SALT LICKS.

Press, Volume LXVI, Issue 19863, 26 February 1930, Page 14

SALT LICKS.

AN ANALYTICAL STUDY. . (By Sheep Farmer.) The following article on sheep licks is contributed by a North Canterbury sheep farmer: — A few months ago there was much talk of a thorough investigation into the mineral content of pastures throughout the British Empire. To my mind the subject of mineral licks for stock is one that opens up far larger possibilities in New Zealand than any investigations concerning pastures. Any definite discoveries made in regard to salt licks would have a far larger influence for usefulness than any discovery in regard to top-dressing because of the very large area of pastoral land in New Zealand which cannot be reached by top-dressing; probably fivesixths of the stock carried in New Zealand to-day is carried on country which could never bo economically top-dressed, but it could be largely influenced by discoveries in the direction of benefits to be gained by suitable salt licks. About the only definitely established thing that can be said about the use of the salt licks to-day is in reference only to the salt therein, and is to the effect that where stock readily take salt when made accessible to them they "do" better with it than without it, and so far no case has been rocorded where free access has resulted in harm by taking excessive amounts. When we start adding to the salt those elements or compounds of them presumed to be deficient in the pasture, we do it entirely on knowledge gained by deduction from any known factors proved by the very little experimental work that has been done; but it must be realised that if definite conclusions from scientific research and experiments were reached in any ono district, that knowledge may have little bearing on the conditions existing in a nearby district, so it simply means that in the absence of definite data to go on, beyond being able to prove that our stock "do" better with salt or salt lick, the rest of our knowledge to some extent must come from our own observation and the little experimental work we are able to undertake ourselves.

An Outstanding Result. Perhaps one of the most outstanding results from the use of salt happended on. a Mackenzie Country station over 40 years ago. This run consisted of about 60,000 acres, and was then regarded as perhaps the least desirable among the runs of that area. It had ruined two successive owners, and the then owner could never find a ration sheep on the place with sufficient fat. on it to fry the station chops in. The sheep were poor clippers, always low in condition and the death rate heavy. One day noticing a few sheep standing on the track leading from the homestead to the front gate he found the object of attraction was a case that had dropped from the store cart a few days previously containing salt, and a little had leaked out. Trying out a few lumps of sack salt round the place, he then speculated in three trucks for back loading at that season's wool carting, and 'dropped it on the various sheep tracks all over the run. The result of this was apparent next year, and within two years his wool clip went up to 2}lb a fleece, the death rate became negligible and the cook always had drums of fat waiting to go to town for sale. Incidentally I might add that this same owner whose position before the salt episode was little more than head shepherd, on a wage by results basis, was reputed, shortly before the war, to be paying the third largest income tax of any pastoralist in Canterbury. The change in his fortunes was entirely due to putting a few tons of salt in the right place. Perhaps in viewing this subject of minerals in salt lick, we should bring a quite frequent experience of many of the earlier farmers of Canterbury into the picture. How often they found in breaking up for the first time virgin tussock land that they could grow only one satisfactory crop of turnips without the assistance of any manure, and a second crop could only be grown with the aid of one or two hundredweight of phosphatic manure. This was a positive experience of many, yet in an analysis of a sample of the virgin soil, and the once-cropped, soil, it was difficult to discover any apreciable difference in soluble phosphate content. However, it is fairly safe to assume that to some very appreciable extent as far,as growing turnips was concerned, that land by its first crop had been depleted of some of its essential phosphorus and the addition of one or two cwt of phosphatic manuro was sufficient to restore the balance.

Is the Soil Depleted? Now we know that for the last 70 or £0 years blood, bone, hoof flesh, and wool have been walking off our natural pastures, and so removing some of the essentia] elements required for animal growth. Has ,it depleted our soil for stock as that one crop of turnips depleted the soil for future crops of turnips? The feed looks the same, though perhaps to some extent the composition of the different kinds of grasses making up that pasture has altered, but not as far as one can see, materially, for the worse. As to the stock? Are they thriving! Are' they clipping the same as they did 40 or 50 years ago? Records were not kept, or are not available, that would throw much light on the subject. We can only quote a remark by the "Old Timers" during our annual ewe fairs, to the effect that despite the improvements in breeding and selection the average quality of the sheep penned is markedly falling off, both as to fleece and bone, and also constitution. Is it not time we began to sit up and take a little notice? I suggest that we might pool our experiences and also make a few experiments for ourselves.

