WO2009079707A1 - Grain treatment process and animal feed product - Google Patents

Abstract

A method of treating grain for use in animal feed is described. The method includes the steps of a) introducing additional moisture into the grain, preferably at a predetermined temperature, b) subjecting the moistened grain to a rest phase; and then c) heating the grain at a temperature within a predetermined range for a predetermined time period. The resulting grain, in which carbohydrate and protein is altered such that it is protected from degradation in the rumen by microbial activity, is preferentially digested by the animal so that the animal is able to directly metabolise the nutritional components in the grain.

Description

GRAIN TREATMENT PROCESS AND ANIMAL FEED PRODUCT

Field of the Invention

The present invention relates to a method of processing grain for the purpose of manufacturing an animal feed product and to an animal feed product manufactured by said process. The present invention is particularly suited for the processing of grain for the manufacture of animal feed and to improve feed conversion ratios in livestock. Background to the Invention

A primary economic concern in the manufacture and provision of animal feed is the ability of the feed product to be efficiently converted to usable animal mass. That is, the capacity of the feed product to promote growth of the animal being fed with said product. Manufactured feed products must fulfill the most basic requirements in maintaining the health and well being of the animal. However, the higher the feed conversion rate that can be achieved from any particular feed, the more economically viable the feed and hence the manufacture of animal products, such as meat, can become. In a competitive market environment, and with forecasts of global food shortages in the future, the attainment of high feed conversion rates is highly desirable.

Agricultural practices have long utilized the use of grain based products as animal feed. However, grains are not naturally suited as an animal food. It is only with the artificial intervention of agricultural practices that grains have been implemented as feedstuff for animals. The biological purpose of grains is for plant reproduction. In order to effectively carry out this function, seeds have evolved with a range of mechanisms to protect a single seed from false germination or from breaking down prematurely from, for example, microbial activity. The evolution of such protective mechanisms in seeds, whilst effective in fulfilling their biological purpose, inherently renders such seeds as having an anti- nutritional impact upon an animal that eats said seeds. This arises due, at least in part, to the fact that many of these protective mechanisms have in fact evolved so as to prevent animals from consuming the seed, or at least to prevent the seed from being digested upon consumption. There are any number of elements naturally present in grains, which can for the purposes of this specification, be readily referred to as "anti-nutritional factors". That is, they are factors which reduce the nutritional value of the grain to the animal that consumes the grain, and/or are intrinsically toxic to the animal. A sample of the most commonly encountered anti-nutritional factors is described as follows:

Enzyme inhibitors: are those which interfere or interact with an enzyme, specifically a digestive enzyme, to prevent the enzyme from working effectively or optimally. These inhibitors can be non-specific, irreversible, and/or competitive or non-competitive with the enzyme substrate. A large proportion of poisons and drugs are enzyme inhibitors. In terms of animal nutrition, these inhibitors can interfere with digestive function and protein digestion, which can slow down absorption in the small intestine. Common examples include trypsin, chymotrypsin and amylase inhibitors. Trypsin inhibitors can cause pancreatic problems, whereas amylase inhibitors typically reduce the rate of carbohydrate reduction and absorption;

Phytin (phytic acid): is generally considered to be an anti-nutrient as it is highly reactive and readily chelates with calcium, iron, magnesium, copper, zinc, carbohydrates and proteins. These resulting complexes have a very low solubility in the small intestine and therefore become unavailable as a nutrient source to the animal. In addition, phytins are very stable compounds and are not readily degraded by heat or pressure. The phosphorous content of phytic acid is generally not bioavailable to non-ruminant animals, as such animals lack the enzyme phytase. Thus, in non-ruminant animals especially, upon being fed grains such as soy and maize, the phytic acid passes unabsorbed through the digestive system. In fact, recent studies, such as that conducted in Dubois, Idaho - "The effect of low-phytate mutant-M 995 barley grain on phytate degradation and mineral digestion in sheep fed high-grain diets" (Reference) indicates that phytates are still active and able to affect mineral uptake in ruminant animals also. It is often the case that the bioavailability of the phosphorous in phytic acid is increased by supplementing the animal diet with phytase; Haemagglutinins, including lectins: are considered to be toxins and can cause slow growth, nausea and diarrhea. Clotting of red blood cells can also occur, and sometimes cause death;

Saponins: a toxin which can cause bloat in the animal, sometimes leading to death by suffocation. When saponins are absorbed into the blood stream, they are able to dissolve red blood cells;

Alkaloids: a very large complex group of phyto-chemicals, which are a common plant defence mechanism, often to prevent ingestion of the plant by animals. The effects of alkaloids range from reduced palatability to toxicity leading to death;

Mycotoxins, including anatoxins: typically highly stable toxic compounds produced by fungal organisms which typically infect moist or weather damaged grain. At high levels, some mycotoxins can cause death, whereas others compromise the general health of the animal; Tannins: astringent, bitter-tasting plant polyphenols that bind and precipitate proteins, thereby reducing their nutritional availability to the animal. In addition, tannins typically affect the palatability of the feed, leading to decreased feed intake;

Oligosaccharides: whilst oligosaccharides are substantially digestible, they do have some properties that can be considered to be anti-nutrients. Upon commencement of grain digestion, in the stomach, the oligosaccharides are released into stomach chyme, whereupon they firstly tend to line the wall of the stomach, thereby preventing digestive enzymes from being released into the chyme. Secondly, the oligosaccharides tend to expand greatly, thereby creating a sensation of satiety. This sensation inhibits the feed intake of the animal, which in turn reduces rumen outflow which slows weight gain. Furthermore, when oligosaccharides are consumed, there is an undigested portion, which is utilized as a nutrient source by intestinal microflora. Not only does this redirect nutritional material away from the animal, but depending on the type of oligosaccharide, different bacterial groups within the digestive tract can be either stimulated or suppressed.

A further feed element or factor which can adversely affect feed conversion rates, particularly in ruminants, is the degradation and utilization of nutrients by rumen microflora and microfauna. Whilst rumen microbial activity is a necessary part of ruminant digestion, particularly to permit digestion of otherwise generally undigestible plant components such as cellulose, these microbes also utilize other nutritional components, such as protein and carbohydrate. The mere process of first processing valuable nutritional components through rumen microbes before these nutritional components can be made available to the consuming animal itself can constitute a loss of feed conversion efficiency and thus end product.

