ASSESSMENT OF PROCESSED ROCK PHOSPHATE AS SOURCE OF INORGANIC PHOSPHORUS AND SUBSTITUTE FOR BONE MEAL IN BROILER DIETS
A feeding trial was conducted for six weeks to assess the optimum replacement value of processed rock phosphate (PRP) for bone meal and as a source of inorganic phosphorus in maize-cotton seed meal based diets. A total of 144 day old Snack 80 strain broiler chicks were used. Triplicate groups of 12 birds were randomly placed on 4 diets containing 0. 1.8, 2.8 and 5.64% PRP which contributed 0,0.16, 0.25 and 0.5% inorganic phosphorus in the diets respectively, Results showed PRP levels in dicts had no significant (P>0.05) effect on weight gain, growth rate and feed intake at 0 - 4 weeks. When 2.8% PRP replaced 2% of bone meal, feed efficiency was not significantly different from those birds fed 3% bone meal in control diet. Inclusion of 5.64% PRP significantly (P<0.01) depressed feed efficiency more than other treatment groups during the period. Addition of 5.64% PRP supported higher growth rate than other treatment groups during 5 - 6 weeks, but this was not significantly different from birds fed on control and 2.8% PRP diets. Feed efficiency was significantly (P>0.01) lowest in the group fed on 1.8% PRP diet. Weight gain, growth rate and feed intake were not significantly (P<0.01) affected by treatments during 0-6 weeks. It was concluded that 5.6+% PRP which supplied 0.5% inorganic phosphorus supported optimum performance in broiler birds replacing 100% bone meal in a liu diet and caused growth that was equinob-ut to the group fed on 3% bone meal mentraal diet.