Effects of Encapsulated Nano- and Microparticles of Peppermint (Mentha piperita) Alcoholic Extract on the Growth Performance, Blood Parameters and Immune Function of Broilers under Heat Stress Condition

This study was aimed to investigate the effects of encapsulated nano- and microparticles of peppermint (Mentha piperita) extract on the growth performance, blood parameters and immune system of broilers under heat stress conditions. In total, 320 one-day-old broilers (Ross, 308) were assigned into 4 experimental treatments: the control, peppermint alcoholic extract (PE, 200 ppm/kg body weight (BW)), encapsulated nanoparticles of peppermint alcoholic extract (ENPE, 200 ppm/kg BW), and encapsulated microparticles of peppermint alcoholic extract (EMPE, 200 ppm/kg BW). Each treatment consisted of 4 replicates with 20 chicks. Results showed PE, ENPE and EMPE treatments significantly improved feed conversion ratio (FCR). The birds administered by PE, ENPE and EMPE had significantly higher blood serum, total protein, albumin and globulin. Administration of PE, ENPE and EMPE resulted in lower total cholesterol, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), LDL:HDL ratio and triglyceride, and higher levels of high-density lipoprotein (HDL). The birds treated by peppermint had higher bursa relative weight, in particular, in those that received ENPE and EMPE than control. Treated birds with PE, ENPE and EMPE showed significantly lower H:L ratio. The serum antibody titers against sheep red blood cells (SRBC) were significantly higher in birds administrated by PE, ENPE and EMPE. Birds receiving ENPE and EMPE treatments had significantly higher titers of IgG for primary and secondary responses than that of those receiving the other treatments. In general, this study indicated that encapsulated nano- and microparticles of peppermint alcoholic extract have potential to improve the immunity and growth performance of broilers under heat stress conditions.