This study investigated the effect of dietary supplementation of L- carnitine on the growth performance, carcass traits and serum biochemical parameters of native Egyptian breed (Fayoumi chicken). The present study were performed on 96 male fayoumi chicks divided into four groups each one had 3 replicate each replicate contain 8 chicks, first group was control, second, third and fourth groups receive L-Carnitine (25mg/kg, 50mg/kg, 100mg/kg respectively) the experiment expanded for 3 months. The birds were weighted at the end of each week. The results showed improvement in body-weight gain (BWG) and feed conversion (FC) After 90 days. The obtained results revealed that body weight after slaughtering (bled, de-feathered), semi eviscerated carcass weight, dressed carcass weight and breast weight, significantly increased in all treated groups (G2, G3, G4). Each of Head, liver, heart, and lung weight was recorded and showed non-significant difference at (P<0.05). The sera were obtained during slaughtering for biochemical tests which showed that increasing the level of L-carnitine lead to significant decrease of cholesterol, and significant increase in total protein, albumin and total globulin. While, the decrease
in triglyceride, VLDL and LDL not significant.