Why Ensilage Keeps.

Waikato Argus, Volume XXVI, Issue 4079, 28 April 1909, Page 3

Why Ensilage Keeps.

Dr. E. J. Russell, of the Rothamsted Experimental Station, in a recent number of the Journal of Agricultural Science, discusses the keeping qualities of silage. As is well known, when green parts of living plants are cut up and packed in a loosely covered vessel, allowing entrance of air, mould soon makes its appearance, and decomposition begins. The mass becomes alkaline, and is ultimately converted into black humid bodies, quite unfit for cattle food. But, when air is excluded, the result is radically different. No mould develops, the temperature rises, the mass takes on a greenishbrown colour and characteristic odour, it becomes acid, and for a long period is suitable for cattle food. The former, he explains, is a putrefactive change; the latter gives rise to silage. Dr. Russell evidently does not favour the hypothesis that the changes are caused by fermentations, being brought about by micro-organ-isms, and evolving so much heat that everything is killed, and the mass, consequently, sterilised. This theory, he states, “may be dismissed at once, since silage invariably contains bacteria, and is never sterile. Bacteria must obviously play some part, even if only a secondary part, in the process.” Three sets of agents, he considered, were involved, the living protoplasm, enzymes, agents which give rise to fermentation, and bacteria. Putting together his results, Dr. Russel sketched out fairly completely what happened. When the cells were put in they were alive and their vital functions continued. Respiration went on, and sugar, etc., was used up, but in the absence of air oxidation was not complete, and various acids and other chemical combinations were formed. The heat developed during the chemical action caused the temperature of the mass, and respiration was accelerated. Hut, as no more material was being elaborated, and only decomposition was taking place, the process soon came to an end. The cells then died for more substance to break down; it lost its turgidity, and became flaccid, causing the mass to settle down. The temperature also steadily fell. It was pointed out that the decomposition of the protein, which had also been accelerated by the rise in temperature, could continue even after the cell was dead, because the eny • raes, when once formed, were not dependeent on the life of the cell—in other words, it was an autolytic decomposition. Some of the products formed inhibited the development of mould and the general conditions obtaining in the silo were unfavourable to putrefaction.