ENSILAGE IN CANTERBURY.

Press, Volume LXVI, Issue 20105, 8 December 1930, Page 16

ENSILAGE IN CANTERBURY.

{AGRICULTURAL BULLETIN. The monthly Agricultural Bulletin for November, prepared by the Canterbury Agricultural College, -Lincoln, and the Economics Department of Canterbury College, in conjunction with *he Canterbury Chamber of Commerce, been issued. It deals with the subject of ensilage in Canterbury: Ensilage is the process of storing green crops in a succulent form with a ■final composition, in the case of good pilage, comparing closely with that of (the green material from which it is ;made. Tho purposes of this Bulletin are: first, to summarise our present [knowledge of the part ensilage may play 5n Canterbury farming; and, second, to (describe the process of manufacture. Ensilage in Canterbury. It must be clearly understood at tho "beginning that the case for or against ■the use of silage, as with any other foodstuff, is largely influenced by cost. ( With. good silage there are few difficulties in feeding, and there is no question that stock will thrive upon it. While hay is a perfectly useful crop for winter, there are times of the year kFhen silage is more useful than hay:— 1. In early spring, when grass is plow at coming away. 2. In dry autumn, when hay is unpalatable. Further advantages aTe, that hoggets, ►when their teeth are failing, will eat ksilage when they would refuse hay or turnips, and that silage can be kept jfor at least five years, while hay would Wpoil in a much shorter time. The Use of Silage. Improved returns from pasture are obtained by tho elimination of waste. *rhia waste can be avoided by grazing the grass while its food content is 3iigh and before tho plant has started sto change that food into a form which enables it to produce seed, and which is much less easily used by the animal. ■This elimination of waste is necessarily associated with the carrying of more stock. If no grass is allowed to reach the dry stalky stage, there is no pasture Toughage, which in the past could "be depended upon as a reserve for dry spells—though admittedly a poor one — ■and since more stock is being carried, •the importance of other forms of re"jrervq feeds becomes doubly apparent. Is "silage, then, destined to become aii economical reserve food in Canterrbury? Feeding Value of Silage. While emphasis is laid upon costs, p.t seems necessary to indicate the feeding value of silage as compared with pother foodstuffs. Providing that the green material from which it is made is 'a good food, the final product, if wellmade, compares closely in composition '•with the original material. During the i ensilage of green material, losses ranging from 8 to 25 per cent, may take slace, but under good conditions these fosses may affect the quantity without .seriously reducing the quality. of the feed; Improper making may result in Jieavy fosses of the proteins or fleshforming portion—a definite reduction in quality. (a) As an Early Spring Feed. 1 The necessity for a succulent, nutritious food for newly-lambed ewes is •well recognised, and the need is generally met by the provision of green feed. In a backward season the green feed may be insufficient to bridge over the gap in the feed supply between the turnip crop and the spring growth of .grass. In this case, silage would be ■very valuable, and since the feeding .should not extend over more than a few weeks, the expense would not be jgreat. When no green feed is available, a stock of silage would fill the gap. Where sheep or cattle are being (wintered on hay or chaff and meat meal, silage can successfully keep the ■breeding ewes .or. cows going until spring growth starts, being more suited to milk production than the winter "ration. (b) As a Mid-Summer Supplement. This .is a role in which silage has indistinct possibilities, particularly in [those parts of Canterbury where lambs may not go away as fats until April. X>ast season, at Lincoln College, all the .lambs from ewes on the experimental iplots were tagged at birth and weighed at regular intervals from then until they went away as fats. It was found that, for the first two months, they grew at the rat© of 161b per month, and then, as grass growth diminished, the growth rate dropped to about one- ' half. It, therefore, appears that it anight be possible to get a much larger percentage of lambs away fat off their mothers if a start were made at feeding some succulent foodstuff. Silage for this purpose would be particularly suitable, and its possibilities tare well worth exploring. '(c) As a Winter Feea. In those parts of Canterbury where good turnip crops can be grown every year, silage cannot compete with turnips as an economical winter feed, and •where turnips are poor or uncertain, so that something else must be used, hay. or chaff and meat-meal are cheaper than silage. However, the practice of feeding mage to. breeding ewes along ■with the usual winter feed for the last two or three weeks prior to lambing 5s one with much to commend it. Breeding ewes are easily upset by sud- - den changes in the diet just before lambing, and a change over to S silage must be gradual. Ensilage. In America, the best silage is made jfrom a mixture of maize and pea-straw. □England has found a mixed crop of foats, beans and tares the most suitable. Most leafy crops may be ensiled, •with the exception of such plants as cabbages, kale, etc. However, the choice in Canterbury is fairly limited, jand in the following summary tho more important ones are indicated. Grass. C!p most Canterbury farms, the num:ber of stock carried is limited by the •winter carrying capacity. As a consequence, there is not a sufficient number on the average farm to cope with the growth of grass in November. It •will, therefore, be possible to shut up p. paddock for ensilage. Grass so kept is in itself a well-balanced food, and «o makes good silage. The principle of using grass in the Jeafy stage applies with equal force to hay and silage, though if cut too early for the latter, the chances of excessive fermentation losses are increased. Cutting when the grass has just started to .send up the bulk of its seed stalks is [the recommended stage. Clovers and Lucerne. During the ensilage of any green material a certain amount of loss takes 'place, and it is likely to reach an excessive figure in the case of clovers and lucerne, which are particularly rich in proteins or flesh-forming materials. These crops are probably better made into hay. Theoretically, the mixing of wheat or oat straw with the clover or lucerne reduces this loss considerably. In any case, it is a practice worth recommending, since the straw itself is greatly improved in feeding value as result of the heating which takes place in. the stack or sUo, and it also

