"PROCESSES FOR PRODUCING ANIMAL FEED"

FIELD OF THE INVENTION

[0001] This invention relates generally to processes for producing animal feed from plant material, in particular the processes involve treating lignocellulosic plant material with glycerol.

BACKGROUND OF THE INVENTION

[0002] Large volumes of waste lignocellulosic plant material is produced as a by-product of agricultural crop production. This material includes straw and stubble from rice, wheat, barley and oat production; bagasse, cane tops and trash from sugar cane production; palm fronds and baskets from palm oil production; sorghum waste and cassava waste. The waste lignocellulosic material may be disposed of by burning, but this has the drawback of causing air pollution, smoke visibility hazards and, potentially, initiating wildfires. Certain types of plant waste is often disposed of in waterways causing pollution, as may occur in, for example, the sugar cane industry.

[0003] Waste lignocellulosic plant material may be fed to domestic livestock such as cattle and sheep. This has the advantage that the waste plant material may be used in the location where it is produced, without the need for transportation or further investment. However, there is the drawback that much of the plant waste may be indigestible, unattractive or unpalatable leading to animals refusing to eat the plant material, or eating only moderate amounts. If the waste plant material is consumed, the nutritional uptake is generally poor due to lack of access to the nutrients as they are bound within the plant structure. The ingestion of such plant material may also lead to potential animal health issues such as acidosis or laminitis.

[0004] Waste plant material comprises useful organic raw materials. An alternative use for the plant material is in the production of biofuel and other organic chemicals. The conversion of waste lignocellulosic plant material to biofuels such as ethanol or butanol is well known. However, the plant waste must be transported to a dedicated facility for conversion to biofuel, leading to transportation costs. [0005] There is a need for alternative means to utilize lignocellulosic plant waste that addresses one or more of the above-mentioned drawbacks.

SUMMARY OF THE INVENTION

[0006] The present invention is predicated on the discovery that plant material and, particularly, lignocellulosic plant material, can be converted to a more digestible form that improves its suitability for use as animal feed. The conversion is carried out by a simple treatment process without the need for expensive or hazardous chemicals or a source of heat or energy. Furthermore there is no requirement for specialized equipment or other facilities. The plant material can be treated at the location where it is grown, so there is no requirement to transport it to another location for processing. The inventor has found that a process comprising treatment of lignocellulosic plant material with glycerol, optionally with additional compaction, at ambient temperature followed by storage at ambient temperature converts the plant material to a more digestible and appetizing form making it more suitable for animal feed and more readily acceptable to the animal than the untreated plant material.

[0007] Accordingly, the present invention provides a process for producing animal feed comprising treating plant material with glycerol at ambient temperature, optionally with compaction, and storing the treated plant material thus formed at ambient temperature to produce animal feed. The plant material is preferably lignocellulosic plant material. In some embodiments the plant material is waste lignocellulosic plant material such as that remaining after crop harvest. In some embodiments the plant material is compacted prior to storage. In some embodiments the glycerol is crude glycerol derived as a by-product from bio-diesel production. In some embodiments the treated plant material is stored for up to one year. In some embodiments the plant material is treated with glycerol in an amount of 1% to 25% by dry matter weight. In some embodiments the treated plant material is stored until required. In some embodiments the plant material is stored until the moisture level reaches the required level.

[0008] In one aspect, the present invention provides a process for producing animal feed comprising the steps of:

(a) treating lignocellulosic plant material at ambient temperature with glycerol in an amount of 1% to 25% by dry matter weight; (b) optionally compacting the plant material;

wherein the treatment with glycerol and the optional compaction may be carried out in any order, or may be performed simultaneously; and

(c) storing the treated plant material thus formed at ambient temperature.

[0009] The treated plant material so obtained is considered to be suitable animal feed for feeding to animals, particularly domestic livestock, as loose feed without further processing. Accordingly, there is also provided use of treated plant material or animal feed prepared according to a process of the invention for feeding animals, particularly livestock.

[0010] The treated plant material may be combined with one or more additional nutritional components. Accordingly, the present invention further provides a process for preparing animal feed comprising treating lignocellulosic plant material with glycerol at ambient temperature, with optional compaction; storing at ambient temperature; and combining the resulting treated plant material thus formed with one or more additional nutritional components.

[0011] In some embodiments, the treated plant material produced by a process of the invention may be further processed to form an animal feed product, for example in the form of animal feed powder, granules, paste, feed block, cubes, or pellets. In some embodiments the animal feed products of the invention further comprise additional nutritional components and/or formulation excipients.

[0012] The present invention also provides a process for producing an animal feed product comprising treating plant material with glycerol at ambient temperature; optionally compacting the plant material; storing at ambient temperature; and subsequently processing the treated plant material; treating with one or more additional nutritional components and/or one or more formulation excipients; and optionally, extruding the material and forming into pellets.

[0013] In a further aspect, the present invention provides animal feed or an animal feed product obtained, obtainable, prepared or produced by a process of the present invention.

[0014] In a yet further aspect the present invention provides an animal feed product, such as a feed pellet, comprising treated plant material prepared according to a process of the invention, and one or more additional nutritional components, and/or one or more formulation excipients.

[0015] In a yet further aspect, there is also provided an animal feed product comprising animal feed according to the present invention.

[0016] The treated plant material, animal feed or animal feed products of the present invention are useful as animal feed, particularly for feeding livestock. Accordingly, there is also provided the use of treated plant material, animal feed or animal feed product of the present invention for feeding animals.

DETAILED DESCRIPTION OF THE INVENTION

/. Definitions

[0017] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are described. For the purposes of the present invention, the following terms are defined below.

