AU749118B2 - Feed additive - Google Patents

Description

v4.

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

TO BE COMPLETED BY APPLICANT Name of Applicant: PENRICE SODA PRODUCTS PTY LTD Actual Inventors: Les Pollard; Shaun F. Baldacchino Address for Service: A.P.T. Patent and Trade Mark Attorneys GPO Box 772, Adelaide, SA 5001 Invention Title: FEED ADDITIVE Details of Associated Provisional Application No: PP3827 dated 1st June 1998 The following statement is a full description of this invention, including the best method of performing it known to us:- The present invention is directed to a feed additive for use with grain based diet for ruminants.

BACKGROUND OF THE INVENTION Feeding ruminants such as cattle with grain has an advantage over feeding them on pasture because the energy content of the grain is much higher, and growth rates achieved are also much higher. Further, in the case of dairy cattle there is an increase in feed intake which results in an increase in milk production and an increase in butterfat. Additionally, it is considered that the quality of meat produced by grain fed beef cattle is better.

During pasture feeding, a considerable time is spent chewing various grasses, and then chewing the cud, and during that time saliva is produced and passed down the alimentary tract carrying with it neutralising compounds, primarily sodium bicarbonate, to neutralise the acids produced in the rumen by bacterial fermentation. With grain fed ruminants the amount of time available for saliva production is considerably reduced and there is a consequent reduction in the capacity to neutralise the rumen. This decreases the pH from the normally close to neutral level and with adverse effects to the health of the animal concerned. These adverse effects are well known in lactating cows resulting in a decrease in milk yield, dry matter consumption and general health. Adverse affects are also exhibited by other ruminants which are grain fed and are not also fed a neutralising feed additive.

It has been known to supplement feed with rumen modifiers that either affect rumen 25 microbial populations or stabilise rumen pH. To this end, neutralising agents such as sodium bicarbonate and similar agents are often used to supplement the naturally produced neutralising compounds and minimise or overcome the above problems.

Where pelleted feed mixes are used there is no major difficulty in adding a neutralising agent or other nutrient mineral source because the neutralising agent or nutrient mineral 30 source is incorporated into the feed mixture that is extruded and pelleted and the agent can be carried with the pellet.

Where grain itself is used, there is a problem in so far as the neutralising agent or nutrient mineral source is generally in a fine powdered form. Thus where sodium bicarbonate is used as a neutralising agent, this is generally made as fine crystals in the range of 100 microns or less, and will tend to fall to the bottom of the container used and there is a consequent materials handling problem. This is also the case for other additives such as antibiotics or mineral supplements like dicalcium phosphate. Often it might be desired, for example in automatic feeding arrangements, for grain to be carried out by a mechanical means, such as an auger, over a trough, the sodium bicarbonate or other neutralising agent will have a tendency not to be carried along the full length of the trough, but rather to settle out at a first part of the trough, with the remainder being devoid of the sodium bicarbonate or having a much reduced amount. Additionally, the size of the crystals will mean that the powder will have a tendency to fall to the bottom of the trough. This uneven distribution presents a difficulty in ensuring that all animals have a reasonable intake of neutralising compound.

It is therefore desirable to achieve granules made in greatest proportion of neutralising agent or nutrient mineral source, that are suitable for use with grain based feeds that by reason of having a dimension which is suitable for materials handling applications with animal feeds, particularly whole or broken grain based feeds.

One approach to applying a neutralising feed supplement which is somewhat different to the one that is the subject of the present invention, is to provide for a supplement block, which can be licked by the animal concerned. These are generally moulded into shape by pouring a heated mixture and subjecting the mixture to a high pressure, or by chemical setting and include the use of, for example molasses as a binder. Examples of these can be found in US 5264227 by Laroche et al and US 4729896 by Sawhill. With these free choice feeding approaches, there is a great need to ensure that the blocks are palatable and desirable. Additionally, with those known methods there are limitations in the proportion neutralising agent that can be used.

•go° 25 One interesting practical application of sodium bicarbonate has made it desirable to produce granules of a greater size, and that application is the use of sodium bicarbonate in blast S••cleaning processes that might be used in the cleaning of soft surfaces such as aluminium S°which are abraded by the harsher sand blasting. A number of patents address this application of the use of sodium bicarbonate, the most pertinent known for present 30 purposes is US 5322532 by Kurts assigned to Church Dwight Co Inc. This document discloses the formation of a blast medium by agglomeration of sodium bicarbonate particles in aqueous sodium carbonate solution as a binder for the particles. The agglomeration particle which is formed, comprises a composite containing individual sodium bicarbonate particles which are bound together via sodium sesquicarbonate bridges. The size ranges contemplated are up to 1 mm. The method requires spraying or other means of applying the aqueous sodium carbonate onto sodium bicarbonate particles to produce the hard particle for blasting. These particles are not palatable for ingestion and 4 are relatively hard, and generally will be smaller than needed for materials handling purposes with animal feeds.

