英語翻譯
MINERALS AND VITAMINS
In this case the indicator of sustainability is "minimum" dependence on
outside inputs,especially those sold by feed mills and other
intermediaries.Careful selection of the supplement can help to eliminate
part of the need for both minerals and vitamins.For example if some
palatable and digestible green foliage can be given free choice the pigs
will obtain from it most of the vitamins (except for D which is
abundantly provided through the medium of sunlight) and trace minerals
they need.The major minerals provided by the commonly used protein
supplements are shown in Table 3.3.When a mixture of soya bean meal
and fish meal (75:25) is used as the protein
source it will provide much
of the needed calcium,phosphorus and sodium.Sources of calcium
(lime) and sodium (salt) are available in most farm households and rural46 Nutrition of non-ruminants
villages.In some cases the phosphorus can be supplied as phosphate
fertilizer.Useful data on vitamin and mineral content of tropical feed
resources can be found in Tropical Feeds (1994).