[0018] The articles "a" and "an" are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0019] By "about" is meant a quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length that varies by as much 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 % to a reference quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length.

[0020] As used herein, the term "and/or" refers to and encompasses any and all possible combinations of one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative (or).

[0021] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. Thus, the use of the term "comprising" and the like indicates that the listed integers are required or mandatory, but that other integers are optional and may or may not be present. By "consisting of" is meant including, and limited to, whatever follows the phrase "consisting of". Thus, the phrase "consisting of" indicates that the listed elements are required or mandatory, and that no other elements may be present. By "consisting essentially of" is meant including any elements listed after the phrase, and limited to other elements that do not interfere with or contribute to the activity or action specified in the disclosure for the listed elements. Thus, the phrase "consisting essentially of" indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present depending upon whether or not they affect the activity or action of the listed elements.

[0022] The term "plant material" when used herein refers to material obtained from plants. Suitably the plant material does not comprise components that may be toxic or otherwise hazardous to animals, particularly domestic livestock. Skilled persons in the fields of animal feed preparation, agriculture or livestock rearing will be well aware of plant material that is undesirable for consumption by animals. The plant material may be derived from a single plant source, or a specific part of a plant. In some aspects the plant material may be derived from a mixture of plant material comprising more than one plant source or more than one part of a plant. In some aspects the plant material is agricultural plant material, in particular waste plant material remaining after crop harvest. In some aspects the plant material is derived from failed crops or damaged crops such as those damaged by adverse weather events. The plant material may be derived from living or dead plants.

[0023] "Lignocellulosic plant material", and similar terms when used herein refer to plant material comprising lignin and/or cellulose. Lignocellulosic biomass is very abundant throughout the world, and is a source biofuels such as alcohols, polysaccharides, polymers and proteins. Lignocellulosic plant waste material includes, but is not limited to, straw, stubble, husks, seed pods, hulls, leaves, roots, woody stalks and branches, palm fronds and baskets, grasses, and so on. Exemplary sources include crop waste derived from agricultural crops including, but are not limited to, sugar cane, including bagasse, cane tops and/or trash; oil palm; sugar beet; canola; legumes, including beans (haricot, navy, broad, kidney, soya, etc.), peas, chick peas, lentils, alfalfa, clover, lupin; grain crops including rice, oats, wheat, barley, triticale, rye; maize; cotton; sunflowers; temperate grasses, such as rye grass, blue grass, cocksfoot, wheatgrass, grazing brome, phalaris, fescue, veldt and prarie grass; tropical grasses, such as creeping bluegrass, Indian bluegrass, floren bluegrass, digitaria, panic, kikuyu, sabi, buffel, setaria, signal and tall finger grass; reeds, such as arundo donax; monk fruit; sorghum; canola/oil seed rape; and cassava. In some embodiments crop waste includes that typically deposited as a windrow following harvesting by a combine harvester, such as wheat, oats, barley, rye, maize (corn), sorghum, soya beans, flax (linseed) and canola (oilseed rape). In one embodiment, the crop is lucerne. Particular plant sources include rice stubble; cassava waste; oil palm waste (fronds, baskets); and sugar cane waste (bagasse, cane tops and trash). Lignocellulosic plant waste material also includes timber, sawdust, wood shavings and the like.

[0024] The term "treated plant material" when referred to herein refers to plant material that has been combined with glycerol and preferably stored for a period of time.

[0025] The term "animal" when referred to herein includes mammals, aquatic livestock, and avians. Mammals include domestic livestock such as, but are not limited to: sheep, goats, cattle, buffalo, bison, elk, deer, antelope, horses, deer, donkeys, pigs, camels, alpaca and llama. In some embodiments, mammals include rangeland animals such as cattle, sheep, goats, deer, elk, antelope, buffalo and bison. Particular domestic livestock include cattle and sheep, particularly cattle, especially beef cattle or dairy cattle. Avians include chickens, ducks, geese, turkeys and the like. Aquatic livestock include fish, molluscs and crustaceans.

[0026] Glycerol, also known as glycerine, glycerin or 1,2,3-propantriol, is widely available. It is produced cheaply on a commercial scale as a by-product from the hydrolysis of plant triglycerides to form biodiesel. For the purposes of the present invention, pure glycerol, for example greater than 90% purity, may be used. Pure glycerol solidifies at around 17.8 C. If the ambient temperature is too low, it may be necessary to warm the glycerol to facilitate its application and combination with the plant material. However, in a preferred embodiment, glycerol may be used in a crude form. Crude glycerol is typically produced as a by-product, or direct by-product, of biodiesel production. Crude glycerol is formed during the base catalyzed transesterification of triglycerides to form biodiesel. Although it is contemplated that crude glycerol from transesterification of any plant triglycerides may be used, in some embodiments crude glycerol is that formed as a by-product of biodiesel production from virgin canola oil.

[0027] When used herein the term "ambient temperature" refers to the temperature of the surrounding environment, for example outdoor temperature, or that in a farm building, shelter or other facility. Ambient temperatures will depend on the local environment and climate and may typically range, for example, from -IO C to 45 ^° C, 5 ^° C to 40 ^° C, 10 ^° C to 40 ^° C, 15 ^° C to 40 ^° C, 20 ^° C to 40 ^° C, or 15 ^° C to 35 ^° C.