OBJECT OF THE INVENTION It is an object of the present invention to provide a feed additive which has a pellet suitable for materials handling with animal feeds such as grain based feeds which pellet is made in the majority of one or more physiologically acceptable neutralising agents and/or nutrient mineral sources.

SUMMARY OF THE INVENTION It has been found that a suitably sized particle can conveniently be made by balling a neutralising compound or nutrient mineral source and a binder mixture, adjusting the water content and drying and overcoating the pellet by adding a physiologically acceptable drying compound. This permits the formation of a feed additive pellets using minimal energy input, and allows for the formation of a suitably sized pellet. It will be understood that the term pellet as used herein refers to a suitably sized particle that is formed by balling or granulating a neutralising compound or nutrient mineral source and a binder mixture.

Accordingly in one broad form the invention could be said to reside in a method of forming a feed additive pellet, the method including the steps of: making a mixture of at least one physiologically acceptable neutralising compound and/or nutrient mineral source and a binder, the mixture having a water content •"suitable for balling; ooo.

forming a core of suitable size from the mixture of step using a pelleting means; 25 and overcoating the core from step with a physiologically acceptable drying compound so as to absorb excess moisture from the core and to form a dry pellet, S-said dry pellet formed in the majority of one or more neutralising compounds and/or nutrient mineral sources.

In a preferred form of the invention the pellet is formed in the majority of one or more S* neutralising compounds.

The neutralising compound is preferably a non-hydratable compound. In part the use of a non-hydratable compound facilitates the bailing step, otherwise the neutralising compound might need to be hydrated before the mixing step, so that a relatively constant water content is maintained during the balling step. Alternatively, when the neutralising compound is a hydratable compound, it might be possible to add water during the balling step as free water is depleted with progressive hydration of the neutralising compound.

Both of these steps however may add complexity to the manufacturing of the pellets.

Most preferably the neutralising compound is sodium bicarbonate, although the invention also contemplates the use of other non-hydratable neutralising compounds such as potassium carbonate, magnesium oxide and sodium bentonite, and hydratable neutralising compounds such as calcium carbonate.

The nutrient mineral source is preferably non-hydratable and in one form of the invention may be added in conjunction with a neutralising compound or in the absence of a neutralising compound. The nutrient mineral source may be other macro-minerals added to the mixture of part in order to provide a source of particular nutrient minerals. Thus in one form of the invention magnesium oxide may be added to the core to provide a source of magnesium. Further, at times it is desirous to maintain the calcium to phosphate ratio of the rumen diet at a level of about 2:1 and therefore the calcium to phosphate ratio of the core may be adjusted by the addition of appropriate mineral sources such as either dicalcium phosphate or monocalcium phosphate to the mixture of part A benefit of at least one form of the above embodiment of the invention is that the neutralising compound or nutrient mineral source supplied need not be dried, which in the case of sodium bicarbonate is an energy consuming step at the end of the synthesis of sodium bicarbonate.

°It may be necessary to add water to the mixture of binder and non-hydratable neutralising S 25 compound or nutrient mineral source. Adjustment of the water content may be used to vary the size of the cores formed in step but generally the water content of the mixture of is preferably in the range of 10 to 30% w/w. When sodium bicarbonate is used a S°preferred water content is 10.5 to 12% and most preferably about 11.5%. It will be understood that the most preferable water content will vary depending on the neutralising 30 compound or nutrient mineral source used. It is found that when the water content is too low then granulation does not occur and when the water content is too high the resultant 0ooo0 S"pellet tends to lose it physical structure or become 'mushy'. It will be understood therefore that variation of the water content within the upper and lower limits may be used to vary the size of the cores, and the size of the cores can be varied depending upon the size of the grain to which it is to be added.

In a preferred form of the invention the amount of binder used may be decreased by adding at least one granulating agent to the mixture in part Thus the granulating agent may also act as a binder in assisting the formation of cores in step Preferably the granulating agent is itself a source of mineral nutrients. The granulating agent may be selected from the list including calcium carbonate, dicalcium phosphate, sodium chloride, river or brine mud. Most preferably the granulating agent is calcium carbonate (calcite), thus providing a source of calcium. The granulating agent serves to hold individual particles of the neutralising compound together in the core. To achieve this the particle size of the granulating agent should be greater than the particle size of the neutralising compound or nutrient mineral source. In practice, it is found that the more diverse the size range between the granulating agent and the neutralising compound or nutrient mineral source then the easier it is to form granules. When sodium bicarbonate is used as the neutralising agent this form of the invention is particularly useful where the commonly available smaller mesh sizes of sodium bicarbonate are used. Using conventional methods it is difficult to form cores of the desired size using the smaller mesh size of sodium bicarbonate. When sodium bicarbonate is used as the neutralising agent and calcium carbonate as the granulating agent then preferably the sodium bicarbonate has a particle size of less than 120 microns with an average of 50 microns, whilst the calcium carbonate has particle size of less than 500 microns with an average of 250 microns.

