Investigation of the effects of adding probiotic and encapsulated thyme essential oil on growth performance and immune responses of broiler chicks by multi attribute decision making

The current study aimed to investigate the effects of adding probiotic and encapsulated thyme essential oil (TEO) on growth performance and immuneresponses of broiler chicks by multi attribute decision making (MADM). In the current study, 420 broiler chicks were allocated into 7 experimentalgroups with 6 replication and 10 broiler chicks per replication for 42 days. The experimental treatments were included 1) diet lack of TEO andprobiotic (control), 2) diet containing 100 mg probiotic, 3) diet containing 100 mg TEO, 4) diet containing 200 mg probiotic, 5) diet containing 200mg TEO, 6) diet containing 100 mg probiotic+100 mg TEO, and 7) diet containing 200 mg TEO+ 200 mg probiotic. Growth performance andhumoral immune responses were investigated. Index weights for weight gain, feed conversion ratio, production index were 0.2, 0.15 and 0.25,respectively and index weight of 0.1 was considered for other parameters. Coefficients for control, probiotic 100, TEO 100, probiotic 200, TEO 200,probiotic 100 + TEO 100 and probiotic 200 + TEO 200 were 0.0476, 0.126, 0.198, 0.315, 0.427, 0.727 and 0.956, respectively. Thus, adding 100 mgprobiotic and 100 mg TEO into diet increased immune response and growth performance. Based on obtained results, it is suggested that dietaryinclusion of 100 mg TEO + 100 mg probiotic in diet of broiler chicks has a potential to improve immune response and growth performance.