Background of the Invention Trace element deficiency, for example copper deficiency, is an important disease in ruminant animals in certain areas of the world. Treatment and prevention of trace element deficiency in ruminants involves administration of supplementation, either orally or by injection. Excess trace elements are commonly toxic, therefore any medication designed to deliver them must deliver sufficient trace element to meet the ruminant's needs without causing toxicity through overdose or too-rapid systemic uptake.

Oral administration of trace elements may include daily in-feed or water administration, or daily drenching, however such methods are only suitable for treatment of ruminants that are routinely handled on a daily basis, such as dairy cattle. Daily treatment is not suitable for ruminants that are grazed under extensive systems, that are not provided with supplementary feed daily and that are handled only infrequently.

An alternative method for oral supplementation is by delivery of a form that provides a prolonged release of the trace element. For example to combat copper deficiency, such a prolonged release supplement may be copper oxide wire particles (COWP).

COWP may be delivered to the rumen and lodge there by virtue of their high density.

Over time the COWP are slowly released from the rumen to the abomasum. The acid environment in the abomasum slowly causes dissolution of the copper oxide and release of copper for absorption into the blood and uptake by the liver.

It is necessary for the COWP delivery system to readily disintegrate once in the rumen, thereby allowing release of the COWP. The COWP must be of suitable size to lodge both in the rumen and then in the abomasum, allowing for sufficient passage of time to provide prolonged supply of copper for absorption.

COWP-containing boluses are commercially available for treatment and prevention of copper deficiency in ruminants. One commonly available form is as COWP enclosed in a gelatine capsule, which rapidly dissolves when in contact with the aqueous contents of the rumen. When administering such boluses to ruminants, the oral delivery system and person's hands commonly become covered in saliva, so that subsequent boluses come in

contact with moisture and become sticky, making dosage more difficult and the animal less likely to swallow the bolus.

Moreover an additional disadvantage of the COWP bolus presented in gelatine capsules is the increased global restrictions on supply and use of gelatine in medicinal products due to the risk of Transmissible Spongiform Encephalopathies (TSEs). All gelatine so used must be certified free of TSEs, adding to the capsule cost and presenting potential sourcing difficulties.

Another available bolus form is as COWP moulded into a cylindrical block of a solid non-toxic binding substance, usually a salt or sugar that similarly dissolves when in contact with the aqueous contents of the rumen. When such boluses come in contact with moisture such as saliva prior to administration, they can disintegrate prior to administration. Thus, for example, when a farmer provides a bolus to an animal, he/she may get saliva from the animal on his/her hand. When the farmer handles a bolus for a subsequent animal, that saliva may be in part transferred to the bolus, causing it to become sticky and possibly disintegrate.

Additionally, administration during rainy weather of COWP in both gelatine capsules and the cylindrical block form can similarly result in difficult administration due to stickiness or disintegration, due to high humidity or contact with rainwater.

There is therefore a need for a bolus for providing a trace element to a ruminant, wherein the bolus does not become sticky or readily disintegrate during exposure to saliva or other moisture during administration, and that carries no risk of transmission of TSEs.

Object of the Invention It is an object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. It is a further object to address the abovementioned need.

Summary of the Invention The present invention concerns a bolus for oral administration for combating trace element deficiency in a ruminant, whereby the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. The bolus comprises the trace element, and the trace element may be present in the bolus as, or in the form of, the trace element per se, or a compound of the trace element, or a complex of the trace element or a mixture of one or more of these. The

bolus may additionally comprise other ingredients, which may be selected from the group consisting of a water soluble bulking agent, a water insoluble bulking agent, a binding agent, a disintegrating agent, a pigment, a lubricant, a carrier and an adjuvant.

In one form of the invention there is provided a bolus for combatting trace element deficiency in a ruminant, said bolus comprising: - a plurality of particles each of which comprises the trace element, - at least two components selected from the group consisting of a binder, a water soluble bulking agent, a water insoluble bulking agent and a disintegrating agent, whereby the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. At least one parameter selected from the group consisting of the nature of the at least two components, the relative quantities of the at least two components and a compressive force used in making the bolus may be such that the bolus resists the effect following contact with the aqueous fluid.

The invention also encompasses a process for making a bolus for combatting trace element deficiency in a ruminant comprising: - preparing a combination of : . a plurality of particles each of which comprises the trace element, and 'at least two components selected from the group consisting of a binder, a water soluble bulking agent, a water insoluble bulking agent and a disintegrating agent, and - compressing the combination to form the bolus, whereby the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. At least one parameter selected from the group consisting of the nature of the at least two components, the relative quantities of the at least two components and a compressive force used in making the bolus may be such that the bolus resists the effect following contact with the aqueous fluid.

The invention also encompasses a method for prevention or treatment of trace element deficiency in a ruminant comprising administering to the ruminant one or more boluses according to the above form of the invention.

In a first aspect of the invention there is provided a bolus for combatting trace element deficiency in a ruminant, said bolus comprising: - a plurality of particles each of which comprises the trace element, and - a mixture of a binding agent and a disintegrating agent, whereby the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid.

In an embodiment of the first aspect there is provided a bolus for combatting trace element deficiency in a ruminant, said bolus comprising a mixture of : - a plurality of particles each of which comprises the trace element, - a binding agent, and - a disintegrating agent, whereby the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid.

One or more of the relative amounts of the binding agent and the disintegrating agent, the amount of compression when making the bolus, and the homogeneity of the components of the bolus, may be such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid.

The trace element may be a trace metal. The trace element may be selected from the group consisting of copper, zinc, magnesium, manganese, molybdenum, chromium, iron, phosphorus, iodine, selenium, cobalt and any combination thereof. Each of the particles may consist of the trace element per se, or a compound of the trace element, or a complex of the trace element or a mixture of one or more of these, or may consist of a mixture of one or more of the above with one or more other ingredients. The trace element may be in the form of an inorganic salt, a compound or a complex. The compound or complex may be in the form of an inorganic or an organic compound or complex or a mixture thereof.

The trace element may be in the form of one or more inorganic or organic salts of metal ions such as a sulfate, phosphate, chloride, nitrate, oxide, sulfide or acetate of a metal ion or a mixture thereof. The form of the trace element may depend on the nature of the trace element. The trace element is capable of being absorbed by the ruminant. When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be present as, or in the form of, a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element. The particles may have a specific gravity greater than about 1.5, or greater than about 2,2. 5,3, 3.5, 4,4. 5,5, 5.5, 6, 6.5, 7,7. 5 or 8, or between about 1.5 and about 10 or between about 2 and about 9.5 or between about 2.5 and about 9 or between about 3 and about 8. 5 or between about 4 and about 8 or between about 5 and about 7, and may have a specific gravity of about 1.5, 2, 2.5, 3,3. 5,4, 4.5, 5,5. 5,6, 6.5, 7,7. 5,8, 8.5, 9,9. 5 or 10. The bolus may also comprise one or more acceptable carriers and/or excipients and/or adjuvants. The one or more acceptable carriers and/or excipients and/or adjuvants may comprise one or more bulking agents, and said one or more bulking agents may be water soluble or they may be water insoluble, or at least one may be soluble and at least one insoluble. The one or more acceptable carriers and/or excipients and/or adjuvants may additionally comprise one or more pigments and/or lubricants. The bolus is capable of at least partially disintegrating within a suitable time within the rumen of a ruminant. The binding agent, the disintegrating agent and the one or more acceptable carriers and/or excipients and/or adjuvants may provide no risk of transmission of Transmissible Spongiform Encephalopathies (TSEs). The particles, the binding agent and the disintegrating agent in the bolus may be combined as a mixture. The mixture may be homogeneous or heterogeneous. The bolus may be compressed. The surface of the bolus may be hard, and may have a Shore D hardness of between about 30 and 100 or between about 40 and about 100. The surface of the bolus may be hard, and may have a Shore D hardness of 30, 35,40, 45,50, 55,60, 65,70, 75,80, 85,90, 95 or 99.

