MineralsSee also BONE MEALS and EGGSHELLS. This is the most common source of calcium used in livestock feeding. It is almost pure calcium carbonate. Calcitic limestone contains 36-38% calcium and can safely be fed free choice (ad lib) mixed with salt. Dolomitic limestone contains at least 5 % magnesium carbonate and should not be used for poultry, but it is as good as calcitic limestone for other animals. Portland and natural cement can be used instead of limestone. Seashells are almost pure calcium carbonate (95-99%) and are good sources of calcium for all classes of animals. Clam shells, oyster shells, conch shells, coral and coral sand can all be used for feeding. Shells that have been ground to a coarse grit seem to be more palatable to laying hens; for other animals the shells should be finely ground. Seashells and coral contain about 37% calcium and no phosphorus. This contains about 75% tricalcium phosphate. It should not be used unless it is guaranteed to contain less than 0.5% fluorine. Rock phosphates from some areas (e.g., Curacao) are low in fluorine, whereas those from other areas must be defluorinated before they can be used. Defluorination of rock phosphate is an industrial process that is suitable only for large- scale production. Rock phosphate contains about 17% phosphorus and 34% calcium. FERTILIZER SUPERPHOSPHATE. This can also be used as a mineral supplement if no other sources of phosphorus are available. It is necessary to extract the soluble phosphorus by thoroughly mixing the superphosphate with water and allowing the slurry to stand for some time. The fluid containing the phosphorus is then poured off and can either be evaporated or included in liquid mixtures. One kilogram of superphosphate yields about 70 g of phosphorus. Hens store small fragments of stone in their gizzards to grind the food they eat. Poultry on open range can pick up the grit required, but when they are housed intensively indoors it is essential to supply them with a source of insoluble grit. Limestone or crushed seashells are not useful for this purpose as they have no sharp edges for grinding feed. The feeding of insoluble grit to growing chickens up to six weeks of age is not necessary. EDIBLE EARTH. Earth eating is common among range cattle and wild animals, especially in Africa. The patches of soil that attract animals have been chemically analyzed, but no specific mineral that entirely explains this behaviour has so far been found. Some patches have a salty taste which attracts animals; however, even in those patches the sodium is not always in the form of sodium chloride and may occur as sulphate or carbonate. Below are some analyses of edible earth (ref. 499).
| | | | | LOCATIONS | | | | Ca | P | Fe | K | Na | Cu | I | | | | | | | ................percent................ | | | | | 1 Masuku, Zambia | | 4.77 | 0.65 | | 10.1 | 16.2 | | 0.8 ppm | | | 2 M'bala, Zambia | | 4.76 | 0.32 | 1.90 | 1.25 | 13.2 | | | | 3 Kalene, Congo | | 0.74 | 0.41 | | 0.31 | 16.8 | 1.01 | | | 4 Katambora, Zambia | | 0.86 | 0.31 | 0.51 | 4.31 | 30.1 | 0.02 | | | 5 Luanga, Zambia | | 0.19 | 0.41 | | 0.11 | 5.82 | | | 6 Rukwa, Tanzania | | 0.74 | 4.59 | 0.03 | 0.15 | 1.72 | 0.003 | | | | | |
1 This sample is from a hill extensively excavated by game and livestock. It has long been customary to drive stock to this site as the earth is believed to be necessary for the fertility of animals. 2 From a large deposit between Kalambo falls and the Tanzania border that is much used by game and goats. 3 From pan excavations sought out by cattle, which eat the soil avidly. 4 From a pit excavated by elephants but used by other game as well as stock. 5 From an area of edible earth pan of approximately 2 ha that is turned over by a vast number of game.
| MANUFACTURED SOURCES OF MINERALS |
The percentage of minerals in some manufactured sources are shown in the following table.
| | MANUFACTURED SOURCES | | | Ca | P | I | Co | Fe | | | Tricalcium phosphate............ | 13 | 10 | | | Bicalcium phosphate............. | 24 | 20 | | | Monocalcium phosphate........... | 16 | 12 | | | Phosphoric acid (100%).......... | | 32 | | | Potassium iodide................ | | | 76 | | | Sodium iodide .................. | | | 84 | | | Potassium iodate................ | | | 59 | | | Cobalt sulphate ................ | | | | 34 | | | Ferrous sulphate ............... | | | | | 20 | | |
References 156, 301 Abstracts |
