Mathematical models to describe the growth curves of Vietnamese Ri chicken

Abstract Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaikes information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights () were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Resumo O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos () foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike’s information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaikes information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.(AU)

O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.(AU)

Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Abstract Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike's information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Resumo O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados ​​para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Surto de botulismo tipo C em aves de subsistência em Santa Catarina, Brasil / Outbreak of type C botulism in backyard poultry in Santa Catarina, Brazil

Background: Botulism is a disease caused by the ingestion of neurotoxin produced by Clostridium botulinum, characterizedby flaccid paralysis, which can lead to high mortality. They have seven types of neurotoxins (A, B, C, D, E, F, and G) and,in birds, most cases are attributed to type C. They are considered sources of botulinum toxins where the decomposition oforganic matter occurs, like stagnant water and rotting food. The main feature of the disease in birds is ascending symmetricflaccid paralysis. The present study aims to describe an outbreak of type C botulism in backyard poultry in the state ofSanta Catarina, Southern Brazil.Case: A visit was made to the property with 160 backyard poultry with a history of high mortality in the municipality ofAgrolândia, Santa Catarina. Clinical signs were characterized by paralysis of the pelvic limbs, neck and pendular wings,which progressed to death within 48 h. There was a mortality rate of 37.5% (60/160) between March and May 2019. Thesebirds were kept in an overcrowded environment, with different species (chickens, ducks, teals, and turkeys) fed irregularly.The water supplied was provided from kitchen exhaust, accumulating in puddles on the floor that contained organic matterresidues such as animal feces, food waste and bone fragments. The disposal of the carcasses of birds that died was in thesame enclosure, buried superficially, facilitating the access of other birds to dig them up and consume them. Necropsywas performed on 2 chickens and one duck, no macroscopic or histopathological lesions were observed. Blood, liver, andgastrointestinal content samples were sent for research and identification of botulinum toxin through the serum neutralization test in mice. The presence of type C botulinum toxin was confirmed in the liver chicken of one sampled animals.Discussion: The identification of type C botulism toxin enabled the characterization of the outbreak, which is...

Surto de botulismo tipo C em aves de subsistência em Santa Catarina, Brasil / Outbreak of type C botulism in backyard poultry in Santa Catarina, Brazil

Background: Botulism is a disease caused by the ingestion of neurotoxin produced by Clostridium botulinum, characterizedby flaccid paralysis, which can lead to high mortality. They have seven types of neurotoxins (A, B, C, D, E, F, and G) and,in birds, most cases are attributed to type C. They are considered sources of botulinum toxins where the decomposition oforganic matter occurs, like stagnant water and rotting food. The main feature of the disease in birds is ascending symmetricflaccid paralysis. The present study aims to describe an outbreak of type C botulism in backyard poultry in the state ofSanta Catarina, Southern Brazil.Case: A visit was made to the property with 160 backyard poultry with a history of high mortality in the municipality ofAgrolândia, Santa Catarina. Clinical signs were characterized by paralysis of the pelvic limbs, neck and pendular wings,which progressed to death within 48 h. There was a mortality rate of 37.5% (60/160) between March and May 2019. Thesebirds were kept in an overcrowded environment, with different species (chickens, ducks, teals, and turkeys) fed irregularly.The water supplied was provided from kitchen exhaust, accumulating in puddles on the floor that contained organic matterresidues such as animal feces, food waste and bone fragments. The disposal of the carcasses of birds that died was in thesame enclosure, buried superficially, facilitating the access of other birds to dig them up and consume them. Necropsywas performed on 2 chickens and one duck, no macroscopic or histopathological lesions were observed. Blood, liver, andgastrointestinal content samples were sent for research and identification of botulinum toxin through the serum neutralization test in mice. The presence of type C botulinum toxin was confirmed in the liver chicken of one sampled animals.Discussion: The identification of type C botulism toxin enabled the characterization of the outbreak, which is...(AU)

Hepatic changes in Gallus gallus domesticus in Brazil / Alterações hepáticas em Gallus gallus domesticus no Brasil

