Nrs Martins

Occurrence of chicken anemia virus in backyard chickens of the metropolitan region of Belo Horizonte, Minas Gerais

The occurrence of CAV in backyard chickens in the metropolitan area of Belo Horizonte, Brazil, was evaluated. The spleen and thymus of chickens from different origins were collected for DNA extraction and nested-PCR. CAV genome was detected in 30% of the flocks (n=20) examined. CAV origin for backyard chickens is speculated, taking into consideration its widespread incidence in the chicken industry, the contamination of live vaccines with CAV prior to its eradication from SPF flocks, and the use of attenuated CAV vaccines.

Influenza Aviária: Uma Revisão dos Últimos Dez Anos

Avian influenza is an exotic disease in the Brazilian poultry. The National Avian Health Surveillance Program (PNSA) maintains permanent monitoring of AVES of all domestic species, including imported genetic material for the poultry industry, for example chickens (Gallus gallus formadomestica), turkeys (Meleagris gallopavo formadomestica), quail (Coturnix coturnix japonica), ducks (Anas), elite, grand grandparent and grandparent stocks for layers and broilers, as well as species more recently exploited for production, for example, the exotic ostriches (Struthio camelus) or native rheas (Rhea americana). The breeding stocks are monitored by regular sampling for serology, virology and bacteriology, principally looking for Newcastle disease, influenza, salmonellas and mycoplasmas, as established by the PNSA, in addition to monitoring vaccination responses to, for example, infectious bursal disease and infectious bronchitis. The PNSA establishes the rules for the control and eradication of Newcastle disease and avian influenza (Projeto de Vigilância..., 2001), including the need for differential diagnosis, according to the following major actions: I. Notification of outbreaks (and laboratory confirmation at the LARA-Campinas); II. Sanitary assistance to the outbreaks; III. Disinfection and sanitation measures; IV. Sanitary slaughter; V. Sanitary depopulation; VI. Vaccination of flocks and emergency strategies; VII. Control and monitoring of susceptible flocks; VIII. Other sanitary measures; The active surveillance and outbreak attention policies require the diagnosis and differential diagnosis of ND and AI, following the code described by OIE and the PNSA, as follows: 1- Zoning, interdiction and sampling for laboratory confirmation; 2- Registry of AVES, including species, category and numbers; applicable to a 10 km radius: restriction to transportation of animals and materials possible source of infection and propagation; disinfection of sites of entry and exit to affected properties; epidemiological surveillance; 3- Laboratory confirmation by isolating and characterizing AIV: hemagglutinating agent isolated in SPF eggs not inhibited by NDV specific serum, characterized as AIV by detecting antigens of the nucleoprotein and/or matrix and subtyped by assaying for hemagglutinin and neuraminidase subtypes (immunodiffusion, enzyme immunoassays or molecular methodology); 4- Slaughter and cremation of all avian individuals, residues, meats and eggs of all affected and neighboring properties (3 km radius), cleaning and disinfection of premises; sanitary depopulation for 21 days (minimum). 5- Allow transportation for slaughter or incubation within the vigilance area (10 km radius). 6- Prohibit fairs, markets, expositions etc., within the vigilance area (10 km radius). 7- Apply these measures for a minimum of 21 days after disinfection (which follows slaughter, cremation and cleaning) and prohibit transportation of animals and residues/products of properties within the protection area (3 km radius) and for 15 days within the vigilance area (10 km radius). The certification of HPAIV area is according to OIE and PNSA regulations and considers Brazil as a free country, applicable as follows: 1- HPAIV is not diagnosed by the active surveillance for the last 3 years; 2- 6 months after an outbreak of HPAIV is diagnosed, birds and residues/products are destroyed. The major species (chickens and turkeys) maintained in the Brazilian poultry industry employ the state-of-the-art production technology. Flocks are managed with the forefront knowledge in biosecurity, housing, permanent evaluation of critical points and quality and vaccination programs, which guarantee the prevention of most health problems. The geographic localization of the Brazilian poultry industry may also play a role in the absence of influenza outbreaks, in addition to the lower rate of replication of AIV in migratory birds during their subtropical season. Migratory routes may also concentrate in areas not occupied by poultry industry. Added to that, the biosecurity/housing and quality system of the industry may represent the step further to prevent health problems caused by transmissible infectious diseases such as influenza, considering that, for instance, all chicken and turkey industrial flocks are kept in houses, in contrast to open field farming, especially for ducks, geese and turkeys, kept on migratory routes of countries facing influenza problems.

