WO2001001790A1

WO2001001790A1 - Animal feed composition made from settable liquid ingredients

Info

Publication number: WO2001001790A1
Application number: PCT/AU1999/000541
Authority: WO
Inventors: Mark Richard Stansby
Original assignee: RIDLEY RESEARCH AND DEVELOPMENT Corp Ltd
Current assignee: RIDLEY RESEARCH AND DEVELOPMENT Corp Ltd
Priority date: 1997-12-23
Filing date: 1999-07-01
Publication date: 2001-01-11
Anticipated expiration: 2002-01-01
Also published as: AU707606B3

Abstract

A method of forming an animal feed block which comprises the steps of mixing at least one animal feed component with magnesium sulfate and reactive magnesium oxide to form a composition, adjusting the water level of the composition to a level to allow the composition to be poured into a mould, allowing the composition to at least partially set in the mould.

Description

ANIMAL FEED COMPOSITION MADE FROM SETTABLE LIQUID

INGREDIENTS FIELD OF THE INVENTION

This invention relates to an animal feed composition which contains settable liquid ingredients and particularly relates to shaped solid animal feed supplements which contain magnesium oxide and magnesium sulfate as the setting agents.

BACKGROUND ART

It is common to feed animals and particularly ruminant animals with feed supplements to improve animal performance rate. It has been recognised that animal growth and fertility is limited by the level of nutrients in the feed available for consumption. This is particularly likely when animals graze pasture.

Animal growth rate and fertility can be improved by supplementing the diet with supplemental feedstuffs which are fortified with nutrients such as proteins and minerals.

It is well-known to provide feed blocks containing such nutrients to grazing ruminants, and known types of blocks are salt blocks or salt licks, mineral blocks, protein blocks and molasses blocks. It is also known to provide supplemental feedstuffs in the form of loose mixes, pellets, licks, liquids and powders but, in practice, feed blocks are preferred as blocks have the advantage of allowing free choice feeding and reducing the labour required in the feeding out process. Animal feed blocks can also be made weather resistant and so do not require sheltered feeding locations. The feed blocks can be easily transported from one location to another.

Currently, there are several disadvantages in the manufacture of the feed blocks and the present invention has been developed to overcome at least some of these disadvantages. It is known to prepare feed blocks by compressing and moulding a mixture of feed products (proteins, minerals, etc.) to a desired shape and weight. However, feed blocks prepared in this manner require large amounts of pressure to press the blocks and this in turn requires large capital equipment. Blocks produced in this way are also not particularly weatherproof and the pressures need to be varied depending on the ingredients in the block. This makes producing a range of blocks difficult and quite expensive.

It is also known to prepare animal feed blocks by evaporative heating and subsequent pouring of the ingredients, some of which are in the liquid form. However, heating degrades or decomposes any heat sensitive component of the feed block, (for instance the feed block may contain antibiotics which are heat sensitive). Also, the process of heating requires large energy inputs and capital inputs into the manufacture of the block, both of which are undesirable.

Emulsifiers such as gelatinized starch have been used in the preparation of animal feed blocks containing molasses and fatty materials.

It is known to combine calcium oxide with a fatty acid which react with each other to form a soap-type product which can be shaped into an animal feed block.

It is known to prepare feed blocks having molasses and a fat emulsifying agent and heating the components followed by cooling and moulding.

It is known to use magnesium oxide in animal feed blocks. Magnesium oxide is available as "reactive" magnesium oxide and "non- reactive", "dead-buried", "inactive" magnesium oxide. The reactive form of magnesium oxide is used as a setting agent and is of sufficient reactivity, particle size surface area and citric acid activity to form a suitably hard block in an acceptable period of time.