In another embodiment, the particles comprise an oxide of the trace metal.

In another embodiment the trace element is copper.

In another embodiment the particles comprise copper oxide, in the form of copper oxide wire particles (COWP).

In another embodiment the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid present in the environment where the bolus is stored, transported and/or administered to the ruminant.

In another embodiment the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid selected from the group consisting of saliva, water, rainwater, milk and urine.

In another embodiment the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid selected from the group consisting of saliva and rainwater. The saliva may be ruminant's saliva and may have a pH in a range selected from between about 6.5 and about 9, between about 7 and about 9, between about 7 and about 8.5, between about 7 and about 8, between about 7 and about 7.5, between about 7.5 and about 8, between about 8 and about 8.5 and between about 8.5 and about 9. The rainwater may have a pH in a range selected from between about 4.5 and about 6.5, between about 4.5 and about 6, between about 5 and about 6, between about 4.5 and about 5, between about 5 and about 5.5, between about 5.5 and about 6 and between about 6 and about 6.5.

In another embodiment the bolus resists an effect selected from disintegration and becoming sticky, following contact with an aqueous fluid.

In another embodiment the bolus resists disintegration and becoming sticky, following contact with an aqueous fluid.

In another embodiment the bolus resists an effect selected from disintegration and becoming sticky, following contact with an aqueous fluid selected from the group consisting of saliva and rainwater. The saliva may be ruminant's saliva and may have a pH in a range selected from between about 6.5 and about 9, between about 7 and about 9, between about 7 and about 8.5, between about 7 and about 8, between about 7 and about 7.5, between about 7.5 and about 8, between about 8 and about 8.5 and between about 8. 5 and about 9. The rainwater may have a pH in a range selected from between about 4.5 and about 6.5, between about 4.5 and about 6, between about 5 and about 6, between about

4.5 and about 5, between about 5 and about 5.5, between about 5.5 and about 6 and between about 6 and about 6.5.

In a second aspect of the invention there is provided a bolus for combatting trace metal deficiency in a ruminant, said bolus comprising: - a plurality of particles each of which comprises a compound of the trace element, - a mixture of a binding agent and a disintegrating agent, and - a lubricant, whereby the bolus is such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid, and wherein the compound of the trace metal is in a form wherein the trace element or an ion, compound or complex thereof is capable of being absorbed by the ruminant.

In an embodiment of the second aspect, there is provided a bolus for combatting trace metal deficiency in a ruminant, said bolus comprising a mixture of : - a plurality of particles each of which comprises a compound of the trace metal, - a binding agent, - a disintegrating agent, and - a lubricant whereby the bolus is such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid, and wherein the compound of the trace metal is in a form wherein the trace element or an ion, compound or complex thereof is capable of being absorbed by the ruminant.

The trace metal may be for example copper or zinc. The compound of the trace metal may be an oxide of the trace metal, and may be for example COWP. The particles, the binding agent and the disintegrating agent in the bolus may be combined as a homogeneous or a heterogeneous mixture. The lubricant may be located primarily near or at the surface of the bolus. The bolus may also comprise one or more acceptable carriers and/or excipients and/or adjuvants. The one or more acceptable carriers and/or excipients and/or adjuvants may comprise one or more bulking agents. The bolus may be compressed. The surface of

the bolus may be hard, and may have a Shore D hardness of between about 30 and about 100.

In a third aspect of the invention there is provided a bolus for combatting trace element deficiency in a ruminant, said bolus comprising: - a plurality of particles each of which comprises the trace element, and - a mixture of a binding agent and a disintegrating agent, wherein the bolus has been compressed such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. The trace element is capable of being absorbed by the ruminant. When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element.

The bolus may have been compressed with a force of between about 0.5 and about 40 tonnes or between 5 and 30 tonnes or between 10 and 30 tonnes or between 20 and 30 tonnes or between 25 and 30 tonnes. The bolus may have been compressed with a force of about 0. 5, 1, 2,5, 8,10, 12,15, 17,20, 23,25, 26,27, 28,29, 30,31, 32,33, 34,35, 37, or 40 tonnes. The trace element may be a trace metal. The trace element may be selected from the group consisting of copper, zinc, magnesium, manganese, molybdenum, chromium, iron, phosphorus, iodine, selenium, cobalt and any combination thereof. Each of the particles may consist of the trace element per se, or a compound of the trace element, or a complex of the trace element or a mixture of one or more of these, or may consist of a mixture of one or more of the above with one or more other ingredients.

In an embodiment, the bolus comprises a mixture of : - a plurality of particles each of which comprises the trace element, and - a binding agent, and - a disintegrating agent, wherein the bolus has been compressed such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening,

swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. The trace element is capable of being absorbed by the ruminant. When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element.

In a fourth aspect of the invention there is provided a process for making a bolus for combatting trace element deficiency in a ruminant, said process comprising the steps of : - preparing a mixture of a binding agent and a disintegrating agent, - preparing a combination of at least a portion of the mixture and a plurality of particles each of which comprises the trace element, and - compressing the combination to form the bolus, whereby the bolus is such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid.

The trace element is capable of being absorbed by the ruminant. When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element. One or more of the steps of preparing may comprise a step of adding a lubricant. The lubricant may be added before, during or after one or both of the steps of preparing.

In one embodiment the process comprises the steps of : - preparing a combination of a binding agent, a disintegrating agent and a plurality of particles each of which comprises the trace element, and - compressing the combination to form a bolus.

The step of preparing a combination may comprise preparing a combination of a binding agent, a disintegrating agent, a lubricant and a plurality of particles each of which comprises the trace element.

In another embodiment there is provided a process for making a bolus for combatting trace element deficiency in a ruminant, said process comprising the steps of : - preparing a combination of a binding agent, a disintegrating agent and a plurality of particles each of which comprises the trace element, and - compressing at least a portion of the combination to form a bolus, whereby the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. The trace element is capable of being absorbed by the ruminant. When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element. The step of preparing may comprise a step of adding a lubricant, or a lubricant may be added before, during or after the step of preparing.

The trace element may be a trace metal. The trace element may be selected from the group consisting of copper, zinc, magnesium, manganese, molybdenum, chromium, iron, phosphorus, iodine, selenium, cobalt and any combination thereof. The step of preparing a mixture may also comprise mixing one or more acceptable carriers and/or excipients and/or adjuvants with the binding agent, the disintegrating agent and the particles. The one or more acceptable carriers and/or excipients and/or adjuvants may comprise one or more bulking agents, and said one or more bulking agents may be water soluble or they may be water insoluble, or at least one may be soluble and at least one insoluble. The one or more acceptable carriers and/or excipients and/or adjuvants may additionally comprise one or more pigments and/or lubricants.

In another embodiment, the process comprises a step of treating the bolus with a lubricant. The step of treating may be performed before, during or after the step of compressing.