Given that there are so many factors that can each and collectively contribute to reducing the overall nutritional value of the grain to the animal, it is highly desirable for the grain to be subjected to a process or processes so as to minimize the amount of such factors prior to feeding to animals. However, due to each grain type, and even varieties of the same grain species, having different levels of antinutritional factors and variances in the direct availability of nutrient content to the animal, it has been thus far difficult to implement any one process or set of processes that gives credible and consistent reductions of the content, such that the grain has increased nutritional value to the animal.

It may be the case that any single adverse factor or group of factors can be overcome or ameliorated in feed by the application of an appropriate remedy. For example, the adverse effect of phytic acid can be overcome by supplementing feed with phytase; fermentation is known to be able to reduce saponins in some grains and tannins in sorghum. There is no known treatment for significantly reducing the levels of alkaloids in grains. Similarly, the only known way of preventing contamination by mycotoxins is to prevent infection of the grain by fungus in the first place. There is no known and particularly no commercially viable means of making nutritional components directly available to the consuming animal.

It is thus apparent that there is not known any one process that can satisfactorily remove or reduce anti-nutrients such that any significant improvement in nutritional quality and feed conversion rate can be credibly and reproducibly measured. This is despite the fact that it remains that grains are currently a primary alternative to fresh feed such as spring green grass, which is not always available for feed and is generally subject to seasonal availability. There is therefore a definite need to provide a grain feed that improves upon that which is currently available, and that is able to offer greater nutritional value and higher feed conversion rates without compromising on economy and price. Summary of the Invention

The method of the invention seeks to reduce or eliminate content of anti- nutrients that interfere with digestion and absorption from the grain, prior to the grain being fed to animals. The method also seeks to alter the nutritional composition of the grain, such that nutritional components are preferentially digested in an animal's digestive tract, in particular, the small intestine, rather than by microorganisms.

Thus in a first aspect, there is provided a method of treatment of grain wherein grain is processed so as to provide a grain product with nutritional components in an available form that is more readily digested by an animal relative to the digestibility of untreated grain. In particular, the method provides a grain product in which protein and carbohydrate content is altered or otherwise protected from digestion in the rumen and is preferentially available for digestion in the digestive system of the animal. That is, there is provided a grain product in which carbohydrate and protein content is converted to bypass carbohydrate and bypass protein, escaping significant degradation in the rumen.

There is thus provided a method of treatment of grain, the method comprising the steps of: a) introducing additional moisture content into the grain; and b) heating the moistened grain at a temperature within a predetermined range, whereupon the treated grain is suitable for use as a component in animal feed.

Preferably, the method includes the additional step of subjecting the soaked grain to a resting stage, immediately following introduction of additional moisture content. In a preferred embodiment, this resting stage extends for a period of between 8 and 24 hours. It is further preferred that the grain is subjected to a second resting stage following cooking, wherein heat applied to the grain during the cooking phase is retained within the grain for a period of time sufficient to finalise the necessary alterations of nutritional components within the grain. Typically, the moisture content within the grain is introduced and increased by soaking the grain. In a preferred embodiment, the grain is soaked in a liquid which is maintained at a temperature between 20-35°C, preferably at around 30°C.

In one embodiment, the grain is soaked in a slightly acidic solution, such as a sugar solution.

It is particularly preferred that the pH of the solution is maintained within the range of 5.5 to 6.5. The pH can be controlled by the addition of any suitable modifying solution, including acetic acid or citric acid with some molasses.

It is further preferred that the moistened grain is heated at a predetermined temperature, preferably within the range of 100° to 300° C, even more preferably between 100° to 150° C

Advantageously, the resulting grain does not need to be subjected to a crushing stage, to reduce the particle size of the treated grain. The grain that results from the process is whole yet soft and easily consumed by the animal. No reduction in particle size is necessary, avoiding problems that can arise when mechanical crushing reduces particle size to a size that is effectively too small to avoid digestion in the rumen.

Advantageously, soaking the grain can reduce the levels of anti-nutrients within the grain, primarily by way of enzymatic action. The relevant enzymes are activated by temperature and moisture over time and in some circumstances, by the addition of the acidic solution to the grain. Some anti-nutrients are leached into the solution, whereupon management of the soaking solution is required, such as by way of adjustment of pH. The soaking also assists in producing an unfolding action of long chain carbohydrates, causing the grain to expand and thereby exposing the anti-nutrients within the grain to digestive enzymes.

Soaking also provides the significant further advantage whereby significant changes are caused to starch and polysaccharide molecules in the grain. Such modifications, which will be described in further detail, enable significant portions of carbohydrate content of the grain to bypass consumption in the rumen by microbes and rather be preferentially digested in the small intestine of the animal.

The heating step acts to not only further reduces the levels of anti- nutrients, but also converts proteins and starches in the grains into a readily digestible form. That is, the proteins and starches are able to be provided to the animal in a form which is absorbed preferentially in the small intestine.

According to a second aspect of the present invention, there is provided a treated grain for use in animal feed, wherein the treated grain has a protein and starch content which is preferentially digested and absorbed in a small intestine of an animal that has ingested said grain.

Preferably, the starch content of the treated grain is available to the animal in a pre-digested form so that the starch bypasses digestion or breakdown in the rumen, when fed to ruminants.

It is also preferred that the protein in the treated grain is available to the animal in a pre-digested form, such that the percentage of protein bypassing microbial degradation in the rumen is increased compared to that which is achieved from feeding untreated grain. Brief Description of the figures

The present invention will be described in conjunction with the accompanying Figures, wherein:

Figure 1 is a chart showing average weight gain per head of cross bred lamb in kg, over a period of fifty three (53) days;

Figure 2 is a comparison between feedlot ration and standing green oat crop in terms of average weight gain per head and average weight gain per day, when fed to 2.5 year old Merino wethers;

Figure 3 is a chart showing average weight gain per head of 2.5 year old rams when fed oaten hay and stock lick formula; and

Figure 4 is a chart showing average weight gain per head of mixed age merino wethers when fed lupins treated according to the present invention, hay and stock lick formula. Description of the Invention

It is now convenient to describe the invention, by way of example only. It will be understood that variations as would be readily apparent to a skilled addressee are deemed to be within the scope of the invention. As used herein, "grain" refers to all types of grain, cereal grain and grain legumes that can be used in animal feeds. Such grains include, but are not limited to, grain and grain legumes such as lupins, peas, fava beans, soyabeans, rice, wheat, barley sorghum, millet, oat, rye, triticale, buckwheat, (a form of millet), fonio and quinoa. The method in its broadest form is equally useful for use in treating all such grains. However, minor modifications to the specifics of the method can be made so as to attain optimal results for each type of grain or the proportion of each grain type in a mix.