Detection of Mycoplasma gallisepticum in dead captive psittacines in Belo Horizonte, Brazil

Mycoplasma gallisepticum (Mg) infection of wild native Brazilian psittacines (Psittaciformes) which died of any cause during sorting, rehabilitation, or conservation, was investigated by PCR. Two previously described PCR methodologies using Mg specific primers were employed for the analyses of 140 swab samples (cloaca, trachea, or palatine cleft). Average positive Mg detection in cloacal swabs was 51.9%, with 80.0% (n=5) of Blue-and-yellow Macaws (Ara ararauna), 60.0% (n=3) Dusky Parrots (Pionus fuscus), 52.5% (n=59) Amazon Parrots (Amazona aestiva), 50.0% (n=2) Orange-winged Parrots (Amazona amazonica), 50.0% (n=2) Jandaya Parakeetsor Jandaya Conures (Aratinga jandaya), 0% (n=2) Golden Conures or Golden Parakeets (Guarouba guarouba), and 0% (n=2) Hyacinth Macaws (Anodorhynchus hyacinthinus). Palatine cleft swab sampling was more sensitive to detect Mg, with 85.4% (n=17) detection rate, as compared to 67.4% (n=46) obtained with tracheal samples, and 53.5% (n=77) with cloacal swabs. The surprisingly high Mg incidence in psittacines kept in conservation or triage environments is possibly due to the proximity or cohabitation with several bird species during confinement and housing psittacines of different origins together. The implementation of biosecurity measures and species-specific facilities is recommended.

A retrospective PCR investigation of avian Orthoreovirus, chicken infectious anemia and fowl Aviadenovirus genomes contamination in commercial poultry vaccines in Brazil

Vacinas avicolas vivas comerciais produzidas entre 1991 e 2005 foram examinadas para a presenca de genomas dos virus da anemia infecciosa das galinhas (Gyrovirus CAV), da hepatite por corpusculo de inclusao (Aviadenovirus FAdV) e da artrite viral/sindrome da ma absorcao (Orthoreovirus aviario ARV). Vinte e seis partidas de vacinas vivas liofilizadas de oito fabricantes com lacre original foram examinadas. As extracoes de DNA e PCR de CAV e FAdV, e de RNA e RT-PCR para ARV, foram descritas previamente. Contaminacoes triplas de ARV, CAV e FAdV foram detectadas em vacinas de mesmo fabricante, produzidas em 1991 e 1992 contra a doenca de Newcastle (DN), e para a encefalomielite aviaria, produzida em 1994. ARV e CAV em co-infeccao foram encontrados em vacinas contra a doenca de Marek liofilizadas produzidas em 1996 por dois fabricantes diferentes. Genoma de ARV foi detectado em vacinas contra a bronquite infecciosa de setembro e dezembro de 1998, doenca infecciosa bursal, de dezembro de 1998 e DN de janeiro de 1998. Tres dos oito fabricantes apresentaram vacinas com contaminacao e cinco nunca apresentaram vacinas contaminadas. Nenhuma vacina produzida a partir de 2001 apresentou contaminacao. Cogita-se um papel epidemiologico para vacinas vivas, como fonte de infeccao para ARV, CAV e FAdV e, potencialmente determinante da atual alta disseminacao destes.

The occurrence of Orthoreovirus, Rotavirus and chicken anemia virus in chickens of the poultry industry in Minas Gerais, Brazil

Fifty-four fecal samples taken from broiler chickens from 1 to 45 days of age, and of pullets from 10 to 13 weeks of age, original from eight different poultry regions in the state of Minas Gerais, Brazil, were collected from March 2008 to January 2010 for avian Orthoreovirus (ARV) and avian Rotavirus (AvRV) analyses. For the assay of ARV, RNA was immediately extracted (Trizolâ) and transcribed into cDNA for assaying in a nested-PCR with ARV-specific primers. For AvRV, polyacrylamide gel electrophoresis (PAGE) was performed with RNA extracts obtained by phenol-chloroform extraction. CAV was additionally investigated through a nested-PCR of thymus and spleen. Results found 5.55% positive for ARV and 9.25% for AvRV. Also, CAV and ARV genomes were detected in co-infection, in a highly prostrated and claudicating chicken flock. No ARV or AvRV infections were detected in pullets. Material of a clinically affected flock was inoculated into SPF embryos, resulting in embryonic hemorrhage, whitish foci in the chorio-allantoic membrane and death. Sequencing of ARV amplicons and isolate cDNA grouped local strains with the ARV S1133 strain, historically used in live vaccines, suggesting the continued circulation of this vaccine virus strain in intensive poultry regions. Detection rates for ARV and AvRV, as well as the presence of CAV, were additionally indicative of failing biosecurity strategies for the intensive poultry regions examined.