[0028] When used in the processes described herein, the terms "compacting", "compacted" and the like refer to packing the plant material under pressure for storage. Methods of compacting the plant material include binding or baling the plant material into a bundle, bale or the like using a conventional agricultural binder, baler or baling machine, for example a top-loading bailing machine. In some embodiments, the plant material may be stored in a storage silo, whereby pressure is exerted by the weight of the column of plant material. In some embodiments the pressure is from 15 to 100 psi, for example 20 to 100 psi, 30 to 100 psi, 30 to 80 psi, 20 to 70 psi, 30 to 70 psi, 40 to 60 psi, 40 to 70 psi or 50 to 70 psi. In some embodiments the pressure is 103.4 to 689.5 kPa, 137.9 to 689.5 kPa, 206.8 to 689.5 kPa, 206.8 to 551.6 kPa, 137.9 to 482.6 kPa, 206.8 to 482.6 kPa, 275.8 to 413.7 kPa, 275.8 to 482.6 kPa, or 344.7 to 482.6 kPa.

[0029] When used herein, the terms "processed", "processing" and the like with regard to treated lignocellulosic plant material according to the invention relate to reducing the size of the plant matter and/or increasing homogeneity. Techniques for achieving this are well known in the art, and include manual and mechanical means such as chopping, mincing, shredding, homogenizing, blending or grinding. In some embodiments the treated plant material is processed by grinding using a mechanical tub grinder.

[0030] When used herein the term "animal feed product" refers to an animal feed comprising treated plant material according to the present invention which has undergone further processing and/or further comprises one or more additional nutritional components and/or one or more formulation excipients. An animal feed product according to the invention may be in the form of, for example, powder, granules, feed blocks, paste, pellets or cubes. In some embodiments the feed product is in pellet form.

[0031] When used herein the term "pellet", "pellets", "pelleting" and the like refer to individual compressed masses of animal feed and the process of preparing them. Pellets may be prepared by extrusion through a die, for example using commercially available pelleting equipment known in the art. The shape and dimension of the pellet produced will depend on the shape and dimension of the die used. In some embodiments the pellets are substantially spherical or substantially cylindrical and the like. The size and shape of a pellet will depend on the animal. Typically livestock pellets, such as for cattle, pigs or sheep, will have a cross sectional dimension of 6 mm to 10 mm. For smaller animals, birds and fish a typical pellet will have a cross section of approximately 2 mm to 3 mm.

[0032] When used herein, unless otherwise stated, percentages are quoted as % by weight.

2. Methods of the Invention

[0033] The present invention is based, in part, on the identification that treatment of lignocellulosic plant material with glycerol at ambient temperature, with optional compaction, followed by storage of the treated plant material at ambient temperature results in conversion of at least a proportion of the plant material to a more digestible and nutritious form rendering it more suitable for use as animal feed than untreated plant material. Thus the inventor conceived that animal feed could be prepared in an economic, efficient, simple and environmentally friendly manner.

[0034] These surprising findings have enabled the development of methods of converting waste plant material, particularly from agricultural crop production, into animal feed and animal feed product. Furthermore, the methods use glycerol which may be conveniently obtained as a by-product of biodiesel production. The plant material can be converted to animal feed at the site of crop production. No transportation to a conversion facility is required, nor is there a need for specialized equipment or facilities for heating or pressurizing. Application of external energy, in the form of heat, is not required. Glycerol may be used in a crude form, such as that which is readily and cheaply available as a by-product of biodiesel production, accordingly no expensive or hazardous chemicals are required. [0035] Without being bound by theory or mode of operation, it is believed that the glycerol assists in breaking down or hydrolyzing the plant lignocellulosic material, making the plant material more digestible and the nutrients more accessible to the animal during digestion. Due to its highly polar nature, it is believed that glycerol readily penetrates the plant tissue to facilitate hydrolysis. The glycerol further provides a source of nutrition to the animal. Glycerol is also believed to reduce methane production during digestion. The glycerol treated plant material obtained by the processes described herein have been found to be appetizing and palatable to livestock, particularly cattle. Animals fed with glycerol treated plant material have been found to increase in weight, and in some cases by up to approximately 2 kg per day, or more. Typically, commercial beef cattle are fed on a grain, corn or soy ration to increase the energy density of their diet to fatten them for market. This diet can produce commercially desirable marbled beef. However, when cattle are fed on a grain ration, the resulting low fibre diet can adversely affect the health of the cattle, and may also permit harmful bacteria to proliferate (see, for example, Science, vol. 292, issue 5519, pp. 1119-1122, 11 May 2001). In particular, a low fibre diet, such as that containing 50-90% grain, is digested quickly by cattle, thus the cattle are provided with nutrients at a fast rate. However, this also causes fermentation acids to accumulate in the rumen which can lead to ulcers and further health complications such as abscesses. Furthermore, grain can accumulate in the animal's intestines which can lead to growth of Clostridium perfringens which is associated with sudden death in feedlot cattle. The glycerol treated plant material described herein is believed to be beneficial as it provides energy in addition to fibre, thus addressing some disadvantages of fattening animals with grain ration. The effect of glycerol on the plant material also increases release of nutrients to the animal. It is therefore believed that the glycerol treated plant material can provide an economic and environmentally sustainable alternative to grain rations for commercial farming of beef cattle as well as other commercial livestock. A further benefit of replacing grain ration with glycerol treated plant material for feeding livestock is that grain can then be reserved for human food.

[0036] Accordingly, the present invention advantageously provides a process for the preparation of animal feed comprising treating lignocellulosic plant material with glycerol, with optional compaction, at ambient temperature; and storing for a period of time at ambient temperature. [0037] In some embodiments the plant material is treated using 1% to 25% glycerol based on dry weight of plant material. Preferably the plant material is treated with 2% to 25%, 2% to 20%, 2% to 15%, 5% to 15%, 5% to 10%, 5% to 20%, 7% to 14%, 7% to 18% or 8% to 12% glycerol based on dry weight of the plant material. In some embodiments the plant material is treated with 9% to 13% glycerol based on dry weight of plant material. In some embodiments the plant material is treated with 10% to 12% glycerol based on dry weight of plant material. In some embodiments, the plant material is treated with 15% to 18% based on dry weight of plant material.