In another embodiment, the process comprises the steps of : (a) preparing a first mixture comprising a binding agent, a disintegrating agent, a plurality of particles each of which comprises the trace element, and optionally one or more acceptable carriers and/or excipients and/or adjuvants,

(b) preparing a second mixture from the first mixture and a lubricant, and (c) compressing at least a portion of the second mixture to form a bolus, whereby the bolus is such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid.

The trace element is capable of being absorbed by the ruminant. When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element.

Step (a) commonly comprises adding one or more components as a slurry or a solution, or the first mixture may comprise water or an aqueous liquid. In this case, the first mixture is dried before step (b) is performed. The process may additionally comprise the step of passing the first mixture through a sieve. If the first mixture is dried, this step may be performed after said drying. Step (a) may comprise a single mixing step or it may comprise more than one mixing steps, and the components of the first mixture may be added at different times, or at the same time, or some may be added together and some may be added separately.

For example, step (a) may comprise the steps of (i) mixing a plurality of particles each of which comprises the trace element, with an aqueous solution of a binding agent, (ii) mixing one or more bulking agents, pigments and disintegrating agents to form a dry powder mixture, and (iii) adding the dry powder mixture to the mixture obtained in step (i), and mixing until uniform.

In another embodiment, the process comprises the steps of : (a) preparing a first mixture comprising a binding agent, a disintegrating agent, and optionally one or more acceptable carriers and/or excipients and/or adjuvants, (b) preparing a second mixture from the first mixture and a plurality of particles each of which comprises the trace element, and

(c) compressing at least a portion of the second mixture to form a bolus, whereby the bolus is such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid.

The trace element is capable of being absorbed by the ruminant. When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element.

The process may additionally comprise the step of mixing the second mixture with a lubricant before step (c). Commonly either step (a) comprises adding one or more components as a slurry or a solution, or else the first mixture comprises water or an aqueous liquid. In this case, the first mixture may be dried before step (b) is performed.

The process may additionally comprise the step of passing the first mixture through a sieve. If the first mixture is dried, this step may be performed after said drying. Step (a) may comprise a single mixing step or it may comprise more than one mixing steps, and the components of the first mixture may be added at different times, or at the same time, or some may be added together and some may be added separately.

In another embodiment, the particles comprise an oxide of the trace element.

In another embodiment the trace element is copper.

In another embodiment the particles comprise copper oxide, in the form of copper oxide wire particles (COWP).

In another embodiment the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid present in the environment where the bolus is stored, transported and/or administered to the ruminant.

In another embodiment the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid selected from the group consisting of saliva, water, rainwater, milk and urine.

In another embodiment the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid selected from the group consisting of saliva and rainwater. The saliva may be ruminant's saliva and may have a pH in a range selected from between about 6.5 and about 9, between about 7 and about 9, between about 7 and about 8.5, between about 7 and about 8, between about 7 and about 7.5, between about 7.5 and about 8, between about 8 and about 8.5 and between about 8.5 and about 9. The rainwater may have a pH in a range selected from between about 4.5 and about 6.5, between about 4.5 and about 6, between about 5 and about 6, between about 4.5 and about 5, between about 5 and about 5.5, between about 5.5 and about 6 and between about 6 and about 6.5.

In another embodiment the bolus resists an effect selected from disintegration and becoming sticky, following contact with an aqueous fluid.

In another embodiment the bolus resists disintegration and becoming sticky, following contact with an aqueous fluid.

In another embodiment the bolus resists an effect selected from disintegration and becoming sticky, following contact with an aqueous fluid selected from the group consisting of saliva and rainwater. The saliva may be ruminant's saliva and may have a pH in a range selected from between about 6.5 and about 9, between about 7 and about 9, between about 7 and about 8.5, between about 7 and about 8, between about 7 and about 7.5, between about 7.5 and about 8, between about 8 and about 8.5 and between about 8.5 and about 9. The rainwater may have a pH in a range selected from between about 4.5 and about 6.5, between about 4.5 and about 6, between about 5 and about 6, between about 4.5 and about 5, between about 5 and about 5.5, between about 5.5 and about 6 and between about 6 and about 6.5.

In a fifth aspect of the invention there is provided a process for making a bolus for combatting trace element deficiency in a ruminant, said process comprising the steps of : - preparing a mixture of a binding agent and a disintegrating agent, - preparing a combination of at least a portion of the mixture and a plurality of particles each of which comprises the trace element, and - compressing the combination to form a bolus,

whereby the force used for compressing is such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. The trace element is capable of being absorbed by the ruminant.

When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element.

In an embodiment there is provided a process for making a bolus for combatting trace element deficiency in a ruminant, said process comprising the steps of : - preparing a mixture of a binding agent, a disintegrating agent and a plurality of particles each of which comprises the trace element, and - compressing at least a portion of the mixture to form a bolus, whereby the force used for compressing is such that the bolus resists an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky, following contact with an aqueous fluid. The trace element is capable of being absorbed by the ruminant.

When the trace element is absorbed by the ruminant, the trace element may be in the form of an element, an ion, a compound or a complex. The compound of the trace element may be a covalent compound or an ionic compound and the trace element may be in the form of a covalently bound compound, an ion, or a neutral or a charged complex. The compound may be for example an oxide of the trace element.

The force used for compressing may be between about 0.5 tonnes and about 10 tonnes.

The trace element may be a trace metal. The trace element may be selected from the group consisting of copper, zinc, magnesium, manganese, molybdenum, chromium, iron, phosphorus, iodine, selenium, cobalt and any combination thereof. Each of the particles may consist of the trace element per se, or a compound of the trace element, or a complex of the trace element or a mixture of one or more of these, or may consist of a mixture of one or more of the above with one or more other ingredients.

In a sixth aspect of the invention there is provided a bolus for combatting trace element deficiency in a ruminant, wherein the bolus is made by the process of the fourth or the fifth aspect.

In an embodiment the trace element is selected from the group consisting of copper, zinc, magnesium, manganese, molybdenum, chromium, iron, phosphorus, iodine, selenium, cobalt and any combination thereof.

In another embodiment the trace element is copper.

In a seventh aspect of the invention there is provided a method for prevention or treatment of trace element deficiency in a ruminant comprising administering to the ruminant one or more boluses according to the first, second, third or sixth aspect of the invention.

In an embodiment the trace element is selected from the group consisting of copper, zinc, magnesium, manganese, molybdenum, chromium, iron, phosphorus, iodine, selenium, cobalt and any combination thereof.

In another embodiment the trace element is copper.

In an eighth aspect of the invention there is provided a bolus according to the first, second, third or the sixth aspect when used for the prevention or treatment of trace element deficiency in a ruminant.

In an embodiment the trace element is selected from the group consisting of copper, zinc, magnesium, manganese, molybdenum, chromium, iron, phosphorus, iodine, selenium, cobalt and any combination thereof.

In another embodiment the trace element is copper.

Detailed Description of the Invention The present invention describes a novel form of bolus for combatting trace element deficiency, having a plurality of particles each of which comprises the trace element, compressed with a binding agent, a disintegrating agent and optionally one or more carriers and/or excipients and/or adjuvants into a bolus form. The bolus may be a compressed, compacted or pressed bolus suitable for oral administration to a ruminant animal. The bolus may be a solid, compressed dosage form. The bolus may be of a size and shape suitable for oral administration to a ruminant animal. The bolus may be a hard unitary mass of material suitable for oral administration to a ruminant animal. The bolus may have a hard smooth surface. It may have a rough surface. It may be, for example, in

the form of a pellet or a tablet. The hard smooth surface of the bolus that is formed during the compression process provides enhanced resistance to an effect selected from physical deterioration, dispersion, physical breakdown, collapse, crumbling, softening, swelling, dissolution, disintegration and becoming sticky disintegration, following wetting. The bolus of the present invention may be sufficiently resistant to disintegration following, for example, contact with saliva that it is still usable and not appreciably sticky following contact with saliva retained on the hand of a person administering the bolus to said ruminant. The trace element may be for example copper, and the particles may be copper oxide wire particles (COWP).

