[Effects of dietary supplementation of mannan-oligosaccharide on virus shedding in avian influenza [H[9]N[2]] challenged broilers]

ABSTRACT

Avian influenza [AI] is a highly contagious disease causing significant economic losses worldwide. The aim of this study is to evaluate the effect of mannan-oligosaccharide [MOS] on tracheal and cloacal virus shedding in AI challenged broilers and contamination of environment with H[9]N[2]. A total of 300 1-day-old-broiler chicks were randomly divided into 3 groups [A, B and C] and supplemented 0.2, 0.5 and 0.0% MOS, respectively in NRC recommended diet for 36 days. On day 21 the groups were further split into two sub groups A+ve, A-ve, B+ve, B-ve, C+ve and C-ve with 5 replicates each. The positive groups were shifted to remote sheds and were challenged intranasally with 0.1 ml of reference virus [AIV; Pk-UDL/01/08 H[9]N[2]] with EID[50] = 10[-6.66]. Treatment reduces [P<0.05] cloacal virus shedding from day 24 to 26 and 28 to 32. Tracheal virus shedding was lower [P<0.05] on days 25-26 and 28-30 in treatment groups. Day 27 showed highest [P>0.05] virus shedding in all groups. However the reduction of viral shedding is faster in treatment groups and showed no virus shedding on day 32. Maternal antibody titer against AI showed a declining pattern but MOS influenced [P<0.05] the titer in treated groups. Hence the use of MOS may constitute a novel and effective plausible alternative that reduces the spread of disease by decreasing virus shedding and contamination of environment from AIV [H[9]N[2]] infection in poultry