[0038] In some embodiments the plant material may be broken or cut into smaller pieces using manual or mechanical techniques well known in the art such as cutting, shredding, chopping, grinding, and the like. The skilled person would appreciate that this process may be carried out before, during or after treatment with glycerol.

[0039] The assessment of the moisture content of the plant material or treated plant material is conveniently measured by techniques well known in the art, and include the use of a moisture probe, moisture sensor or moisture meter. Suitable instruments for measuring moisture in soil, crops, compost, hay and grain and the like are well known in the art, and are readily available from commercial sources. Suitable moisture probes are available from, for example, Honeywell; Aquaterr Instruments and Automation LLC; Agreto Electronics GmbH; and Delmhorst Instrument Co.

[0040] The amount of water present in the plant material prior to treatment with glycerol is preferably less than 70% by weight, preferably less than 50% or less than 25% by weight. In some embodiments, the amount of moisture present is approximately 40% by weight or less than 40% by weight.

[0041] It has been observed that the amount of water present in the treated plant matter decreases on storage. In some embodiments, the plant matter is stored until a desired level of water is reached. This will depend on the intended use of the treated plant material. For loose animal feed, e.g. for cattle, the amount of moisture will depend on the needs of the animal. In hot, dry weather, or in times of drought, a higher moisture content is desirable. Treated plant material with a lower moisture content can be used to increase the rate of weight gain in the animal. Treated plant material typically comprises 5% to 25%, or 10% to 30% by weight of moisture. [0042] Treated plant material comprising up 25% of water by weight may be utilized for conversion to an animal feed product, for example pellets. In preferred embodiments, the moisture content of the treated plant material used for conversion to an animal feed product is 8% to 15%, preferably 10% to 12% by weight.

[0043] The plant material may be treated with glycerol by combining the components using any suitable means. In some embodiments, the glycerol may be applied to the plant material by pouring, sprinkling, spraying, and the like. In some embodiments the glycerol may be applied by spraying, for example using a spray device. As glycerol is viscous, a pump or spray device suitable for viscous liquids is preferred. A pump device suitable for delivering, for example, molasses is suitable. After application, it will be appreciated that the glycerol will dissipate and permeate throughout the plant material.

[0044] The glycerol and plant material may be combined using any suitable manual or mechanical means for mixing or agitation known in the art. The method of mixing will depend on the scale and nature of the plant material involved. In some embodiments mixing may be effected using a tool such as a pitchfork. In embodiments where the scale is large, mixing may be effected using a mechanical device such as a hay turner or a baler.

[0045] In some embodiments the glycerol and plant material mixture may be stored by piling into mounds on the ground or other surface, or the glycerol may be applied directly to plant material deposited in the form of windrows on the ground following harvesting a crop with a combine harvester. In these embodiments the skilled person will appreciate that the conversion of the plant matter to a more digestible form may take longer to achieve than embodiments where greater pressures, such as those applied by baling, are used.

[0046] It has been discovered that storage of the glycerol treated plant material outdoors may be advantageous as the plant material loses water more easily. This reduces the weight of the final product making it more efficient to transport. The glycerol-treated plant material has been observed to form a "skin" on the surface which serves to provide some protection from the elements.

[0047] The glycerol and plant material may be compacted by binding, baling or compressing by methods well known in the art. In some embodiments the plant material is preferably compacted prior to storage. Where compacting is used, it will be appreciated that the steps of treating the plant material with glycerol and compacting the plant material may be carried out simultaneously or separately. If performed separately, the steps may be carried out in any order, and may be contemporaneous or non- contemporaneous. If the steps are non-contemporaneous, preferably the glycerol treatment step is performed prior to the compaction step. In some embodiments the compaction step may be carried out up to 120 days, for example after up to 90 days, up to 60 days, up to 30 days or up to 21, 14 or 7 days, after treatment of the plant material with glycerol

[0048] In some embodiments the treated plant material may be compacted by forming it into a bale using an agricultural baling or binding machine. Suitable baling implements for forming round or rectangular bales are known in the art and are commercially available from manufacturers such as Massey Ferguson, John Deere, New Holland, AGCO and Case IH. In some embodiments the baling pressure is from 20 to 100 psi, for example 50-70 psi. In some embodiments the compacted material may be wrapped, for example in a plastic wrapping or in a breathable mesh cover. Plastic wrapped bales generally have at least one opening to allow the contents to breathe. In some embodiments the compacted plant material may be stacked for storage. In some embodiments bales are stacked for storage. This will have the additional effect of increasing the pressure during storage.

[0049] If compaction is used in a process of the invention, the glycerol may be applied to the plant material before, after or during compacting. In some embodiments, particularly with respect to crops harvested by a combine harvester, the glycerol may be applied to the plant material in the windrow remaining on the ground following harvesting the crop. The glycerol and plant matter mixture may be left in the windrow for up to several months prior to compacting and storing. In some embodiments the glycerol may be applied during baling. Glycerol may be applied by, for example, spraying, pouring, or sprinkling the glycerol on to the plant material. In some embodiments, this may be effected by adapting the baling equipment to incorporate a device, such as a spray, for applying the glycerol during baling. In a further embodiment, the glycerol may be applied after compaction, for example by spraying a bale after it has been formed. Glycerol may be applied on one or more occasions during a process of the invention. [0050] After compaction, the plant material is stored under ambient conditions to provide animal feed. It is believed that the glycerol facilitates at least partial breakdown or hydrolysis of the plant lignocellulosic structure, thus disrupting the structure and allowing plant nutrients to become more easily available to the animal. A decrease in acidity of the plant material has also been observed during storage. Glycerol has been observed to commence breaking down lignocellulosic matter after only 24 hours. The progress of the breakdown of the plant lignocellulosic structure can be monitored by standard analytical chemical means known to the skilled person, and include infra red spectroscopy.