Experimental Coinfection of Chicken Anemia Virus and Mycoplasma gallisepticum Vaccine Strains in Broiler Chicks

This study aimed at determining the clinical and pathological effects of the coinfection of young SPF chickens with chicken anemia virus (CAV) and Mycoplasma gallisepticum (MG) vaccine strains. The clinical signs, gross and microscopic lesions were determined after the experimental coinfection broilers with a CAV genotype 1 vaccine strain given intraperitoneally on the first day of age and a MG F-strain vaccine given intranasally on the 8th day of age. The experimental groups included the negative control (group 1), a group infected with the MG F-strain vaccine (group 2), and a group coinfected with CAV and MG vaccines (group 3). Chicks were examined clinically and post mortem at 23 days of age, and gross and microscopic lesions of the trachea, thymus, and air sacs were compared among treatments (Kruskal-Wallis test). Infections were confirmed by PCR for specific genetic fragments of each agent in the target tissues. Mortality was only observed in chicks on group 3, with two deaths and more severe lesions in the trachea, thymus and air sacs compared with groups 1 and 2 (p< 0.01). Dead chicks presented reduced thymus and spleen size, hemorrhagic trachea with catarrhal exudate and partial obstruction, pericarditis, catarrhal airsacculitis, lungs with liquid and ascites. The surviving chicks in group 3 showed more severe respiratory changes than those in group 2, in addition to thymus and spleen size reduction. Results indicate the adverse effects of the coinfection of young chickens with MG F-strain and CAV genotype 1 vaccines.

The effects of relative humidity and turning in incubators machines on the incubation yield and chick performance

Due to the high demands and production costs of the poultry industry it is imperative to study alternatives to modify the practice of incubation in order to maximise productivity by ensuring the conditions necessary for the development of embryos of current strains. Such changes in the management of incubation cannot affect the quality of chicks and broiler performance during early growth. To achieve these goals, several factors that work together during artificial incubation should be considered, for example, the relative humidity and turning machine incubators. Some research has already been conducted to define the optimum for these factors. This article reviews the results of studies where relative humidity and use of turning systems in incubators and their impact on incubation yield and chick performance were examined.

Lead poisoning mortality in wild passeriformes and its detection in free-range chicken eggs in Southern Minas Gerais, Brazil

The mortality of passerines native of Southern Minas Gerais, Brazil, in August 2006 and the examination of sentinel free-range chicken eggs in August 2007 in an area surrounding a car battery lead smelter plant is described. The high levels of lead, as detected in the passerines (4.80-12.74 mg/kg) at the onset of mortality and at the follow-up sampling of the free-range chicken eggs (25.02-35.21 mg/kg in shells, 0.41-1.36 mg/kg in yolks and 0.40-0.75 mg/kg in the albumins), used as environmental sentinels, indicated the continuing lead pollution.

Epididymal lithiasis in Gallus gallus domesticus

A study on the occurrence of epididymal lithiasis (EL) in Gallus gallus domesticus of different breeds and from different geographical regions of Brazil was carried out. Forty breeding roosters were collected in the states Santa Catarina, Sao Paulo, Minas Gerais, Espirito Santo and Goias, representing two specific pathogen free Leghorn lines (SPF), one commercial Leghorn layer breeder (Hy-Line) line, two commercial broiler breeder lines (Ross and Cobb), and two backyard chicken flocks. In commercial poultry breeders, EL was observed mainly after 55 weeks of age, and lithus resulted in lower fertility caused by inadequate maturation of spermatozoa and testicular atrophy, which evolved to more severe testicular dysfunction at 100 weeks of age. One hundred percent of the sampled roosters of the evaluated SPF lines presented epididymal lithiasis, which was also observed in all commercial genetic lines. The analysis of EL occurrence revealed no differences among regions and breeds: all regions and genetic lines presented epididymal calculi and the occurrence seemed higher in the more intensively-reared chickens. As for the backyard roosters, 50% presented calculi. Considering the occurrence of EL in the SPF flocks, its primary association with infectious bronchitis virus (IBV) infection was discarded, despite its contribution to fertility loss.

Histomorphological changes by epididymal lithiasis in roosters

Epididymal lithiasis (EL) histopathology is described using light and electronic microscopy in roosters (Gallus gallus domesticus) naturally affected by EL in Minas Gerais, Brazil. The histologic and morphological changes by EL in roosters was performed regarding cellular and subcellular details through light and electron microscopy. Efferent ductules epithelium lysosomal increase in size and numbers, membrane rupture, cellular vacuolation, ciliary loss, basal membrane degeneration, inflammatory reaction with mononuclear infiltrations, edema, epithelial and vascular endothelium losses were described. All industrial and freerange chickens showed EL in varying degrees in the efferent ductules (ED). However, ED altered areas did not correlate with the presence of luminal stones. Non-ciliated ED epithelium cells presented several atypically large lysosomes. Plicae loss and basal vacuoles were observed in the epithelium of dilated regions. Cellular cilia loss and apical cytoplasmic membrane rupture resulted in leakage of the cytoplasmic contents to the ED lumen, and ED epithelium desquamation occurred with or without lesion to the basal membrane. Basal membrane alterations were associated with profound sub-epithelial connective tissue damage. Aggregations of desquamated epithelium and spermatozoa were seen in the lumen of ED and compact aggregates were considered the basis for calculi formation. The widespread occurrence and high severity of EL lesions are indicative of the importance of EL as a cause of infertility in male chickens.