The occurrence and the frequency of hepatic changes in chickens, including broiler (BC), layer (LC) and backyard chickens (BYC) were investigated. The retrospective and prospective study (2006-2021) was conducted with a total of 300 cases of liver disorders. Industrial poultry (BC and LC) were frequently affected (88%) and noninfectious changes were the most diagnosed (69%). Considering etiology or conditions, the hepatic changes were classified as follows: degenerative changes (42%), bacterial (28%), metabolic (15%), toxic (8%), viral (3%), neoplastic (2%), protozoal diseases (1.5%) and circulatory disorders (0.5%). Regarding the type of bird, degenerative, toxic changes and viral hepatitis were more frequent in BC. Circulatory and metabolic disorders, as well as bacterial hepatitis, were more frequently diagnosed in LC. Neoplastic and protozoal hepatitis occurred more frequently in BYC. The macroscopic examination in association with histopathology enabled the diagnosis of the hepatic changes in 59% of the cases. Considering bacterial hepatitis in commercial poultry, the etiological diagnosis is highly important, in view of the risk for public health, despite the obvious importance due to the productivity losses and condemnation at processing.

A ocorrência e a frequência de alterações hepáticas em aves, incluindo frangos de corte (FC), galinhas poedeiras (GP) e aves de subsistência (AS) foram investigadas. O estudo retrospectivo e prospectivo (2006-2021) foi realizado com um total de 300 casos de alterações hepáticas. Aves industriais (FC e GP) foram frequentemente acometidas (88%) e as alterações não infecciosas foram as mais comumente diagnosticadas (69%). Quanto à etiologia ou condição, as alterações hepáticas foram classificadas da seguinte forma: alterações degenerativas (42%), bacterianas (28%), metabólicas (15%), tóxicas (8%), virais (3%), neoplásicas (2%), bem como doenças por protozoários (1,5%) e distúrbios circulatórios (0,5%). Em relação ao tipo de ave, alterações degenerativas, tóxicas e hepatites virais foram mais frequentes nos FC. Distúrbios circulatórios e metabólicos, assim como hepatites bacterianas, foram diagnosticados com maior frequência nas GP. Neoplasias e hepatite por protozoário ocorreram com maior frequência em AS. O exame macroscópico associado à histopatologia possibilitou o diagnóstico da alteração hepática em 59% dos casos. Considerando a hepatite bacteriana em aves comerciais, o diagnóstico etiológico é de grande importância, em vista do risco para a saúde pública, apesar da óbvia importância devido às perdas de produtividade e condenação no processamento.

Investigation of Salmonella spp. in free-range chickens (Gallus gallus domesticus) in Southern Rio Grande do Sul / Pesquisa de Salmonella spp. em galinhas coloniais (Gallus gallus domesticus) no sul do Rio Grande do Sul

Salmonelose é uma doença causada por bactérias do gênero Salmonella, com importância para saúde pública e animal. Dentre os sorotipos hospedeiro-específicos, destaca-se o Gallinarum, que possui os biovares Gallinarum e Pullorum adaptados às aves e amplamente difundidos pelo mundo. Os dados sobre a ocorrência de Salmonella spp. em criações avícolas alternativas no Brasil são escassos. O objetivo deste estudo foi pesquisar a ocorrência de Salmonella spp. em galinhas coloniais encaminhadas para necropsia ao LRD/FV/UFPel. Foram realizadas análises histopatológicas, microbiológicas e moleculares das colônias bacterianas isoladas de 12 amostras de órgãos de galinhas domésticas dos municípios de Pelotas e Piratini, no Rio Grande do Sul. Na análise microbiológica, foram isoladas bactérias do gênero Salmonella sorotipo Gallinarum das 12 amostras, sendo 10/12 bioquimicamente compatíveis com biovar Gallinarum e 2/12 com biovar Pullorum. Na análise molecular PCR 11/12, 91,7% foram identificadas genotipicamente como Salmonella spp. O presente estudo demonstrou uma elevada frequência de isolamento de Salmonella Gallinarum biovar Gallinarum em aves sintomáticas criadas em regime extensivo. Além disso, os dados epidemiológicos das aves analisadas demonstram que a infecção por Salmonella Gallinarum nesses casos está associada ao contato com aves silvestres e falhas de manejo sanitário.(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.(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.

Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014 / Monitoramento da doença de Newcastle em aves domésticas nos sítios de pouso de aves migratórias: Mangue Seco e Cacha Pregos entre 2013 e 2014

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.(AU)

A avicultura tem sido considerada uma das atividades agrícolas mais eficientes, colocando o Brasil no ranking dos maiores produtores de carne de frango. No entanto, uma ameaça à cadeia produtiva da avicultura é a entrada do vírus da doença de Newcastle (NDV) no país, o que acarretaria enormes prejuízos econômicos e sociais. O monitoramento do vírus foi realizado em granjas de aves domésticas (Gallus gallus domesticus) nos locais de desembarque de aves migratórias de Mangue Seco e Cacha Pregos entre 2013 e 2014 para controlar a doença de Newcastle (DCNT) nesses locais. Atividades de educação em saúde, preenchimento de questionário para definição do perfil sanitário das fazendas, cadastro georreferenciado e coleta de amostras de sangue e swabs cloacal e traqueal de aves de quintal foram as ações de vigilância epidemiológica realizadas. Um total de 133 amostras de soro foram analisadas em Mangue Seco e 81 em Cacha Pregos. Os resultados mostraram que tanto Mangue Seco (63,4%) quanto Cacha Pregos (88,9%) apresentaram animais reativos para o NDV. Os resultados da reação em cadeia da polimerase em tempo real (RT-PCR) e das análises de isolamento viral foram negativos, comprovando que as aves domésticas não estavam eliminando o vírus no momento da coleta das amostras. O alto percentual de animais reativos pelo teste ELISA indireto em ambas as unidades epidemiológicas estudadas sugere a presença de cepa lentogênica circulante de NDV, uma vez que não houve registro de óbito e as aves não apresentavam sintomas característicos da doença.(AU)

Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014 / Monitoramento da doença de Newcastle em aves domésticas nos sítios de pouso de aves migratórias: Mangue Seco e Cacha Pregos entre 2013 e 2014

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.(AU)

A avicultura tem sido considerada uma das atividades agrícolas mais eficientes, colocando o Brasil no ranking dos maiores produtores de carne de frango. No entanto, uma ameaça à cadeia produtiva da avicultura é a entrada do vírus da doença de Newcastle (NDV) no país, o que acarretaria enormes prejuízos econômicos e sociais. O monitoramento do vírus foi realizado em granjas de aves domésticas (Gallus gallus domesticus) nos locais de desembarque de aves migratórias de Mangue Seco e Cacha Pregos entre 2013 e 2014 para controlar a doença de Newcastle (DCNT) nesses locais. Atividades de educação em saúde, preenchimento de questionário para definição do perfil sanitário das fazendas, cadastro georreferenciado e coleta de amostras de sangue e swabs cloacal e traqueal de aves de quintal foram as ações de vigilância epidemiológica realizadas. Um total de 133 amostras de soro foram analisadas em Mangue Seco e 81 em Cacha Pregos. Os resultados mostraram que tanto Mangue Seco (63,4%) quanto Cacha Pregos (88,9%) apresentaram animais reativos para o NDV. Os resultados da reação em cadeia da polimerase em tempo real (RT-PCR) e das análises de isolamento viral foram negativos, comprovando que as aves domésticas não estavam eliminando o vírus no momento da coleta das amostras. O alto percentual de animais reativos pelo teste ELISA indireto em ambas as unidades epidemiológicas estudadas sugere a presença de cepa lentogênica circulante de NDV, uma vez que não houve registro de óbito e as aves não apresentavam sintomas característicos da doença.(AU)