In particular, whilst the examples below primarily refer to lupins, namely Australian sweet lupin (Lupus angustifolius), the inventive concepts upon which the present invention is based is equally applicable to other grains suitable for use in animal feesds.

"Feed conversion ratio" or "feed conversion rate" refers to a measurement of an animal's efficiency in converting feed mass into increased body mass. Body mass can refer to any aspect of the animal, whether it be muscle mass or other useable product such as wool.

"Ration" refers to a 24 hour allotment of feed for a single animal. "By-pass protein" refers to the portion of intake protein in a feed that is not broken down in the rumen, but is digested directly in the small intestine of a ruminant animal. It is desirable that the present method be able to increase the level of bypass protein in the grain, by altering or otherwise protecting the protein from digestion in the rumen.

"Acid detergent fibre" (ADF) refers to the percentage of fibrous, highly indigestible parts of feed, including lignin, cellulose and insoluble components such as silicon and nitrogen. "Neutral detergent fibre" (NDF) is an estimate of fibre constituents of feed, measuing cellulose, hemicellulose, lignin, silica, tannins and cutins. "Nitrogen free extract" (NFE) refers to an estimate of crude starch and sugar content of a feed.

"Metabolisable energy" refers to the digestible energy minus energy expelled or lost in digestion, often expelled in urine and/or faeces. The treatment method commences with the soaking of a quantity of grain in a slightly acidic solution for a predetermined period of time. The soaking stage may be conducted in a static solution or in a continuous flow system. Regardless of the mechanical means of soaking, the grain can be soaked in any suitable solution, such as, but not limited to, a slightly acidic solution. A preferred example is a solution which includes molasses, with the addition of citric or acetic acid to control pH levels of the solution. The use of molasses is particularly preferred for use in a static soaking process, as the molasses is typically substantially or completely absorbed by the grain. Should molasses be included in the soaking solution in a continuous flow system, it is likely that fermentation would commence. However, any fermentation can in practice be remedied by application of techniques known to those well versed in the art of continuous flow systems, such as implementing controlled solution recycling or replacement.

Ethanol can also optionally be added to the soaking solution. Addition of ethanol is of particular use when soaking cereals such as oats. In particular, the ethanol can advantageously assist with release of protein structures bound within cellulose or lignin of the whole grain. However, since the overall protein content of oats is relatively low, it may not always be economically feasible to include ethanol since the overall percentage increase of protein may not justify the added expense of the ethanol. It is favourable to the efficacy of the soaking process if the pH of the soaking solution is within the range of 5 to 7.9. However, it is preferred that the pH be maintained within the range of 5.5 to 6.5. The pH can be maintained during the soaking process by addition of suitable agents, such as acetic and/or citric acid. The pH of the soak solution is important as it is the acidity of the solution that converts anti-nutrient alkaloids into salts. These salts are then advantageously precipitated out of grain and into the soaking solution. The period of time for which the grain is soaked is correlated with the associated levels of anti-nutrient and toxic factors within the grain. For example, when the grain is completely or predominantly comprised of lupins, which generally contain relatively low levels of such factors, (refer to Table 1 ) a soaking time of between 2 to 24 hours, typically 2-6 hours is appropriate. On the other hand, grains containing high levels of phytates, such as soybean, maize or cereal grains, can benefit from being subjected to a longer soaking period of, for example, 72 hours.

^* sum of raffinose, stachyose and verbascose Table 1 : Anti-nutritional factors in Australian sweet Lupins

From Grains Research & Development Corporation (GRDC Australia) "The Chemical Composition and Nutritive Value of Australian Pulses"

Similarly, the temperature of the soaking solution is critical to the process, particularly for alteration of the nutritional components within the grain. It is optimal that the temperature during the soaking stage be maintained between 20- 35°C, preferably around 30°C In particular, the temperature during the soaking stage should not exceed 35°C. Exceeding this temperature inactivates enzymes within the grain, particularly those most sensitive to heat.

Temperature and time of soaking are related to each other when determining a precise optimal of each for application to different types of grains. Generally speaking, it has been found that increasing soak temperature requires less time spent soaking. Conversely, decreasing soak temperature requires that the grain be soaked for a relatively longer period. In any event, temperature should not exceed 35°C. In the case of lupins, soak temperature has been found to be more than adequate if maintained at about 30°C and the grain is soaked for a period of about 2-6 hours. Temperature and time period of the soaking phase is instrumental in effective alteration of nutritional components within the grain as the combined effect of each has a direct effect upon enzyme activity within the grain. If each or both of temperature and soak time and/or solution levels are too low, moisture absorption into the interior of the grain is slowed considerably. Without adequate amount of water absorption into the grain, enzyme activity is slowed or is not effected or even initiated to any significant degree. In particular, it has been found that enzymatic breakdown of long chain sugars is slowed or does not occur at all. The significance of soak temperature in particular is exemplified by results from trials conducted with sheep over a winter period. Test batches of grain treated by the method of the present invention underwent a soaking stage as described, however, difficulty was experienced in maintaining the temperature during the soak stage. The test sheep were observed to frequent an energy lick, as they required the extra energy the lick provided. However, once soak stage temperature was increased to the prescribed range, the sheep no longer required the lick since their energy requirements were being met by the nutritional value of the treated grain alone.

The soak stage should swell each individual grain to no more than 2.5 times the original size. If the grain swells more than this, the outer seed coat is caused to rupture. Rupture of the outer seed coat prematurely releases the valuable nutritional components before it can reach the animal and also further before the complete necessary alterations have been made. It is essential that a significant portion of individual grains proceed from the soak stage in a swollen, yet intact state. That is, the structure of outer seed coat must not be compromised, particularly at this stage of the process.