In another preferred form the granulating agent may be river or brine mud. The river or brine mud preferably contains significant levels of calcium carbonate and/or magnesium •hydroxide as well as trace elements and inert material. The levels of calcium carbonate may be between 10 and 90% and the levels of magnesium hydroxide may be between and 90%. Thus the river or brine mud may be used in conjunction with sodium bicarbonate, for example. Preferably the river or brine mud has a particle size of less than 355 microns.

A variety of binders might be used and there are known in the food industry a very large *o a.

S•range of binders, and without limiting these, the following could be used: a water soluble saccharide such as refined sugar, raw sugar, glucose, mannose, fructose, maltose, 30 molasses, molasses extract or cane sugar extract with water. The binder might be a starch based compound such as flour. In a preferred form of the invention the binder is refined sugar. The amount of binder added can be in the range of 0.2-40% w/w of the mixture of part The amount of binder required will vary depending upon whether a granulating agent is added to the mixture of part With a granulating agent added the binder is preferably present at 0.2-4% w/w, and most preferably at 2-3% w/w. In contrast, where there is no granulating agent present the amount of binder required is increased and the binder is preferably present at 5-40% w/w, and most preferably at 6-7% w/w. It will be 7 understood that these binders will not generally form covalent or hydrogen bonds with the neutralising compounds.

The drying compound serves to absorb excess moisture from the cores formed during step so as to dry them and in doing so hardens to form an overcoat on the surface of pellets formed during step The extent to which the drying compound is dry will depend upon the capacity to take up moisture from the cores, thus it is not intended that the drying compound has a zero water content, and does not also mean that the compound needs to be anhydrous, provided that the compound can still absorb excess water in the mixture of step to give the desired overcoating and the desired final moisture content.

The drying compound may be any compound that is capable of taking up moisture from the cores and may be a suitable oxide, carbonate, chloride or sulphate of magnesium, calcium, sodium, zinc, copper, manganese or cobalt, although it will be understood that the drying compound is not limited thereto.

The final free water content of the pellets may be desired to be in the range of 4-10% w/w.

Most preferably it is 6-8% on a w/w basis.

The amount of drying compound added may be varied depending upon the amount of S:i •drying agent required to absorb the excess moisture and also upon the thickness of the coating required on the core.

In one form of the invention the drying compound is also preferably a source of nutrient S.minerals, and in a most preferred form is magnesium oxide which is preferably provided at S• •a mean particle size of 7 microns. In another form calcium oxide (lime) may be used.

Alternatively and in another form of the invention the drying compound is also preferably a 30 neutralising compound, and in one preferred form is sodium carbonate (soda ash).

The addition of the drying compound in step can be to the same pelleting means in which cores are formed in step so that the drying compound is simply added to cores after substantially all the mix of has formed into cores.

It will be appreciated that other additives may also be added to the mixture of part which additives may include a range of mineral sources so that the feed additive provides a full mineral supplement. Thus the additive may include suitable salts or compounds that 8 are a source of one or more of the micro-minerals zinc, copper, manganese, cobalt, iron, chromium or selenium. Alternatively ionophores and antibiotics that directly influence rumen microbial populations may be added. Examples of ionophores include lasalocid, monensin, posistac and navarin whilst examples of antibiotics include avoparcin and virginiamycin.

In one form of the invention the pellet will also include a flavouring compound, to mask the relatively unpalatable taste of the neutralising compound. The flavouring compound will preferably be present in the core as well as the overcoat of the pellet. However it may be sufficient simply to have the flavouring applied only to the core, or alternatively only to the overcoat of the pellet. The flavouring will be one that makes the pellet more palatable to the animal concerned. The flavouring might be an artificial flavour, such as various aromatic compounds that are used for imparting a desirable flavour in the food industry.

Alternatively the flavouring can be a sugar, which is readily accessible, such as cane sugar, or alternatively other forms of sugar particularly those that are readily available such as dextrose, glucose, fructose, sorbitol or lactose and perhaps might be in the form of molasses, or perhaps as another natural sweetener such as a corn sweetener or many others. Alternatively the flavouring may be an artificial sweetener such as Sucram 200 (Pancofma, pellitant). These are preferably added at least to the mixture of step so that they additionally act, at least to some extent as a binder, to facilitate balling, however, generally this will be in addition to a binder of another type, for example flour. A further advantage of using a sugar as a sweetener is that these may act also as a humectant to maintain the free water balance of the pellets notwithstanding periods of storage.

25 One preferred form includes the use of sodium bicarbonate as the neutralising agent, together with calcium carbonate as the granulating agent, and raw sugar as the binding agent, with dry magnesium oxide being added at step The size of the pellet formed can be varied to complement the size of the particular feed 30 used and will generally be greater than 1 mm, whilst larger pellets can be formed these will normally not be greater than 5 mm and most preferably will be in the range of 2 to 3 mm in •size. The pellets formed will normally not describe a true sphere. The methods trialed to o date form a generally spherical shaped pellet, however, depending upon the shape of the pellet forming means a different shaped article, such as for example a more cylindrical shape, may be formed.