Esophageal squamous cell carcinoma in a backyard rooster

Squamous cell carcinoma, a malignant epithelial neoplasm originating from the epidermis squamous cells or the digestive mucosa epithelium, was diagnosed in an adult rooster. The rooster was lethargic and presented difficulties in swallowing. Physical examination revealed a large deep mass in the cranial cervical region. Due to poor prognosis, the bird was euthanized and then post mortem examined. Grossly, in the oral portion of the esophagus, there was a mass invading and partially occluding the lumen. Microscopically, the mass had neoplastic cells interconnected by evident desmosomes junctions and keratin pearl formations. Microscopic findings confirmed the diagnosis of squamous cell carcinoma. This neoplasia is an important differential diagnosis for esophageal lesions in birds. There are various carcinogens for squamous cell carcinoma such as sunlight, virus, some chemicals and chronic wounds, the last one being a possible cause of the squamous cell carcinoma in this rooster as no evidence of other etiologies were found.

Esophageal squamous cell carcinoma in a backyard rooster

Squamous cell carcinoma, a malignant epithelial neoplasm originating from the epidermis squamous cells or the digestive mucosa epithelium, was diagnosed in an adult rooster. The rooster was lethargic and presented difficulties in swallowing. Physical examination revealed a large deep mass in the cranial cervical region. Due to poor prognosis, the bird was euthanized and then post mortem examined. Grossly, in the oral portion of the esophagus, there was a mass invading and partially occluding the lumen. Microscopically, the mass had neoplastic cells interconnected by evident desmosomes junctions and keratin pearl formations. Microscopic findings confirmed the diagnosis of squamous cell carcinoma. This neoplasia is an important differential diagnosis for esophageal lesions in birds. There are various carcinogens for squamous cell carcinoma such as sunlight, virus, some chemicals and chronic wounds, the last one being a possible cause of the squamous cell carcinoma in this rooster as no evidence of other etiologies were found.(AU)

Highly Pathogenic and Multidrug Resistant Avian Pathogenic Escherichia Coli in Free-Range Chickens from Brazil

Avian pathogenic Escherichiacoli (APEC) virulence mechanism has been continuously studied and it is believed to be multifactorial and because of this, this work aimed to characterize potentially APEC strains isolated from free-range hens. Isolates were submitted to PCR for the detection of virulence genes, which were of high prevalence. In vivo inoculation of day-old chicks revealed that 49 of these strains were of high and intermediate pathogenicity. In addition, isolates were submitted to antimicrobials susceptibility test with the majority of the strains presenting multiresistance. Phylogenetic analysis showed a greater presence of potentially APEC isolates in-group B2. In addition, high heterogeneity was detected among the isolates byXbaI enzyme. Fifteen serogroups were identified, being the O8 the most frequent. These results strengthen the fact that a combination of diverse factors are associated with the pathogenicity APEC strains, as well as to highlight its importance to public health and that free-range hens can act as a reservoirs of potentially zoonoticbacteria.(AU)

Highly Pathogenic and Multidrug Resistant Avian Pathogenic Escherichia Coli in Free-Range Chickens from Brazil

Avian pathogenic Escherichiacoli (APEC) virulence mechanism has been continuously studied and it is believed to be multifactorial and because of this, this work aimed to characterize potentially APEC strains isolated from free-range hens. Isolates were submitted to PCR for the detection of virulence genes, which were of high prevalence. In vivo inoculation of day-old chicks revealed that 49 of these strains were of high and intermediate pathogenicity. In addition, isolates were submitted to antimicrobials susceptibility test with the majority of the strains presenting multiresistance. Phylogenetic analysis showed a greater presence of potentially APEC isolates in-group B2. In addition, high heterogeneity was detected among the isolates byXbaI enzyme. Fifteen serogroups were identified, being the O8 the most frequent. These results strengthen the fact that a combination of diverse factors are associated with the pathogenicity APEC strains, as well as to highlight its importance to public health and that free-range hens can act as a reservoirs of potentially zoonoticbacteria.

Occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chicken breeding in Northeast, Brazil

Abstract The aim of the present study was to investigate the occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chickens bred in the metropolitan area of Recife, Brazil. In total, 212 serum samples were collected from 16 properties, and 12 backyard chickens were collected in the six sanitary districts of Recife. An indirect immunofluorescence assay (IFA) was used to investigate the occurrence of anti-Toxoplasma gondii antibodies. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in brain, heart, liver and lung specimens. Of the samples analyzed by serology, 86/212 (40.56%) were positive; of the samples analyzed by PCR, 2/12 (16.7%) were positive, with both samples positive by both tests (serological and molecular). The presence of antibody anti-T. gondii and parasite DNA in tissues of these animals are worrying aspects for public health because there is a risk of transmission of the parasite to humans through eating undercooked or raw meat. Based on the results, the adoption of preventive measures to prevent the cats access to the chickens creations should be encouraged, since these animals were identified in most of the studied properties.

Resumo O objetivo do presente estudo foi investigar a ocorrência de anticorpos anti-Toxoplasma gondii e de DNA do parasito em galinhas de criações domésticas, na região metropolitana de Recife, Brasil. No total, 212 amostras de soro foram coletadas de aves de 16 estabelecimentos e de 12 galinhas de criações domésticas nos seis distritos sanitários de Recife. Para a pesquisa de anticorpos anti-Toxoplasma gondii foi utilizada a Reação de Imunofluorescência Indireta (RIFI). A Reação em Cadeia da Polimerase (PCR) foi utilizada para detectar o DNA de T. gondii em fragmentos de cérebro, coração, fígado e pulmão. Das amostras analisadas por sorologia, 86/212 (40,56%) foram positivas. Das amostras analisadas por PCR, 2/212 (16,7%) foram positivas, em ambos os testes (sorológicos e moleculares). A presença de anticorpos anti-T. gondii e de DNA parasitário nos tecidos desses animais são aspectos preocupantes para saúde pública, porque há o risco de transmissão do parasita para humanos através da ingestão de carne mal cozida ou crua. Com base nos resultados obtidos, a adoção de medidas preventivas que evitem o acesso de gatos às criações de galinhas deve ser incentivada, uma vez que esses animais foram identificados na maioria das propriedades estudadas.

Occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chicken breeding in Northeast, Brazil / Ocorrência de anticorpos anti-Toxoplasma gondii e DNA do parasita em galinhas de criações domésticas no Nordeste, Brasil

The aim of the present study was to investigate the occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chickens bred in the metropolitan area of Recife, Brazil. In total, 212 serum samples were collected from 16 properties, and 12 backyard chickens were collected in the six sanitary districts of Recife. An indirect immunofluorescence assay (IFA) was used to investigate the occurrence of anti-Toxoplasma gondii antibodies. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in brain, heart, liver and lung specimens. Of the samples analyzed by serology, 86/212 (40.56%) were positive; of the samples analyzed by PCR, 2/12 (16.7%) were positive, with both samples positive by both tests (serological and molecular). The presence of antibody anti-T. gondii and parasite DNA in tissues of these animals are worrying aspects for public health because there is a risk of transmission of the parasite to humans through eating undercooked or raw meat. Based on the results, the adoption of preventive measures to prevent the cats access to the chickens creations should be encouraged, since these animals were identified in most of the studied properties.(AU)

O objetivo do presente estudo foi investigar a ocorrência de anticorpos anti-Toxoplasma gondii e de DNA do parasito em galinhas de criações domésticas, na região metropolitana de Recife, Brasil. No total, 212 amostras de soro foram coletadas de aves de 16 estabelecimentos e de 12 galinhas de criações domésticas nos seis distritos sanitários de Recife. Para a pesquisa de anticorpos anti-Toxoplasma gondii foi utilizada a Reação de Imunofluorescência Indireta (RIFI). A Reação em Cadeia da Polimerase (PCR) foi utilizada para detectar o DNA de T. gondii em fragmentos de cérebro, coração, fígado e pulmão. Das amostras analisadas por sorologia, 86/212 (40,56%) foram positivas. Das amostras analisadas por PCR, 2/212 (16,7%) foram positivas, em ambos os testes (sorológicos e moleculares). A presença de anticorpos anti-T. gondii e de DNA parasitário nos tecidos desses animais são aspectos preocupantes para saúde pública, porque há o risco de transmissão do parasita para humanos através da ingestão de carne mal cozida ou crua. Com base nos resultados obtidos, a adoção de medidas preventivas que evitem o acesso de gatos às criações de galinhas deve ser incentivada, uma vez que esses animais foram identificados na maioria das propriedades estudadas.(AU)

