effects of various levels of mallvasylvesteris extract on performance, carcass characteristics and some immune and blood parameters of broiler chickens

this experiment was conducted in order to evaluate the effect of different levels of malva sylvestris extract on performance, carcass characteristics and some immune and blood parameters of broiler chickens with 16 experimental units with 4 treatment, 4 replicate and 11 broilers in each replicate  in completely randomized design for 42 days. the dietary treatments consisted of basal diet (control), and different levels of extract of malva sylvestris (0.1, 0.2 and 0.3 percentage of diet).  feed intake and weight gain were recorded weekly. at 25 and 32 days of age, sheep red blood cell (srbc) injected to 2 broilers of each replicate.at 32 and 39 days, blood samples were collected to quantify antibody titer production against srbc. the results of this experiment showed that effect of malva sylvestris extract on weight gain, feed intake, feed conversion ratio and carcass characteristics were not significant (p>0.05). but there were significant difference between treatments in immune parameters (p<0.05). the highest antibody titer against srbc was observed at 0.3 percent of extract at 32 days of age, but the highest antibody titer was at 0.2 and 0.3 percent of extract at 39 days of age. the addition extract significantly decreased cholesterol, triglyceride, hdl and ldl concentrations (p<0.05). the highest percentage of eosinophil was observed at the level of 0.3 percentage and percentage of heterophile and heterophile to lymphocyte ratio  lowest were in the control treatment. according to the results of this experiment, it appears that different levels of extract were not effective on performance parameters but this extract affected the immune system of broiler chicks