The pellet forming means is usually in the form of a rotating drum, with the mixture of step added into the drum. The inside of the drum will be shaped to enhance adequate 9 rolling of the mixture to take up the shape of a core, and various vanes or other protrusions, or grooves may be formed on the inside of the drum to enhance this formation. The speed of rotating the drum does not appear to be critical, but it is expected that this may play a role in achieving a desired pellet size. It is believed that the granulating process has at least two stages in the formation of the granules. The initially formed granules are thought not to be well compacted and therefore at this stage the pellets tend to break down physically or crumble when handled. However, further tumbling of the pellets tends to bring about a further compacting of the pellet resulting in the attainment of a certain internal structure which results in a pellet that is physically more robust and less prone to physical breakdown or crumbling.

It will also be understood that the invention will also encompass a feed additive pellet formed by any of the methods defined or described herein.

Thus in an alternate form the invention could be said to reside in a feed additive pellet made in majority by one or more physiologically acceptable neutralising compounds and/or nutrient mineral sources, said pellet having a core comprising a mixture of at least one of said physiologically acceptable neutralising compounds and/or nutrient mineral sources, granulating agent, and a binder, and an overcoating comprised of a physiologically acceptable drying compound which has absorbed excess moisture from the core.

Most preferably the feed additive pellet is made in a majority by one or more S: !•physiologically acceptable neutralising compounds.

*.i 25 In a further alternate form of the invention the invention could also be said to reside in a feed mixture including a feed additive pellet made in majority by one or more physiologically acceptable neutralising compounds and/or nutrient mineral sources, said pellet having a core comprising a mixture of at least one of said physiologically acceptable neutralising compounds and/or nutrient mineral sources, granulating agent, and a binder, and an overcoating comprised of a physiologically acceptable drying compound which has ooooo absorbed excess moisture from the core, and an animal feed.

In a preferred form of the invention the animal feed is a grain based feed. The grains based feed may be any suitable grain feed and may be selected from the list including barley, wheat, oats, lupins, sourgham and millet.

Preferably the feed additive pellet is of dimensions that are similar to the granules or particles of the animal feed. Thus, when the animal feed is a whole or broken grain based the feed additive pellets are preferably of a similar size to the grain, thus allowing material handling operations to be carried out without substantially separating the feed additive pellets from the feed.

DETAILED DESCRIPTION OF THE INVENTION The invention will now be described by way of example wherein various features of the invention are particularly shown and described in connection with the exemplified embodiment of the invention, however, it must be understood that these particular examples merely illustrate and that the invention is not limited thereto and can include various modifications falling within the spirit and scope of the invention.

EXAMPLE 1 Pellets formed with a binder and no granulating agent.

The granulation procedures were carried out in a 3m 3 cylindrical drum which was operated in approximately a horizontal position with the mixer speed approximately 17 rpm.

A mixture of 400 kg of sodium bicarbonate (particle size 150 microns; Penrice Soda Products Pty Ltd, South Australia), 40 kg of raw sugar and 8 kg of flour was added to the drum and allowed to mix for 15 minutes. Granulation was then initiated by adding 32 kg of water as a fine spray in several bursts whilst the mixture was tumbling. Upon complete addition of the water the granules were allowed to tumble for a further 30 minutes. The granules were then coated by adding a total of 60 kg of magnesium oxide (Causmag grade 25 A14; particle size <120 gim; Causmag International) in three stages followed by the addition of approximately 9 kg of water after each stage (for a total of 28 kg of water).

The granules were tumbled for a further 25 minutes and cooled.

b.

The granules formed by this method had a size range of between 1 to 5 mm. The 30 approximate composition (after complete hydration of the magnesium oxide) was NaHCO 3 Mg(OH) 2 binders (sugar and flour) and free water EXAMPLE 2 Pellets formed with a binder and a granulating agent.

The granulation procedures were carried out in a 3m 3 cylindrical drum which was operated in approximately a horizontal position with the mixer speed approximately 17 rpm.

A mixture of 200 kg of sodium bicarbonate (particle size 150 microns; Penrice Soda Products Pty Ltd, South Australia), 200 kg of calcium carbonate (particle size 250 microns; Penrice Soda Products Pty Ltd, South Australia) 32 kg of raw sugar and 8 kg of flour was added to the drum. The mixture was allowed to mix for 15 minutes. The mixture was granulated by adding 40 kg of water as a fine spray in several bursts whilst the mixture was tumbling. Upon complete addition of the water the granules were allowed to tumble for a further 30 minutes. The granules were then coated by adding a total of kg of magnesium oxide (Causmag grade A14; particle size <120 gm; Causmag International) in three stages followed by the addition of approximately 9 kg of water after each stage (for a total of 28 kg of water). The granules were tumbled for a further minutes and cooled.