[0051] During treatment and storage of sugar cane bagasse, no appreciable development of mycotoxins has been observed in the treated plant material.

[0052] Without being bound by theory or mode of operation, it is believed that sugar cane bagasse treated with glycerol may provide a habitat for micro-organisms in the form of bio-films. It is believed that this may provide a location for detoxification of certain plant compounds, such as lactic acid.

[0053] The treated plant material may be stored until required, or until the moisture content has reached the desired levels. In some embodiments, substantially all of the lignocellulosic plant material has been broken down or hydrolyzed. In some embodiments, the lignocellulosic plant material is broken down by substantially 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% or 10%. In some embodiments the glycerol/plant material mixture is stored for up to one year, up to 18 months, or up to two years. In some embodiments the treated plant material is stored for up to nine months, up to six months, or up to three months. In some embodiments the treated plant material is stored for 1 to 90 days. In some embodiments the treated plant material is stored for up to 90 days or up to 60 days; for example for 30 to 60 days or 30 to 90 days. In some embodiments the treated plant material is stored for up to 7, 14, 21 or 28 days. In some embodiments the treated plant material is stored for up to 30 days, for example 2 to 30 days, 5 to 30 days, 7 to 28 days, 7 to 14 days, 14 to 28 days, 5 to 20 days, 10 to 20 days, or 10 to 30 days. In some embodiments the plant material is stored for greater than 1 day; greater than 1 week; greater than two weeks, or greater than 1 month. In some embodiments, the treated plant material may be used within 24 hours, within 48 hours, or within 72 hours. [0054] In some embodiments, the treated plant material is stored until the moisture content has reached the desired levels. In some embodiments the moisture content of the treated plant material is up to approximately 50%, 40%, 35%, 30%, 25%, 20%, 15% or 10% by weight. In some embodiments the desired moisture content of the treated plant material is 5% to 25%, 5% to 20%, 5% to 15%, 10% to 15% or 10% to 20%.

[0055] In some embodiments, the present invention provides a process for the preparation of an animal feed or animal feed product comprising treating plant lignocellulosic material with glycerol in an amount of 1% to 25% by dry weight of plant lignocellulosic material at ambient temperature; compacting the treated plant material at a pressure of 15 psi to 100 psi; and storing at ambient temperature.

[0056] After the desired storage period, the animal feed thus produced may be used directly, for example from the bale, as a loose animal feed. In some embodiments the loose feed is used to feed animals, for example cattle, in a feed lot. The animal feed is nutritious and palatable and may be used on its own, or may be used as the fiber component of a diet.

[0057] In a further aspect, the resulting animal feed may be combined with one or more additional nutritional components and used as a loose animal feed, for example in a feedlot.

[0058] The resulting animal feed may also undergo one or more further processing steps including addition of one or more nutritional components and/or one or more formulation excipients to produce an animal feed product.

[0059] Nutritional components and formulation excipients are well known in the art of animal feedstuff preparation. Nutritional components may be selected in accordance with the dietary needs of the animal. Formulation excipients may be selected according to the physical form of the animal feed product. In some embodiments the animal is selected from domestic livestock such as cattle or sheep, especially cattle. In some embodiments the animal feed product is for maintaining weight of livestock during periods of drought. In some embodiments the animal feed product is for maintaining breeding livestock. In some embodiments the animal feed product is for increasing weight gain in livestock, such as fattening livestock in a feedlot. In some embodiments the animal feed product is for young animals, for example weaner pellets for livestock.

[0060] Accordingly, in a further aspect, the present invention also provides a process for the preparation of an animal feed product comprising treating plant lignocellulosic material with glycerol in an amount of 1% to 25% by dry weight of plant lignocellulosic material at ambient temperature and optionally compacting the plant material at a pressure of 15 psi to 100 psi; storing the material at ambient temperature; and then combining the resulting treated plant material with one or more additional nutritional components and/or formulation excipients to provide an animal feed product.

[0061] In some embodiments, preferably the treated plant material is processed manually or mechanically to reduce it to smaller pieces and increase the degree of homogeneity. In some embodiments the plant material is chopped, shredded, ground, minced, cut, crushed or pounded. In some embodiments the plant material is processed using a mechanical tub grinder.

[0062] The selection of additional nutritional components will depend on the diet requirement of the animal to be fed. The diet requirements of animals varies according to factors such as the species, breed, age, and sex. The skilled person will realize that certain nutritional components are not suitable for feeding to certain animals, and will readily be able to determine the most suitable additional nutritional components for a given situation. In some embodiments an animal feed product of the invention is suitable for cattle, particularly beef cattle. In some embodiments, additional nutritional components for a cattle feed product include monoammonium phosphate (MAP), urea, distiller's dried grains with solubles (DDGS), bentonite and molasses.

[0063] The skilled person will understand that the animal feed product may be prepared in the form of, for example, powder, liquid, paste, granules, feedblocks, cubes or pellets. In some embodiments the animal feed product is pelleted.