Non-reactive magnesium oxide is not sufficiently reactive for use as a setting agent. The non-reactive form is also used in animal feed block production as a nutritional source of magnesium. Such bocks include setting agents other than magnesium oxide. It is known to prepare an animal feed block using magnesium oxide and ferrous sulfate together with various additives to give a solid block. The ferrous sulfate is initially mixed with various nutrients including major minerals and trace elements, and magnesium oxide is added. However, to manufacture blocks having good weatherability and hardness using ferrous sulfate and magnesium oxide required careful selection of the various other additives, and usable feed blocks cannot readily be manufactured with many desired additives. The variety of feed blocks which can be made in this manner is therefore quite limited. Another disadvantage with using magnesium oxide and ferrous sulfate is that the mixture sets too quickly which makes it difficult to thoroughly mix the ingredients prior to setting. If the amount of magnesium oxide or ferrous sulfate is lowered to slow down the set rate, the formed blocks have undesirable qualities, e.g. poor hardness. Another known method to manufacture feed blocks is described in Australian patent 471601 which uses a chemical hardening process employing the reaction between magnesium oxide and molasses. This process however requires molasses to always be present, therefore making the process unsuitable for molasses-free blocks. Australian patent 516816 improves on the chemical hardening process by using magnesium oxide and dicalcium phosphate as the setting agents. This resulted in a reduction in the time required to manufacture the feed blocks and allow the feed blocks to be made from water bearing media other than molasses. Blocks manufactured in this manner required heating as a process step which is undesirable.

International patent application WO 88/01475 describes animal feed pellets formed from a mixture which contains magnesium sulfate and magnesium oxide, but in this specification the composition is not initially liquified by the addition of sufficient water to allow it to be simply poured into moulds and hardened without requiring any pressing equipment. In contrast, the international patent application describes and claims a dry feed composition where the mixture is pressed using expensive capital equipment into the required blocks or pellet shapes. The specification does describe the introduction of some moisture preferably as steam, but the amount of moisture is not described as being sufficient to allow the product to be simply poured into moulds and hardened. There is no description in this specification that animal feed blocks can be made from magnesium oxide and magnesium sulfate, and optionally other components by adding sufficient water to liquify or slurry the components and pouring the slurry into moulds with the composition still being able to harden into commercially usable blocks.

French patent specification 8,007,259 describes a mineral pre- mix for manufacture of animal blocks using magnesium sulfate as a setting agent. In the French patent specification, there is no teaching or disclosure of the use of magnesium oxide in its reactive form as a setting agent. Instead, the magnesium oxide is described as a nutritional source of magnesium to the animal. There is no clear and unmistakable teaching in the French patent specification that blocks having acceptable weatherability and water resistance can be manufactured using magnesium sulfate and reactive magnesium oxide mixed with sufficient water to provide a pourable mixture which can subsequently set. The French patent specification teaches only the addition of inorganic water soluble elements to provide the blocks and there is no description or teaching that other ingredients can also be added and which can set into an acceptable block. For instance, the French patent specification does not teach or disclose any organic ingredients such as meal, lupins, soy bean or oil. There is no teaching in the French patent specification that introduction of these organic components would result in an acceptable block.

German patent specification 1,925,180 is mainly directed to a fertiliser but has some description to the use of the compositions as mineral feeds. The compositions are described as being magnesium-calcium- phosphate compositions and indeed all the claims are directed to the manufacture of such a composition. There is no description or teaching of the ability to manufacture animal food blocks by the interreaction of magnesium sulfate and magnesium oxide which is initially mixed with sufficient water to allow the product to be moulded. In summary, it has not been realised that reactive magnesium oxide and magnesium sulfate can be used as efficient setting agents to manufacture feed blocks of acceptable weatherability and hardness while still being able to incorporation a very large range of other additives without compromising the weatherability of the blocks. Although it is known to mix magnesium sulfate and magnesium oxide together, the prior art teaches away from a much easier manufacturing process of these blocks which does away with the requirement for mechanical compression and pelletising equipment by allowing the blocks to be formed by a simple moulding process. The prior art teaches away from the realisation that animal feed blocks can be made by initially slurrying the components together in sufficient water to allow the components to be simply poured into moulds, without the subsequent set product becoming too weak.

