The Nonpartisan Leader Newspaper, April 12, 1920, Page 5

Principles in Canning Forage Crops Ensilage Is Superior to Product Preserved by Drying—Must Contain Sugar or Starch and Moisture and Be Kept Airtight BY R. A. HASTE Editor of Campbell’s Scientific Farmer zmmm | HAT the tin can is to civilized hu- manity the silo is to livestock. The progress of the dairy interests and the path of the intensive farmer is marked by the silo. The principles involved in the preservation of fruit and garden truck are the same as those involved in the preservation of silage. It is simply a ques- tion of fermentation and keeping out the air. All organic substances, whether animal of veg- etable, begin to decay at once as the life processes cease. Unless measures are taken to prevent this disintegration the result in the case of vegetable fiber is rot and in the case of animal tissue putre- faction. This is nature’s way of restoring useless organic matter to its original elements to be used over and over again in the endless cycles of creation. Man, however, has learned to check or wholly prevent this natural decay and preserve most or- ganic tissues in a state closely resembling normal living conditions. The first method, doubtless used by primitive man and still almost universally em- ployed in the preservation of certain products, is the “drying” process, which consists of nothing more than curing or driving out the moisture either by exposure to the sun or by the application of artificial heat. The second methed, evidently the result of experience aided by a slight knowledge of natural chemistry, is the “pickling” process— packing the substance to be preserved in a vessel containing an acid solution or a solution of brine. The third method, known as “canning,” is the re- sult of modern scientific knowledge and consists of two processes: First, subjecting the material to a temperature of not less than 212 degrees; and second, while hot placing it in cans or jars that are hermetically sealed until wanted for use. A fourth method which likewise postpones decay is cold storage. Owing to its bulk the preservation of forage crops by the canning process is not practical. It has been demonstrated during the last 25 years, however, that the pickling process is not only prac- tical but the most economical method of preserving the ordinary forage crops for the use of stock dur- ing the entire year. The pickling is accomplished by simply storing the fodder in a silo where, like sauerkraut, it is pickled in its own juices. The result is ensilage, a little sour, but with all the desirable qualities of green stuff as feed. Strictly speaking, the process by which ensilage is formed is a combination of pickling and : canning. Before entering upon a discus- sion of ensilage as an economical factor in modern farming let us thoroughly understand the prin- ciples underlying its formation. CONTROL OF BACTERIA IS SECRET OF ENSILAGE Decay is defined as the decom- position of organic compounds, ~ such as sugar, fats, proteids and the cell walls of plants into sim- ple substances and finally into fluids and gases. The products of this decomposition, in new chemical combinations, are finally used in the constructive processes of new growth. The principal agents in this tearing-down pro- cess are the bacteria and other microscopic growths that infest the soil, the food we eat and the air we breathe. They are untir- ing scavengers of the earth and by their ceaseless energy prevent the dead and useless bodies of organic matter from clogging the earth. No sooner is life extinct in any organic body than it is at- tacked by millions of these mi- nute destroyers, who with ham- mer and tongs begin to break it up and transform it into new and useful compounds., To kill these . bacteria, hinder their growth or exclude them is to prevent or delay natural decomposition. The farmer who prepares ensilage must exclude the air from his product. The absence of air al- lows the acid bacteria to transform the sugar of the corn or other ensilage material into acid, which acts as a preservative, whereas when air is present other bacteria known as molds destroy the acid-forming bacteria and decay begins. The formation of acid in the pickling process is brought about by what we call fermentation. Fer- mentation takes place at a certain relative high temperature, and acid is formed only when there is sugar enough in the mass to produce the re- quired acid. When this is accomplished air must be excluded to prevent acid-destroying bacteria from getting in their work. It has been found that corn juice contains about 4 per cent of sugar. This absolutely disappears in the fermenting process, being changed into acid. It has also been ascertain- ed that fermentation begins as soon as the material is siloed. This is shown by a rising temperature of the mass, reaching a maximum of about 140 