Evaluation of a mixture of carvacrol, cinnamaldehyde, and capsicum oleoresin for improving growth performance and metabolizable energy in broiler chicks fed corn and soybean meal

The objective of this study was to evaluate the effect of a mixture of carvacrol, cinnamaldehyde, and capsicum oleoresin (XT, Pancosma S.A., Geneva, Switzerland) on the ME_n of cornsoybean meal diets for broilers (experiment 1) and to confirm the energy effect in a growth performance trial (experiment 2). For experiment 1, 12 replicate groups of 5 chicks were assigned to each of the 4 treatments in a 2 × 2 factorial design. Factor 1 was diet type [corn-soybean meal or corn-soybean meal with 10% corn distillers dried grains with solubles (DDGS)]. Factor 2 was XT (0 vs. 100 mg/kg of XT). Diets were fed from 1 to 22 d. For experiment 2, chicks were fed a corn-soybean meal diet (no DDGS) from 9 to 34 d of age. Two factors were again organized in a complete 2 × 2 factorial design. Factor 1 was dietary ME_n content (3,000 vs. 2,950 kcal of ME_nkg), and factor 2 was XT (0 vs. 100 mg of XT/kg). For experiment 1, from d 1 to 8, XT significantly increased BW gain (P < 0.05). The XT also significantly increased ME_n content at 22 d, with the increase being 68 kcal/kg for the corn-soybean meal diet with no DDGS. The 90% CI for the 68 kcal/kg value was 50 to 86 kcal/kg. The latter is the reason the value of 50 kcal/kg was selected as the energy difference between diets in experiment 2. The decrease in ME_n from 3,000 to 2,950 kcal/kg significantly depressed BW gain (2.4%) and G:F (2.1%). Conversely, XT significantly increased BW gain (2.4%) and G:F (2.3%). We observed that a 100 mg/kg mixture of carvacrol, cinnamaldehyde, and capsicum oleoresin increased the dietary ME_n of the corn-soybean meal diet. The ME_n value of 50 kcal/kg for 100 mg of XT/kg corresponded to the lower limit of the 90% CI and was confirmed in a growth performance trial.