The Effects of Common and Encapsulated Thyme Essential Oil with Fats on Blood Parameters and Safety of Broilers with Diets Formulated with Normal and Low Crude Protein Levels

In the present experiment, the effects of normal and encapsulated thyme essential oil along with saturated and unsaturated fats on blood parameters and safety of broilers with normal and low protein diets were evaluated.

In this study, 384 Ross 308 broilers in a 2 × 2 × 2 factorial engagements with 8 treatments including (zero and normal and encapsulated thyme essential oil), (beef tallow and rapeseed oil) and common crude protein and 5% less than the recommended strain in 4 replications and 12 chicks per replication in 42 days and in the three experimental periods included starter (1 to 10 days), growing (11 to 24 days) and finisher (25 to 42 days) for investigation. Blood parameters and immunity of broiler chickens were tested by ELISA method and by spectrophotometer and using commercial biochemistry kits, in a completely randomized design.

In relation to the effects of experimental treatments on the biochemical parameters of the blood of chickens, the use of cow tallow, normal thyme essential oil and normal protein level, and rapeseed oil along with thyme essential oil and low protein diets, reduced the LDL level of chickens (P<0.05). The use of encapsulated essential oil of thyme and tallow increased the percentage of blood lymphocytes (P<0.05).

The results of this research show that in Ras 308 broiler chickens, the use of unsaturated fat, along with encapsulated thyme essential oil and the level of crude protein recommended for the strain, improves blood parameters in blood LDL level and the immunity of chickens on the percentage of lymphocytes. It seems that the combination of these substances has synergistic effects and can strengthen each other's biological effects.