Newcastle disease in white Pekin ducks: response to experimental vaccination and challenge

A total of 120 Pekin ducks were distributed at random into four experimental groups, vaccinated or not against Newcastle disease (ND): G1 (Ulster 2C strain), G2 (B1 strain), G3 (LaSota strain), and G4 (nonvaccinated group). At 60 days of age, all groups were challenged with a pathogenic ND virus (NDV) suspension, and a group of specific pathogen free (SPF) chicks (G5) was also inoculated. Cloacal and tracheal swabs from all birds were collected after six, 14, 20, and 30 days post-challenge for virus isolation. NDV was isolated in 100% of SPF chicks. Pekin ducks from all groups, vaccinated or not, did not show any ND clinical signs, demonstrating that these birds are not susceptible to ND clinical disease. In the control group (G4), the virus was isolated 20 to 30 days after challenge, suggesting their possible NDV carrier state. In the vaccinated groups, no virus was isolated. This demonstrates that vaccination of white Pekin ducks against NDV is important to reduce NDV shedding in the field.

Newcastle disease in white Pekin ducks: response to experimental vaccination and challenge

A total of 120 Pekin ducks were distributed at random into four experimental groups, vaccinated or not against Newcastle disease (ND): G1 (Ulster 2C strain), G2 (B1 strain), G3 (LaSota strain), and G4 (nonvaccinated group). At 60 days of age, all groups were challenged with a pathogenic ND virus (NDV) suspension, and a group of specific pathogen free (SPF) chicks (G5) was also inoculated. Cloacal and tracheal swabs from all birds were collected after six, 14, 20, and 30 days post-challenge for virus isolation. NDV was isolated in 100% of SPF chicks. Pekin ducks from all groups, vaccinated or not, did not show any ND clinical signs, demonstrating that these birds are not susceptible to ND clinical disease. In the control group (G4), the virus was isolated 20 to 30 days after challenge, suggesting their possible NDV carrier state. In the vaccinated groups, no virus was isolated. This demonstrates that vaccination of white Pekin ducks against NDV is important to reduce NDV shedding in the field.

Evaluation of anatomopathological, serological, immunological responses and protection in broilers vaccinated with live infectious bursal disease vaccines

ABSTRACT The study was divided into three experiments. In the first one, broilers were distributed into six groups and vaccinated against infectious bursal disease at 14 days of age: T1-not vaccinated, T2-Lukert1 (intermediate), T3-Lukert2 (intermediate plus), T4-228E, T5-V877 and T6-Winterfield 2512 (hot strains). Bursas of Fabricius (BF) were collected at 17, 21, 28 and 35 days to measure BF relative weight (BFRW), diameter, histological examination and image processing analysis (IPA). At one, 14, 21, 28 and 35 days of age, samples of blood taken from eight birds from each group for serology analysis by ELISA test. Hot strains vaccines induced reduction of BFRW and BF diameter, higher histological score lesion degree, more lymphocyte depletion on the BF follicles and higher IBD antibody titer. In the second experiment, 16 birds from groups T1 to T6 were isolated and challenged with a very virulent strain of IBDV (vvIBDV) at 25 days of age. Only groups T4, T5 and T6 were totally protected against vvIBDV challenge. In the third experiment, the immunosuppressive potential of each vaccine was determined by examining the ability of IBDVvaccinated birds to respond to Newcastle disease (ND) vaccination and challenge. None of the vaccines was found to be immunodepressive.

RESUMO O estudo foi dividido em três experimentos. No primeiro, frangos foram distribuídos em seis grupos e vacinados contra a Doença Infecciosa da Bursa (IBD) aos 14 dias de idade: T1-não vacinados, T2-Lukert1 (intermediária), T3-Lukert2 (intermediária plus), T4-228E, T5-V877 e T6-Winterfield 2512 (cepa forte). As bursas de Fabrícius (BF) foram colhidas aos 17, 21, 28 e 35 dias para mensurar o seus pesos relativos da BF (BFRW), diâmetros, exames histológicos e processamento de imagem imagens(IPA). Ao primeiro, 14, 21, 28 e 35 dias de idade, foram colhidas amostras de sangue de oito aves de cada grupo para a realização de sorologia através do método ELISA indireto. As vacinas cepa forte induziram redução do BFRW peso e do diâmetro da BF, maior grau de lesão histológica e depleção linfocitária e títulos mais elevados de anticorpos. No segundo experimento, 16 aves dos grupos T1 ao T6 foram isoladas e desafiadas com o vírus muito virulento da IBD (vvIBDV) aos 25 dias de idade. Somente os grupos T4, T5 e T6 foram completamente protegidos do desafio com vvIBDV. No terceiro experimento, o potencial imunossupressor de cada vacina foi determinado através da capacidade das aves vacinadas responderem à vacinação contra a Doença de Newcastle (ND) e posterior desafio. Nenhuma vacina apresentou-se imunossupressora.