Thirty years ago the writer owned a good limestone property where salt was said to be not required, but putting out rock salt, I found the sheep taking and responding to- it readily. After rain I frequently noticed jagged pieces of impurities on the licking surface that caused bleeding in the mouths or tongues of hoggets, so I- tried agricultural salt in feeders covered from the weather. This seemed more satisfactory. It was more easily got at by the sheep, they took full advantage °f ** by S oin g through larger quantities, care being taken to prevent any tendency to cake and harden in the trough, and no check was placed on the quantity they wished to consume. Later I added air-slaked lime, sulphur, and sulphate of iron to the salt, and the

health and appearance of the flock seemed all that could be desired. I feel convinced that the mixture showed a decided improvement on the straight out salt, but can offer no definite proof on this point. Some years later, taking a property as a going concern with a very inferior flock and inferior pasture, being at a fairly high altitude, with heavy rainfull and sweet vernal as the predominating pasture plant, principally tussock with some old run-out pasture, I put agricultural salt in the feeders out on the country in March, and it was not till a mob of sheep from the home property used the salt and salt and salt feeders was mixed in with the flock in November that they took quite freely of it, as they were apparently more shy of the feeders than of the salt. In the few years that I owned this property, from cutting barely 6 pounds of wool, a heavy death rate and black scour in the spring amongst the hoggets, the last shearing (no wethers) was 841b, death rate practically nil, except a few of the usual casualties at lambing, and no scour amongst tho hoggets, and the whole flock stood out as one of the best in the district. No practical alteration was made in the pasture management, and no breaking up was done, though better breeding and a little culling was done in the flock. The difference in the sheep must be mainly attributed to their taking freely of the salt mixture.

A Curious Happening. Incidentally, a rather curious thing happened one year which serve as a base for some future worth-while experimental work. A mob of 400 ewe hoggets was put up for the winter on the coldest, most back lying block on the place with a good getaway of rough feed. Being out of the mixture I filled the feeders with some agricultural salt that the agents apologised for sending on account of the very visible amount of impurity in it. It had landed from .some sailinj; boat shipped as ballast, probably from "somewhere East of Suez" and showing whitish looking lumps of stuff through it. A cold, wet winter followed, and I was a little apprehensive about these hoggets; however, they "hoed" into the salt (not the mixture this time) and all seemed well. In the spring, with practically no death rate they went into the shearing shed standing out as something markedly better than anything in the way of hoggets I had ever brought through the winter. The best young pasture of Italian ryegrass couldn't have done them better. I did my best to get some more of that salt, but it was "off the market." I strongly suspect it was of the sea salt variety without the clarification process that it usually goes through, and remembering that sea water contains something of every known element in the world it cortainly suggests nossibilities for research. In dealing with aalt and salt licks a rough survey may be made of their relation to animal economy generally. Agricultural salt, the basis of licks, is about 97 to 98 per cent, pure salt, or sodium chloride, which is essential in the body, and enter freely into its life stream. It adds palatability and digestibility to the food, and acts as ■a deterrent to the presence of wormß of various kinds that gain access to the alimentary tract. Its value should be evident in an appearance of greater thriftiness and health generally in the stock. Varying amounts will be taken by each individual animal according to its natural inclination, but it may be said that the amount taken will vary only according to the individual requirements. For top-dressed pastures, in young grass, and on sea Coast lands the craving may be entirely absent or only slightly in evidence, but on pasture of this description no anxiety need be felt as to the "doing" of the stock, from the salt point of view.