[0064] Processes for forming animal feed product such as preparing powder, liquid, paste, granules, feedblocks, cubes or pellets are well known in the art, and include manual or mechanical mixing, extruding, pelleting, granulation, and the like. [0065] Accordingly, in a further aspect the present invention provides a process for producing animal feed product comprising the steps of:

(a) treating lignocellulosic plant material at ambient temperature with glycerol in an amount of 1% to 25% by dry matter weight;

(b) optionally compacting the plant material;

wherein the treatment with glycerol and the optional compaction may be carried out in any order, or may be performed simultaneously;

(c) storing the plant material and glycerol mixture at ambient temperature to provide treated plant material; and in any order:

(d) if required, processing the treated plant material; and

(e) combining the treated plant material with one or more additional nutritional components and/or one or more formulation excipients; and

(f) forming an animal feed product.

3. Compositions of the Invention

[0066] The treated plant material produced by the processes of the invention as described herein is useful as animal feed, particularly for use in feeding domestic livestock such as cattle. The treated plant material may be fed to livestock without further treatment or processing. In another aspect, the present invention advantageously provides animal feed obtained, obtainable, produced by or prepared by a process of the invention.

[0067] In a further aspect, the present invention provides animal feed according to the invention in the form of a loose feed. In some embodiments the loose feed may be combined with one or more additional nutritional components, for example DDGS.

[0068] In a yet further aspect, the present invention provides an animal feed product comprising treated lignocellulosic plant material according to the invention. In some embodiments there is provided an animal feed product comprising treated lignocellulosic plant material according to the invention and one or more additional ingredients selected from nutritional components and formulation excipients.

[0069] In some embodiments, the treated plant material comprises 25% to 95% by weight of the animal feed product. In some embodiments the treated plant material comprises 25% to 90%, 25% to 85%, 25% to 80%, 25% to 75%, 25% to 70%, 25% to 65%, 25% to 60%, 25% to 55%, 35% to 75%, 35% to 65%, 40% to 60%, 40% to 70%, 40% to 80%, 45% to 70% or 45% to 80% by weight of the animal feed product. In some embodiments the treated plant material comprises 40% to 70% by weight of the animal feed product.

[0070] In some embodiments, the animal feed product is in the form of granules, pellets, cubes, paste or feedblock.

[0071] In some embodiments the treated plant material comprises approximately 40% to 80% by weight of the animal feed product, for example 40% to 70%, or 55% to 65% by weight.

[0072] In some embodiments the animal feed product is prepared from 30% to 70% by weight lignocellulosic plant material and 10% to 20% of glycerol by weight.

[0073] In some embodiments the animal feed product is prepared from 40% to 50% by weight lignocellulosic plant material and 10% to 20% or 8% to 15% of glycerol by weight.

[0074] In some embodiments the animal feed product is prepared from 40% to 60% by weight of lignocellulosic plant material and 10% to 20% of glycerol by weight.

[0075] In some embodiments the plant material is sugar cane bagasse. In some embodiments the animal feed product is in pellet form.

[0076] In some embodiments the one or more additional nutritional components are selected from nutritional components and supplements such as mineral sources, protein sources, cereals, carbohydrate sources; and oils and fats; and liquid sources. Animal feed in the form of pellets may additionally include formulation excipients such as binders, surfactants, anti-oxidants. In some embodiments a food supplement, such as a multi vitamin, mineral source, and/or protein supplement or concentrate may be included. Additional nutritional components and formulation excipients are readily available from commercial sources. The skilled person will be able to determine the most suitable stage to add nutritional components and/or formulation excipients. In some embodiments the nutritional components and/or formulation excipients are added after the plant material has been treated with glycerol and stored. [0077] Additional mineral sources include sources of elements such as, but not limited to, phosphorus and nitrogen. Suitable sources include, but are not limited to, phosphate salts such as calcium phosphates, sodium phosphates; non-protein nitrogen sources, such as, but not limited to, urea, biuret, ammonium salts such as ammonium nitrate and ammonium polyphosphate, and nitrates such as potassium nitrate, sodium nitrate and calcium nitrate. Mineral clays such as bentonite, for example sodium bentonite, may also be included to absorb ammonia and toxins and reduce the rate of feed passage through the animal's digestive system.

[0078] Additional protein supplements include, but are not limited to, cottonseed meal, sunflower seed meal, linseed meal, soya bean meal, and canola meal.

[0079] Additional cereals include, but are not limited to, maize, wheat, rye, oats, barley, rice, millet, sorghum, triticale and buckwheat.

[0080] In some embodiments, a further nutritional component is distiller's dried grains with solubles (DDGS). DDGS is a nutritious by-product from dry milled bioethanol production.

[0081] In some embodiments, a further nutritional component includes one or more commercially available protein, mineral and vitamin supplements or concentrates. The skilled person will understand which nutritional components will be acceptable or unacceptable according to the specific animal. In some embodiments suitable for cattle a protein, mineral and vitamin concentrate is Rumevite ©Feedlot 80™.

[0082] Liquid sources include, but are not limited to, water, and plant syrups such as corn syrup, sorghum syrup and molasses.

[0083] Examples of oils and fats include linseed oil, sunflower oil, canola oil.

[0084] Formulation excipients for preparation of animal feed pellets are well known in the art and include binding agents, humectants, rheology modifiers, buffers, and surfactants. Clays such as bentonite, for example sodium bentonite, are examples of binding agents and rheology modifiers suitable for use in pelleting.