Evaluation of experimental vaccination of white pekin ducks (anas platyrhynchos) against newcastle disease

ABSTRACT This study aimed the characterization of the importance of vaccination against Newcastle disease of white Pekin duck (Anas platyrhynchos). There were used 120 Pekin ducks, distributed at random into 4 groups, vaccinated or not. At 60 days of age, all groups were challenged with a pathogenic virus (NDV) suspension, EID50 = 108.15/0.1 mL and a group of Specific Pathogen Free (SPF) chicks were used as control of the virus. Cloacal and tracheal swabs from each bird were collected after 6, 14, 20 and 30 days post-challenge for viral isolation in SPF embryonated eggs. White Pekin ducks of all groups did not demonstrate symptoms of the Newcastle Disease (ND). They were refractory to the ND clinical disease. In Pekin ducks from control group, the viral isolation was obtained from 20 up to 30 days after challenge. The NDV isolation was possible in 100% of SPF chicks that died after challenge with ND clinical signs, suggesting the possible state of carrier of NDV by Pekin ducks. In vaccinated groups, the viral isolation was null. It was also demonstrated therefore the relevance of the vaccination to control the virus dissemination by white Pekin ducks infected with NDV.

RESUMO O objetivo do trabalho foi estudar a importância da vacinação de marrecos de Pequim (Anas platyrhynchos) contra a Doença de Newcastle (DN). Foram utilizados 120 marrecos, distribuídos aleatoriamente em 4 grupos, vacinados ou não. Aos 60 dias de idade, todos os grupos foram desafiados com uma suspensão de vírus patogênico (VDN), EID50 = 108,15/0,1 mL e um grupo de aves livres de patógenos específicos (SPF) foi utilizado como controle do vírus . Suabes cloacais e traqueais foram colhidos após 6, 14, 20 e 30 dias após o desafio para isolamento viral, realizado em ovos embrionados SPF. Os marrecos de Pequim de nenhum dos grupos demonstraram sinais clínicos da DN, mostrando-se refratários à doença clínica. Nos marrecos do grupo controle, o isolamento viral foi positivo de 20 até 30 dias após o desafio, sugerindo o possível estado de portador do VDN pelos marrecos de Pequim. Foi realizado o isolamento viral em 100% das aves SPF, que apresentaram sinais clínicos e vieram a óbito após o desafio com o VDN. Nos grupos vacinados, o isolamento do VDN foi nulo. Tais dados demonstraram a importância da vacinação para o controle da disseminação do vírus pelos marrecos de Pequim infectados pelo VDN.

Evaluation of yeast cell wall on the performance of broiles fed diets with or without mycotoxins

This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb) and ochratoxin (500 or 250 ppb), and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.

Evaluation of yeast cell wall on the performance of broiles fed diets with or without mycotoxins

This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb) and ochratoxin (500 or 250 ppb), and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.

Importancia das perdizes (rhynchotus rufescens) como fonte potencial de vírus patogênico da doença de newcastle para aves domésticas / Relevance of partridge (rhynchotus rufescens) a potential source of pathogenic virus of newcastle disease to domestic fowl

RESUMO Foram realizados estudos para esclarecimento do real papel exercido pela perdiz (Rhynchotus rufescens), no plano epidemiológico, dentro da perspectiva de fonte de infecção do vírus da doença de Newcastle (VDN). Para tanto, foram empregadas aves SPF ("specificpathogen free") conviventes com perdizes inoculadas com uma estirpe patogênica (velogênica viscerotrópica) do VDN ( DIE50 = 108,15/ 0,1 mL), pela via óculo-nasal. Cada grupo foi constituído por 6 aves SPF e 6 perdizes. Decorridos cinco (grupo 1), 15 (grupo 2) e 30 dias (grupo 3) após inoculação das perdizes com VDN, 6 aves SPF foram alojadas junto a cada grupo de perdizes, havendo contato direto entre as espécies. Decorridos também 5, 15 e 30 dias após o desafio das perdizes com o VDN, foram colhidos suabes de cloaca das perdizes, para o isolamento viral (vírus patogênico) em embriões de galinhas SPF. As perdizes apresentaram-se refratárias à doença clínica com o VDN. Nestas, o isolamento viral ocorreu de 5 até 15 dias após o desafio com o VDN, demonstrando-se assim o estado de portador do VDN da perdiz, passados até 15 dias da infecção experimental com este patógeno. Já 100% das aves SPF conviventes com perdizes infectadas com o VDN, passados agora 5 (grupo 1) e 15 dias (grupo 2), morreram de 4 a 8 dias após o contato direto entre as espécies. Nestas, os sintomas clínicos e lesões sugestivos da enfermidade de Newcastle foram confirmados pelo reisolamento e identificação do VDN, a partir de suabes de traquéia e cloaca. Desse modo, ficou evidente a transmissão de vírus patogênico (VDN) da perdiz, decorridos até 15 dias da infecção experimental com este patógeno, para aves SPF conviventes, o que vem realçar a importância da perdiz (Rhynchotus rufescens), do ponto de vista epidemiológico, como fonte potencial de infecção do VDN para aves domésticas em convívio ou próximas a sua criação.

