The Feasibility of Using Natural Rocks as Sources of Calcium, Magnesium and Phosphorus in Livestock Feeding in Ethiopia
In Ethiopia, feed industries are widely using limestone as a cheap source of Ca without adequate information on the bioavailability of its Ca content and the presence of other toxic minerals. This being the case, the present study was conducted to determine the Calcium, Phosphorus and Magnesium content of samples of limestone and marble powder collected from different parts of Ethiopia. Adequate quantities of lime stone, marble powder and gypsum were procured from different parts of Ethiopia and subjected to laboratory chemical analysis in triplicate. The results of this study clearly showed that the total ash content of all the materials analyzed in this study ranged between 81 and 99%, indicating the potential use of these materials (limestone, marble powder and gypsum) collected from different part of Ethiopia) as supplementary mineral feed source in a very small amounts. The Ca content of the samples collected varied from 16.62 to 89.19%, with mean value of 74.4% the value of which was significantly higher than the Ca content of Calcium-carbonate and Calcite powder (39.17 ± 0.3%). On the contrary, the mean P and Mg content of all the test materials was 0.12 and 0.32-0.69% the values of which are comparable to the P and Mg content of common animal feed in Ethiopia. In summary the results of this study showed that lime stone and marble powder widely available in different parts of Ethiopia seems to have potential value as a Ca supplement for livestock feeding. Testing the bioavailability of these materials with animal seems to be the future direction of research.