Following the soaking stage, the grain is subjected to a rest phase. That is, the grain is simply allowed to sit, in a moistened state, for a period of time. It is not only instrumental for the success of the present method that the moistened soaked grain be permitted to sit, but that the rest phase be for at least a minimum prescribed time period, preferably from about 8-24 hours.

In preliminary testing, soaked grain was permitted to rest for a period of only 3-4 hours. Upon subsequent cooking of the grain, as described later, the grain reverted to a hardened state, essentially as if it had undergone no treatment whatsoever. However, once the post-soak rest phase was increased to at least 12 hours, it was discovered, surprisingly, that the resulting grain remained soft inside. The importance of this result is discussed further below. The soaked grain must therefore be subjected to a post-soak rest phase of at least 8, preferably 24 hours and generally no more than about 30 hours. Resting period which extend beyond 24 hours have not been found to assist the process and excessive resting whilst in a moistened state can increase chances of significant contamination from microbes, particularly fungus. Upon completion of the soaking stage and subsequent post-soak rest phase, the moistened grain is then subjected to a heating or cooking stage. In the present embodiment, the grain is moved, in a moistened state, to a continuous flow cooker. In such a cooker, radiant heat is applied to the grain from a series of high temperature heaters so as to cook the grain in its own steam. It has been determined that a cooking temperature within the range of 100° to 300° C, preferably 120° to 150° C is effective in achieving the desired result of reducing anti-nutrient content and ensuring that protein and carbohydrate in the grain is reduced to a form that is available to the animal in a pre-digested form. By "pre-digested" is generally meant that the carbohydrate and protein is reduced, broken down or otherwise altered into a form that is able to be directly digested in the small intestine of the animal and which substantially avoids metabolisation by microbes, particularly rumen microbes. The carbohydrate and protein can therefore pass directly through to the small intestine, where the nutritional value is directly absorbed by the animal and not by microbes.

The grain is cooked in this manner for a predetermined period. It has been found, somewhat surprisingly, that the length of this predetermined period of cooking is critical in terms of the end result to the nutritional content and digestibility of the resulting grain. The moist soaked grain is therefore preferably cooked for a period of 3 to 40 minutes depending upon temperature and grain type. Cooking time has also been found to correlate to cooking temperature. That is, lupins have been found to require a cooking time of about 15-30 minutes at 150°C. However, cooking time can be reduced to about 10 minutes by increasing the cooking temperature to about 200°C. Regardless, it is imperative that the grain is neither undercooked nor overcooked.

Smaller cereal grains typically require less time at the same temperature to cook then do larger grains such as lupins or fava beans. However, care must be taken so as not to cook the grain excessively. Excessive cooking can damage the protein or induce the Maillard reaction. The Maillard reaction occurs when excessive heat and humidity are applied to the grain, causing chemical reactions between reducing sugars and amino acids. The end result is a browning of the grain with a distinctive aroma. Maillard reactions are not considered desirable in the feed industry as the altered sugars and amino acids are no longer fully digestible.

Conversely, if the grain is still able to germinate at the end of the cooking stage, then insufficient heat has been applied. In this instance, the digestibility of the protein and carbohydrate content is unlikely to have been positively altered such that the useful nutritional content is absorbed preferentially by the small intestine.

Upon completion of the heating stage of the process, the grain is subject to a second rest phase. This rest phase is useful to finalise the enzymatic activity initiated in the grain by the soak and rest phases and set the structure of the nutritional components within the grain in a form that is advantageous to the animal, as will be discussed further below. In particular, heat that is applied to the grain in the cooking stage has been found, surprisingly, to be retained within the grain for a significant period of time. The post cooking rest phase therefore permits complete cooking of the grain without application of additional heat. This rest phase is for a period of 10-30 minutes and will vary according to different grain types. In the present embodiment, conducted in respect of lupins, the rest phase extended for a period of 15-20 minutes.

The cooked and rested grain is ultimately permitted to cool. A drying phase is included if the moisture content of the treated grain is above a predetermined level. Moisture in the grain is significantly controlled by the period of time the grain has been subjected to the soaking stage. Essentially, the longer the period of soaking, the higher the moisture content will be. The moisture level is also dependent on the type of grain being treated. For example, lupins will typically attain maximum moisture content after about 36 hours of soaking, whereas many grains will require longer. In either case, excessive soaking is to be avoided, so as to prevent bursting of the grain due to excessive moisture absorption. As an example, lupins may be soaked for approximately four hours and thereby have a moisture content of 40%.

If the moisture level of the treated grain is greater than approximately 10 to 15%, preferably no more than 12%, the grain can be subjected to a drying phase so as to reduce the moisture to within these parameters. Drying of the grain is conducted by any suitable means, such as by subjecting the grain to a heating source, preferably at a temperature significantly less than that of the heating stage of the process. Drying temperatures are typically in the range of 40° to 60⁰C for periods varying from 5 to 24 hours, depending upon grain type. Typically, larger grains require more drying than smaller grains.

Whilst drying of the grain is a viable, and in some instances, a necessary action, the end moisture percentage of the grain is preferably manipulated by control of the soaking stage parameters, whereby moisture levels can typically be reduced to about 20%. For example, it has been found that increasing the soaking temperature to just below 35°C or at least to about 30°C and reducing the soaking time to about 2-4 hours results in grain having adequate final moisture content. After draining of the soak solution, the grain can then be left to sit, whereby the absorbed water and increase in temperature initiates and continues internal enzymatic activity to alter the internal protein and carbohydrate structures. The enzymatic activity is permitted to continue until halted completely by the cooking phase and also from any post-processing dehydrating of the grain. Whilst subjecting the grain to a drying stage prior to cooking or manipulating soaking parameters is preferable in order to reduce moisture content to a prescribed percentage in most instances, it should be understood that there are some circumstances in which drying is not completely necessary and may therefore be optional. For example, if the finished feed product need not be stored for any significant period of time, the finished feed product can be fed to the animal at high moisture levels. In such instances, the grain can be cooked when it is still moist, for example, having a moisture content of around 40%. The grain that results from this process is intact, with the outer seed coat remaining uncompromised. However, the entire grain is itself soft, particularly inside. This is despite the fact that the interior of the grain is in fact substantially dry. This of itself is indicative that the internal chemical and structural composition of the grain has been altered by the process, even without chemical analysis.

