Supplementation with a blend based on micro-encapsulated carvacrol, thymol, and cinnamaldehyde in lambs feed inhibits immune cells and improves growth performance

The objective of this study was to determine whether supplementation with a blend based on micro-encapsulated carvacrol, thymol, and cinnamaldehyde added to concentrate in growing lamb feed would affect performance or produce antioxidant and immunological responses. In our study, the blend mixed with concentrate was technically defined as a phytogenic. Thirty female animals were randomly distributed in three groups with five repetitions and two animals per repetition, as follows: Control (basal feed), T500 (basal feed supplemented with 500 mg phytogenic/kg of concentrate) and T1000 (basal feed with 1000 mg phytogenic/kg of concentrate). Weights were measured and blood was collected on days 0, 15, 30 and 40 of the study. The T1000 animals had greater weight gain during the experimental period (0 to 40) as well as from day 30-40 of the experiment compared to the Control group. The T500 and T1000 lambs had greater weight gain on the 15th to 40th day when compared to Control. T1000 lambs had lower numbers of leukocytes and lymphocytes on days 30 and 40 compared to Control. Cholesterol levels were greater on day 30 in the T500 group than in the Control group. Levels of reactive oxygen species, lipid peroxidation and glutathione S-transferase did not differ between treatments. The activities of glutathione peroxidase (GPx) and glutathione reductase were lower in the T1000 animals than in the Control at day 30; this was different from what was observed on day 40, when GPx showed a significant increase in T1000. We conclude that supplementation with this phytogenic product in lamb feed stimulated antioxidant and anti-inflammatory responses and consequently increased weight gain in lambs. In practical situations, we expect that the inclusion of this additive in the diet of female lambs will produce more healthy and heavier ewes that achieve the reproductive life earlier.