The granules formed by this method had a size range of between 1 to 5 mm. The approximate composition (after complete hydration of the magnesium oxide) was NaHCO 3 CaCO 3 Mg(OH) 2 binders (sugar and flour) and free water EXAMPLE 3 Pellets formed with a binder and a vitamin mix.

The granulation procedures were carried out in a tumbler (internal diameter of approximately 0.5 m) and the bowl was operated in approximately a horizontal position Goo.

as& with the mixer speed approximately 26 rpm.

*4*e A mixture of 13 kg of sodium bicarbonate (particle size 150 microns; Penrice Soda 25 Products Pty Ltd, South Australia), 3.5 kg of vitamin mix (LACGROTM; Rhone-Poulenc), 1.2 kg of raw sugar and 0.3 kg of flour was added to the tumbler. The mixture was Sallowed to mix for 15 minutes. The mixture was granulated by adding a total of 3 kg of •water as a fine spray in several bursts whilst the mixture was tumbling. Upon complete addition of the water the granules were allowed to tumble for a further 30 minutes. The 30 granules were then coated by adding a total of 1.5 kg of magnesium oxide (Causmag grade A 14; particle size <120 lm; Causmag International). The granules were tumbled for a further 25 minutes and cooled.

The granules formed by this method had a size range of between 1 to 3 mm. The approximate composition (after complete hydration of the magnesium oxide) was NaHCO 3 vitamin mix Mg(OH)2 binders (sugar and flour) and free water EXAMPLE 4 Pellets formed with a binder and a granulating agent.

The granulation procedures were carried out in a tumbler (internal diameter of approximately 0.5 m) and the bowl was operated in approximately a horizontal position with the mixer speed approximately 26 rpm.

A mixture of 10 kg of a dry river or brine mud (particle size <355gtm; containing CaCO 3 46-50% dry w/w and Mg(OH)2; 20-29% dry 5.0 kg of sodium bicarbonate (particle size 150 microns; Penrice Soda Products Pty Ltd, South Australia), 1.2 kg of raw sugar and 0.3 kg of flour was added to the tumbler. The mixture was allowed to mix for minutes. The mixture was granulated by adding a total of 2 kg of water as a fine spray in several bursts whilst the mixture was tumbling. Upon complete addition of the water the granules were allowed to tumble for a further 30 minutes. The granules were then coated by adding a total of 1.5 kg of magnesium oxide (Causmag grade A14; particle size <120 gm; Causmag International) and the granules were tumbled for a further 25 minutes and cooled.

The granules formed by this method had a size range of between 1 to 3 mm. The composition was NaHCO 3 CaCO3 Mg(OH) 2 binders (sugar and flour) free water and inerts .ooooi

S

EXAMPLE 5 Pellets formed with a binder and a granulating agent.

The granulation procedures were carried out in a tumbler (internal diameter of 0: 25 approximately 0.5 m) and the bowl was operated in approximately a horizontal position with the mixer speed approximately 26 rpm.

A mixture of 5 kg of sodium bicarbonate (particle size 150 microns; Penrice Soda Products Pty Ltd, South Australia) and 5 kg of ground calcite (particle size 500 microns; 30 Penrice Soda Products Pty Ltd, South Australia) were added to the tumbler. The mixture was granulated by adding 1.5 kg of a 12.5% solution of raw sugar in water as a fine spray whilst the mixture was tumbling. Upon complete addition of the sugar/water solution the oo.o granules were allowed to tumble for a further 20 minutes. The granules were then coated by adding a total of 2.5 kg of magnesium oxide (Causmag grade A14; Causmag International) and 1.0 kg of a 12.5% solution of raw sugar in water. The magnesium oxide was added in three equal aliquots, and one third of the sugar/water solution was added as a fine spray after each magnesium oxide addition. The granules were tumbled for a further two hours, with good strength granules being attained after one hour.

The granules formed by this method had a size range of between 1 to 3 mm. The approximate composition (after complete hydration of the magnesium oxide) was CaCO3 NaHCO 3 Mg(OH)2 sugar and free water EXAMPLE 6 Pellets formed with a binder and no granulating agent.

The granulation procedures were carried out in a tumbler (internal diameter of approximately 0.5 m) and the bowl was operated in approximately a horizontal position with the mixer speed approximately 26 rpm.

A mixture of 10 kg of sodium bicarbonate (ungraded; Penrice Soda Products Pty Ltd, South Australia), 1. 5 kg of sodium carbonate (ungraded; Penrice Soda Products Pty Ltd, South Australia) and 1.0 kg of sugar were added to the tumbler. The mixture was granulated by adding 1.85 kg of water as a fine spray whilst the mixture was tumbling.

Upon complete addition of the water the granules were allowed to tumble for a further minutes. The granules were then dried, whilst tumbling, by a stream of hot air generated by an industrial gas heater (approximately 60'C) for 2 hours.

