Abstract
Context The ban on antibiotics in broiler feed has led to the need for alternative additives that can be used in poultry production, particularly in tropical climates where animals experience high levels of stress. A capsicum extract (CE), derived from chili peppers, is a potential feed additive that may enhance the performance of broiler chickens. Aims This experiment investigated the effects of CE on the growth performance, blood parameters, and intestinal bacterial population of broilers raised under high stocking density in a tropical region. Methods Four hundred and thirty-two 1-day-old Ross-308 male broiler chicks were divided into six treatments, each with six replicate pens of 12 birds. The experiment followed a randomised complete-block design. Feeding was conducted for 38 days in the following three phases on the basis of breeder recommendations: starter, grower, and finisher. CE was supplemented in the feed at concentrations of 80, 160, 240, and 320 mg/kg. All feeds were pelleted to different sizes for each phase. Growth performance was assessed at the end of each phase. Blood samples were collected to determine the complete blood count (CBC) and serum growth-hormone concentration. Chicks were euthanised using CO2 inhalation, and samples from the jejunum were collected for histological analysis. The caecocolonic contents were sampled for microbiological testing. Key results CE supplementation at concentrations of 160 and 240 mg/kg improved the performance of broilers equivalent to enramycin supplementation at 250 mg/kg, with additional benefits observed in water intake when supplemented at 240 mg/kg. The slight improvement in villous height may have contributed to the enhanced growth performance. Both the lowest (80 mg/kg) and highest (320 mg/kg) supplemented concentrations of CE slightly improved broiler performance compared with the control group. The lowest dose of CE also had a beneficial effect in reducing the E. coli:Lactobacillus ratio. Conclusions It is concluded that CE supplementation may improve performance of broilers under moderate heat-stress conditions by increasing feed and water intake with an enhanced bodyweight gain. Implications A capsicum extract can be used as an antibiotic alternative in broiler production in hot tropical environments.