The objective of this study was to compare the efficiency of washing and trimming broiler carcasses to reduce bacterial contamination. At the postevisceration site, 100 broiler carcasses were collected during 4 visits to a slaughterhouse in Santa Catarina State, Brazil. Birds were from the same flock, age, and approximately 2.4 kg of weight. Groups were as follows: group 1, with fecal contamination; group 2, without fecal contamination; group 3, with fecal contamination and trimmed; group 4, with fecal contamination and washed; group 5, with fecal contamination, and washed and trimmed. Carcass washings were performed with at least 1.5 L/bird of potable water (0.5 to 1 mg/kg of residual chlorine) at room temperature (20-25°C) using spray cabinets with 44 spray nozzles distributed into 2 chambers (pressure of 2 kgf/cm(2) and 4 kgf/cm(2)). Washed carcasses (trimmed or not) showed significantly (P < 0.05) lower counts of aerobic mesophiles (plate count agar) on the third evaluation, and even lower (P < 0.01) counts for total coliforms (CT) and fecal coliforms (Escherichia coli). Trimmed carcasses showed significantly lower counts (P < 0.05) for plate count agar; however, we observed higher counts for E. coli (P < 0.05). The association of both treatments (washing and trimming) showed significantly higher (P < 0.05) counts for coliforms (CT and E. coli). We can conclude that the washing method is overall more efficient than the trimming method to decontaminate chicken carcasses at the postevisceration site. Hopefully, our findings can help poultry companies to minimize production costs by applying the washing method for carcass decontamination.
Adhesion proteins from Mycoplasma gallisepticum (MG) encoded by cytadhesion genes mgc1 and mgc2 were cloned into plasmid vectors and transformed into E. coli. Seventeen groups of specific-pathogen free (SPF), birds at four weeks of age were used to inoculate these two proteins (MGC1 and MGC2) mixed into an oil emulsion creating a novel MG vaccine. Six different protein concentrations (50, 100, 200, 400, 800, and 1000µg/bird) were tested with two equal concentration doses at four and seven weeks of age. In addition, many control groups were needed such as bacterin, membrane, no vaccine or challenge, oil emulsion alone, and no vaccine but challenged. Three weeks following the second vaccination, 50% of the birds in each treatment group were challenged with MG strain S6. The remaining birds were left as contacts to verify protection against horizontal transmission. All birds were bled before vaccinations, challenge and euthanasia. Birds were negative for MG at the first vaccination, as shown by serum plate agglutination test. At necropsy, tissue samples (trachea, lungs, and air sacs) were collected for histopathological examination. Swabs from trachea were used for PCR analysis. ELISA results showed a strong immune response to both protein preparations and almost the same response level for different doses tested, proving the immunogenic features of MGC1 and MGC2. However, humoral responses failed to prevent MG infection and disease when challenged as demonstrated by PCR and histopathology. MGC1 contact birds showed some degree of infection by PCR analysis. In addition, histopathological and ELISA results suggest that contact birds did not have enough time to develop lesions and to mount an immune response.Keywords: evaluation, development, mycoplasmas, poultry, vaccine (50, 100, 200, 400, 800, e 1000µg/ave) RESUMO Os genes mgc1 e mgc2, codificadores de duas proteínas de adesão (MGC1 e MGC2) da bactéria Mycoplasma gallisepticum, foram clonados em E. coli. Dezessete grupos de aves livres de patógenos específicos (SPF), com quatro semanas de idade, foram inoculados com uma emulsão oleosa contendo as proteínas MGC1 e MGC2 purificadas. Seis concentrações
In order to analyze the influence of vitamin E on the immune response of birds vaccinated and challenged with Infectious Bronchitis Virus in poultry (IBV), and which dose of vitamin E is the best to answer this, an experiment was conducted using 50 SPF birds housed with one day of life at Embrapa -Suínos e Aves. All birds were divided into 10 groups of five birds each, including positive and negative control groups, supplemented with 15, 50, and 200 IU of vitamin E/Kg added into the feed. On the 14th day of life the birds were vaccinated with a commercial vaccine for infectious bronchitis (H-120) and after 28 days, one group for each treatment was challenged with IBV, strain classical (M-41). Five days after challenge birds were necropsied and abdominal macrophages were collected for analysis of microbicidal activity and measurement of nitric oxide (NO). The lung was collected for cell count by flow cytometry and also for NO dosage. Organs of predilection were also collected for histological analysis and virus isolation to analyze the efficiency of the vaccine. The results were evaluated by ANOVA and Student t-test. An increased of microbicidal activity of abdominal macrophages was observed in the groups of birds with higher levels of vitamin E (200 IU/Kg) supplementation when compared with groups that did not receive or received minor amounts (0, 15, 50 IU/Kg), indicating an improvement in the innate immune response influenced by vitamin E supplementation in the diet. The supplementation of this vitamin in high doses also increases the ability of macrophages to produce NO. And, by flow cytometry, suggests that the macrophages are the primary cells recruited in the lung tissue to combat infectious bronchitis and this action was potentiated by the addition of vitamin E, independent of the dosage. Key words: Immunity, nutrition, vaccine, vitamin E ResumoA fim de analisar a influência da vitamina E sobre a resposta imunológica de aves vacinadas e desafiadas com o Vírus da Bronquite Infecciosa das aves (VBI), e qual dose da vitamina E é melhor para essa resposta, foi realizado um experimento utilizando 50 aves SPF alojadas com um dia de vida na Embrapa -Suínos e Aves. As aves foram divididas em 10 grupos de cinco aves cada, incluindo grupo controle positivo e negativo, suplementadas com 15, 50 e 200 UI/Kg de vitamina E na ração. No décimo quarto dia de vida as aves foram vacinadas com a vacina comercial para Bronquite Infecciosa (H-120) e após 28 dias, um grupo por tratamento foi desafiado com VBI cepa clássica (M-41). Cinco dias após o desafio as aves foram necropsiadas e os macrófagos abdominais foram coletados para análise da atividade microbicida e dosagem de óxido nítrico (NO). O pulmão foi coletado para contagem de células através de citometria de fluxo e também dosagem de NO. Órgãos de eleição também foram coletados para análise histológica e realização do isolamento viral para analisar a eficiência vacinal. Os resultados foram avaliados pelo teste ANOVA e Student t-test. Um aumento da atividade micr...
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