Abstract
Objective: To investigate the effects of dietary supplementation with different levels and molecular weights of fungal beta-glucan on productive performances, health, carcass traits and meat quality in broilers. Methods: Two hundred and ten of one-day-old chicks with equal sex were assigned to seven experimental groups in 2x4 factorial arrangement. These groups were supplemented with (0, 10, 30, and 60 ppm) of molecular weight 1-3, 1-6 beta-glucan (low or high). High molecular weight beta-glucan (H: 943 kDa) was obtained from Ophiocordyceps dipterigena BCC 2073, whereas H with.-Irradiation treatment was performed to achieve low molecular weight beta-glucan (L: 8 kDa). Results: There was no statistical significance in productive performances, apparent digestibility and interaction between fixed factors along 42 days of experiment (p>0.05). A higher caecal amylase activity was present in the group that received L, while there was a dramatic decrease in H and the control groups, respectively (p<0.05). The increase of supplemental dose increased caecal amylase activity (p<0.05). Immunomodulatory effects from L was revealed by the marked increase of phagocytic activity, relative weight of thymus and bursa of fabricius (p<0.05). Similarly, the additive dose at 30 ppm provided the same results, whereas the only significant difference with supplementation at 60 ppm was an increase in phagocytic activity (p<0.05). Interestingly, villi height of broilers fed L was higher than other groups (p0.05). Conclusion: The supplementation of L at 30 ppm was suggested to achieve benefits of immune modulation without adverse effects on other parameters.