ABSTRACT Studies were made to clarify the real role that was played by the partridge (Rhynchotus rufescens) in the epidemiological plan, under the perspective of its being an infection source of the Newcastle disease virus (NDV). For this, the study used specific-pathogen-free birds (SPF) that were housed with partridges inoculated with a pathogenic strain (velogenic viscerotropic) of NDV (DIE50=108,15/0,1 mL), by the ocular-nasal via. Each group was composed by 6 SPF birds and 6 partridges. At 5, 15 and 30 days after the inoculation of the partridgeswith NDV, 6 SPF birds were put together with each group of partridges, so that there was a direct contact between the species. After 5, 15 and 30 days since the challenge of the partridge with NDV, the samples were collected by means of cloacal swabs of the partridge for the viral isolation (pathogenic virus) in SPF embryos. There was no clinical disease in the partridges inoculated with NDV. Therefore, there was viral isolation from 5 to 15 days after the challenge with the NDV, demonstrating, this way the state of carrier of the partridge NDV which happened until 15 days of the experimental infection with this pathogen. So, 100% of the SPF birds which were housed with the NDV infected partridges, after 5 (group 1) and 15 days (group 2), died from four to eight days after the direct contact among species. This way, the transmission of the pathogenic virus of the partridgeswas evident until 15 days of the experimental infection with this pathogen (NDV) for the SPF birds that were housed together, and that calls the attention to the importance of the partridges from the epidemiological point of view as potential source of infection of the NDV to domestical birds that housed with these specie or near this breeding.

Efeitos de Produto de Exclusão Competitiva na Prevenção dos Efeitos Tóxicos da Ocratoxina A em Frangos

This experiment aimed at evaluating the action of competitive exclusion (CE) on the effects of ochratoxin A (OA). Birds fed 2ppm OA in the diet had significant lower feed intake, weight gain, and feed conversion than birds not exposed to OA in the diet. The use of CE on the first day of age did not minimize these effects nor the performance parameters studied. Birds fed OA has lower vaccinal titers of Newcastle disease virus, showing the interference of this mycotoxin on the humoral immune response of broilers. CE did not interfere in the humoral immune response of broilers vaccinated for Newcastle disease. OA and CE did not influence villus height, crypt depth, nor villus:crypt ratio in seven-day-old birds as compared to control broilers of the same age.

Esse experimento foi realizado com o objetivo de avaliar a ação de produto de exclusão competitiva (EC) sobre os efeitos da ocratoxina A (OA). As aves alimentadas com 2 ppm de OA na dieta reduziram significativamente o consumo de ração e ganho de peso, além de apresentarem pior conversão alimentar quando comparadas às aves não expostas à OA na dieta. O emprego da EC no primeiro dia de vida não minimizou esses efeitos, bem como não afetou os parâmetros zootécnicos estudados. Aves alimentadas com OA apresentaram diminuição nos títulos vacinais contra o vírus da doença de Newcastle, evidenciando-se assim a interferência dessa micotoxina na resposta imune humoral de frangos de corte. De outra forma, a EC não interferiu na resposta imune humoral de frangos de corte vacinados contra a doença de Newcastle. Tanto a AO como a EC não alteraram os dados de altura de vilo, profundidade de cripta e relação vilo:cripta nas aves aos sete dias de idade quando comparados àqueles do grupo controle na mesma idade

Efeitos de Produto de Exclusão Competitiva na Prevenção dos Efeitos Tóxicos da Ocratoxina A em Frangos

This experiment aimed at evaluating the action of competitive exclusion (CE) on the effects of ochratoxin A (OA). Birds fed 2ppm OA in the diet had significant lower feed intake, weight gain, and feed conversion than birds not exposed to OA in the diet. The use of CE on the first day of age did not minimize these effects nor the performance parameters studied. Birds fed OA has lower vaccinal titers of Newcastle disease virus, showing the interference of this mycotoxin on the humoral immune response of broilers. CE did not interfere in the humoral immune response of broilers vaccinated for Newcastle disease. OA and CE did not influence villus height, crypt depth, nor villus:crypt ratio in seven-day-old birds as compared to control broilers of the same age.