[0085] In some embodiments an animal feed product of the invention further comprises bentonite, monoammonium phosphate (MAP), urea, distiller's dried grains with solubles (DDGS) and molasses. [0086] In a further aspect, the present invention provides a pelleted animal feed product comprising treated lignocellulosic plant material according to the invention, bentonite, monoammonium phosphate (MAP), urea, distiller's dried grains with solubles (DDGS) and molasses.

[0087] In some embodiments the animal feed product comprises:

(a) 40% to 70% by weight of treated lignocellulosic plant material prepared according to the invention;

(b) 10% to 20% by weight of distiller's dried grains with solubles

(DDGS);

(c) 10% to 20% by weight of molasses; and

(d) 1% to 2% by weight of bentonite.

[0088] In some embodiments the animal feed product comprises:

(a) 40% to 70% by weight of treated lignocellulosic plant material prepared according to the invention;

(b) 10% to 20% by weight of distiller's dried grains with solubles

(DDGS);

(c) 10% to 20% by weight of molasses;

(d) 1% to 2% by weight of bentonite; and

(e) 3% to 10% by weight of additional nutritional components.

[0089] In some embodiments, the remaining mass of the animal feed product comprises water.

[0090] In some embodiments, the treated lignocellulosic plant material according to the invention comprises up to 25% water by weight. In some embodiments the treated lignocellulosic plant material according to the invention comprises 8% to 20% water by weight, preferably 10% to 12.5% water by weight.

[0091] In some embodiments the animal feed product is in pellet form.

[0092] In some embodiments the present invention provides animal feed product in pellet form comprising:

(a) 50% to 70% by weight of treated lignocellulosic plant material prepared according to the invention;

(b) 10% to 20% by weight of distiller's dried grains with solubles

(DDGS); (c) 10% to 20% by weight of molasses;

(d) 1% to 2% by weight of bentonite;

(e) 0.5% to 1% by weight of phosphate source; and

(f) 0.5% to 1% by weight of nitrogen source.

[0093] In some embodiments the lignocellulosic plant material is derived from sugar cane bagasse.

[0094] In some embodiments the present invention provides animal feed product in pellet form comprising:

(a) 55% to 65% by weight of treated lignocellulosic plant material prepared according to the invention;

(b) 10% to 20% by weight of distiller's dried grains with solubles

(DDGS);

(c) 10% to 20% by weight of molasses;

(d) 1% to 2% by weight of bentonite;

(e) 0.5% to 1% by weight of phosphate source; and

(f) 0.5% to 1% by weight of nitrogen source.

[0095] In some embodiments the present invention provides animal feed product in pellet form comprising:

(a) 60% to 65% by weight of treated lignocellulosic plant material prepared according to the invention;

(b) 12% to 16% by weight of distiller's dried grains with solubles

(DDGS);

(c) 15% to 20% by weight of molasses;

(d) 1% to 2% by weight of bentonite;

(e) 0.5% to 1% by weight of phosphate source; and

(f) 0.5% to 1% by weight of nitrogen source.

[0096] In some embodiments, the animal feed product further comprises 1% to 15% by weight additional nutritional components, for example 2% to 10%, 2% to 8%, or 2% to 5%.

[0097] In some embodiments, the treated lignocellulosic plant material prepared according to the invention comprises 8% to 15% moisture by weight, for example 8% to 10% moisture by weight. In some embodiments the animal feed product comprises 4% to 15% moisture, for example 5% to 10% or 4% to 8% moisture when calculated on the weight of treated plant material present.

[0098] In some embodiments the animal feed product comprises 1% to 10% moisture by weight, for example 1% to 5% moisture by weight.

[0099] In order that the invention may be readily understood and put into practical effect, particular preferred embodiments will now be described by way of the following non-limiting examples.

EXAMPLES

Materials and Methods

[0100] Lignocellulosic plant material may be used fresh, for example as freshly cut plant material, or in a dried form, or various stages in between.

[0101] Glycerol used in the Examples was obtained as a by-product from the conversion of virgin canola oil to biodiesel. The glycerol was added to the plant material by spraying or sprinkling. As glycerol is viscous, for applications where large volumes are required, a pump such as one suitable for pumping of molasses or other viscous liquids is considered useful. Suitable molasses pumps are readily available from, for example, Scintex, Eagle Farm, QLD, Australia (www.scintex.com.au). The materials were be combined during baling, although sufficient mixing may be obtained by, for example, stirring, raking, or agitating.

[0102] The plant material/glycerol mixture may be compacted by any suitable means known in the art. Conveniently the plant material may be formed into a bale using, for example, a top loading baling machine such as those available from Case IH, North St Marys, NSW, Australia; or AGCO, Sunshine West, VIC, Australia.

[0103] The treated lignocellulosic plant material was used as a loose feed for cattle without further processing, or was combined with distiller's dried grains with solubles (DDGS) obtained from Bremer Stockfeeds, Laidley, QLD, Australia.

[0104] In some Examples, treated lignocellulosic plant material was converted to animal feed pellets. The preferred amount of water present for pellet production is generally about 10-12%, although up to 25% water by weight is considered acceptable. The treated plant material was ground using a tub grinder (available from, for example, AGCO, Sunshine West, VIC, Australia; or Case IH, North St Marys, NSW, Australia) and was combined with additional nutritional components and formulation excipients. The mixture was then extruded and pelleted using commercially available pelleting equipment suitable for preparation of animal feed. Suitable equipment may be obtained from, for example, Palmer Milling, Griffith, NSW; LGPM Process Innovation (Scoresby, VIC, Australia); or Satake Milling (Penrith, NSW, Australia). Pelleting facilities for animal feed include HyFeed Holdings Pty Ltd, Toowoomba, QLD, Australia. [0105] Additional nutritional components for animal food products of the invention are readily available from commercial sources. The skilled person will be able to determine suitable additional nutritional components based on the dietary needs of the animals to be fed. Monoammonium phosphate (MAP), urea, distiller's dried grains with solubles (DDGS), and molasses are suitable nutritional components for cattle feed. Rumevite® Feedlot 80 is a protein, mineral and vitamin concentrate available from Ridley AgriProducts, Melbourne, VIC, Australia

[0106] Formulation aids such as sodium bentonite are readily available from commercial sources, such as Ridley AgriProducts.