Vigilância epidemiológica dos vírus da influenza aviária, da doença de Newcastle e da laringotraqueíte infecciosa das galinhas em propriedades avícolas

A sanidade avícola é necessária para garantir a posição de destaque mundial da avicultura brasileira. O objetivo deste trabalho foi realizar a vigilância epidemiológica do vírus da IA (VIA) e do vírus da DNC (VDNC) em 2017 e 2018, além de avaliar a circulação de estirpes do vírus de laringotraqueíte infecciosa das galinhas (VLTI) nas granjas de postura comercial em duas regiões quarentemadas (Bastos e Guatapará) entre 2010 e 2018. Diferentes programas vacinais contra a LTI foram implementados na região, com a substituição de vacinas vivas atenuadas por recombinantes em 2012 (Bastos) e 2013 (Guatapará). Para a vigilância de VIA e VDNC foram coletados pools de suabes (traqueais e cloacais, n=220) de aves de subsistências localizadas no entorno de propriedades avícolas de reprodutoras. Essas amostras foram testadas pela reação de transcrição reversa-PCR em tempo real (RRT-PCR). O estudo longitudinal de VLTI coletou amostras de pools de suabes orofaríngeos de aves localizadas em Bastos (n=364) e Guatapará (n=214) para a detecção de VLTI por PCR. O sequenciamento de DNA dos genes ICP4, TK e genomas completos das amostras positivas foram realizados usando sequenciamento Sanger e sequenciamento de última geração (NGS). As bibliotecas de DNA foram preparadas com o kit Nextera DNA Flex Library Prep e sequenciadas com o sequenciador MiSeq. Análise filogenética e as identidades genéticas foram inferidas com as sequências obtidas. Nosso estudo não detectou VIA e do VDNC em nenhuma das amostras no período avaliado. O VLTI foi detectado em 11,85% e 12,6% das amostras testadas de Bastos em 2013 e 2018. A região de Guatapará apresentou a maior taxa de detecção (60,5%) em 2010. A taxa de detecção de amostras testadas da região de Guatapará variou de 12,2% e 21,7% após 2013. Análise filogenética do gene ICP4 agrupou as sequências das amostras de Bastos com vacinas de CEO e outras sequências de Bastos detectadas em anos anteriores, com 99% da identidade genética entre estas sequências. As análises filogenéticas dos genes ICP4, TK e do genoma completo agruparam as amostras de Guatapará separadamente das amostras vacinais. A sequência completa do genoma de uma amostra obtida de aves sintomáticas sem vacinação na região de Guatapará em 2010 (IB8098) teve 152.985 nucleotídeos, com 4755 leituras e 98,2% de cobertura. A análise filogenética agrupou a amostra IB8098 com outras estirpes virulentas, como da Rússia (MF405079). As identidades genéticas apresentaram 99,9%, quando comparadas à estirpe russa e 99,6% em relação às vacinais (CEO e TCO). Nosso estudo mostrou o VLTI ainda está presente nas regiões de Bastos e Guatapará, apesar das medidas de controle e vacinação vigentes. Os programas de vacinação nas regiões quarentenadas diminuíram a circulação do vírus com um leve aumento da detecção do VLTI com a utilização apenas das vacinas recombinantes. Esse é o primeiro relato da obtenção do genoma completo de VLTI no Brasil e sua caracterização genômica desde o início da circulação do vírus na região há pelo menos dez anos. O monitoramento contínuo da área é essencial para auxiliar as ações da defesa agropecuária, avaliar as medidas de vacinação implementadas contribuindo para a melhoria da sanidade avícola.

