Discipline: Animal Science
A total of 280 all-male, 7 -day old broiler chicks were randomly assigned to four treatments. Treatment I was the basal broiler diets with 100% limestone. For Treatments II to V, limestone in the basal broiler diet was replaced by marble dust (MD) on a weight for weight basis at four different levels, i.e., 25, 50, 75 and 100%, respectively. The calcium content of MD used in this study was 2% higher than that of limestone powder. Trace amount of magnesium and fluorine were detected from MD but not in limestone powder. Weight for weight substitution of limestone with MD consistently increased the calcium content of the broiler diets. Feed consumption, feed efficiency, mortality and bone hardness of broilers were not significantly affected by marble dust as partial or complete replacement of limestone in the diets. However, body weight gain and IOFCC (income over feed and chick cost) were lower in broilers fed diets with marble dust than those fed diets with 100% limestone.