Resumo
ABSTRACT The study aimed to explore the effect of dietary supplementation of synbiotics on growth performance, carcass characteristics and nutrient digestibility in broiler chicken. For this purpose, three hundred 1-day-old Cobb-500 broiler chicks were purchased from the hatchery and randomly distributed into five dietary treatment groups. Each treatment had six replicates, each containing 10 chicks. The experimental diets were supplemented with 0, 700, 1200, 1700 or 2200 g/ton of feed synbiotics and respectively designated as A, B, C, D and E, with A being the control diet. Feed intake, weight gain and feed conversion ratio data were recorded on a weekly basis. At the research trials end, two birds from each pen were randomly selected and slaughtered to get data on carcass characteristics. Results showed that group Cs feed intake was reduced (p 0.05) when compared to control. Body weight was similar (p>0.05) among all treatments. However, feed conversion ratio was significantly improved (p 0.05) in group C as compared to other dietary treatments. Nutrient digestibility was improved (p 0.05) in group B and C, as compared to control. Carcass characteristics were not significantly affected and remained the same across all treatments. However, liver weight decreased in birds fed diet C. Meat quality and antibody titer were not affected in any of the dietary treatments. It is concluded that synbiotics can be safely used up to 1200 g/ton of feed, improving bird performance without harmful effects on bird health.
Resumo
Especialmente nos últimos anos a avicultura brasileira tem alcançado índices elevados de crescimento, tornando-se o terceiro principal produtor mundial de carne de frango e líder de exportações, atingindo 142 países. Fatores como saúde e bem-estar animal, qualidade e preço contribuíram para aperfeiçoar a produtividade no setor. Diante disso, a preocupação com a sanidade dos animais é um dos grandes desafios do mercado, sendo que o controle da Bronquite Infecciosa das galinhas (BI) e a erradicação do Mycoplasma synoviae (Ms) em granjas de reprodução são questões de enorme relevância sanitária. A BI, causada por um coronavírus, o Vírus da Bronquite Infecciosa (IBV), trata-se de uma doença viral aguda e altamente contagiosa. Já a micoplasmose, causada pela menor bactéria existente, o Ms, possui uma grande capacidade de disseminação no lote de matrizes sendo que, uma vez positivo, o lote permanece com esse status até o fim da sua vida. Ambas as doenças apresentam sinais clínicos semelhantes afetando a parte respiratória, tornando-se secundária uma à outra. Assim sendo, é importante avaliar se as aves que apresentavam sintomas sugestivos à IBV e que já eram sabidamente positivas para Ms, estavam realmente protegidas através da vacinação. No presente estudo foram avaliados os títulos vacinais de Bronquite Infecciosa a fim de verificarmos a existência de interferência na resposta sorológica frente ao IBV pela positividade de Ms. Para isso, foram verificados os resultados de 326 amostras de soro coletadas no período de 2014 à 2018, em lotes de matrizes de uma agroindústria do Oeste catarinense. Para avaliar o efeito da presença de Ms sobre o titulo médio de bronquite foi aplicado o teste t para comparação de dados não pareados. Através da presente análise verificou-se que não houve interferência de Ms nos títulos de anticorpos frente ao vírus da Bronquite Infecciosa (IBV).
Especially in recent years, Brazilian poultry has achieved high growth rates, becoming the third major worldwide producer of chicken meat and leader in exports, reaching 142 countries. Factors such as animal health and welfare, quality and price have contributed to improving productivity in the sector. Given this, the concern with the health of animals is one of the main challenges of the market, and the control of Infectious Bronchitis of chickens (IB) and the eradication of Mycoplasma synoviae (Ms) in breeding farms are issues of enormous animal health relevance. IB, caused by a coronavirus, the Infectious Bronchitis Virus (IBV), is an acute and highly contagious viral disease. Mycoplasmosis, on the other hand, is caused by the smallest existing bacteria, Mycoplasma synoviae (Ms), has great capacity for dissemination in the breeding flock, and once the flock is positive, it remains with this status until the end of its life. Both diseases show similar clinical signs affecting the respiratory part, becoming secondary to each other. Therefore, it is important to assess whether birds that had symptoms suggestive of IBV and that were already known to be positive for Ms, were actually protected through vaccination. In the present study the vaccine titers of Infectious Bronchitis were evaluated in order to verify the existence of interference in the serological response against IBV by the positivity of Ms. For this, the results of 326 serum samples collected in the period from 2014 to 2018 in batches of matrices of an agribusiness in the West of Santa Catarina were verified. To evaluate the effect of the presence of Ms on the mean titer of bronchitis, the t test was applied in order to compare unpaired data. Through the present analysis it was verified there were no interference of Ms in the antibody titers against the Infectious Bronchitis virus (IBV).