gene found (38/62); other resistance genes found were blaCTX-M (2/62), blaSHV (3/62) and blaTEM-1 (38/62). No carbapenemase genes was found. The Pulsed-Field Gel Electrophoresis showed 58 different profiles. Strains with a larger number of antimicrobial resistance were grouped into ten major clusters apart from others. The spread of resistance by ampC continues to rise, thereby turning concern to public health, since the β-lactam antimicrobials are used as a therapeutic treatment in humans.

ANÁLISE ECONÔMICA DA PRODUÇÃO AVÍCOLA DE CORTE POR GÊNERO EM DIFERENTES ESTRUTURAS DE GOVERNANÇA

A avicultura de corte brasileira sustenta-se sobre a estrutura de governança híbrida estabelecida entre empresas integradoras e unidades de produção rural. Contudo, algumas empresas ainda investem na manutenção e aquisição de instalações próprias para criação das aves. Objetivou-se avaliar o desempenho zootécnico de frangos de corte de acordo com o gênero alojado e analisar o resultado econômico da atividade sob diferentes mecanismos de governança. Estudos de caso foram utilizados como procedimentos de pesquisa para avaliação da atividade em núcleos de criação da empresa integradora e de produtores rurais integrados. Dados primários sobre custos, receitas e indicadores zootécnicos foram coletados em 24 unidades de produção de aves pertencentes a uma empresa integradora e cinco produtores rurais integrados, localizados no estado de Minas Gerais. Foram utilizadas informações provenientes de 144 lotes de frangos de corte COBB® produzidos entre agosto de 2015 e agosto de 2016. Indicadores zootécnicos de lotes exclusivos para machos foram melhores que os observados para criação mista de aves e para lotes de fêmeas, respectivamente. Entretanto, na comparação dos resultados com os valores esperados para a linhagem, o potencial genético das aves poderia ter sido melhor aproveitado pelas unidades de produção rural. Independente do gênero das aves, análises econômicas indicaram que somente a criação de frangos de corte no modelo de integração foi capaz de conferir lucro econômico à atividade. Constatou-se que, para qualquer estrutura de governança avaliada, a criação de aves não se sustenta financeiramente sem receitas secundárias provenientes da venda de cama dos aviários.

Insect as feed: An emergy assessment of insect meal as a sustainable protein source for the Brazilian poultry industry

Projections point to a global increase in meat consumption as a result of rising income and changes in food patterns, especially in developing countries. Poultry meat is an option for supplying this demand and Brazil is currently the main global exporter of this protein. Of the resources involved in this industrial process, soybean meal, which is a protein source for farmed animals, requires a large quantity of energy. In order to increase the sustainability of the poultry industry, it is necessary to find a more efficient alternative to this poultry feed. Through emergy assessment, this study proposes to evaluate the production and processing of Black Soldier Fly Larvae (BSFL) as an insect meal and to compare its use with soybean meal in a Brazilian poultry production system. The biological capacity of BSFL to convert the remaining energy from a previous process (grain residue) into a novel protein is demonstrated by emergetic indices, whose best values favor this new technology. Transformity (emergy per energy of the product) decreased 144.74% while renewability increased by 45.64%. The emergy yield ratio (EYR) reduced from 1.71 to 1.00 in insect meal production compared to soybean meal, the environmental loading ratio (ELR) improved from 1.99 to 1.04 and the emergy sustainable index (ESI) improved from 0.86 to 0.96. Gains were also observed in poultry production: the transformity of poultry meat decreased by 16.45% (156,104 sej/J), renewability increased by 25.03%, EYR increased from 1.33 to 1.41 and ELR reduced from 4.96 to 3.68, when insect meal was used in comparison to soybean meal. These results, based on an experimental model, imply that BSFL meal can improve sustainability in the Brazilian poultry production process. Challenges and possibilities regarding the use of insect meal by the Brazilian poultry industry are discussed.

English

The Brazilian poultry production currently has a substantial impact on the national and international economy. Brazil ranks sixth in the world rankings of the largest egg producers. However, the activity still has barriers related to management and facilities, such as high waste of electrical energy due to the low energy efficiency of the lighting systems. The artificial lighting programs represent an important management tool to accelerate or delay sexual maturity of laying, stimulate the release of reproductive hormones, increase the egg production, besides promoting improvements in the shell quality and the size of the eggs. There is a large number of lamps that are available for use in artificial lighting systems, however, each light source has different characteristics (light intensity, wavelength, color, temperature and fluctuations) which may cause positive or negative effect on hens performance, egg quality and production costs. The LED technology is an innovative alternative that can improve the sustainability of the activity, since it has better energy efficiency, longer lifetime and emits light of different colors. This literature review aims to discuss the beneficial characteristics of the LED and its effects on the production of commercial layers.   Key words: Eggs, electric energy, layer production, layers, lighting program.