Grain in this softened yet cooked state has advantageously been found to have an increased shelf life of at least 10-14 days. That is, the treated grain is not immediately susceptible to mould or fungal attack, as would be expected from grain that is soft and has retained a certain degree of moisture. Treated grain can therefore be stored for a short period prior to feeding to animals without compromising the nutritional value.

It is usual, in most grain processing methods, that the grain is, prior to being fed to animals, processed through suitable machinery or equipment to mechanically crack or otherwise reduce the size of the grain. In such circumstances, the grain usually needs to have a moisture content of about 12% or less. In a process such as this, the machinery or equipment utilized for this typically reduces the grain size to approximately half or quarters. Whilst conventional methods that incorporate mechanical reduction of grain size requires that grain size is not reduced below approximately one quarter of the original size, it has been found that when the method of the present invention is applied to grain, the mechanical processing stage is essentially unnecessary.

Grain treated with the present process can be fed to animals in an intact form. No further processing is required, since the grain itself is soft and readily consumed by the animal. Reduction of particle size has been found to be unnecessary, avoiding the need and associated expense of crushing machines and the like.

Not only does the present process save costs from negating the need to process through crushing machinery, but the act of feeding of intact grain to the animal also avoids nutrition absorption problems that arise when the grain particle size becomes too small. This is a problem that can eventuate if the often imprecise mechanical crushing process crushes the grain to less than about a half or quarter of original size. If the broken grain size is too small, the small particles in particular can undergo degradation by microorganisms within the rumen. Should this occur, a significant component of the nutritional value of the grain is lost before the grain is able to move into the second stomach and beyond as by-pass protein and by- pass carbohydrate. As such, at least part of the nutritional value of the grain is directed to the microorganisms instead of being directly available to the animal itself. This is a situation that the process of the present invention is seeking to avoid and indeed reverse. Clearly then, negating the need for mechanical reduction of grain particle size contributes further to the purpose of the present process.

It is clearly a distinct advantage in that grain treated by the present process can be fed directly to animals. Further, the treated grain can be used directly for production of commercial feed pellets.

It is not intended that the treated grain be the only source of dietary protein to the animal, as other sources of feed should also make up the complete feed ration for each animal. It is expected that it is within the knowledge of persons who have training and experience in the scientific field of formulating animal feed rations to be able to formulate amounts of treated grain in conjunction with other feed sources, so as to achieve growth rates and/or production levels that are deemed appropriate for the particular application.

In treating grain intended for use as animal feed by the aforementioned process, it is considered that the nutritional quality of the resulting grain is altered in such a way so as to at least partially mimic digestive characteristics of green feed. It is known that the percentage of protein which bypasses rumen microorganisms when an animal is fed on green feed is high, when compared to that of untreated grain. In this manner, the feed conversion ratios and growth rates that are able to be attained when animals are fed on green feed, are achievable by feeding the animal grain treated by the present process.

For example, it is known that feed conversion ratios are typically lower when an animal is fed on green feed, relative to that which is attainable when an animal is fed untreated or conventional commercially available grain feed supplies. This is essentially due to the fact that green feed, such as green oats, has no anti-nutrients or feed inhibitors and the feed intake is therefore utilized by the animal itself. For example, referring to Figure 2, which compares the average weight gain per head and average weight gain per day of sheep fed grain feed lot ration (comprising a selection of hay, lupins, oats and triticale fed in individual containers) with those fed standing green oat crop, it can be seen that greater weight gains are attained when the animals have been fed the green feed. Thus whilst there was an average conversion ratio of 8.5 for those fed feedlot ration, it is likely that the ratio was significantly lower for those fed green feed. In this particular trial, an exact feed conversion ratio was not attained as the intake was not able to be weighed for each animal. It is proposed that the same digestive effects are attained by feeding animals a grain feed that has been subjected to the process of the present invention. Green grass feed, particularly young grass, has significantly lower levels of carbohydrate than grains and grain feed. It is postulated that the soaking step of the present process acts to cause a significant change to the structure of the carbohydrates in the grain.

Indeed, chemical analysis of grain prior to and after subjection to the present process indicates that soaking the grain causes significant and important changes to starch molecules within the grain. It is advantageous for starch to undergo modification so that it is able to bypass consumption in the rumen by microbes (i.e., become "bypass starch") and is rather, preferentially digested in the small intestine of the animal. In order for the grain starch to become bypass starch, it is necessary for a change in the molecular state to occur.

Starches are stored in grain in the form of tightly packed coils, forming coils or spirals when in a dry state. This is distinct from other polysaccharides such as cellulose, pectins, hemicellulose and lignin, which do not form such structures and are rather flatter in configuration. Upon absorption of moisture . by these starch spirals, the spiral begins to expand and unfold generally proportionally to the increase in moisture content. It is this unfolding of the starch structure that assists in causing the physical size of the grain to increase. In addition, the introduction of moisture causes the starch to develop gel- like qualities, which is akin to the dough quality in bread mixes. As each starch granule unfolds, it is caused to align with other starch granules upon the application of movement or pressure. In each grain particle, this pressure is applied by the action of the inside of the grain expanding inside the outer skin.

The introduction of moisture at 30°C importantly also initiates enzymatic reactions within the grain to enable further alterations of nutritional compositions. For example, break down of long chain sugars into shorter chains of oligosaccharides. In particular, the process of resting the grain in the moistened and warmed state enhances this enzymatic activity, which is effectively concluded when the grain is cooked.

It is known also, from the fact that protein has been shown to pass through the rumen and be digested preferentially in the small intestine, that this process also alters the protein structure, converting significant amounts to by-pass protein. It is postulated that the three dimensional protein structure is altered so that it is protected from degradation by rumen microbes. Alternatively, the amino acids or shorter chains of amino acids from the original proteins are themselves protected from further degradation or absorption by rumen microbes.

