Effects of Guar meal with and without B-mannanas enzyme on performance and immune response of broiler chicks

ABSTRACT: This experiment was conducted to study the effects of guar meal (0, 3, 6 and 9 %) and B-mannanase enzyme (0 and 0.05 %) on performance, immune response and ileal viscosity in broiler chicks. Ross male broiler chicks (480 birds) allocated to 8 treatments with five replications (12 chicks in each pen) and reared on floor pen for 42 day. Immunity was assessed as antibody production to Infectious Bronchitis Virus (IBV) and Sheep Red Blood Cell (SRBC). On 10 day, chickens were inoculated intramuscular with 0.5 ml of 5 % SRBC. The injection with SRBC was repeated 12 d later. The data were analyzed as 4×2 factorial arrangement in a completely randomized design. Daily weight gain and body weight (42d.) significantly reduced and FCR increased in chicks fed diets containing 9 % guar meal. Feed intake was lower in chicks fed 9 % guar meal than other groups only at starter period. The ileal viscosity increase by elevating amounts of guar meal in chick diets at 21 and 42 day, as well as B-manannase enzyme supplementation relatively decrease the ileal viscosity. Antibody titers for primary and secondary responses to SRBC was highest in chicks receiving 3 % guar meal diet and was lowest in chicks receiving 9 % guar meal diet. Humoral immunologic response showed that antibody titer to IBV significantly increased in all chicks receiving guar meal diets. In spite of a trend to improve FCR and bodyweight gain with B-mannanase supplementation, feed intake was not affected by enzyme supplementation. The greatest positive effect of enzyme supplementation was related to improve immune responses. The results of this experiment showed that use of guar meal up to 6 % not only have no negative effect on performance but also improve immune response in broiler chicks. The supplementation of B-mannanase enzyme to guar meal diets improves performance and immune response in broiler chicks.