degrees. From what has been said we may lay down the follow- ing basic principles: First, the material to be used should contain a certain per cent (from 3 to 4) of sugar or its chemical equivalent in order to supply the acid necessary to preserve it. Second, it should contain sufficient moisture in either original juices or ap- plied in the form of water to develop immediate fermenta- tion. Third, it should be confined in a silo or other suitable structure so built that the heat developed by fermentation will not be lost but will be main- tained uniformly throughout the mass. Fourth, air must be excluded in order to maintain the tem- perature and give the acid-forming bacteria a chance to work and to keep out the acid-destroying bacteria. To sum up—silage material rich in sugar, abundant moisture, an airtight structure in which the material is tightly packed, and heat developed by fermentation, are the essentials necessary in the production of good ensilage. It was ascertained very clearly in ensilage prac- tice that certain plants known as carbohydrates, such as corn, sorghum, timothy, oats and kaffir, made good silage, but that the plants classed as R. A. HASTE. Filling the silo by modern methods. PAGE FIVE 2 [ ] proteids, such as alfalfa, the clovers and cow peas, did not keep as well. But it was also found that when these two kinds were mixed they produced a superior quality of ensilage greatly relished by stock. Let us get at the reasons. Carbohydrates among plants are those that con- tain a large per cent of compounds made up of carbon, hydrogen and oxygen, such as starch, glu- cose or sugar. These are known as nitrogen free extracts and with the crude fiber make up the car- bohydrates. It will be seen that carbohydrates rich in sugar, or starch which is convertible into sugar, make the best silage for the reason that they are readily pickled by the process of fermentation which changes the starch or sugar, as the case may be, into acid. FERMENTATION OF ENSI' AGE SIMILAR TO THAT OF MILK Discussing silage fermentation, Bulletin No. 70 of the Storrs (Conn.) agricultural experiment sta- tion states that the amount of acid present in fresh corn juice is about two-tenths of 1 per cent, being but little more than the acidity of fresh milk. These acid bacteria and yeasts grow in the presence or absence of air. But when they grow in contact with free air the acid is neutralized and the fer- menting material is changed to a black humus-like mass as the top of the silage or a lot of sour milk putrefies when left open to the air. There is a marked similarity between the fermentation of milk and silage. Milk contains 5 per cent of lac- tose or milk sugar and 3% per cent of protein com- pounds. Lactic acid bacteria in the presence of protein and a fermentable sugar change the sugar into lactic acid and we have sour milk. In silage juices we find protein and sugar, ideal conditions for the production of lactic acid by fermentation. In the souring of milk many of the several va- rieties of bacteria commence to increase along with the lactic acid bacteria, but the miscellaneous va- rieties are soon checked by the acid produced by the lactic acid bacteria. By the time milk curdles from the acid produced most of the miscellaneous bacteria are killed or pickled. Soured milk is pick- led milk, as silage is pickled corn, pickled by the acids produced from the sugars by the acid bac- teria. The acid prevents the growth of putrefac- tive bacteria. Sour milk and silage will keep as long as acid-destroying organisms are kept from them. These destroying organisms are certain molds and when they neutralize or destroy the acid present the silage will spoil or decay. It is an important fact that these acid-destroying bac- teria require the presence of air. To keep silage then is to keep it from air. According to theory silage if sealed from the air should keep indefinitely Here we come upon the princi- ple of modern canning combined with the practice of pickle mak- ing. A silo is a quick-process vin- egar factory. In the cutting of silage every particle is covered with a film of sweet juice. This film of juice affords an ideal me- dium for the growth of sugar, fermentation yeasts and bacteria which begin to grow as soon as the silage enters the silo. The work of the bacteria in changing the sugar to acids and the yeasts in changing the sugar to alcohcl goes on till the lactic acid bac- teria cease to work and the yeasts complete the fermentation of the remaining sugar. The alcohol is immediately acted on by lactic bacteria and changed to acetic acid. The direct change of sugar to acid is brought about by lactic acid bacteria, which are abun- dantly present on farm teams, men handling the corn, and in the dust of the air of the stables and yards. Some varieties of bac- teria are likely indigenous to the corn plant. e e s e e —-—w—--«-»u-—A‘