The Main Point. The main point in considering salt licks generally is to determine whether salt can be improved by adding anything further, and it is at this point that one feels that each man must act for himself, according to his own deduction, on what he sees in front of him, bearing in mind those things which are proved, those things that are known but not proved as possible factors for good, and are entitled to consideration on that basis alone. To act on these lines one wants a little information as to the general action and function of some of these additions, and it is here where our knowledge seems to come to a dead end, for in writing what I do it must be clearly understood that I claim to know nothing more than any ordinary farmer who may take an interest in these things. A fairly comprehensive lick is given by the Victorian Department of Agriculture, and perhaps may be taken as a standard sort of lick, bearing in mind the difference of conditions between the two countries. It is: Agricultural salt,. 1 bag (1871b); ground phosphate, 621b, or 931b sterilised bone meal; sulphur, 141b; sulphate of iron, I'lb; Epsom salts, 71b; potassium iodide, 4oa, manganese sulphate, 4oz. The two latter should be dissolved in water and sprayed thoroughly over the mixture. Tor New Zealand conditions Epsom salts may be left out, as it is mainly there to act as an aperient under the dry, hard feed conditions of Victoria. Also manganese sulphate, sufficient being contained in the agricultural salt itself, if of the average Australian quality. There seems some doubt about the advisability of ground phosphate in a lick, but none about the bone meal, and as the average Canterbury soil is not so naturally deficient in phosphates as the Victorian it may be cut down considerably. A leading veterinarian approves the following:—Agricultural salt, 1 bag, 1871b; sterilised bone meal, 101b to 121b' sulphur, 51b to 61b; sulphate of iron, 41b to 51b; potassium iodide, 2oz to 2* oz. Taking the bone meal as supplying both calcium and phosphorus and remenrbering the many hundredweights of bones removed per acre over a period of, say, 70 years, we may feel as if we are making some slight contribution towards reparation. No harm can accrue and the importance of phosphorus with regard to animal nutrrtion generally is strongly stressed by Professor Brailsford Eobertson, of Adelaide. Another writer mentions that "in South Africa the remedy for and prevention of diseases resulting from phosphorus deficiency is to supply bonemeal. All this should establish bonemeal for serious consideration for inclusion in the lick. Now for sulphur. Except on country where free sulphur is known to exist sulphur may be included in a lick if it is only for its well-known vernicidal properties in keeping stock Free from stomach and intestinal worms, And

we know that applied externally to hair or wool it has a beneficial effect. Nearly all' hair restorers contain some proportion of sulphur, and taken per medium of a lick some of it rapidly finds its way through the skin to the fleece of the sheep. Apart from that fact, it is known that wool and >hoof and hair contain comparatively large amounts of sulphur, and as these three have also been walking off the land for upwards of 70 or 80 years, are we sure that the deterioration of the fleeces of our sheep is not due to a deficiency of sulphur content in the pasture? At least the evidence goes part of the way towards justifying its inclusion in the lick.

Now we come to sulphate of iron. Apparently the reason for its inclusion is to act in the same way aB when given to human beings—as a general tonic to the system. It has, of course, a great influence in making for good, rich, red blood in the body, and the well-known bush sickness that afflicted parts of the North Island some few years ago has been accounted for largely by a lack of sulphate of iron in the soil. Have we any reason to suppose that it is not needed when its inclusion in a salt lick can do no harm?

Potassium iodide.—lnvestigation into the incidence of goitre throughout New Zealand indicated the South Island as that portion of New Zealand where a shortage of iodine in the soil would be found, and more particularly those districts removed from the immediate influence of the sea. If there is a deficiency of iodine in the soil of our grazing lands would that deficiency not be more marked to-day than it was 70 years ago? The advisability of the inclusion of iodine in a salt lick can be easily made the subject for a little experimental work by the farmer himself. If left out it can be included later by merely spraying the mixture with a solution in tho proportion given in the salt lick mixture, and in view of the additional cost of the lick containing iodine (about 3s per cwt) this course may be the better one to adopt, if there is any question on its inclusion. It may be well, too, for a man. to start in a tentative way before going in for a "whole hog" mixture. There is a useful lick on the market in Christchurch, and two or three pounds' worth for a start can hardly go wrong. Put it near an open gateway or on a sheep track or in a. sheepyavd if sheep are left in overnight. To save it from the rain a firm selling concrete goods in Christchurch makes quite an effective and reasonably priced container for this purpose, and one that has many advantages over the home-made article. A good salt mixture is worth protecting from the weather, and the mud and dirt that get round it, so the farmer wishing to make a start on salt licks is well catered for, and even if "highly sulphurous flocks"—vide, Dr. Barker —do not come to pass, well salted ones should be shortly a la mode in Canterbury.

"Voyage of Discovery." In conclusion, let me say that there can be no doubt that much of our native pasture has been lessened if not depleted of its mineral content, and if our farmers could only regard their mission in life as a voyage of discovery instead of a chase after lucre, we would see in our saleyards fewer of those pens of hoggets—not always culls—with stunted bodies, pathetic faces and running eyes and noses, and hear less of the constant racking cough that goes on by day and through the niffht The whole subject constitutes a most promising field for. research by farmer and scieatist together.