Prebiotics, probiotics and thyme (thymus vulgaris) for broilers: Performance, carcass traits and blood variables

Background: a stressful environment predisposes broilers to various diseases. Probiotics, prebiotics and essential oils can be used as an alternative to antibiotics in poultry production. Objective: to evaluate the effects of the Fermacto (prebiotic), Bioplus 2B (probiotic), and thyme essential oil on growth, organs and carcass traits, and hematology of “Ross” broiler chicks during 42 days. Methods: five-hundred sixty broilers were randomly assigned to seven dietary treatment groups (with 20 broilers in each group), with four repetitions. The diets contained 1 or 2 g/Kg Fermacto, 1 or 2 g/Kg Bioplus 2B, and 0.5 or 1 g/Kg thyme essential oil. A control group was also included (without aditives). Results: when compared with the control group, Fermacto, Bioplus 2B, and thyme essential oil resulted in an increase in body weight gain and feed intake. The feed conversion ratio (FCR) was enhanced by 2 g/Kg Fermacto. Thyme essential oil at 1 g/Kg also improved FCR but it led to a reduction in the relative weight of thighs and wings. Limited differences were observed in blood parameters between groups. Conclusion: Fermacto, Bioplus 2B and thyme essential oil improved the average daily gain of broilers and had a limited effect on carcass, organs and plasma constituents.