The effect of essential fennel oil (EFO) as an alternative to antimicrobials in the diet of broiler chickens allotted on two type of new (LNo) and recycled (LRe) litter was evaluated. 1,050 birds were housed and adopted a completely randomized design in which from 1 to 21 days the birds were housed only LNo, with seven treatments and 10 replicates of 15 birds: T1 = positive control diet (PC) with antimicrobials (AM), T2 = negative control diet (NC) without AM and EFO, T3 = NC + 0.004% EFO, T4 = NC + 0.008% EFO, T5 = NC + 0.016% EFO T6 = NC + 0.032% EFO and T7 = NC + 0.064% EFO. From 22 to 42 days half of the birds housed in LRe and half continued in LNo, resulting in 14 treatments with five replicates of 15 birds. The EFO was added in the morning, at a ratio of 1/4 of the daily diet and in the afternoon the supply was at ease. In the pre-initial inclusion of 0.015 and 0.026% of EFO, feed intake and weight gain improved, respectively. The inclusion of 0.031% of EFO improved feed conversion of broilers from 1 to 21 days. The EFO promoted higher carcass in birds housed in LNo, higher drumstick weight, and thigh and drumstick yield for broilers reared in LRe. EFO improved the performance of chickens accommodated under LRe.
antimicrobial activity; plant extract; performance