In the present invention, animal feed blocks or other types of solid shaped animal feed compositions can be prepared without requiring heating or pressure pressing as an essential step, and useful blocks can be made with a large range of additives, and is not necessarily limited to a narrow range of additives.

This has been achieved with the surprising and unexpected discovery that when magnesium oxide and magnesium sulfate are used as setting agents, a large range of feed blocks can be made without requiring expensive capital equipment and where blocks have acceptable parameters of weatherability etc.

OBJECT OF THE INVENTION It is an object of the invention to provide an animal feed supplement which may overcome the abovementioned disadvantages or provide the public with a useful or commercial choice. In one form, the invention resides in a shaped animal feed composition comprising at least reactive magnesium oxide and magnesium sulfate as setting agents. In another form, the invention resides in a shaped animal feed composition comprising at least reactive magnesium oxide and magnesium sulfate as setting agents and where the composition has been formed by mixing the components of the composition with sufficient water to allow the mixture to be simply poured into moulds and subsequently set. In another form, the invention resides in a method of manufacturing an animal feed composition comprising adding to the composition reactive magnesium oxide and magnesium sulfate, adding sufficient water to the composition to allow it to be poured into moulds, and subsequently allowing the composition to set to form animal feed blocks. The amount of magnesium sulfate and magnesium oxide in the block can vary to suit the other additives in the block, the desired weatherability, hardness of the block and the like.

In a preferred form, the feed composition can comprise between 1 to 50% by weight and preferably between about 2 to about 15% by weight of reactive magnesium sulfate and between 1 to 50% by weight and more preferably between about 2 to about 15% by weight of reactive magnesium oxide. The ratio between magnesium oxide and magnesium sulfate can be from 1 :1 up to 2:1 with larger amounts of magnesium oxide relative to magnesium sulfate increasing the hardness of the blocks. The size and shape of the shaped feed composition can vary and can comprise small cubes or pellets which can be mixed with other animal feedstuffs, or larger blocks which can be licked or nibbled by the animals. The blocks can weight between, for instance, a gram or less to up to 1 tonne or more depending on their use. The feed composition can contain a variety of additives which can include organic and inorganic additives.

The additives may include various inorganic ingredients such as salt, urea, calcium compounds such as calcium carbonate, calcium bicarbonate, calcium phosphate, calcium sulfate; phosphate additives such as ammonium polyphosphate and tetra sodium pyrophosphate. These additives can be between about 5 to about 80% by weight of the composition. It will be appreciated that the block can also contain non- reactive magnesium oxide as a nutritional source of magnesium oxide.

Other additives can include feedstuffs such as cotton seed meal, soy bean meal, mill run, lupins, molasses, dunder, other molasses byproducts (dried); grains, cereals, legumes, straw, hay, soy flakes, dried alfalfa, soy meal, wheat middlings, corn; fats such as edible animal and vegetable fats and oils, for instance soy bean oil, cotton seed oil, fish oil, grease, tallow, beef fat and the like; barley meal, blood meal, dried buttermilk, linseed meal, meat and bone meal, peanut meal, rice meal and sunflower meal. If these additives are present, they can be present in an amount of up to about 50% by weight or more.

The feed composition may include various vitamins, trace elements and minerals, and if these are present, they can be present in an amount of up to about 10% by weight or more. These ingredients include copper sulfate, cobalt sulfate, zinc sulfate, manganese sulfate, sulphur, zinc oxide, ferrous sulfate, ferrous oxide, iodines, potassium iodate, selenium and its compounds such as sodium selenite and the like. Added vitamins may include vitamins A, E, the B group vitamins, D and K.

The feed composition may include further additives such as clays including the bentonite and kaolin clays. Other additives such as medicaments, antimicrobials, probiotics, enzymes, insecticides and anthelmintics may be added to the composition in an amount to about 25% by weight.

