Circulation of Major Respiratory Pathogens in Backyard Poultry and their Association with Clinical Disease and Biosecurity

Raising backyard birds is a common practice in Brazil, mainly in the countryside or suburban areas. However, the level of respiratory pathogens in these animals is unknown. We sampled two hundred chickens from 19 backyard flocks near commercial poultry farms and performed ELISA to Infectious Bronchitis Virus, avian Metapneumovirus, Mycoplasma synoviae and Mycoplasma gallisepticum. We evaluated the association between the predictive ability of ELISA and Hemagglutination-inhibition (HI)by comparing results from eight flocks positive to Mycoplasma gallisepticum on ELISA. Besides, we assessed essential biosecurity measures in the properties (multiple species birds, rodent control, hygienic conditions, and water quality for the bird`s consumption). We could access the vaccination program only on four properties; in three of them, the birds were supposedly vaccinated for IBV. Overall the properties had a poor score for the biosecurity measures, and the seroprevalence in backyard poultry flocks for IBV, a MPV, MS, and MG were respectively 87.5% (14/16), 89.5% (17/19), 100 (19/19) and MG 84.21% (16/19). We found low specificity and predictive value between ELISA and HI in MG analysis and a positive correlation between the presence of clinical symptoms and mean MG titers. Backyard chicken are pathogens reservoirs and pose a risk for the commercial poultry farms in the region, and further efforts of the governmental entities and private sector of poultry production should consider these information to avoid future economic losses.(AU)

Circulation of Major Respiratory Pathogens in Backyard Poultry and their Association with Clinical Disease and Biosecurity

Raising backyard birds is a common practice in Brazil, mainly in the countryside or suburban areas. However, the level of respiratory pathogens in these animals is unknown. We sampled two hundred chickens from 19 backyard flocks near commercial poultry farms and performed ELISA to Infectious Bronchitis Virus, avian Metapneumovirus, Mycoplasma synoviae and Mycoplasma gallisepticum. We evaluated the association between the predictive ability of ELISA and Hemagglutination-inhibition (HI)by comparing results from eight flocks positive to Mycoplasma gallisepticum on ELISA. Besides, we assessed essential biosecurity measures in the properties (multiple species birds, rodent control, hygienic conditions, and water quality for the bird`s consumption). We could access the vaccination program only on four properties; in three of them, the birds were supposedly vaccinated for IBV. Overall the properties had a poor score for the biosecurity measures, and the seroprevalence in backyard poultry flocks for IBV, a MPV, MS, and MG were respectively 87.5% (14/16), 89.5% (17/19), 100 (19/19) and MG 84.21% (16/19). We found low specificity and predictive value between ELISA and HI in MG analysis and a positive correlation between the presence of clinical symptoms and mean MG titers. Backyard chicken are pathogens reservoirs and pose a risk for the commercial poultry farms in the region, and further efforts of the governmental entities and private sector of poultry production should consider these information to avoid future economic losses.

Genetic and environmental effects on tonic immobility duration of red-winged tinamou applying survival analysis

Fear behavioral studies provide knowledge on animal welfare, and fearful behaviors can be used as selection criteria of individuals adapted to intensive rearing system. The survival analysis methodology was applied to estimate tonic immobility (TI) duration, as an indicator of fear, of red-winged tinamous (Rhynchotus rufescens) reared in captivity and to determine if TI is genetically influenced. A number of 539 birds born between 2006 and 2010 were evaluated. The exploratory data analysis was performed using the Kaplan-Meier estimate (KM), and the covariates were then fit to a Cox model, considering month of observation nested within year of birth and body weight as fixed effects and the random effect of sire as frailty term. In order to predict genetic values and to estimate heritability, the model of proportional hazards was applied, using a Weibull distribution as the baseline hazard. Birds born in the last year presented shorter TI duration than those born in the previous year, as shown by the survival KM curves, indicating a decline in fearfulness from one year to the next. The Cox analysis detected that hazard function was reduced as body weight increased. The frailty term was significant (p<0.05), showing that sires induced variation in the TI duration of the offspring. Heritability estimated as 0.37, indicating the influence of additive genes. These findings suggest that the selection of for short TI duration may allow reducing fearfulness of a red-winged tinamou population after some generations.(AU)

Genetic and environmental effects on tonic immobility duration of red-winged tinamou applying survival analysis

Fear behavioral studies provide knowledge on animal welfare, and fearful behaviors can be used as selection criteria of individuals adapted to intensive rearing system. The survival analysis methodology was applied to estimate tonic immobility (TI) duration, as an indicator of fear, of red-winged tinamous (Rhynchotus rufescens) reared in captivity and to determine if TI is genetically influenced. A number of 539 birds born between 2006 and 2010 were evaluated. The exploratory data analysis was performed using the Kaplan-Meier estimate (KM), and the covariates were then fit to a Cox model, considering month of observation nested within year of birth and body weight as fixed effects and the random effect of sire as frailty term. In order to predict genetic values and to estimate heritability, the model of proportional hazards was applied, using a Weibull distribution as the baseline hazard. Birds born in the last year presented shorter TI duration than those born in the previous year, as shown by the survival KM curves, indicating a decline in fearfulness from one year to the next. The Cox analysis detected that hazard function was reduced as body weight increased. The frailty term was significant (p<0.05), showing that sires induced variation in the TI duration of the offspring. Heritability estimated as 0.37, indicating the influence of additive genes. These findings suggest that the selection of for short TI duration may allow reducing fearfulness of a red-winged tinamou population after some generations.