That is, the process of the present invention creates a change within the grain that effectively converts carbohydrate and protein substantially into bypass carbohydrate and bypass protein, thereby passing undigested through the rumen and becoming available for digestion in the hind gut of the animal. The exact mechanism of protein and carbohydrate alteration and/or protection is not completely clear, but it is known that a greater proportion of the protein content and a significantly greater proportion of carbohydrate, including that derived from previously indigestible cellulosic components of the grain becomes directly available to the animal after treatment with the present process. Chemical analysis of grain following treatment by the present process gives some indication of the mechanisms by which the carbohydrate and protein content is altered to effectively become bypass protein and carbohydrate. Specifically, nitrogen in NDF has been observed to increase significantly after treatment with the process, as is set out in the Examples, in particular, Example 7, described below. A significant reduction in NFE levels has also been observed. It is postulated then, that the nitrogen and at least some of the free sugars, released by the enzymatic activity within the grain, are caused to attach to fibre content of the grain. Fibre content is known to be digested in the hind gut of ruminants, rather than in the rumen itself. Therefore, attachment of sugars, proteins and/or amino acids to fibrous content can cause these components to bypass into the abomasums and intestine, in particular the hind gut, where the fibre is then digested, thereby releasing these nutritional components. In this manner, these valuable nutritional components can be metabolized directly by the animal itself and not by rumen microbes.

Lignin, for example, is known to be recalcitrant to digestion, yet is thought to shield associated nutrients from digestion and hence limits degradation of these nutrients. A similar process is thought to occur here, where a significant portion of the available carbohydrate and protein content of the grain is shielded.

It is thought that this effect is caused in the present process at least partially by the physical process of swelling of carbohydrates, thereby pressuring the protein and sugars into the fibrous content. The process is seen to be reversible if soaked grain is left to set and dry of its own accord. As such, the cooking or heating stage of the process is integral to the success of the treatment of the grain.

The subsequent heating step serves to lock in this changed protein and carbohydrate state into an irreversible condition. This in turn enables the length of the carbohydrate chain to be broken down by enzymatic activity, into digestible single sugar molecules. Thus, by increasing the digestibility of the carbohydrate, the energy can be transferred to the animal itself and not be lost in fuelling digestive processes.

It is postulated that the heating stage may also cause bonding reactions to occur between the expanded starch molecules, wherein chemical bonding or crosslinking occurs between the molecules. Free sulphur ions are typically found in grains and sulphur has a particular affinity to bind or form cross linkages between starch molecules. Once this bonding has occurred, the molecular size and weight of the starch molecule is altered. The effect of the present process can be further illustrated by the following

Examples.

Example 1 : Lupin Analysis Referring to Table 2 below, there is shown an analysis of lupins that are (a) raw; (b) soaked; (c) soaked then cooked for 20 minutes; and (d) soaked then cooked for 30 minutes.

It can be seen from Table 2 that there is variation in the content, dependent on the treatment regime applied. For example, it is seen that the hemicellulose content increases from 4% in raw lupins, to 13.7% in sample (d). Furthermore, the neutral detergent fibre (NDF), which also relates to the volume of hemicellulose present in the sample shows a similar increasing trend. The content of nitrogen free extracts (NFE), which are made up of non-protein material such as sugars and is indicative of the soluble carbohydrate content of the grain (starch and sugar) is essentially halved from sample (a) to (d). This indicates that there has been a change in the status of the soluble polysaccharides into longer and more complex forms.

Furthermore, it is seen that cellulose levels, such as measured by the acid detergent fibre (ADF) method, increased from sample (a) to (b), again from (b) to (c) and decreased from (c) to (d). This is indicative that there is some breakdown of carbohydrate into smaller compounds upon the application of prolonged heat exposure.

It is these changes in the molecular structure and complexity of the starches and polysaccharides that acts to slow down the speed of digestion, preferentially enabling digestion in the small intestine rather than the rumen. Thus, the energy that can be attained from a significant proportion of the carbohydrate content of the grain bypasses consumption in the rumen by microbes and is instead utilized by the animal itself, thereby leading to increases in growth, feed conversion ratio and overall production.

ar = as received; db = dry basis

Table 2 - analysis of lupins

It is advantageous then, and essential that the grain first be moistened prior to subjecting to the heating stage. Whilst heating alone will alter and protect a significant proportion of the grain protein and thus protect from degradation in the rumen, if no moisture is first introduced to the grain, the same protection will not be afforded to the carbohydrate content. It is thus apparent that this application of two distinct stages of moistening or soaking, followed by heating, offers advantages that have thus far not been achieved by prior art grain treatment methods.

Example 2 - Comparative Feed Trial

The practical effects of feeding animals with grain that has been first subjected to the process of the present invention, in comparison to untreated grain is apparent from experimental data. Referring to Table 3, there is shown comparative results of trial animals fed different types of feed. The animals of Trial 4 were the only stock fed grain which was first treated by the process of the present invention. It is immediately apparent that these animals were able to attain a greater average daily weight gain, as well as demonstrating a significant improvement in feed conversion ratio in comparison to those fed known or standard feed types.

Table 3: Comparative feed trial data

Example 3 - Processing of lupins

Lupins were left in a slightly acidic solution, maintained within pH 5.5 and 6.5 by the addition of citric acid as required. pH of the solution was monitored using a standard pH meter and more acid added as required. Since lupins are known to contain relatively low levels of toxic factors, the soaking time in this solution was 4 hours.

Upon completion of the soaking stage, the lupins were transferred to a continuous flow cooker so as to subject the lupins to radiant heat from a series of high temperature heaters. The lupins were subjected to a heat of at least 110°C for a period of 30 minutes and thus cooked in their own steam.

Upon completion of the cooking stage, the lupins were allowed to cool. In this particular trial, the option of further drying the lupins was omitted, as the resulting feed was intended to be fed to the animals immediately. It was therefore possible to provide the feed to the animals at a high moisture level.

Since the resulting lupins were intended to be fed at a high moisture level, no mechanical treatment to reduce particle size was required. The resulting treated lupins were provided to the animals in combination with hay and stock lick formula, as per Trial 4, referred to in Table 2 and Figure 4. Example 4 - Lupin Temperature Trial

A trial to test the moisture absorption in Lupus augustifoliosis lupins at 30°C for a soaking time of 2-4 hours was conducted. 500ml of water was heated to 35°C and pH was measured as 7.0. 25Og of lupins was added to the heated water. Lupin temperature was measured as 17⁰C immediately prior to adding to the water. Temperature and time changes were as in the Table below:

After 3 hours, the water was drained off and the grain permitted to sit. It was measured that 276g water was removed, leaving 224 g in the grain, equating to 44.8% of the soaking water being absorbed by the grain in 3 hours.