acts as an absorbent, and reduces the loss of valuable plant juices, which would otherwise drain away and bo lost. About one-third of straw would be required for these crops when they are fairly mature, i.e., in full bloom. Oats and Tares. If it is worth while growing a special crop for ensilage, the most suitable crop, also the heaviest yielder for Canterbury conditions, is oats and tares. One and a-half bushels of Scotch tares and one of Garton oats, sown at the end of March, will provide a heavy crop, which may be cut in December. An average crop on the College farm yields 0-10 tons green material per acre. The best stage for ensiling this crop is when the tares have finished flowering and are starting to form pods. Silo, Pit, or Stack? Of all methods of ensiling, the silo 5s admittedly the least wasteful, but it is expensive to erect. Its erection should probably not be undertaken until experience has shown that, silage is a profitable feed under each individual farmer's conditions. To gain experience, one of the cheaper forms of ensilage should be used for a start. The hillside silo—or pit—which may be filled from above and emptied from below, such as is recommended by the Department of Agriculture, comes next in order of preference, except where underground water currents are likely to cause flooding or excessive drainage and losses from the stored material. The stack is more likely to be used at the beginning by the majority, and, though it is frequently condemned as being wasteful, it is possible to reduce the amount of waste by careful building. Carting and Stacking. The best silage is made by gathering each day's cutting before night. Though it is often asserted that rainy weather does not interfere with ensilage, the losses through drainage bc--1 come very large when very wet material is ensiled. Where the freshly-cut crop has been wetted, or too immature, it should be allowed to dry out a little before stacking. If a pit is being used, care should be taken to pack it evenly. The amount of heating which takes place in a silage pit is controlled by the amount of air present, and since sufficient air is always present to allow all the necessary heating to take place, the aim should be to pack the material as closely as possible by tramping. The pit may be filled one day, allowed to settle, this will usually take place over-night, filling proceeded with on the next day; this in turn is allowed to settle, and filling continued. Stack Silage. The most important feature of success is careful building. Heating is beneficial up to a temperature of .L-0" P.; beyond that a rapid falling off in the quality of the silage takes place. Since excess air causes overheating, and since a stack is much more exposed than material in a pit or silo, even packing is important. The packing of the sides may be accomplished in either of two ways: (1) by trimming off an 18in. strip all round the stack with a hay knife and tossing this material on top after each day's work; after the first day, of course, it will be necessary to build out over tho trimmed edge, so that after trimming, the second day's building will be flush with the first; or (2) by pushing in the loose ends with the edge of a spade, as in digging. Temperature control has appeared a sufficiently great difficulty to -prevent many from making silage. In pratice, this difficulty need not occur. Air supply controls the temperature, and a rise in the latter can be checked by putting more green material on top, thus excluding air by sheer weight. The use of a thermometer in an iron pipe in the centre of the stack, about 18 inches from the top, gives an indication of the temperatures within, but most good silage is made without the use of a thermometer. The actual stacking process is slower than haymaking, because of the greater bulk and weight of material to be handled. Silage occupies 50 cubic feet to tho ton when made, and about 200 cubic feet to the ton when freshly built. A stack usually finishes up about eight feet high, and so every square yard of base represents one and a-half tons of silage. A grass crop that yields 2 tons of hay would yield 6 tons of silage, so that such a crop would require a stack 4 square yards to each acre. More simply, divide tho silage yield per acre—most farmers can estimate the hay that would be produced per acre, and silage yield can be taken as three times that —by one and a-half, and multiply by the number of acres,e.g., 10 acres of a 6-ton crop would require a stack having a base area of: — 6 over 14 x 10, equal 40 square yards. Round stacks are least wasteful. Square stacks are better than oblong ones. The amount of green material put on each day should be sufficient to compress the previous day's layer, and so stop the fermentation in it. Hence tho object of the above calculation. The waste that takes place during ensilage is greatly reduced as the size of the stack increases. Small stacks, and also the making of small areas into silage, are Uneconomical. However, it is possible to make a stack too large—in which case insufficient thickness of material is put on in one day to compress the layer which was put on the previous day. An attempt should be made to build the stack up to at least tho 14 foot level each day. A diary of operations will serve to illustrate this. First day—Stack built up to 14 feet. Second day—Stack has settled to 8 feet; built up again to 15 feet. Third day—Stack has settled to 9 feet; built up again to 15 feet, and so on, until all the material is stacked. When stacking is completed, it is necessary to compress the top layers, otherwise moulds will gain entrance and ruin tho top layer of the silage. It is usual to leave the stack without weighing down for a day to allow heating to take place. Compression may be achieved by several methods, but the most satisfactory is: Weighting down with earth—a layer of 18 inches being. required. Boards placed along the sides and held in place by wires running across the stack permit the building of the earth out to the edges of the stack. A • further precaution is worth mention. A wind blowing on one side of the stack during building will often cause uneven settling. This may be prevented by hanging a tarpaulin over the side of the stack exposed to the prevailing wind. Feeding Out. _ The changes that take place in a silage stack are complete after four to six weeks, and feeding out may bo started at any time after that. In the interests of economy, stock should not be given more silage than they can clean up at one feed. A full ration for an adult sheep is 5 to 61bs. On fair grass 31b per day should be sufficient. Properly made and properly protected, silage may be kept for two to three years or longer without spoiling, and will form one of the cheapest and most effective insurances that can be made against feed shortage.