The granules formed by this method had an approximate composition (after complete hydration of the magnesium oxide) of: NaHCO 3 Na 2

CO

3 sugar •and free water o.

.:o.oe

Claims (99)

1. A method of forming a feed additive pellet, the method including the steps of: making a mixture of at least one physiologically acceptable neutralising compound and/or nutrient mineral source and a binder, the mixture having a water content suitable for balling; forming a core of suitable size from the mixture of step using a pelleting means; and overcoating the core from step with a physiologically acceptable drying compound so as to absorb excess moisture from the core and to form a dry pellet said dry pellet formed in the majority of one or more neutralising compounds and/or nutrient mineral sources.

2. A method of forming a feed additive pellet according to claim 1 wherein the size of the pellet formed is between 1 mm and 5 mm.

3. A method of forming a feed additive pellet according to claim 2 wherein the pellet is formed in the majority of one or more neutralising compounds.

4. A method of forming a feed additive pellet according to claim 3 wherein the neutralising compound is a non-hydratable compound. ooooe oeee A method of forming a feed additive pellet according to claim 4 wherein the neutralising compound is sodium bicarbonate.

S

6. A method of forming a feed additive pellet according to claim 3 wherein the nutrient mineral source is non-hydratable. o

7. A method of forming a feed additive pellet according to claim 3 wherein the nutrient mineral source is one or more macro-minerals that provides a source of nutrient minerals. o

8. A method of forming a feed additive pellet according to claim 7 wherein the nutrient mineral source is selected from the group comprising magnesium oxide, dicalcium phosphate and monocalcium phosphate.

9. A method of forming a feed additive pellet according to claim 5 wherein water is added to the mixture in step so that the water content of the mixture from step is in the range of 10 to 30% w/w.

A method of forming a feed additive pellet according to claim 5 wherein the water content is between 10.5 and 12% w/w.

11. A method of forming a feed additive pellet according to claim 3 wherein the binder is selected from the list including water soluble saccharides and starch based compounds.

12. A method of forming a feed additive pellet according to claim 11 wherein the water soluble saccharide is selected from the list including refined sugar, raw sugar, glucose, mannose, fructose, maltose, molasses, molasses extract or cane sugar extract.

13. A method of forming a feed additive pellet according to claim 12 wherein the water soluble saccharide is refined sugar or raw sugar.

14. A method of forming a feed additive pellet according to claim 11 wherein the starch based compound is flour.

A method of forming a feed additive pellet according to any one of claims 13 or 14 wherein the amount of binder added is in the range of 0.2-40% w/w of the mixture of part

16. A method of forming a feed additive pellet according to claim 15 wherein the amount of binder added is in the range 5-40% w/w. o S: 25

17. A method of forming a feed additive pellet according to claim 15 wherein the o amount of binder added is in the range 6-7% w/w.

18. A method of forming a feed additive pellet according to claim 11 wherein the S•amount of binder used in step is decreased by adding at least one granulating agent to the mixture in step

19. A method of forming a feed additive pellet according to claim 18 wherein the S "granulating agent is a source of mineral nutrients.

20. A method of forming a feed additive pellet according to claim 19 wherein the granulating agent is selected from the list comprising calcium carbonate, dicalcium phosphate, sodium chloride and river or brine mud. Il 16

21. A method of forming a feed additive pellet according to claim 20 wherein the particle size of the granulating agent is greater than the particle size of the neutralising compound and/or nutrient mineral source.

22. A method of forming a feed additive pellet according to claim 21 wherein the neutralising compound has a particle size of less than 120 microns and the granulating agent has particle size of less than 500 microns.

23. A method of forming a feed additive pellet according to claim 22 wherein the neutralising compound has an average particle size of 50 microns and the granulating agent has an average particle size of 250 microns.

24. A method of forming a feed additive pellet according to claim 23 wherein sodium bicarbonate is used as the neutralising compound and calcium carbonate as the granulating agent.

A method of forming a feed additive pellet according to claim 22 wherein sodium bicarbonate is used as the neutralising compound and river or brine mud as the granulating agent.

26. A method of forming a feed additive pellet according to claim 25 wherein the river or brine mud contains 10 to 90% dry w/w calcium carbonate. *o o 2

27. A method of forming a feed additive pellet according to claim 25 wherein the river S• 25 or brine mud contains 10 to 90% dry w/w magnesium hydroxide.

28. A method of forming a feed additive pellet according to claim 22 wherein sodium ••bicarbonate is used as the neutralising compound and sodium chloride as the granulating S•agent.

29. A method of forming a feed additive pellet according to claim 20 wherein with a granulating agent added in step the binder is present at 0.2-4% w/w.

A method of forming a feed additive pellet according to claim 24 wherein the drying compound absorbs excess moisture from the cores formed during step so as to dry them and in doing so hardens to form an overcoat on the surface of pellets formed during step .P 17

31. A method of forming a feed additive pellet according to claim 30 wherein the drying compound is also a source of nutrient minerals.