Commonly, a bolus according to the present invention which resists becoming sticky following contact with an aqueous fluid can be conveniently administered to a ruminant within a suitable period following said contact, and does not adhere to other boluses of the same type to an extent that they are inconvenient to separate, within a suitable period following said contact. The suitable period may be about 1 hour, or about 50 minutes, or about 40,30, 25,20, 15,10, 5,4, 3, or 2 minutes.

The contact of the bolus with the aqueous fluid may be contact of the whole of the bolus surface or with a part of the bolus surface. It may comprise complete or partial immersion of the bolus in the aqueous fluid. The contact may come about for example by transfer of the fluid (e. g. saliva) from a person's hand to the bolus (for example, when a farmer provides a bolus to an animal, he/she may get saliva from the animal on his/her hand: when the farmer handles a bolus for a subsequent animal, that saliva may be in part transferred to the bolus). Alternatively the fluid (e. g. rain) may contact the bolus during transportation, or during storage (e. g. with splashed milk when boluses are stored prior to administration).

Commonly, a bolus that is sufficiently resistant to disintegration following contact with an aqueous fluid would not completely disintegrate within a specified time when continuously stirred at 37°C in water. The specified time may be about 1 hour, or about 50 minutes, or about 40,30, 25,20, 15,10, 5,4, 3, or 2 minutes. The bolus may disintegrate within the specified time to a degree of less than about 30% or less than about 25,20, 15, 10,5, 2 or 1 %, and may disintegrate within the specified time to a degree of about 0,1, 2, 3,4, 5,10, 15,20, 25 or 30% by weight or by volume. The bolus is capable of at least partially disintegrating and/or deteriorating and/or breaking down and/or dispersing, or completely disintegrating and/or deteriorating and/or breaking down and/or dispersing, in

the rumen of a ruminant. In doing so, the particles which comprise the trace element may be released. By virtue of their high density, the particles may lodge in the rumen and only slowly migrate from the rumen through the reticulum and the omasum to the abomasum.

Following passage through the rumen, the reticulum and the omasum, the particles are presented to the abomasum of the ruminant such that the trace element is provided to the ruminant at rate sufficient to prevent or treat trace element deficiency in the ruminant without causing toxicity through overdose or too-rapid systemic uptake. A bolus may disintegrate in the rumen of a ruminant in less than about 24 hours or less than about 18 hours or less than about 12 hours or less than about 8 hours or less than about 4 hours, and may disintegrate in about 1,2, 4,8, 12,18 or 24 hours, although a disintegration time of greater than about 24 hours may also be acceptable, since the bolus of the present invention is intended for long term treatment. The degree of disintegration within the rumen within the suitable time may be greater than about 95%, or greater than about 90, 85,80, 75 or 70%, or may be about 70,75, 80,85, 90,95, 96,97, 98, 99 or 100% by weight or by volume. The rate of disintegration and/or deterioration and/or breakdown and/or dispersal of the bolus in the rumen may be between about 0.1 and about 2 cm/day, and may be between about 0.2 and about 1.8 cm/day or between about 0.3 and about 1.6 cm/day or between about 0.4 and about 1.4 cm/day or between about 0.5 and about 1.2 cm/day or between about 0.75 and about 1.0 cm/day, and may be about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0. 8, 0.9, 1,1. 1,1. 2,1. 3,1. 4,1. 5,1. 6,1. 7,1. 8,1. 9 or 2 cm/day.

The dosage rate of particles to a ruminant will depend on the nature of the trace element, the form of the trace element, the size of the ruminant and on the particle size of the particles. Typically the number of boluses administered to an animal in a single treatment may be between 1 and 5, or between 1 and 4 or between 1 and 3, and may be 1,2, 3,4 or 5. Typically one bolus would be administered to a sheep in a single treatment, 2 to a deer and 3 to a cow. Commonly the dosage rate for a deer or a cow would be about 1 bolus per 100kg of bodyweight, but may be between about 0.2 and about 5 boluses per 100kg of bodyweight, or between about 0.3 and about 4 or between about 0.4 and about 3 or between about 0.5 and about 2 boluses per 100kg bodyweight, and may be about 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0. 8, 0.9, 1, 2,3, 4 or 5 boluses per 100kg bodyweight. One or more boluses may be administered to an animal at a rate of between one dose of boluses per 6 months and one dose of boluses per 18 months, or between one dose of boluses per 8 months and one dose of boluses per 15 months or between one dose of boluses per 10 months and one dose of boluses per 12 months, and may be administered at a rate of

about one dose of boluses per 6,7, 8,9, 10,11, 12,13, 14, 15,16, 17 or 18 months. A common dosage rate of COWP may be between about 0.2 and about 20 mg/kg body weight/day, and may be between about 0.2 and about 10 or between about 0.2 and about 5 mg/kg body weight/day, and may be about 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1,1. 5,2, 2.5, 3,3. 5,4, 4.5, 5,6, 7,8, 9,10, 12,14, 16,18 or 20 mg/kg body weight/day. The residence time of COWP in the abomasum may be between about 0.2 and about 8 months, or between about 0.5 and about 6 months or between about 1 and about 5 months or between about 2 and about 5 months, and may be about 0.2, 0.4, 0.6, 0.8, 1,1. 2,1. 4, 1.6, 1.8, 2,2. 5,3, 3.5, 4,4. 5,5, 5.5, 6,6. 5,7, 7.5 or 8 months, and will depend on the particle size of the COWP.

The bolus may be manufactured by preparing a granulation of the particles, a binding agent, a disintegrating agent and optionally carriers and/or excipients and/or adjuvants, drying the granulation using heat, and compressing the granulation to form the bolus.

Alternatively the bolus may be manufactured by preparing a granulation of a binding agent, a disintegrating agent and optionally carriers and/or excipients and/or adjuvants, drying the granulation using heat, preparing a mixture of the granulation with particles and compressing said mixture to form the bolus. In a further alternative, a dry mixture of the particles, a binding agent, a disintegrating agent and optionally carriers and/or excipients and/or adjuvants may be subjected to direct compression to form the bolus. In the context of this specification, a"granulation"refers to a mixture in the form of a plurality of granules, or a slurry which on drying can form a plurality of granules. The bolus of the present invention may be any convenient shape, and may for example have a shape selected from the group consisting of a sphere, an ellipsoid, a toroid, an ovoid, a modified oval shape, a cone, a truncated cone, a dome, a hemisphere, a cylinder, a round ended cylinder, a capsule shape, a caplet shape, a frustoconical shape, a disc, discoid, a tabular shape, a prismatic shape, an acicular shape and a polyhedron (either regular or irregular) such as a cube, a rectangular prism, a rectangular parallelepiped, a triangular prism, a hexagonal prism, rhomboid or a polyhedron with between 4 and 60 or more faces, or it may be some other shape, for example an irregular shape. The shape may or may not have at least partially rounded edges and/or at least partially rounded corners.

