The effects of rosemary on growth performance, carcass characteristics and blood parameters of broilers under heat stress

The application of medicinal herbs with high anti-oxidant properties could reduce the detrimental effects of oxidative stress and free radicals under heat stress and improve the performance of broilers. The effects of rosemary powder and extract on growth performance, carcass characteristics and blood parameters of broilers were evaluated under heat stress.
For studying the effect of experimental treatments including control, different levels of rosemary powder (5, 10 and 15 g/kg), rosemary extract (3.5,7 and 10.5 g/kg) and Vit-Asp (1 g/L) on growth performance (feed intake, body weight and feed conversion ratio), carcass characteristics and blood parameters (cholesterol, triglyceride, hematocrit, glucose and heterophil to lymphocyte ratio), 160 one-day old chicks (Ross male-308) were used applying a randomized complete block design with 8 treatments, 4 replicates and 5 chicks per replicate during a 42-day period. Heat stress schedule was 32±2ºC as cyclic from 10.00 AM to 6.00 PM.
Rosemary had significant effects on feed intake and final live weight of chicks (p0.05). Significant effects from rosemary on glucose and heterophil to lymphocyte ratio were found (p0.05).
In general, inclusion of rosemary in broilers diet under heat stress improved the performance because of anti-oxidant effects.