SILAGE

Waikato Times, Volume 128, Issue 21336, 5 February 1941, Page 11

SILAGE

SCIENTIFIC INVESTIGATION NEW METHODS INTRODUCED During the past few years scientific investigations into the principles underlying the preservation ox green fodder in the form of siiage have Deen undertaken both in Europe and America. As a result, new methods have been introduced and a more reliable product witn considerable improvement in feed value can be od tamed uy the application ox these metnods. The Übe ox mecnanical aids for handling me neavy loamer nas also been Drought to a hign degree ox efficiency and wneie mis equipment is availaoie, muen time anu neavy labour can be saved. nay win continue to hold its place as tne main source of winter leea ana it is not suggested tnat nay snouid De replaced even in part Dy siiage wnen conditions peimit good hay to De maae witn certainty. lsui tne conversion 01 green loauer into silage wnen tne weainer is unsettled! is a sure way ox securing tne xun vaiue or me surplus grow in and avoiding me losses which occur 11 tne hay is spoilt Dy rain. Tms appnes, in canterbury, particularly to tne eariy crops or tne nrst cut of lucerne 11 tne ground is wet ana tne weainer unsettled at tms period. biiage is a vaiuaole leeu xor making cows ana ior breeding ewes wnenever a grazing snortage is nauie to occur. Once tney nave Decome accustomed to it, an classes of stock eat good siiage witn avidity. it can De fed witnin three weeks of making and, if properly seaied, it can De stored ior two or three years without deterioration, .finally, tnere is no risk oi obstruction oy spontaneous cumoustion or Dy nre. Yvniie siiage is easy to make, care and judgment are necessary in order to make good siiage. Principles of Preservation When green material rich in carbohydrates and pro Lems is stacked in a heap it ferments as a result oi bacterial action and a rise m temperature occurs. The kind and amount of fermentation depends on several factors;—(l/ The air supply, (2) the moisture content, (8) the proportion oi soluble carbohydrates

(sugars) to soluble proteins (nitrogenous materials). The most desirable type of fermentation is the one in which the soluble carbohydrates are mainly converted to lactic acid. There is less loss of nutrients, the prodfuce is palatable and the acid acts as a preservative which prevents undesirable bacterial action such as the decomposition of the protein compounds.

Lactic acid fermentation is favoured by the following conditions: (1) The material should be rich in soluble carbohydrates in proportion to its protein content. Lucerne, vigorous growing pastures with a high proportion of clover and young grass, are too rich in protein to make the best quality silage by themselves. As a result of the decomposition of proteins bad flavours may develop, i.e., putrefaction takes place. This can be prevented by the addition of materials in which carbohydrates predominate. Layers of more mature grass in the hay stage or cereals are suitable, but molasses is now being recommended. It provides a readily available source of sugar which is quickly converted to lactic acid. Oats and vetches cut at the flowering stage make a good mixture for silage. In general, the more immature the crop the higher the proportion of protein to carbohydrate and the greater the need for adding molasses. The crop should not be allowed to become too mature, for while, in the case of lucerne, the composition for silage may be improved, yet the material becomes fibrous and stemmy with the result that it will not pack tightly and the silage will over-heat. Exclusion of Air (2) The exclusion of air by tight packing causes the fermentation to stop at the lactic acid stage and the temperature does not rise much above 95 to 100 degrees F. When careful attention is not given to tight packing, the supply of air may allow the temperature to rise up to 120-160 degrees F. and this is accompanied by an excessive loss of nutrients. High temperature silage is associated with an over mature crop, with wilting the cut crop before stacking, with coarse stemmy crops and with uneven spreading and loose packing of the material in the stack. It is very important to tease out the heaps of herbage, spread it evenly and tramp firmly to the outer edge of the stack. With coarse material such as maize, grass and cereals in the hay stage, it is advisable to chaff prior to stacking. Special cutters and blowers have been designed for this purpose and are used when silage is made from such crops. The aim should be to exclude the air as much as possible and this is best accomplished by cutting the crop while still soft and succulent, by stacking immediately, and by tramping firmly. (3) If too much moisture is present in the ensiled material there will be copious drainage from the stack and many valuable nutrients will be lost. This is likely to occur if the crop is young and the conditions within the standing crop are damp and humid. Such material should be allowed to wilt for a few hours before stacking. Silage can be made during inclement weather but it is not advisable to continue stacking when the cut crop becomes really wet. It is obvious that all the conditions recommended for making the best quality silage cannot be accurately controlled and in practice a fair amount of judgment is necessary. An understanding of the principles outlined above, combined with actual experience, will enable the farmer to make a good quality product under the varying conditions which occur. Crops For Silage The most popular silage crops in New Zealand are surplus pasture growth and lucerne. Any crop, however, which is grown for hay can be used and of these, oats and vetches or even oats alone and maize are equally good. Crops which are rich in protein such as lucerne, clover and young grass should be mixed with a more mature cereal or with molasses. Potatoes, sugar beet tops, kale and such like crops can also be used. Cabbages and rape do not make good silage. Potatoes have been made into silage by building a stack with layers about 3in thick of raw potatoes, alternating with layers one foot thick of herbage. A second method is to cook or steam the potatoes and ensile them in a pit or any convenient, strong container such as a concrete pen; or for small quantities, oil drums are useful. The cooked potatoes should be tightly packed and sealed with a Ift layer of soil. Stack Silage The stack has been and is likely to remain the most popular method of storing silage. A certain proportion is wasted on the top and round the sidies as a result of too much air gaining access to these parts. This is unavoidable but can be reduced to small proportions by making large circular stacks. In England and America, portable silos and sisalkraft paper silos are being used to minimise this loss. The size of the stack will depend on the quantity of material to be ensiled. Alter an estimate of the yield is made, (1 ton hay—3 tons silage), the following list of sizes and capacity will enable the farmer to select a suitable size for a particular crop. They have been calculated on a basis of mature silage weighing approximately 451 b per cubic ft. Diameter in Feet Capacity in Tons 16 35 - 40 20 50 - 60 24 80 - 100 30 120 - 150 When stacking silage the walls must be kept upright and firm by tramping to the outer edge and the herbage should be teased out and not put on in lumps. The top should be kept level until the stack is completed when the sides can be built up higher than the centre. When a strong wind is blowing it is advisable to hang a sheet on the windward side in order to prevent uneven setiln “' (To be continued) ,