The bolus may have a mean diameter of between about 1 cm and about 5 cm, or between about 2 cm and about 4 cm or between about 2.5 cm and about 3.5 cm, and may have a mean diameter of about 1,1. 5,2, 2.5, 3,3. 5,4, 4.5 or 5 cm, where the mean diameter of a bolus is defined as the mean of the maximum diameter of the bolus and the minimum

diameter of the bolus. The bolus may be between about 10 and about 20g in weight, or between about 11 and about 18g or between about 12 and about 16 or between about 13 and about 15g, and may be about 10,11, 12,13, 14,15, 16,17, 18, 19 or 20g. The density of the bolus may be between about 1 and about 6g/cc, or between about 1.2 and about 5g/cc or between about 1.4 and about 4g/cc or between about 1.6 and about 3g/cc or between about 1.8 and about 2. 5g/cc or between about 2 and about 2. 5g/cc, and may be about 1,1. 2,1. 4,1. 6,1. 8,2, 2.5, 3,3. 5,4, 4.5, 5,5. 5 or 6g/cc. The surface of the bolus may be hard, and may have a Shore D hardness of between about 30 and 100, or between about 40 and about 100, or between about 50 and about 90 or between about 50 and 80 or between about 60 and about 80, and may have a Shore D hardness of about 30,35, 40,45, 50,55, 60,65, 70,75, 80, 85,90, 95 or 99. An alternative measure of hardness is the minimum weight that can break or crack the bolus when dropped thereon. The weight may be dropped from a specific height, which may be between about 2 and 100cm, or between about 2 and 50,2 and 20,2 and 10,10 and 50,20 and 50,10 and 30 or 50 and 100cm, and may be about 2,3, 4,5, 6,7, 8,9, 10,11, 12,13, 14,15, 16,17, 18, 19,20, 15,30, 35,40, 45,50, 60,70, 80,90 or 100cm. The minimum weight may be between about 10 and 200g or between about 10 and 100,10 and 50,10 and 20,20 and 200,50 and 200,100 and 200,20 and 100,20 and 50 or 20 and 30g, and may be about 10,15, 20, 21,22, 23,24, 25,26, 27,28, 29,30, 35,40, 45,50, 55,60, 65,70, 75,80, 85,90, 95, 100,110, 120,130, 140,150, 160,170, 180,190 or 200g. The minimum weight may depend on the height from which the weight is dropped. In order to avoid premature decomposition the minimum dimension (e. g. length or diameter) of the bolus should not be below a minimum value. The minimum value may be about 5mm. The dimension of the bolus may be about 5,6, 7,8, 9,10, 11,12, 13,14, 15,16, 17,18, 19,20, 21,22, 23, 24,25, 26,27, 28, 29,30, 31,32, 33,34, 35,36, 37,38, 39,40, 45, or 50mm.

For the purpose of this invention,"ruminant"is defined as relating to a multiple- stomached animal, such as a bovine, caprine or ovine animal, and may include for example domestic cattle, sheep, goats, bison, buffalo, deer, and antelopes.

In this specification, unless otherwise stated, all percentages are on a weight basis, and are based on the dry weight of the formulation.

The particles which comprise the trace element may be spherical or rod-shaped or may be some other convenient shape, and may for example have a shape selected from the group consisting of a sphere, an ellipsoid, a toroid, an ovoid, a cone, a truncated cone, a dome, a

cylinder and a polyhedron, such as a cube, a rectangular prism, a triangular prism or a polyhedron with between 4 and 60 or more faces, or they may be some other shape. Each particle may have a maximum diameter of between about 0.2 and about 2. 0mm, and or between about 0.4 and about 1. 8mm or between about 0.6 and about 1. 6mm or between about 0.8 and about 1. 4mm or between about 0.8 and about 1. 2mm, and may have a maximum diameter of about 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1. 8 or 2mm. The particles may be all the same dimensions, or they be of a variety of dimensions. The particles may have a specific gravity greater than about 1.5, or greater than about 2,2. 5,3, 3.5, 4,4. 5,5, 5.5, 6,6. 5,7, 7.5 or 8, or between about 1.5 and about 10 or between about 2 and about 9.5 or between about 2.5 and about 9 or between about 3 and about 8.5 or between about 4 and about 8 or between about 5 and about 7, and may have a specific gravity of about 1.5, 2,2. 5,3, 3.5, 4,4. 5,5, 5.5, 6,6. 5,7, 7.5, 8,8. 5,9, 9. 5 or 10. The concentration of the particles in the bolus may be between about 5 and about 95% by weight, and may be between about 10 and about 90% or between about 20 and about 88% or between about 30 and about 86% or between about 40 and about 84% or between about 50 and about 82% or between about 60 and about 80% by weight, and may be about 10,20, 30,40, 50, 60,65, 70,75, 80,85 or 90% by weight. The particles that comprise the trace element may comprise a suitable form of the trace element. The suitable form should be veterinarilly acceptable. Examples of forms of trace elements include cobalt carbonate, cobalt sulfate, cobalt chloride, copper sulfate, copper carbonate, copper oxide, copper chloride, copper nitrate, calcium iodate, ethylenediamine dihydriodide (EDDI), potassium iodide (stabilised), pentacalcium orthoperiodate, iron oxide, ferrous sulfate, ferrous carbonate, manganous sulfate, manganous oxide, calcium phosphate, monocalcium phosphate, monosodium phosphate, sodium selenate, sodium selenite, zinc carbonate, zinc chloride, zinc sulfate and zinc oxide. An example of a convenient particle for use in the present invention is COWP. COWP is a combination of copper (I) oxide and copper (II) oxide in the form of rods. The diameter of said rods may be between about 0.2 and about 2. 0mm, and may be between about 0.4 and about 1. 8mm or between about 0.6 and about 1. 6mm or between about 0.8 and about 1. 4mm or between about 0.8 and about 1.2mm, and may be about 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8 or 2mm. The length of the rods may be between about 0.2 and about 2. 0mm, and may be between about 0.4 and about 1. 8mm or between about 0.6 and about 1. 6mm or between about 0.8 and about 1.4mm or between about 0.8 and about 1. 2mm, and may be about 0.2, 0.4, 0.6, 0.8, 1.0,

1.2, 1.4, 1.6, 1.8 or 2mm. The lengths of the rods may be all the same, or they may have different lengths.

The binding agent may be for example Povidone or it may be some other suitable polymer or gum. Povidone is polyvinylpyrrolidinone, and is commonly sold under the trade name Plasdone. Typically the binding agent will be represent between about 0.1 and about 2% of the formulation by weight, and it may represent between about 0. 2 and about 1.5% or between about 0.3 and about 1% or between about 0.4 and about 0.7%, and it may represent about 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 1,1. 2,1. 4,1. 6,1. 8 or 2% by weight of the formulation. A commonly used level of binding agent may be about 0. 5% by weight.

Other binding agents that may be used include for example Gum Acacia, alginic acid, sodium carboxymethylcellulose, microcrystalline cellulose, ethyl celllulose, gelatin, glucose liquid, guar gum, hydroxypropylmethyl cellulose, methyl cellulose and pregelatinised starch.

