Two experiments were conducted to evaluate the effects of using black cumin seeds (BCS), Artemisia leaves (AL), and Camellia L. plant extract (CLE) in the diets of broiler chicks. Experiment 1 was conducted as a completely randomized design in a factorial arrangement (2 × 2) with 8 replicates of 4 chicks in each battery cage. Factors included 2 levels of BCS and AL (0 and 1%). Experiment 2 was conducted as a completely randomized design with 4 treatments (control, 0.3 and 0.5 g/kg of CLE, and 0.5 g/kg of mannanoligosaccharide) of 8 replicates and 4 chicks in each. Body weight and cumulative feed intake were measured at 21, 35, and 42 d of age. Antibody response against SRBC was measured on d 28 and 42. Blood characteristics, relative weight and length of different parts of the carcass, gastrointestinal pH, villi length, and crypt depth were measured at 42 d of age. Artemisia addition did not affect BW and feed conversion ratio (FCR) but decreased feed intake significantly up to 21 d of age (P ≤ 0.01). Black cumin significantly increased BW (P ≤ 0.05) at 21 and 42 d of age and decreased FCR throughout the experimental period (P ≤ 0.01). Artemisia significantly increased monocytes but had no effect on gastrointestinal pH, antibody response, and relative weight and length of different parts of the carcass. Black cumin increased red blood cells, hematocrit, hemoglobin, gizzard relative weight, and pH but decreased antibody response and monocytes percentage (P ≤ 0.01). Artemisia did not affect plasma lipid profile but decreased coliform and Escherichia coli populations of ceca significantly (P ≤ 0.01 and P ≤ 0.05, respectively). Addition of 0.5 g/kg of CLE decreased BW, feed intake, and FCR throughout the experiment (P ≤ 0.01). Camellia increased gizzard and proventriculus pH, villi length, and crypt depth (P ≤ 0.01) but decreased primary antibody response, total white blood cell count, and cholesterol concentration (P ≤ 0.05). The results of this experiment showed that using BCS alone or mixed with AL improved broiler health and performance but CLE negatively affected broiler BW and feed intake and is not a good alternative to commercial mannanoligosaccharide.