EXAMPLE 1

[0107] Rice stubble (1 tonne) was sprayed with glycerol (12% by dry matter weight). The mixture was compacted into bales using a commercial top loading baling machine. The bales were stored at ambient temperatures for 21 days.

EXAMPLE 2

[0108] Cassava waste (1 tonne) was sprayed with glycerol (12% by dry matter weight). The mixture was compacted into bales using a commercial baling machine, and stored at ambient temperatures for 21 days.

EXAMPLE 3

[0109] The treated cassava plant material of Example 2 was fed to yellow cattle. This resulted in an average 0.85 kg weight gain per head of cattle per day in a breed that is considered to be notoriously difficult to fatten. The cattle had reduced methane production of approximately 70%.

EXAMPLE 4

[0110] Sugar cane bagasse was treated with glycerol (10% by dry matter weight) and baled using a commercial baler. The plant material was aged for three months prior to using as the fibre content in cattle feed trials.

EXAMPLE 5

[0111] Ten head of Droughtmaster cross cattle were split into two pens in a feedlot trial. One group were fed on the bagasse based feed ration of Example 4

(Bagasse Ration group), and the control group were fed on a grain only ration (Control Group) using a standard commercially available grain based feed ration (prepared and purchased from Bremer Stockfoods, Laidley, Queensland).

[0112] The Bagasse Ration group began to eat immediately and showed no hesitation in accepting the feed mixture. They were settled, and lot feeding as a group. The fast acceptance resulted in limitation of potential health issues, and reduced the time to achieve weight goals. The manure odour was low, and of good quality. The daily feed uptake per head was similar in both the Bagasse Ration and Control Group, however, after 10 days the visual appearance of the Bagasse Ration group appeared superior to the Control Group. After 19 days the average per head intake of the Bagasse Ration group was 6.66 kg per day, and up to 12.5 kg per day during the final days of the 55 day trial. A total of 2.65 tonnes of the bagasse ration was fed to the 5 head of cattle during the 55 day trial.

[0113] The cattle were considered good quality at sale. The positive condition of the cattle confirmed that treatment of the bagasse converted it to a viable and beneficial feedstuff with livestock reaction of palatability, digestibility and overall well being in addition to weight gain.

Example 6

[0114] Rice stubble (moisture content approximately 40% by weight) was formed into a 500 kg bale and enclosed in a plastic bale wrapping containing a breathing hole. After 60 days, crude glycerol (50 L) was injected into the bale. The contents of the bale were left to cure in a paddock at ambient temp for 21 days. During this time, the glycerol dissipated and permeated the rice stubble. The stubble was then spread on the ground in a small fenced paddock and two young steers were placed in the paddock with the ration. The steers consumed the entire ration in only 20 days. Accordingly, this corresponds to an average consumption of approximately 13.75 kg of food per day. This is considered to be several kg in excess of the normal expected consumption. Visually, the weight gain on both animals appeared to be greater than the weight gain in comparative animals located in an adjacent paddock feeding only on grass. It was also observed that the two steer on the rice stubble ration drank less water than normal. This is believed to be due to the fact that moisture is retained in the fully enclosed rice stubble. This confirms that plant material treated with glycerol may have application in providing effective and efficient drought relief rations for livestock. It is also believed that the two steer consuming the rice stubble ration were obtaining energy from the glycerol, thus providing them with additional energy to continue eating and digesting additional ration. In addition to providing a commercial use for plant waste, the glycerol treated plant matter also provides a cost effective, convenient and useful source of energy and nutrition for the animal. This suggests that the amount of grain used in animal feed can be reduced, thus freeing up grain supplies for human consumption.

Example 7

Preparation of Feed Pellets

[0115] Cattle feed in pelleted form (one tonne) was prepared by HyFeed Holdings Pty Ltd, Toowoomba, using the following ingredients:

Sugar cane bagasse (464 kg)

Glycerol (152 kg)

Sodium bentonite (nutrient, pelleting aid, 11 kg)

Monoammonium phosphate (MAP, phosphate source, 7 kg)

Urea (nitrogen source, 7 kg)

Feedlot 80 (protein, mineral, vitamin concentrate, 29 kg)

DDGS (nutritional component, 146 kg)

Molasses (nutritional component 182 kg)

[0116] The sugar cane bagasse was treated with glycerol (25% by dry matter weight), compressed into bales and stored for 30 days. The moisture content was 10- 12% by weight. The treated bagasse was homogenised using a tub grinder and combined with the remaining components. The mixture was pelleted using a pelleting machine. The resulting pellets had good integrity and a smooth surface.

[0117] The disclosure of every patent, patent application, and publication cited herein is hereby incorporated herein by reference in its entirety.

[0118] The citation of any reference herein should not be construed as an admission that such reference is available as "Prior Art" to the instant application.

[0119] Throughout the specification the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. Those of skill in the art will therefore appreciate that, in light of the instant disclosure, various modifications and changes can be made in the particular embodiments exemplified without departing from the scope of the present invention. All such modifications and changes are intended to be included within the scope of the appended claims.