The purpose of the disintegrating agent is to facilitate the disintegration of the bolus in the rumen of the ruminant. A typical disintegrating agent that may be used in the invention is sodium starch glycollate. The disintegrating agent may represent about 4% of the formulation by weight, and may represent between about 1 and about 10% or between about 1.5 and about 9% or between about 2 and about 8% or between about 2.5 and about 7% or between about 3 and about 6% or between about 3.5 and about 5% by weight, and may represent about l, 1.5, 2,2. 5,3, 3.5, 4,4. 5,5, 5.5, 6,6. 5,7, 7.5, 8,8. 5,9, 9. 5 or 10% by weight of the formulation. Other disintegrating agents that may be used in the present invention include starch, microcrystalline cellulose, croscarmellose sodium, alginic acid, crospovidone and mixtures thereof.

The carriers and/or excipients and/or adjuvants may include one or more bulking agents and these may be water soluble and/or water insoluble bulking agents. A common water soluble bulking agent is lactose monohydrate. Lactose monohydrate may provided in the form of Ludipress which is a mixture of lactose monohydrate with Povidone, or it may be provided in an unmixed form. Lactose monohydrate commonly represents about 12.7% of the formulation by weight and may represent between about 11 and about 14%, or between about 11.5 and about 13.5 or between about 12 and about 13% by weight and may represent about 11,11. 2,11. 4,11. 6,11. 8, 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13,13. 2,13. 4,13. 6,13. 8 or 14% by weight of the formulation. Other water soluble bulking agents that may be used include sugars such as sucrose, dextrose

and fructose, and sugar alcohols such as mannitol and sorbitol, other suitable water soluble bulking agents, and mixtures thereof. A commonly used water insoluble bulking agent is calcium hydrogen phosphate. The water insoluble bulking agent commonly represents about 12% of the formulation, and may represent between about 11 and about 14% of the formulation, or between about 11.5 and about 13.5 or between about 12 and about 13% by weight and may represent about 11, 11.2, 11.4, 11.6, 11.8, 11.9, 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12. 8, 12.9, 13,13. 2,13. 4,13. 6,13. 8 or 14% by weight of the formulation. Other water insoluble bulking agents that may be used include calcium carbonate, calcium sulfate, kaolin, talc, other suitable water insoluble bulking agents, and mixtures thereof. If no water soluble bulking agent is used, a water insoluble bulking agent may commonly represent between about 20 and about 30% of the formulation by weight, and may represent between about 22 and about 28% or between about 24 and about 26%, and may represent about 20,21, 22,23, 24,25, 26,27, 28,29 or 30% by weight. This may provide a bolus that has a long disintegration time. If no water insoluble bulking agent is used, a water soluble bulking agent may commonly represent between about 20 and about 30% of the formulation by weight, and may represent between about 22 and about 28% or between about 24 and about 26%, and may represent about 20,21, 22,23, 24,25, 26,27, 28,29 or 30% by weight. This may provide a bolus that has a short disintegration time.

The carriers and/or excipients and/or adjuvants may include a pigment, which may be used for the purpose of product identification. The pigment may be any pigment that is non-toxic to the animal to which the bolus is to be delivered. It may be for example FD&C Blue Lake No. l. The pigment may be present in sufficient concentration to provide the bolus with the desired level of colour. For FD&C Blue Lake No. l, a suitable level may be about 0.4% by weight of the formulation, and may be between about 0.1 and about 0.5% or between about 0.2 and about 0. 5% or between about 0.3 and about 0.5%, and may be about 0.1, 0.2, 0.3, 0.4 or 0.5% by weight of the formulation.

The bolus may include a lubricant. Suitable lubricants include stearate salts, for example magnesium stearate, and sodium lauryl sulfate. The lubricant may represent between about 0.2 and about 5% of the formulation by weight, and may represent between about 0.2 and about 4% or between about 0.2 and about 3% or between about 0.2 and about 2% or between about 0.2 and about 1% or between about 0.3 and about 0.8% or between about 0.4 and about 0.6%, and may represent about 0.2, 0.3, 0.4, 0.5, 0.6, 0. 8, 1.0, 2,3, 4

or 5% by weight of the formulation. All stearates should be obtained from vegetable sources to avoid the risk of TSEs.

The carriers and/or excipients and/or adjuvants typically do not include gelatine. This is of benefit since gelatine for use in medicinal products must now be certified free of Transmissible Spongiform Encephalopathies, which adds to the cost of a bolus which comprises gelatine, and may also present sourcing difficulties.

It will be understood by one skilled in the art that where reference is made to a binding agent, a bulking agent, a disintegrating agent, a lubricant, a pigment etc. , these may each refer to mixtures of such materials, so that for example"a binding agent"may refer to a mixture of more than one binding agent, or it may refer to a mixture of one or more binding agents with one or more other components.

The process for making a bolus may comprise the steps of : - preparing a mixture of a binding agent and a disintegrating agent, - preparing a combination of at least a portion of the mixture and a plurality of particles each of which comprises the trace element, and - compressing the combination to form a bolus.

The step of preparing a mixture or a combination may comprise one or more of the processes of mixing, blending, combining, stirring, shaking, tumbling, adding and agitating the components of the mixture or combination. For example, the particles, optionally with one or more other ingredients, may be coated, or otherwise combined, with the mixture of a binding agent and the disintegrating agent to form a combination which is then compressed to form a bolus. The one or more other ingredients may be for example one or more of a binding agent, a disintegrating agent, a bulking agent, an aggregating agent or some other type of ingredient or a mixture thereof.

In another example, the process comprises the steps of : - preparing a mixture of a binding agent, a disintegrating agent and a plurality of particles each of which comprises the trace element, and - compressing at least a portion of the mixture to form a bolus, The step of preparing a mixture may also comprise mixing one or more acceptable carriers and/or excipients and/or adjuvants with the particles, binding agent and disintegrating agent. The one or more acceptable carriers and/or excipients and/or

adjuvants may comprise one or more bulking agents, and said one or more bulking agents may be water soluble or they may be water insoluble, or at least one may be soluble and at least one insoluble. The one or more acceptable carriers and/or excipients and/or adjuvants may additionally comprise one or more pigments and/or lubricants. A common formulation for a bolus, therefore, may comprise particles, a binding agent, a disintegrating agent and optionally at least one of a water soluble bulking agent, a water insoluble bulking agent, a pigment and a lubricant.

One method for preparing the mixture is to blend all of the components dry. In this method, all components may be mixed at the same time, or two or more may be mixed and other components, or mixtures of components, added subsequently.

Another method for preparing the mixture comprises the step of preparing a granulation.

The granulation may comprise particles, a binding agent, a disintegrating agent, and optionally at least one of a water soluble bulking agent, a water insoluble bulking agent and a pigment. In preparing the granulation, at least one component thereof may be added in an aqueous carrier, for example in solution, or as an emulsion, a suspension or a slurry.

Alternatively or additionally, water or an aqueous liquid may be added. After mixing, the wet granulation components are then dried and, optionally, sieved. Commonly a lubricant is then added and mixed with granulation to form the mixture.

Mixing the granulation components may be accomplished in various ways, which will be well known to one skilled in the art. For example, the particles may be mixed with an aqueous solution of a binding agent, and the resulting mixture blended with a dry blend of bulking agents, pigment and disintegrating agent. Alternatively, the particles may be blended dry with a binding agent, blending agents and pigment, and the resultant blend treated with a solution of a disintegrating agent. The mixing and/or blending may be performed in a blender such as a ribbon blender, a mixer granulator or a fluid bed or some other suitable equipment.