The nitrogen cycle and loss within a broiler chicken barn: a review

Brazilian poultry production has reached unprecedented levels in recent years, especially regarding to the broiler chickens production activity. This increasing productivity is due to progressive implementation of technology in this sector of the animal production in Brazil, which is being mainly focused on improving the animal environment and also, the diets offered to the birds combined with genetic advances. One consequence of high productivity of broiler chickens is the exacerbated production of waste, especially used litter, which has high levels of nutrients, among which is the nitrogen (N), that makes the poultry litter a material with high biological potential to be used as fertilizer. One way of depleting the quality of the litter is through volatilization of N as gaseous ammonia (NH3). The cycling of N for a whole broiler barn has been poorly treated in the current Brazilian scientific literature, which is the reason why this literature review was developed. The aim was to depict all possible sources and sinks and the mechanisms transformation of N inside the barn. Special focus was given to the processes of formation and models of NH3 volatilization. As main conclusion, we observed that the increase in feed conversion ratio with age is one of the factors that contributed to non-utilization of N offered to broilers, implying in a higher concentration of this nutrient in the litter with increasing age and consequently potential of its loss through volatilized NH3.

First phylogenetic analysis of Avipoxvirus (APV) in Brazil

Abstract: This study represents the first phylogenetic analysis of avian poxvirus recovered from turkeys in Brazil. The clinical disorders related to fowlpox herein described occurred in a turkey housing system. The birds displaying characteristic pox lesions which were observed on the neck, eyelids and beak of the turkeys. Four affected turkeys were randomly chosen, euthanized and necropsied. Tissues samples were submitted for histopathological analysis and total DNA was further extracted, amplified by conventional PCR, sequenced and phylogenetically analyzed. Avian poxviruses specific PCR was performed based on P4b core protein gene sequence. The histological analysis revealed dermal inflammatory process, granulation tissue, hyperplasia of epithelial cells and inclusion bodies. The P4b gene was detected in all samples. Sequencing revealed a 100% nucleotide and amino acid sequence identity among the samples, and the sequences were deposited in GenBank®. The four Avian poxviruses fragments sequenced in this study clustered along the A1 clade of avipoxviruses, and were classified as Avipoxvirus (APV). Additional studies, such as virus isolation, PCR and sequencing includinga large number of specimens from the Brazilian turkey production must be conducted due to the hazardous risk that poxvirus infections may cause to the Brazilian poultry production scenario, given that Brazil's turkey production attracts attention due to its economic importance worldwide. Our findings point to the need to identify the prevalence of APV in Brazilian turkey production, to perform risk assessment studies and continued surveillance of APV infections in both wild and commercial avian species.

Thermal environment in two broiler barns during the first three weeks of age

ABSTRACT The objective of this research was to evaluate the internal thermal environment of two broiler barns featuring different ventilation systems representative of Brazilian and South American poultry production industry: (a) a negative-pressure tunnel and (b) a positive-pressure lateral ventilation system. Environmental parameters such as dry bulb temperature, relative humidity and temperature-humidity index were assessed; temperature maps for day and night average conditions were determined for the first three weeks of life. Better uniformity of the thermal environment and comfort conditions inside the negative-pressure tunnel were found.

Characterization of antimicrobial resistance in Salmonella enterica strains isolated from Brazilian poultry production.

Antimicrobial resistance profiles and presence of resistance determinants and integrons were evaluated in Salmonella enterica strains from Brazilian poultry. The analysis of 203 isolates showed that those from the poultry environment (88 isolates) were significantly more resistant to antimicrobials than isolates from other sources, particularly those isolated from poultry by-product meal (106 isolates). Thirty-seven isolates were resistant to at least three antimicrobial classes. Class 1 integrons were detected in 26 isolates, and the analysis of the variable region between the 5' conserved segment (CS) and 3' CS of each class 1 integron-positive isolate showed that 13 contained a typical 3' CS and 14 contained an atypical 3' CS. One Salmonella Senftenberg isolate harbored two class 1 integrons, showing both typical and atypical 3' CSs. The highest percentage of resistance was found to sulfonamides, and sul genes were detected in the majority of the resistant isolates. Aminoglycoside resistance was detected in 50 isolates, and aadA and aadB were present in 28 and 32 isolates, respectively. In addition, strA and strB were detected in 78.1 and 65.6% isolates resistant to streptomycin, respectively. Twenty-one isolates presented reduced susceptibility to β-lactams and harbored bla(TEM), bla(CMY), and/or bla(CTX-M). Forty isolates showed reduced susceptibility to tetracycline, and most presented tet genes. These results highlight the importance of the environment as a reservoir of resistant Salmonella, which may enable the persistence of resistance determinants in the poultry production chain, contributing, therefore, to the debate regarding the impacts that antimicrobial use in animal production may exert in human health.