Conductivity of the water was measured at 0.4mS prior to combining with the grain. At the end of the soak period, conductivity was measured at 1.6mS. This indicates that a reasonable level of salts has been removed. It is also indicative that anti-nutrient alkaloids have been converted into salts and precipitated out of the grain and into the soaking solution.

Example 5 - Lupin Temperature Trial 5 litres of soak water was added to each of three separate containers and 2kg of lupins added to each container. Temperature of the soak solution and lupins was adjusted to: a) 12°C, b) 20⁰C and c) 30°C. Lupins were added at time = zero and by time = 0.5hr the temperature adjustments were complete. Container c), intended to be maintained at 30°C was initially brought to a temperature of 35°C to permit cooling to 3O⁰C whilst essentially unattended. pH of the water in each was measured as 6.9 and electrical conductivity measured at 0.7mS. Soak water was drained from the samples after a total of 4 hours of soaking, whereupon pH and electrical conductivity were tested and the liquor weighed and tested. A 20Og sample of soaked grain was taken from each test container and immediately frozen. Results of the trial are as shown in the table below:

*Room temperature 17⁰C

These results show that maximum absorption can be attained by increasing the temperature at which the grain is soaked. Importantly, the grain can attain this level absorption without compromising the integrity of the outer shell of the grain.

Example 6: Faecal sampling of sheep - lupins test

One year old wethers were fed either a control of green grass from a paddock or a mix of 50% hay and 50% lupin treated by the present method. Resulting faeces was tested in both the control and at weeks one, two and three of feeding in the test subjects. Results are below, wherein the first table refers to values from matter sampled as is and the second table refers to values from dried matter.

Faecal samples: dry version

H2O moisture after drying at 105⁰C Ash ash after combination at 600⁰C

Protein (crude) measured by SFA method P1 ADF Acid Detergent Fibre

DMD Dry Matter digestibility calculated using formula

DMD=83.58-(ADF x 0.824) + (protein x 0.42) ME Ruminant metabolisable energy using formula

ME= 0.164 (DDM% + fat) - 1.6 %db %dry basis

The above results, in particular the drop in pH, indicate that there has been a good breakdown of sugars, particularly from long chain sugars to shorter chains. It is typical that the pH measurement of faecal samples is around 7-8.

The drop in pH was in particular found to be an entirely unexpected and surprising result.

It would generally be expected that such a drop in pH is indicative of acidosis generated from excessive free sugar levels in the rumen. Usually, this is accompanied by a measurable mortality rate, where between 5-20% of sheep can die.

Mortality rate in these trials was zero, despite the fact that the protein levels consumed by the sheep were around 20%. Under normal circumstances, it would be expected that a significant percentage of sheep would by suffering ammonium toxicity or having heart attacks from excessive blood urea levels. This occurs even though protein levels in commercially available pellets is only 12%.

Further, it is also usually the case that sheep will suffer a significant mortality rate if their feed is instantaneously changed from green grass to feed (grain) pellets. It is usual practice that the sheep need to have at least a day of hay feed before being transferred to pellets.

In the present trials, sheep were moved immediately from green grass to treated grain. No adverse effects were noted or measured. Indeed, even when the sheep were starved for one or two days then moved directly onto the treated grain, no adverse effects were noted, despite the sheep being free to eat as much of the treated grain as they desired.

A further exceptionally surprising result was that in the faecal matter from sheep fed with grain treated by the present method, there were no observable signs of the outer coating of the grain. The outer coating of grain is predominantly comprised from indigestible matter such as cellulose and therefore, despite some digestion in the rumen, passes through the animal largely intact. This matter is usually clearly visible in the resulting faecal matter. This was not the case in these trials, where absolutely no visual sign of outer shell of the grain could be observed. This indicates that even the usually undigestible cellulosic matter is being broken down and converted into usable energy in the animal. Needless to say, conversion from this extra available energy translates into lower feed conversion ratios and higher productivity.

Example 7 - Lupin analysis

Samples of lupins that were: 1 ) untreated;

2) soaked for four hours;

3) soaked for four hours then cooked for 20 minutes at 150°C; and

4) soaked for 4 hours then cooked at 150°C were sampled and underwent chemical analysis. The results are as per the table below, where the first is results on dry basis and the second is on the sample as is.

Example 8 - Oats Analysis Samples of oats that were: 5 1) untreated;

2) soaked for 4 hours;

3) soaked for 4 hours then cooked at 150°C for 15 minutes;

4) soaked for 4 hours then cooked at 150°C for 30 minutes; and

5) soaked for 4 hours then cooked at 150°C for 45 minutes

10 were sampled and underwent chemical analysis. The results are per the tables below, where the first is the as is samples and the second table refers to samples tested on a dry basis:

With reference to examples 7 and 8 above, it should be noted that the grains were subjected to a shortened (3-4 hours) rest period following soaking. It is postulated that the shortened rest phase period at least partially explains the trends in, for example, ADF and NDF, which is expected to decrease after the grain is treated by the method. The upward trend as cooking time was increased is attributed to grain reverting back to the untreated state due to insufficient rest phase period. Increasing rest phase to at least 12, preferably 24 hours is expected to maintain the decreasing trend following treatment.

It is expected that the inclusion of this significant and extended rest phase is introduced into the method, results will be optimized.

Example 9: Alkaloid analysis of treated lupins Samples of lupins soaked at the different temperatures of a) 12°C; b) 20

°C and c) 30°C, substantially as per the process described in Example 4 above. The results are as below, with alkaloids measured as %ar:

* this data point is considered to have arisen from a lab error

The results above, particularly those from the sample soaked at 3O⁰C are indicative that alkaloids show a reduction that is proportional to the soak time. These results suggest that a soak time of 12 hours at 30⁰C is likely optimal for removing anti-nutrient alkaloid levels from lupins.

Example 10 - Cross-bred lambs: comparative urine and faecal samples Cross bred lambs were fed either at pasture (control) or a mixture of 50% treated lupins and 50% hay. Notably, lupins were treated by the present process wherein rest phase following soaking ran for a period of 24 hours. Urine and faecal samples were tested, with the test subjects (lupin/hay) being sampled twice, one week apart. A third sample was taken from the test subjects a further 18 days later, after the feed ration had been modified for a period of 24 hours to lupins/hay + added canola meal lick (35% protein). Results are shown in the table below:

The varying pH in the above results is of significance. It is noted that urine pH showed a steady increase in the test subjects until feedlot ration was changed to include added canola meal lick. Conversely, faecal pH dropped significantly until the feedlot ration was changed. This suggests that no ammonium is being passed in the faeces, thereby suggesting that protein degradation is not the cause of the pH change.