Esse experimento foi realizado com o objetivo de avaliar a ação de produto de exclusão competitiva (EC) sobre os efeitos da ocratoxina A (OA). As aves alimentadas com 2 ppm de OA na dieta reduziram significativamente o consumo de ração e ganho de peso, além de apresentarem pior conversão alimentar quando comparadas às aves não expostas à OA na dieta. O emprego da EC no primeiro dia de vida não minimizou esses efeitos, bem como não afetou os parâmetros zootécnicos estudados. Aves alimentadas com OA apresentaram diminuição nos títulos vacinais contra o vírus da doença de Newcastle, evidenciando-se assim a interferência dessa micotoxina na resposta imune humoral de frangos de corte. De outra forma, a EC não interferiu na resposta imune humoral de frangos de corte vacinados contra a doença de Newcastle. Tanto a AO como a EC não alteraram os dados de altura de vilo, profundidade de cripta e relação vilo:cripta nas aves aos sete dias de idade quando comparados àqueles do grupo controle na mesma idade

Avaliação da eficiência de um probiótico no controle de diarréia e no ganho de peso de bezerros

A total of 99 pregnant cows were dividided into eight groups and submitted to the following treatments: group I (n = 29) non vaccinated cows whose calves did not receive probiotic and was used as control; group II (n FONT FACE="Symbol" > or = /FONT> 10) vaccinated cows whose calves did not receive a probiotic; groups III, IV and V (n FONT FACE="Symbol" > or = /FONT> 10 each) vaccinated cows whose calves received a probiotic for 5, 15 and 30 days, respectively; groups VI, VII and VIII (n FONT FACE="Symbol" > or = /FONT> 10 each) non vaccinated cows whose calves received a probiotic for 5, 15 and 30 days, respectively. Each animal in the vaccinated groups received two vaccine doses, subcutaneously, containing pili K99 and A14 of Escherichia coli. The probiotic containing Ruminobacter amylophilum, Ruminobacter succinogenes, Succinovibrio dextrinosolvens, Bacillus cereus, Lactobacillus acidophilus and Streptococcus faecium at the dose of 3.0× 10(8) live cells (CFU) of each sample resuspended in 250ml of milk, was administered orally. All animals were observed clinically and bacteriologically and anti-K99 and anti-A14 antibody titers were determined in serum and colostrum. Mean calf weight was mensured at birth and at 30 days of age. The results showed that the combination of vaccine with the probiotic administered for 15 and 30 days were the most efficient treatments for the control of diarrhea and weight gain.

Foram utilizadas 99 vacas prenhes distribuídas em oito grupos que receberam os seguintes tratamentos: grupo I, com 29 vacas não vacinadas e seus bezerros que não receberam probiótico, ficando como controle; grupo II, com 10 vacas vacinadas e seus bezerros que não receberam probiótico; grupos III, IV e V, com 10 animais cada, vacas vacinadas e seus bezerros que receberam probiótico durante 5, 15 e 30 dias, respectivamente; os grupos VI, VII e VIII, com 10 animais cada, vacas não vacinadas e seus bezerros que receberam probiótico durante 5, 15 e 30 dias, respectivamente. Cada animal dos grupos vacinados recebeu duas doses vacinais contendo os pili K99 e A14 de Escherichia coli na dose de 5,0ml por via subcutânea. O probiótico contendo Ruminobacter amylophilum, Ruminobacter succinogenes, Succinovibrio dextrinosolvens, Bacillus cereus, Lactobacillus acidophilus e Streptococcus faecium, na dose de 3,0× 10(8) células vivas (UFC) de cada amostra em 250ml de leite, era adiministrado por via oral. Os animais foram observados diariamente e foram determinados os títulos de anticorpos anti-K99 e anti-A14 no soro e no colostro. Anotaram-se os pesos dos bezerros ao nascimento e aos 30 dias. Os resultados mostraram que a associação de vacina com probiótico administrado por 15 e 30 dias foram os tratamentos mais eficientes no controle da diarréia e ganho de peso.