STOCK FEEDING

Wanganui Chronicle, Volume 74, Issue 138, 13 June 1931, Page 20 (Supplement)

STOCK FEEDING

TWO METHODS FEED SOIL; FEED ANIMAL THE DLR.ECT ROUTE “The writer looks to the stock-lick to effect a great step forward in the pastoral development of this Dominion, and this method of improvement is all the more attractive owing to the comparatively low expense entailed.” These are the concluding words of an article in this month’s Journal of Agriculture, by Mr B. C. Aston, Chief Chemist of the Department of Agrieul ture, who deals with the problem of mineral deficiency in farming. Defi ciency of a mineral may be a deficiency of the pastuie or a deficiency of the soil. Water as Mineral-Carrier It has been shown that there may be in the pasture a deficiency of phosphates not due to any deficiency of phosphates in the soil. For instance, a certain amount of water is needed in the soil to carry the, soil phosphates to the pasture. Lacking the necessary water (a lack possibly due to normal or abnormal summer dryness) tho pasture becomes deficient in phosphates—that is to say, deficient not from the point of view of the pasture but of the animals grazing on it, which animals give the best results when there is an excess of phosphates in the pasture. Or, as Mr Aston puts it—- “ Phosphates of caieium, which are the chief fertilisers used for New Zea'and soils, are highly effective in Increasing production and quality of pasture; and as these pnospnates are an important animal requirement, it has become the fixed practice to give such phosphates through the grass to the animal, so initiating a benoficient cycle of improvement on the farm, which finds immediate response in the well being of pasture and animal. Should however, droughty soil conditions occur as the result of an abnormally drseason (or it may be even that the normal drought of summer is responsible but is not recognised as an adverse factor) the pasture is unable to assimilate from the soil an excess of phosphate required by the animal, which suffers from mineral hunger, resulting in diminished production. ’ ’

Giving Phosphates as a Lick As the above implies, water acts as a carrier of minerals from the soil to the plant, and is one of tho most important constituents of tho soil. The dependence of pasture’s nutritive value on rainfall has been proved in the Wairarapa (as shown in the April issue of the Journal of Agriculture) where “in three consecutive summers the phosphoric acid content of the pastuie varied correspondingly with the changing amount of rainfall. . . . When the animal is unable to obtain sufficient phosphate from the pasture, the obvious treatment is to give phosphates .as a lick, mixed with salt, direct to the animal.” In considering this problem of giving direct to the animal mineral foods that are deficient in the soil, or that are deficient in the pasture for lack of water, the advantage of low cost is in favour of the direct method. A distinction is made between those mineral foods which “do increase production of pasture or carrying capacity, and those which do not but are of primary value to the animal.” If the latter mineral foods can be fed direct to the animal through the lick, deterioration of the animal can be prevented. Some mineral foods that are “essential to the animal” but which “do not increase production of pasture” are not included intentionally (though they may be present accidentally) in pasture top-dress-ing mixtures as at present used. Examples of mineral foods benefiting the animal, but not the plant (foods which it is customary to give the .nimal direct as a salt lick) arc: Sodium and chlorine given as common salt (sodium chloride); iron (highly necessary in some sandy districts and perhaps in some peaty districts) given as citrate, carbonate, or hydrated oxide mixed with the salt; and iodine given in minute doses with tho salt as potassium iodide. Special crops such as mangels, asparagus, and some others benefit by application of salt as a manure, while potatoes and some other crops may have iron sulphate and profit by it; but. pasture is not in general practice dressed with salt or iron, although both may at times be applied as impurities in the fertiliser used—salt in kainit or potash manures, and iron in basic slag. Auxiliary to Top-dressing For phosphate deficiency, Mr Aston recommends the use, as a lick, of bonedust mixed with an equal quantity of salt. Of all phosphates, bonedust is that from which the elements are most readily absorbed by the animal. Any excess not utilised by the animal passes through its digestive system and is voided on the pasture, so that nothing is wasted. “Bonedust supplies both lime and phosphoric acid. In the event, therefore, of caieium being deficient in the food supply, bonedust may also supply this deficiency. If the animal gets low enough in condition, however, medicinal drenching is the appropriate remedy.” Ho emphasises the proved value of animal licks for supply ing direct to sheep and cattip the iron deficient in the pastures of “bush sick” districts. “lodine has been used successfully in lick form in the iodine deficient districts of Lake Wanaka. Salt is universally recognised as a necessity for farm stock wherever the best results are desired.” The extension of the salt lick method to include phosphate is “a logical development,’’ and one which will overcome phosphate hunger that occurs in spite of top dress ing the pasture.