| Animal traction |
|Appendix B: Animal nutrition|
It can be assumed, generally, that a ration formulated from high quality pasture grasses and grains will supply, in addition to an animal's energy needs, the proteins, vitamins, and minerals necessary for overall health. However, imbalances can result from seasonal unavailability of feeds or conditions which affect the quality of feed. As pasture grows older, for example, the minerals tend to move from the leaves and stems downward into the roots where the grazing animal does not get them; or, if soils are low in phosphorus (as is often the case on tropical range), the grass which derives its nutrients from the soil also will be low in phosphorus. Such considerations make it advantageous for the stockowner to have some knowledge of the classes of feeds and their nutritional composition.
The protein and mineral needs of draft animals are summarized in the table below. While nutrition lists have shown that these needswith the exception of salt, which is lost in sweat-do not increase as the animal performs more work, serious problems can result from deficiencies. Without protein, the body cannot renew cells that form muscles and other tissues. Minerals are important in the growth and maintenance of skeletal structure as well as in metabolic and digestive function. Calcium and phosphorous values are given in most feed composition tables; if they are absent in natural feeds, they must be given as an additive in the concentrate mix (grains or meal) or in a block lick with salt.
A standard mineral supplement is made of two parts calcium, one part phosphorus and one part salt. Bone meal is prepared by boiling or steaming fresh bones and then pulverizing and drying them. This feed contains about 20% calcium and 10% phosphorus, a good ratio of these important minerals.
Requirements may be adjusted depending on the elements available in the pasture where the animal grazes. A mineral-starved animal should not be given free access to a lick or loose mixture. Instead, mix the correct does in with its concentrate.
A ration is a combination of feeds which provides the daily requirements for energy, protein, vitamins and minerals. Since the chemical composition or nutritional value of grain or pasture is determined by soil, weather, and other environmental factors, rations should be formulated using data obtained from regional testing centers. When this is not possible, other tables may be used, but with attention to the system of measuring as well as basic principles of feeding.