The effects of different amounts of Mentha pulegium L. on immune system performance of broiler chickens

ABSTRACT:The purpose of this study was the investigate of the effects of different amounts of Mentha pulegium L.on immune system performance of broiler chickens. 300 one-day-old broilers (308 Ross strain) were used in a completely randomized design in 5 treatments and three replicates(20 birds per replicate) for 42 days. The treatment groups consisted of a control(Group1) assigned to the basal diet and experimental groups 2, 3, 4 and 5were basal diet supplemented with 0.5%, 1%, 1.5% and 2% Mentha pulegium L.of aerial parts powder in the feedstuff, respectively. B1 Newcastle vaccine was used in all groups of broilers at 10,25 and 35 days of age. Two birds from each replicate were randomly chosen and blood sample was taken on the 24th and 34th days of experimental period and Hemagglutination Inhibition (HI) test was performed on sera and the heterophil: lymphocyte ratio was calculated. Regarding HI test(Antibody levels against Newcastle virus vaccine), it didn’t show statistical significance in different treatment groups. Regarding heterophil: lymphocyte ratio, it didn’t show statistical significance in different treatment groups(P > 0.05). But, on the basis of results ,group 3 (1% Mentha pulegium L.) showed the best performance in comparison with the other groups.