Water is added to the composition in sufficient amounts to allow the composition to be poured into moulds. The water can include aqueous solutions as well as substantially pure water. If the components of the composition are already watery (e.g. molasses), a smaller amount of extra water can be added. If the components absorb water, a larger amount of water may need to be added provided that sufficient water exists to allow the composition to be poured into moulds. As an example, the composition can contain up to about 30% by weight of water.

With current blocks, difficulties are experienced in ensuring adequate block supplement consumption by animals. It is critical that the animals consume at least a minimal amount of the feed supplement without the intake being excessive. Therefore, the supplement needs to be nutrient dense, palatable to encourage consumption, and hard enough to limit consumption. Molasses and salt are widely used to attract animals to the supplement and to manage consumption. However, blocks containing high levels of molasses (typically 30% by weight or more), while being palatable to animals, are not hard enough to limit animal intake to the required level. Supplement blocks containing high levels of salt (typically 40% by weight or more), are difficult to form and require large amounts of applied pressure to form the block. However, such salt enhanced blocks are effective in controlling intake. Because of the difficulty in manufacturing pressed blocks with a high salt content, these blocks have hitherto been limited to relatively small sizes (typically 25kg or less) as the pressure required to form larger blocks requires extremely expensive capital equipment. It is found that the present invention allows salt enriched blocks to be formed without requiring pressure or heat with the blocks having desirable hardness, palatability and weatherability. Thus, salt enriched blocks of up to 1000kg or more can now be manufactured in an economical manner. By using reactive magnesium oxide and magnesium sulfate as setting agents in the feed composition, it has now surprisingly and unexpectedly been found that a greater range of raw materials can be included into the block formation thereby offering more flexibility in the nutrient analysis of the supplement. There appears to be improved control over block hardness and therefore regulation of animal intake (the harder the block, the less the intake will be). Feed blocks made according to the present invention also appear to show improved weatherability allowing the blocks to be used under various weather conditions (expensive covered feeders do not appear to be necessary). Also, the blocks can be manufactured using simple economical machinery without the requirement of high heat input or high pressure.

Magnesium oxide is well-known as an ingredient of animal feed compositions and reactive magnesium oxide is known as a setting agent. It appears that the reactive magnesium oxide has water binding properties to facilitate the formation of a hard feed block. However, reactive magnesium oxide by itself provides blocks having undesirable strength and stability, and the time required to harden the blocks is undesirable. After much research and experimentation, we have found that improvements can be made to the block and methods of making the block by including magnesium sulfate in the formulation as a setting agent.

It appears that by using reactive magnesium oxide with magnesium sulfate as the setting agents, a large range of materials can be used that can be mixed in a water containing medium. It is preferred however that the mix prior to setting is neutral to alkaline in pH.

The reactive magnesium oxide can be obtained from various commercial sources.

It is preferred that the magnesium sulfate is magnesium sulfate heptahydrate as this product is available commercially and is relatively easy to work with.

The addition of magnesium sulfate appears to dramatically improve the weatherability of the shaped animal feed composition. Tests have shown that blocks containing magnesium sulfate and magnesium oxide can be immersed in water for extended periods of time and show only minimal weathering at the surface. Thus, these blocks are particularly suitable for high phosphate-containing blocks and high urea-containing blocks which may be toxic if overconsumption occurs due to block softening from exposure to water. In the manufacture of the shaped animal feed composition, water , or an aqueous mixture, is preferably added to reduce the viscosity of the block mix, to improve the intermixing of the various components and to allow the mixed product to be poured into moulds for setting. The amount of water can be varied with lower levels of water producing harder blocks. If some of the additives are water-containing (for instance molasses, dunder or liquid whey), less water can be added to provide the required viscosity. It appears that magnesium sulfate reduces the viscosity of the mix thereby allowing lower levels of water to be included in the formulation while maintaining flowability. Thus, harder blocks can be formed using magnesium sulfate and magnesium oxide than would be possible by using magnesium oxide by itself or in a mixture with other ingredients. The shaped animal feed composition can be produced simply and economically, and there is no strict order of addition of the raw materials.

