Agriculture and Food Systems - Theses
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ItemSome aspects of the meat rendering industryMcCrum, James Wilson ( 1937)For many years the chief objective in the rendering of meat has been the recovery of its fats and oils. In all animals there is a very large variety of fats and oils and their uses may vary from the production of edible materials such as dripping, margarine and salad dressings to such commonplace things as leather dressings and soap. The tallow produced from the rendering of meat is of great importance in war materials, for from this harmless substance, glycerine is obtained and in turn, is used for the manufacture of many explosives. The so-celled edible tallows or fats are generally produced under different conditions to the inedible and as a result are much more expensive. The oils from animals are also important. tin oil such as neatsfoot oil is regarded as quite a common oil, but little thought is ever given to the tedious processes necessary in its manufacture. When - it ultimately reaches the world's markets, its uses are much greater than one would ever imagine. Today a very large amount of the famous "fish and chips" are fried in neatsfoot oil. The delicate machinery of a spinning mill (either silk or woollen threads) is lubricated with an oil that has neatsfoot oil as its basis. Even the very threads are often lubricated with an emulsified form of neatsfoot oil. The foregoing products have up to comparatively recent years been the chief by-products of the meat rendering industry. When Laws discovered that bones could be used as a fertilizer, then, another aspect of the industry was opened up and bones were much in demand for soil fertilization purposes. Following this, flesh and blood came to be used to make up a more complete fertilizer. With the discoveries of bacterioligists that various diseases could be transmitted by bones, then sterilization of these bones became necessary. Today all fertilizers of animal origin are sterilized under steam pressures generally in the region of 50 lbs. per square inch. With further progress in studies on the feeding of animals, the meat industry was again called upon to supply important articles. Bones that had previously been used as fertilizer were diverted to other channels and now supply that important compound, calcium phosphate, as a lick or a mixture in the food of animals subject to phosphate deficiency. The next avenue opened up was the protein side of the question. The continual demand for increased production from all animal life has rendered it necessary that high protein foods should be available to animals. Cows that are heavy producers of butter - fat, poultry under intense production and similar branches of agriculture demand a protein concentrate. The meat industry has risen to the occasion and produced a meat meal, liver meal and blood meal with protein percentages as high as 70%. Originally a protein content of 35.` in a meat meal was considered quite good, but today the tendency is to aim at 7u and exceed this mark if possible. One of the chief reasons for this great advance, is, that raw materials producing these "meals",are for the most part low fat bearing offals and a means of getting rid of them, without expensive treatment, has been long sought after. Apart from the foregoing reason, the overseas demand for meat meals, liver meals and such concentrates has increased tremendously in the last two years. Some of the larger rendering companies ship almost their entire out ? to overseas consumers. The Australian consumer has still to be educated to the use of concentrated foods for his animals and when this happens the bones and meat now going into fertilizer will be diverted into animal foods. In England the shank bones from lambs are ground into a special bone meal which is entirely strange to Australia, although its results are far ahead of anything we produce here at present. The meat industry is one in which nothing is wasted and every year sees some new use for one of its many by-products.