Naturally Occurring Co-infection of Avian Leukosis Virus (subgroups A-E) and Reticuloendotheliosis Virus in Green Peafowls (Pavo muticus)

Most of the neoplastic diseases affecting poultry have a viral etiology, such as Mareks disease, avian leukosis/sarcoma and reticuloendotheliosis. In the present paper, histopathology and molecular methods were performed, in addition of necropsy and gross morphology evaluation, for the differential diagnosis of these diseases in two green peafowls (Pavo muticus). The affected birds showed non-specific signs, such as depression, anorexia, and diarrhea. At necropsy, diffuse enlargement by several times the normal size of the liver and the spleen was observed. In one of the birds, the liver presented white to grayish discoloration was present, and focal and nodular growths in the other bird. Grossly, the other visceral organs and the peripheral nerves were normal. Microscopically, most of the tumor cells were large and uniform with pleomorphic nuclei. The PCR analysis for Mareks disease virus (MDV), avian leukosis virus (ALV), lymphoproliferative disease virus (LPDV), and reticuloendotheliosis virus (REV)based on their specific sequences showed the presence of ALV subgroups A-E and REV. According to these results, definitive diagnosis was co-infection of ALV and REV in naturally-infected green peafowls.(AU)

Naturally Occurring Co-infection of Avian Leukosis Virus (subgroups A-E) and Reticuloendotheliosis Virus in Green Peafowls (Pavo muticus)

Most of the neoplastic diseases affecting poultry have a viral etiology, such as Mareks disease, avian leukosis/sarcoma and reticuloendotheliosis. In the present paper, histopathology and molecular methods were performed, in addition of necropsy and gross morphology evaluation, for the differential diagnosis of these diseases in two green peafowls (Pavo muticus). The affected birds showed non-specific signs, such as depression, anorexia, and diarrhea. At necropsy, diffuse enlargement by several times the normal size of the liver and the spleen was observed. In one of the birds, the liver presented white to grayish discoloration was present, and focal and nodular growths in the other bird. Grossly, the other visceral organs and the peripheral nerves were normal. Microscopically, most of the tumor cells were large and uniform with pleomorphic nuclei. The PCR analysis for Mareks disease virus (MDV), avian leukosis virus (ALV), lymphoproliferative disease virus (LPDV), and reticuloendotheliosis virus (REV)based on their specific sequences showed the presence of ALV subgroups A-E and REV. According to these results, definitive diagnosis was co-infection of ALV and REV in naturally-infected green peafowls.

A criptococose e sua importância na Medicina Veterinária / Cryptococcosis and its importance in Veterinary Medicine

A criptococose é uma micose de natureza sistêmica oportunista, considerada uma zoonose causada pelo complexo Cryptococcus neoformans que compreende dois agentes etiológicos, o C. neoformans e o C. gattii, capazes de acometer aves, homens, animais domésticos e silvestres. A infecção ocorre por inalação dos esporos do agente que é frequentemente isolado em excretas de pombos (Columba livia), considerados os reservatórios naturais do fungo. As alterações são encontradas em diversos sistemas do organismo. A criptococose é uma das micoses de mais fácil diagnóstico por apresentar marcado tropismo neurológico, abundância de elementos fúngicos no líquor e nas lesões. Para o tratamento em animais e humanos, as drogas selecionadas são diferenciadas para que não haja a seleção de estirpes resistentes.

Cryptococcosis is an opportunist systemic mycosis considered as zoonosis caused by the complex Cryptococcus neoformans that comprises two etiologic agents, C. neoformans and C. gattii. Both of them can attack birds, humans, domestic animals and wild ones. The infection is produced by spores inhalation. These spores are often isolated from pigeon (Columba livia) faeces. These birds are considered as the natural fungus reservoir. The lesions of this disease can be found in several organ systems and it is one of the mycosis with prompt diagnosis because the infectious agent presents a marked neurological tropism, plenty of fungy elements in the CSF and in the lesions. The treatment of animals and humans must be performed with selected different drugs to prevent the selection of resistant strains.

A criptococose e sua importância na Medicina Veterinária / Cryptococcosis and its importance in Veterinary Medicine

A criptococose é uma micose de natureza sistêmica oportunista, considerada uma zoonose causada pelo complexo Cryptococcus neoformans que compreende dois agentes etiológicos, o C. neoformans e o C. gattii, capazes de acometer aves, homens, animais domésticos e silvestres. A infecção ocorre por inalação dos esporos do agente que é frequentemente isolado em excretas de pombos (Columba livia), considerados os reservatórios naturais do fungo. As alterações são encontradas em diversos sistemas do organismo. A criptococose é uma das micoses de mais fácil diagnóstico por apresentar marcado tropismo neurológico, abundância de elementos fúngicos no líquor e nas lesões. Para o tratamento em animais e humanos, as drogas selecionadas são diferenciadas para que não haja a seleção de estirpes resistentes.(AU)

Cryptococcosis is an opportunist systemic mycosis considered as zoonosis caused by the complex Cryptococcus neoformans that comprises two etiologic agents, C. neoformans and C. gattii. Both of them can attack birds, humans, domestic animals and wild ones. The infection is produced by spores inhalation. These spores are often isolated from pigeon (Columba livia) faeces. These birds are considered as the natural fungus reservoir. The lesions of this disease can be found in several organ systems and it is one of the mycosis with prompt diagnosis because the infectious agent presents a marked neurological tropism, plenty of fungy elements in the CSF and in the lesions. The treatment of animals and humans must be performed with selected different drugs to prevent the selection of resistant strains.(AU)