Poultry health is important to ensure the world's leading position in Brazilian poultry production. The present study performed the epidemiological surveillance of avian influenza virus (AIV) and Newcastle disease virus (NDV) in 2017 and 2018; the circulation of virulent avian infection laryngotracheitis virus (ILTV) strains was also evaluated in commercial layer farms from two quarantined regions (Bastos and Guatapara) between 2010 and 2018. Different vaccine programs against ILT were established in the area, and a replacement of live vaccines by recombinant vaccines was done in 2012 (Bastos) and 2013 (Guatapara). For the AIV and NDV surveillance, swab pool samples (trachea and cloacal, n=220) were collected from backyard birds located closed to breeder farms. Real-time reverse-transcription polymerase chain reaction (RRT-PCR) tested these samples. The longitudinal study collected oropharyngeal swab pool samples from commercial layer chickens located in Bastos (n=364) and Guatapara (n=214) for virus ILTV detection by PCR. DNA sequencing from the ICP4, TK genes and complete genomes was performed in positive samples using Sanger sequencing and next-generation sequencing (NGS). DNA libraries were prepared with the Nextera DNA Flex Library Prep kit, sequenced with the MiSeq sequencer for NGS. Phylogenetic analysis and genetic identities were inferred using the obtained sequences. AIV and NDV were not detected in any sample during the study. ILTV was detected in 11.85% and 12.6% of tested samples from Bastos in 2013 and 2018. Guatapara region had the highest detection rate (60.5%) in 2010. The detection rate from tested samples of the Guatapara region ranged from 12.2% and 21.7% after 2013. Phylogenetic analysis based on ICP4 gene grouped sequences from Bastos samples with CEO vaccines and other sequences detected previously in Bastos, with 99% of nucleotide identity among them. Phylogenetic analysis based on ICP4, TK, and complete genomes grouped sequences from Guatapara separately from vaccine strains. The complete genome sequence of a sample (IB8098), collected from layer chickens displaying clinical signs without vaccination in the Guatapara region in 2010, had 152,985 nucleotides, with 4,755 reads and 98,2% coverage. The phylogenetic analysis grouped the IB8098 sample with other virulent ILTV strains, such as from Russia (MF405079). Nucleotide identities were 99.9% compared to the Russian, and 99.6% to vaccine strains (CEO and TCO). Our study showed the ILTV is still present in the Bastos and Guatapara regions, despite the control and vaccination measures. The vaccination programs in the quarantine regions decreased the virus circulation, slightly increasing when only recombinant vaccines were applied. That is the first report of complete genome ILTV sequences in Brazil and its genomic characterization, after its circulation in the region for at least ten years. Continuous monitoring in poultry flocks is essential to help the poultry health measures, evaluate the vaccination programs placed in the area contributing to the Brazilian poultry health plans improvement.

Toxoplasma Gondii and Neospora Caninum Antibodies in Backyard Chickens in Rio Grande do Sul, Brazil

Toxoplasma gondii and Neospora caninum are two intracellular apicomplexan protozoa with worldwide distribution, and are responsible for reproductive disorders in sheep and cattle. These protozoa may infect a wide variety of domestic and wild animals, including birds, and backyard chickens can be used as sentinels of their infection. Parasites investigation in backyard chickens may be useful for the evaluation of environmental contamination with oocysts, of the disease cycle, and of risk factors associated with public health. The aim of this study was establish the importance of backyard chickens as T. gondii and N. caninum hosts. A number of 137 serum samples were collected from chickens in 23 farms in Rio Grande do Sul State, Brazil, and tested for toxoplasmosis and neosporosis by indirect fluorescence antibody test (IFAT). Anti-Toxoplasma and anti-Neospora antibodies were detected in 20 (87%) farms. Total prevalence of T. gondii was 74.4% (102/137) and 36.5% (50/137) for N. caninum, while 12.4% (17/137) of the chickens were positive for both protozoa. The results show that backyard chicken can used as indicators of the presenced of the protozoa N. caninum and T. gondii, emphasizing yours importance in the public health. Considering the high prevalence of toxoplasmosis in backyard chickens in the region, control measures should be taken to prevent transmission of the infection to the animals and humans.(AU)