Instead, these results, together with observed sheep behaviours suggests that the sheep were in fact, until supplied with the canola meal lick, experiencing a sugar/protein imbalance and required more protein in their diet. The test sheep were observed, over time of the trial, to frequent a salt lick more regularly than usual. Salt intake behaviour such as this is an indicator of dietary protein deficiency, which led to the feed being supplemented with the canola meal lick.

The results suggest not that the percentage of available protein in the ration was insufficient (measured at 21%), but that the process of the invention made sugars so much more readily available and digestible that the ratio of available sugars to protein was increased, thereby causing a protein/sugar imbalance. The fact that faecal pH returned to normal levels and urine pH started dropping to normal levels after the ration was supplemented with extra available protein supports this proposal. This proposal is also supported by the fact that canola (untreated) husks in the lick were observed in the sheep faeces after 24 hours, whereas there was no sign, at any time, of lupin husks. It therefore appears that the present process enables complete breakdown of sugars, even from highly cellulosic matter.

Whilst the above examples have been described primarily in terms of application to lupins, it should be understood that the process is equally applicable to all other grains. The variables of soaking time, rest phase and cooking time and temperature can be varied to optimize the results for each type of grain. The resulting treated grain or grains can be fed to animals in such quantities that provide the animal with required levels of protein and carbohydrate. It is not intended that the treated grain be the sole source of animal nutrient. It is considered to be within the knowledge of a person or persons experienced in the formulation of animal feeds to include amounts of other factors and minerals as necessary so as to achieve maximum growth and production rates.

Similarly, the actual proportions of various grains in any one feed can be modified to suit the desired production outcome and the species of animal being fed. For example, a mixed grain ration containing treated barley, triticale and lupins may be developed and be more suitable for pigs, whereas a ration of treated lupins, wheat and hay is more appropriate for cattle. Suitable rations can therefore be developed on a least cost method prior to processing by the present process, depending on the desired outcome.

Claims

CLAIMS:

1. A method of treatment of grain, comprising the steps of: introducing additional moisture content into the grain; and heating the moistened grain at a temperature within a predetermined range, whereupon the treated grain is suitable for use as a compound in animal feed.

2. The method according to claim 1 , wherein the grain is subjected to a rest phase following introduction of additional moisture content into the grain.

3: The method according to claim 1 or 2, wherein moisture content within the grain is increased by soaking the grain.

4. The method according to claim 3, wherein the grain is soaked in a slightly acidic solution, having a pH within the range of 5.5 to 6.5.

5. The method according to claim 4, wherein the pH of the solution is controlled at least partially by the addition of a pH modifying substance or solution.

6. The method according to claim 5, wherein the pH modifying substance is acetic acid or citric acid, optionally with molasses.

7. The method according to any one of claims 3 to 5, wherein the grain is soaked at a temperature between 15 and 35°C

8. The method according to any one of claims 3 to 5, wherein the grain is soaked at a temperature around 30⁰C.

9. The method according to any one of claims 3 to 8, wherein the grain is soaked for a period of between 2 to 10 hours.

10. The method according to any one of claims 3 to 8, wherein the grain is soaked for a period of 4 hours.

11. The method according to any one of claims 2 to 10, wherein the rest phase is between 4 and 30 hours.

12. The method according to any one of claims 2 to 10, wherein the rest phase is 24 hours.

13. The method according to any one of claims 1 to 12, wherein the moistened grain is heated at a temperature within the range of 100° to 300° C.

14. The method according to claim 13, wherein the moistened grain is heated at a temperature within the range of 120° to 250° C.

15. The method according to any one of claims 1 to 14, wherein the grain is subjected to a second rest phase following heating.

16. The method according to claim 15, wherein the second rest phase extends for a period of 10 to 30 minutes.

17. The method according to claim 15, wherein the second rest phase extends for a period of 15 to 20 minutes.

18. The method according to any one of claims 1 to 17, wherein introduction of additional moisture into the grain initiates enzymatic reactions within the grain to change the state of nutritional compositions.

19. The method according to claim 18 wherein heating of the grain acts to fix the changed state of the nutritional compositions.

20. The method according to claim 18 or 19, wherein molecular size and weight of protein and carbohydrate content is altered.

21. The method according to any one of claims 1 to 20 wherein carbohydrate and protein content in the grain is substantially converted to bypass carbohydrate and bypass protein.

22. The method according to any one of claims 1 to 21 , wherein the resulting grain is whole and has an outer seed coat that is substantially uncompromised.

23. The method according to any one of claims 1 to 22, wherein carbohydrate and/or protein content is caused to attach to fibrous content of the grain.

24. The method according to claim 23, wherein carbohydrate and/or protein content is attached to fibrous content by a process of pressuring protein and carbohydrate into the fibrous content.

25. The method according to claim 24, wherein the pressuring of protein and carbohydrate is caused at least partially by the swelling of carbohydrates within the grain.

26. A treated grain for use in animal feed, wherein nutritional components of the treated grain are preferentially digested and absorbed by the digestive system of an animal that has ingested said grain.

27. The treated grain according to claim 26, wherein the nutritional components are carbohydrate and protein.

28. The treated grain according to claim 27, wherein the carbohydrate and protein content is substantially bypass carbohydrate and bypass protein.

29. The treated grain according to any one of claims 26 or 27, wherein nutritional components of the grain are altered or protected such that they are able to pass through a rumen of the animal without significant degradation.

30. The treated grain according to claim 29, wherein nutritional components of the grain are protected by attaching to fibrous content of the grain.

31. The treated grain according to claim 29, wherein attachment of the nutritional components to fibrous content permits the nutritional components to be metabolized directly by the animal.

32. The treated grain according to claim 31 wherein the nutritional components are digested in the small intestine or hind gut of the animal.

33. The treated grain of any one of claims 27 or 28, wherein the carbohydrate and/or protein content of the grain substantially bypasses microbial degradation in the rumen of ruminant animals.

34. The treated grain according to any one of the preceding claims wherein the nutritional components and quality of the grain at least partially mimics digestive characteristics of fresh pasture feed.