High energy feed supplements are currently extensively employed in the raising of cattle, sheep, and other domestic animals. These feed supplements include such materials as molasses, fat, and urea, and these materials are usually sold separately and mixed by the animal feeder with such feeds as grains or mixed feeds.
For more convenient handling and distribution, various high energy feed supplement materials have heretofore been combined in two distinctive composite forms, namely, in the form of a liquid feed supplement, and in the form of a block type of feed supplement. However, both of these prior art types of composite feed supplement preparations have involved serious problems in production, handling and usage, and have been undesirably limited in the amounts of certain feed supplement substances which could be contained therein.
Thus, prior art liquid feed supplements have been available which contain a large percentage of molasses for high energy content, and which also contain a substantial amount of urea as a source of nitrogen for protein equivalent. However, the amount of fat content which could be provided in such prior art liquid feed supplements is severely limited, and is much less than is desirable for an optimum feed supplement composition. The biggest difficulties in connection with prior art liquid feed supplements have been in the handling and ultimate use thereof. Thus, special tanks are required for storage of liquid feed supplements, and tank trucks are required for primary distribution thereof. Additionally, putting such liquid feed supplements out for consumption by cattle or other domestic animals presents a very serious problem, as open troughs of the sweet, sticky liquids attract flies and other undesirable insects. Accordingly, special closed liquid feed dispensing containers have been required which meter the liquid feed supplement material out through mechanical devices. Even when thus dispensed, cattle tend to get the sweet, sticky feed supplement liquid all over their faces, which draws flies and is accordingly unsanitary.
Block types of animal feed supplements have heretofore been produced by combining chopped alfalfa, straw, or grains, and proteins, with from about 10% to about 30% molasses in a mixer, and then pressure forming the combination under extremely high pressure, as for example about 100 tons per square inch. This prior art method of forming block feed supplements involves the use of very costly machinery, and labor is also quite costly as it is principally a hand operation. In such prior art feed supplement blocks the maximum percentage of molasses which can be satisfactorily combined in the mixture is only about 3:%, as combinations with larger percentages of molasses are too much of a gooey mess for satisfactory pressure forming. Similarly, the amounts of fat which could be contained in such pressure formed feed supplements were inadequate.
In general, it is desirable in a feed supplement for animals to include a relatively large percentage of molasses, because of the high content of inverted sugars therein (over 50%), because of the good mineral content, and in particular because of the large amount of energy available cheaply. A substantial amount of fat has also been found to be desirable in such feed supplements. While prior art liquid feed supplements were able to obtain an adequate amount of molasses, they were generally deficient in the desirable amount of fat, and were difficult to handle and use. On the other hand, while prior art block type feed supplements were much more convenient to use, they were deficient in both the amount of molasses they could contain and the amount of fats they could contain, and they have the further disadvantage of undesirably high production cost and investment in machinery.
Prior to the method of the present invention wherein the molasses is first heated at substantially ambient pressure to remove a major portion of the water content thereof and then without further heating subjected to a vacuum to further reduce the water content without foaming, there has been no method in the art capable of producing dense, hard, vitreous molasses feed blocks, and particularly such blocks wherein substantial quantities of other important animal feed ingredients are integrally combined in such blocks with the molasses solids serving as a supporting matrix.
Molasses has heretofore been dried by vacuum methods for animal feed purposes. However, prior art methods of this type were directed to the drying of the molasses for later mixing with other feed ingredients, and did not produce a dense, hard, vitreous molasses feed block; nor were they capable of producing such a block. Examples of such prior art vacuum drying methods were the methods described in U.S. Pat. No. 1,983,434, issued Dec. 4, 1934 to Black et al, and U.S. Pat. No. 2,089,062 issued Aug. 3, 1937 to Hougland.
In the Black et al patent, prior to the removal of any water from the molasses, it was passed into a high speed vacuum evaporator at low temperature (150.degree. to 160.degree. F.), in which most of the water was removed, and then it was heated to between 200.degree. F. and 238.degree.F. and spray dried. The purpose of the Black et al method was to avoid having to mix the molasses and other feed ingredients while the molasses was in its liquid form, because the stickiness of the molasses made mixing so difficult.
In the Hougland patent, a thin film of molasses was applied to a heated surface in an evacuated drum, so that the vacuum was applied to the molasses prior to and during the heating thereof, and hence before the removal of any of the water from the molasses. The purpose of the Hougland method was to dry the molasses so that when it was later mixed with other feeds it would not be subject to fermentation.
The application of vacuum for drying before the removal by heating of any water from the molasses in the Black et al and Hougland methods precluded the formation of dense, hard, vitreous feed blocks by such methods; and also precluded the inclusion of other feed materials with the molasses when it was being treated, and hence precluded the integral inclusion of other feed materials within a matrix of hard molasses.
Such prior art methods also were rather severely limited in production rate because of the tendency of the molasses to swell and foam when thus subjected to the vacuum with initial water content, making animal feed production by such methods generally costly and inefficient.