In an example, liquid raw materials and soluble raw materials are added together followed by insoluble raw materials with the reactive magnesium oxide being added last. There is no requirement for heating in the process and the magnesium sulfate prevents premature setting of the composition before it can be properly mixed and poured into moulds. There appears to be no requirement for time delays between raw material addition and therefore the production rate is limited only to the speed by which the raw materials can be added to the mixer, blended together and poured into the moulds for setting.

The setting time for the blocks is somewhat dependent on the choice of raw materials and ambient temperatures. External heat can be applied if it is necessary to set the blocks more quickly. It is found that blocks with low levels of molasses (typically 10% or less) set within 3 to 24 hours, while blocks with up to 50% molasses may take up to 7 days to set.

BEST MODE Thirty-nine different animal feed blocks were prepared by mixing together various amounts of components using reactive magnesium oxide and magensium sulfate as setting agents as shown in Table 1. TABLE 1

The blocks have acceptable hardness and a typical range of hardness is from 4Kg cm² to 50Kg cm². It can be seen that these hardnesses are quite surprising and unexpected considering the amount of water added to the composition to allow it to be poured into moulds. To date, conventional teaching has been away from adding too much water as the blocks were considered to be too soft and therefore unusable. The present invention has realised that this is not the case with the careful selection of the setting agents. Throughout this specification (including the claims) unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. It should be appreciated that various other changes and modifications may be made to the embodiments described without departing from the spirit and scope of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method of forming an animal feed block which comprises the steps of mixing at least one animal feed component with magnesium sulfate and reactive magnesium oxide to form a composition, adjusting the water

5 level of the composition to a level to allow the composition to be poured into a mould, allowing the composition to at least partially set in the mould.

2. The method of claim 1 , wherein the composition comprises between about 1 to about 50% by weight of the magnesium sulfate and about

1 to about 50% by weight of the magnesium oxide 0

3. The method of claim 2, wherein the composition comprises between about 2 to about 15% by weight of the magnesium sulfate and about

2 to about 15% by weight of the magnesium oxide.

4. The method claim 1, wherein the ratio between magnesium oxide and magnesium sulfate is from 1:1 up to 2:1.

5 5. The method of claim 1 , wherein the at least one animal feed component is selected from the group consisting of salt, urea, calcium carbonate, calcium bicarbonate, calcium phosphate, calcium sulfate, ammonium polyphosphate and tetra sodium phosphate and the composition comprises between about 5 to about 80% by weight of the component. 0

6. The method of claim 1 , wherein the at least one animal feed component is an animal feed stuff in the composition comprises up to about 50% by weight of the component.

7. The method of claim 1 , wherein the at least one animal feed component is selected from the group consisting of vitamins, trace elements 5 and minerals and the composition comprises up to about 10% by weight of the component.

8. The method of claim 1, wherein the at least one animal feed component is selected from the group consisting of medicaments, antioxidants, prebiotics, enzymes, insecticides and anthelmintis and the o composition comprises up to about 25% by weight of the component..

9. An animal feed block prepared by the method of claim 1.

10. The feed block of claim 9 which has a hardness of between about 4 kg cm² to about 50 kg cm².

11. The feed block of claim 9, which includes between about 5 to about 10% magnesium oxide and between about 5 to about 10% of magnesium sulfate.

12. The feed block of claim 11 which includes from about 10 to about 30% by weight water.

13. The feed block of claim 12 wherein the at least one animal feed component is selected from the group consisting of molasses, salt, urea, limestone, diocalcium phosphate, cottonseed meal, lupins, soybean, oil a and soybean meal.