32. A method of forming a feed additive pellet according to claim 31 wherein the drying agent is selected from the group including magnesium oxide and calcium oxide.

33. A method of forming a feed additive pellet according to 32 wherein the drying agent has a mean particle size of 7 microns.

34. A method of forming a feed additive pellet according to claim 31 wherein the drying compound is also a neutralising compound.

A method of forming a feed additive pellet according to claim 34 wherein the drying compound is sodium carbonate.

36. A method of forming a feed additive pellet according to claim 3 wherein the pellet also includes one or more additives.

37. A method of forming a feed additive pellet according to claim 36 wherein the one or more additives is a range of mineral sources so that the feed additive provides a full mineral supplement.

38. A method of forming a feed additive pellet according to claim 36 wherein the one or 2 more additives are ionophores that directly influence rumen microbial populations. i

39. A method of forming a feed additive pellet according to claim 38 wherein the ionophore is selected from the group including lasalocid, monensin, posistac and navarin.

40. A method of forming a feed additive pellet according to claim 36 wherein the one or more additives are antibiotics that directly influence rumen microbial populations.

41. A method of forming a feed additive pellet according to claim 40 wherein the S"antibiotic is selected from the group including avoparcin and virginiamycin.

42. A method of forming a feed additive pellet according to claim 36 wherein the one or more additives is a flavouring compound. a, 18

43. A method of forming a feed additive pellet according to claim 42 wherein the flavouring compound is selected from the group including an artificial flavour, such as an aromatic compound that is used in the food industry, a sugar such as cane sugar, dextrose, glucose, fructose, sorbitol or lactose, molasses, corn sweetener, an artificial sweetener.

44. A method of forming a feed additive pellet according to claim 43 wherein the flavouring compound is present in the core as well as the overcoat of the pellet.

A method of forming a feed additive pellet according to claim 43 wherein the flavouring is applied only to the core of the pellet.

46. A method of forming a feed additive pellet according to claim 43 wherein the flavouring is applied only to the overcoat of the pellet.

47. A method of forming a feed additive pellet according to claim 45 wherein the flavouring compound is added to the mixture of step so that it additionally acts as a binder.

48. A method of forming a feed additive pellet according to claim 3 wherein the neutralising compound and/or nutrient mineral source is a hydratable compound and water is added during step as free water is depleted with progressive hydration of the neutralising compound. 2

49. A method of forming a feed additive pellet according to claim 3 wherein the o• neutralising compound and/or nutrient mineral source is a hydratable compound and water is added during step as free water is depleted with progressive hydration of the neutralising compound.

50. A method of forming a feed additive pellet according to claim 49 wherein the pelleting means is a rotating drum, with the mixture of step added into the drum.

51. A method of forming a feed additive pellet according to claim 50 wherein the .oeoo addition of the drying compound in step is to the same pelleting means in which cores are formed in step so that the drying compound is added to cores after substantially all the mix of has formed into cores.

52. A feed additive pellet made in majority by one or more physiologically acceptable neutralising compounds and/or nutrient mineral sources, said pellet having a core 19 comprising a mixture of at least one of said physiologically acceptable neutralising compounds and/or nutrient mineral sources and a binder, and an overcoating comprised of a physiologically acceptable drying compound which has absorbed excess moisture from the core.

53. A feed additive pellet according to claim 52 wherein the size of the pellet is between 1 mm and 5 mm.

54. A feed additive pellet according to claim 53 wherein the pellet is made in the majority of one or more neutralising compounds.

A feed additive pellet according to claim 54 wherein the core includes the neutralising compound and no nutrient mineral source.

56. A feed additive pellet according to claim 54 wherein the neutralising compound is selected from the list including sodium bicarbonate, potassium carbonate, magnesium oxide, calcium carbonate and sodium bentonite.

57. A feed additive pellet according to claim 56 wherein the core is made from a neutralising compound that is a non-hydratable compound. fleeo.

58. A feed additive pellet according to claim 57 wherein the neutralising compound is *o sodium bicarbonate. eeoc

59. A feed additive pellet according to claim 54 wherein the core is made from a nutrient mineral source that is a non-hydratable compound.

60. A feed additive pellet according to claim 59 wherein the nutrient mineral source is one or more macro-minerals that provides a source of nutrient minerals.

61. A feed additive pellet according to claim 60 wherein the nutrient mineral source is selected from the group comprising magnesium oxide, dicalcium phosphate and monocalcium phosphate.

62. A feed additive pellet according to claim 61 wherein the amount of binder in the core is decreased and a granulating agent is present in the core, said granulating agent assisting in the formation of the core.

63. A feed additive pellet according to claim 14 wherein the granulating agent is a source of mineral nutrients.

64. A feed additive pellet according to claims 57 wherein the binder is selected from the list including water soluble saccharides and starch based compounds.