Drying of the wet granulation components may be accomplished using an oven or a fluid bed dryer or it may be by air drying or freeze drying or vacuum drying or it may be by some other suitable method. Drying may be accomplished at a temperature between about 20 and about 90°C, or between about 30 and about 85°C, or between about 40 and about 80°C or between about 50 and about 80°C or between about 60 and about 80°C, and may be at about 20,30, 40,50, 60,65, 70,75, 80, 85 or 90°C, or it may be at some other temperature. The time required for drying will depend on various factors including the

temperature of drying and the equipment used for drying, and may be between about 4 and about 20 hours or between about 6 and about 19 hours or between about 8 and about 18 hours or between about 10 and about 17 hours or between about 12 and about 16 hours or between about 14 and about 15 hours, and may be about 4,6, 8,10, 11,12, 13,14, 15, 16,17, 18,19 or 20 hours. Commonly the granulation is dried until the moisture content of the granulation is below a predetennined level. Since the bolus is not prone to degradation by moisture, the moisture content is not critical, provided that it is sufficiently low for a satisfactory bolus to be made.

Following drying, the granulation may optionally be sieved. The mesh size of the sieve is preferably at least as large as the smaller of the diameter of the particles and the length of the particles, and may be about 2mm, or may be between about 1 and about 3mm or between about 1.5 and about 2. 5mm and may be about 1,1. 5,2, 2.5 or 3mm.

Following the step of drying, and optionally sieving, the granulation may be blended with a bolus lubricant. The step of blending is typically for a short period and may commonly be for less than about 5 minutes, or less than about 4,3, 2 or 1 minute, and may be for about 1,2, 3,4 or 5 minutes.

In yet another method for preparing the mixture, the granulation is made as described above, but omitting the particles. In this method, particles are mixed with the dried, and optionally sieved, granulation, and then treated with a lubricant to form a mixture. An advantage of this method is that the volume of the wet granulation is reduced, leading to reduced energy consumption and shorter time for drying the granulation.

The mixture may then be compressed into boluses. Compression is typically achieved using a tabletting machine, but may be achieved with any other suitable equipment. The force used in the step of compressing may be between about 0.5 and about 10 tonnes, or between about 1 and about 8 tonnes or between about 2 and about 6 tonnes or between about 3 and about 4 tonnes, and may be about 0.5, 1,2, 3,4, 5,6, 7, 8, 9,10, 11,12, 13, 14,15, 16,17, 18,19, 20,21, 22,23, 24,25, 26,27, 28, 29 or 30 tonnes, for example. The resulting boluses typically have a hard smooth surface which provides enhanced resistance to disintegration and to becoming sticky on wetting during administration of the bolus to a ruminant.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Figure 1 is a flow diagram of a process for making compressed boluses according to the present invention; Figure 2 is a flow diagram of another process for making compressed boluses according to the present invention; Figure 3 is a graph showing the results of the field trial separately for each herd; and Figure 4 is a graph showing the results of the field trial with data averaged for all herds.

Detailed Description of the Preferred Embodiments One preferred embodiment of the description is described with reference to Fig. 1. In this preferred embodiment, the trace element is copper and the particles are copper oxide wire particles (COWP). In Figure 1, step 5 entails dissolving a binding agent in water. This is preferably done by adding water to a mixing vessel, then adding the binding agent. The mixing vessel may be for example a mixer granulator. A preferred binding agent is Povidone. A preferred concentration of binding agent in the solution is about 6.8 wt% (ie about 72g binding agent per kg water). The mixture may be stirred in order to disperse the binding agent in the water. Following dispersion, the mixture is commonly allowed to stand until the binding agent has dissolved, although mixing may be continued while the binding agent is dissolving. Following dissolution of the binding agent, the solution is stirred in order to homogenise the solution.

Step 10 involves adding COWP to the solution of binding agent obtained in step 5.

Commonly the ratio of COWP to binding agent solution is about 9. 5kg COWP per kg of solution. Typically COWP will be added to the binding agent solution in the mixing vessel used in step 5. Step 10 also comprises stirring the mixture of COWP and binding agent solution in order to form a relatively homogeneous slurry.

Step 15 involves dry blending a disintegrating agent, for example sodium starch glycollate, with one or more acceptable carriers and/or excipients and/or adjuvants. The one or more acceptable carriers and/or excipients and/or adjuvants may include one or more of a water soluble bulking agent, for example lactose hydrate, a water insoluble bulking agent, for example calcium hydrogen phosphate, and a pigment, for example FD&C Blue Lake No. l. These components may be, for example, in the ratios of 41.1

wt% of water insoluble bulking agent, 43.8 wt% water soluble bulking agent, 1.4 wt% pigment and 13.7 wt% disintegrating agent in the dry mix. The dry blending may be performed using a mixer or a blender or any other common equipment for blending dry materials.

Step 20 involves mixing the dry blend obtained in step 15 with the slurry obtained in step 10. A typical ratio of dry blend to slurry may be about 340g of dry blend per kg of slurry.

Commonly the mixing will be conducted in the same vessel in which the step 10 was conducted. Step 20 comprises both adding the dry blend to the slurry, and subsequently mixing in order to achieve a uniform wet granulation.

Step 25 involves drying the wet granulation produced in step 20. Step 20 thus comprises initially transferring the wet granulation to an oven. In one example of a drying process, the wet granulation is loaded into wire trays lined with kraft paper, and the trays are then loaded into the oven. The oven containing the granulation is then held at about 75°C for between 5 and 16 hours, or until the granulation is sufficiently dry.

Step 30 involves passing the dried granulation through a sieve. After the drying step 25, the trays are removed from the oven and the dried granulation is passed through a sieve.

Preferably the mesh size of the sieve is about 2mm in diameter. Dried granulation that does not pass through the sieve may be crushed using any convenient method in order to reduce its grain size sufficiently to pass through the sieve. Following the sieving process, the sieved granulation is loaded into a mixer. The mixer may be a ribbon blender or a mixing vessel or some other convenient form of mixer.

Step 35 comprises mixing the sieved granulation in order to produce a mixed granulation.

This is accomplished in the mixer described in step 30.

Step 40 comprises taking a sample of the mixed granulation from step 35 and testing it in order to determine its bulk density. The target result is typically in the range of between 70 and 80ml per 100g (ie a bulk density between 1.25 and 1.43g/ml) for a formulation that is 70 wt% COWP (based on dry ingredients only), however this value depends on the precise formulation.

Decision point 42 represents choosing whether to continue to mix according to step 35 or to proceed to step 45.

Step 45 comprises treating the uniform granulation from step 35 with a COWP bolus lubricant. Thus a suitable lubricant, for example magnesium stearate, is added to the

sieved granulation in the mixer. A typical addition ratio is about 5g of lubricant per kg of sieved granulation. Mixing of the sieved granulation with the lubricant is commonly for about 1 minute, or until the mixture is homogeneous.

Step 50 comprises compressing portions of the sieved granulation in order to form a compressed COWP bolus. The compressing is typically accomplished using a tabletting machine, and produces boluses with a hard smooth surface. The compressing may be carried out at a compression of between about 0.5 and about 40 tonnes and, in particular, between 15 and 30 tonnes, preferably at about 20 tonnes.

In this embodiment, the process comprises the steps of : - preparing a mixture of copper oxide wire particles (COWP), a binding agent and a disintegrating agent, together with one or more acceptable carriers and/or excipients and/or adjuvants, according to steps 5 to 45, and - compressing at least a portion of the mixture to form a bolus, according to step 50, whereby the amounts of the binding agent and the disintegrating agent are such that the bolus resists both disintegration and becoming sticky for more than about 3,4, 5 or 10 minutes, optionally between 5 and 60 minutes, following contact with ruminant's saliva.

