Effect of hops β-acids (Humulus lupulus) on performance and intestinal health of broiler chickens

To evaluate a novel feed additive, hops beta-acids, a pen trial using 1,440 one-day-old broiler chickens, in a randomized design with 6 treatments and 6 replicates of 40 birds/pen, was conducted. The experimental treatments were a negative control (NC) basal diet, a positive control (PC) basal diet supplemented with zinc 30 mg/kg of bacitracin, and 4 additional treatments consisting of the basal diet supplemented with 30, 60, 120, and 240 mg/kg of hops beta-acids in a microencapsulated form. All birds were vaccinated against coccidiosis by eye drops. Productive performance, jejunum morphology, and Clostridium spp. count in jejunum and cecum contents were evaluated. At 21 d of age, the birds fed the PC, 30, or 60 mg/kg of beta-acids had the same weight gain of those fed the NC, whereas the highest level of beta-acids decreased the gain. In addition, feed intake was decreased and FCR was improved in all treatments when compared with the NC. At 42 d, compared with the NC, the treatments containing 30 or 240 mg/kg of beta-acids and the PC resulted in improved FCR. No differences were found for other performance variables. No difference was observed among the treatments on villus length, crypt depth, and villus-to-crypt ratio. Except for one sample, all others had negative results for Clostridium spp. based on the methodology of sulphite reduction. In this study, we demonstrated positive effects of supplementation of hops beta-acids on productive performance of broilers, and the best results were obtained with addition of 30 mg/kg.