Each pen was equipped with a tray feeder and a manual drinker. At 7 d of age, the tray feeder was replaced with a round-bottom feeder. The birds were vaccinated for Newcastle disease at 7 d of age and for Gumboro disease at 14 d of age.The experiment was a completely randomized design with 6 experimental treatments: control (negative control), control with 5 ppm of chlortetracycline (positive control), and 0.5, 1.0, 1.5,and 2% DPM. All diets were formulated to similar levels of calculated ME and CP according to the recommendation of NRC [19]