A feed additive pellet according to claim 64 wherein the water soluble saccharide is selected from the list including refined sugar, raw sugar, glucose, mannose, fructose, maltose, molasses, molasses extract or cane sugar extract.

66. A feed additive pellet according to claim 65 wherein the water soluble saccharide is refined sugar or raw sugar.

67. A feed additive pellet according to claim 64 wherein the starch based compound is flour.

68. A feed additive pellet according to any one of claims 66 or 67 wherein the amount of binder in the core is in the range of 0.2-40% w/w of the core.

69. A feed additive pellet according to claim 68 wherein the amount of binder is in the range 6-7% w/w of the core. .see.:

70. A feed additive pellet according to claim 63 wherein the granulating agent is 25 selected from the list comprising calcium carbonate, dicalcium phosphate, sodium chloride S• 25 and river or brine mud.

71. A feed additive pellet according to claim 70 wherein the particle size of the S•granulating agent is greater than the particle size of the neutralising compound and/or S•nutrient mineral source.

72. A feed additive pellet according to claim 71 wherein the neutralising compound has a particle size of less than 120 microns and the granulating agent has particle size of less oooQ• than 500 microns.

73. A feed additive pellet according to claim 72 wherein the neutralising compound has an average particle size of 50 microns and the granulating agent has an average particle size of 250 microns. 21

74. A feed additive pellet according to claim 73 wherein the neutralising compound is sodium bicarbonate and the granulating agent is calcium carbonate.

A feed additive pellet according to claim 73 wherein the neutralising compound is sodium bicarbonate and the granulating agent is river or brine mud.

76. A feed additive pellet according to claim 75 wherein the river or brine mud contains to 90% dry w/w calcium carbonate.

77. A feed additive pellet according to claim 75 wherein the river or brine mud contains to 90% dry w/w magnesium hydroxide.

78. A feed additive pellet according to claim 73 wherein the neutralising compound is sodium bicarbonate and the granulating agent is sodium chloride.

79. A feed additive pellet according to claim 73 wherein the binder is present at 0.2-4% w/w of the core.

A feed additive pellet according to claim 79 wherein the binder is present at 2-3% w/w of the core.

81. A feed additive pellet according to claim 57 wherein the drying compound is a source of nutrient minerals. S• 25

82. A feed additive pellet according to claim 81 wherein the drying agent is selected *t .o, from the group including magnesium oxide, calcium oxide, magnesium sulphate, sodium carbonate and potassium carbonate. oO.

83. A feed additive pellet according to claim 82 wherein the drying agent has a mean particle size of 7 microns.

84. A feed additive pellet according to claim 83 wherein the drying compound is a S* neutralising compound.

85. A feed additive pellet according to claim 84 wherein the drying compound is sodium carbonate. ,,,Lo 22

86. A feed additive pellet according to claim 84 wherein the drying compound is magnesium oxide.

87. A feed additive pellet according to any one of the preceding claims wherein the pellet contains one or more additives.

88. A feed additive pellet according to claim 87 wherein the one or more additives are selected from the list including mineral sources, antibiotics, ionophores and flavouring compounds.

89. A feed additive pellet according to claim 88 wherein the additive is a flavouring compound selected from the group including an artificial flavour, such as an aromatic compound that is used in the food industry, a sugar such as cane sugar, dextrose, glucose, fructose, sorbitol or lactose, molasses, corn sweetener, an artificial sweetener.

A feed additive pellet according to claim 89 wherein the flavouring compound is present in the core of the pellet.

91. A feed additive pellet according to claim 89 wherein the flavouring compound is present in the core as well as the overcoat of the pellet.

92. A feed additive pellet according to claim 89 wherein the flavouring is present only in the overcoat of the pellet. **oo 25

93. A feed additive pellet according to claim 54 wherein the core is made from a neutralising compound and/or nutrient mineral source that is a hydratable compound.

94. A feed additive pellet according to any one of the illustrated examples.

95. A feed mixture including: a feed additive pellet made in majority by one or more physiologically acceptable neutralising compounds and/or nutrient mineral sources, said pellet having a core Scomprising a mixture of at least one of said physiologically acceptable neutralising compounds and/or nutrient mineral sources and a binder, and an overcoating comprised of a physiologically acceptable drying compound which has absorbed excess moisture from the core, and an animal feed. 23

96. A feed mixture according to claim 95 wherein the feed additive pellet is made in the majority of one or more neutralising compounds.

97. A feed mixture according to claim 96 wherein the animal feed is a grain based feed.

98. A feed mixture according to claim 97 wherein the animal feed is selected from a list including barley, wheat, oats, sourgham and millet.

99. A feed mixture according to claim 95 wherein the feed additive pellet is the same as the one described in any one of claims 55 to 94. Dated this 1st day of June 1999 PENRICE SODA PRODUCTS PTY LTD By their Patent Attorneys A.P.T. Patent and Trade Mark Attorneys S...i i