Typically the ratio of binding agent to disintegrating agent will be between about 1: 5 and about 1: 10 by weight, but this may depend on the nature of the binding agent, the disintegrating agent and the carriers and/or excipients and/or adjuvants of the formulation.

The one or more acceptable carriers and/or excipients and/or adjuvants may comprise one or more bulking agents, and said one or more bulking agents may be water soluble, for example lactose hydrate, or they may be water insoluble, for example calcium hydrogen phosphate, or at least one may be soluble and at least one insoluble. The one or more acceptable carriers and/or excipients and/or adjuvants may additionally comprise one or more pigments, for example FD&C Blue Lake No. 1, and/or lubricants, for example magnesium stearate.

The step of preparing a mixture may comprise the steps of : - preparing a first mixture comprising COWP, a binding agent, a disintegrating agent, and optionally one or more acceptable carriers and/or excipients and/or adjuvants, according to steps 5 to 35, and

- preparing a second mixture from the first mixture and a lubricant, according to step 45.

The step of preparing a first mixture commonly comprises adding one or more components as a slurry or a solution, and may additionally comprise drying and passing through a sieve.

For example, the step of preparing a first mixture may comprise the steps of - mixing COWP with an aqueous solution of a binding agent to form a slurry, - mixing one or more bulking agents, pigments and disintegrating agents to form a dry powder mixture, and - adding the dry powder mixture to the slurry, and mixing until uniform.

The first mixture may then be dried and passed through a sieve.

A typical process for making a compressed COWP bolus according to the process of Figure 1 therefore comprises the steps of : dissolving according to step 5, followed by adding COWP and mixing to form a slurry according to step 10, followed by mixing a dry blend made according to step 15 with the slurry, according to step 20 to form a wet granulation. Step 15 may be performed before, at the same time as or after either step 5 or step 10, provided that it is performed before step 20. Step 15 may be used to produce a large quantity of the dry blend, which may be stored and used subsequently for making a plurality of batches of compressed boluses. Alternatively step 15 may be used to produce sufficient of the dry blend for a single batch of boluses. Step 20 is followed by drying the wet granulation according to step 25 to form a dry granulation, followed by sieving the dry granulation according to step 30 to from a sieved granulation, followed by remixing the sieved granulation according to step 35 to form a mixed granulation, followed by 'testing the mixed granulation according to step 40. After testing, the test sample is preferably recombined with the mixed granulation. Following testing, the decision of decision point 42 is made. If the bulk density of the mixed granulation is found to be

with the acceptable range, the process proceeds to step 45. If it is not found to be with the acceptable range, steps 35 and 40 are repeated until the bulk density of the mixed granulation is within the acceptable range. Once the mixed granulation is found to be within the acceptable range, the process continues with . mixing a lubricant with the mixed granulation according to step 45, to form a lubricated granulation, followed by tabletting the lubricated granulation according to step 50 to form compressed COWP boluses.

Another preferred embodiment of the description is described with reference to Fig. 2. In this preferred embodiment, the trace element is copper and the particles are copper oxide wire particles (COWP). In Figure 2, step 105 is the same as step 5 of Figure 1.

Step 110 is the same as step 15 of Figure 1.

Step 115 involves mixing the dry blend obtained in step 110 with the solution obtained in step 105. A typical ratio of dry blend to solution may be about 4kg of dry blend per kg of solution. Commonly the mixing will be conducted in the same vessel in which the step 105 was conducted. Step 115 comprises both adding the dry blend to the solution, and subsequently mixing in order to achieve a uniform wet granulation.

Step 120 involves drying the wet granulation produced in step 115, and is conducted as described for step 25 of Figure 1.

Step 125 involves passing the dried granulation through a sieve. After drying step 120, the trays are removed from the oven and the dried granulation is passed through a sieve.

Preferably the mesh size of the sieve is about 2mm in diameter. Dried granulation that does not pass through the sieve may be crushed using any convenient method in order to reduce its grain size sufficiently to pass through the sieve. Following the sieving process, the sieved granulation is loaded into a mixer. The mixer may be a ribbon blender or a mixing vessel or some other convenient form of mixer.

Step 130 involves adding COWP to the dried, sieved granulation obtained in step 125.

Commonly the ratio of COWP to granulation is about 2. 5kg COWP per kg of granulation.

Step 135 comprises mixing the combination of COWP and granulation in order to produce a relatively homogeneous mixture.

Step 140 comprises taking a sample of the mixture from step 135 and testing it in order to determine its bulk density. The target result is typically in the range of between 70 and 80ml per 100g (ie a bulk density between 1.25 and 1. 43g/ml) for a formulation that is 70 wt% COWP (based on dry ingredients only), however this value depends on the precise formulation.

Decision point 142 represents choosing whether to continue to mix according to step 135 or to proceed to step 145.

Step 145 comprises blending the mixture from step 135 with a COWP bolus lubricant.

Thus a suitable lubricant, for example magnesium stearate, is added to the sieved granulation in the mixer. A typical addition ratio is about 5g of lubricant per kg of mixture. Blending of the mixture with the lubricant is commonly for about 1 minute, or until the blend is homogeneous.

Step 150 comprises compressing portions of the blend from step 145 in order to form a compressed COWP bolus. The compressing is typically accomplished using a tabletting machine, and produces boluses with a hard smooth surface. The compressing may be carried out at a compression of between about 0.5 and about 40 tonnes and, in particular, between 15 and 30 tonnes, preferably at about 20 tonnes.

In this embodiment, the process comprises the steps of : - preparing a mixture of copper oxide wire particles (COWP), a binding agent and a disintegrating agent, together with one or more acceptable carriers and/or excipients and/or adjuvants, according to steps 105 to 145, and - compressing at least a portion of the mixture to form a bolus, according to step 150, whereby the amounts of the binding agent and the disintegrating agent are such that the bolus resists both disintegration and becoming sticky for more than about 3,4, 5 or 10 minutes, optionally between 5 and 60 minutes, following contact with ruminant's saliva.

Typically the ratio of binding agent to disintegrating agent will be between about 1: 5 and about 1: 10 by weight, but this may depend on the nature of the binding agent, the disintegrating agent and the carriers and/or excipients and/or adjuvants of the formulation.

The one or more acceptable carriers and/or excipients and/or adjuvants may comprise one or more bulking agents, and said one or more bulking agents may be water soluble, for example lactose hydrate, or they may be water insoluble, for example calcium hydrogen phosphate, or at least one may be soluble and at least one insoluble. The one or more

acceptable carriers and/or excipients and/or adjuvants may additionally comprise one or more pigments, for example FD&C Blue Lake No. 1, and/or lubricants, for example magnesium stearate.

The step of preparing a mixture may comprise: - preparing a first mixture comprising a binding agent, a disintegrating agent, and optionally one or more acceptable carriers and/or excipients and/or adjuvants, according to steps 105 to 125, - preparing a second mixture from the first mixture and COWP according to steps 130 to 140, and - mixing the second mixture with a lubricant according to step 145.

Commonly preparing the first mixture comprises adding one or more components as a slurry or a solution, in which case the first mixture is dried before preparing the second mixture. The process may additionally comprise the step of passing the first mixture through a sieve after said drying.

A typical process for making a compressed COWP bolus according to the process of Figure 2 therefore comprises the steps of : 'dissolving according to step 105, followed by mixing a dry blend made according to step 110 with the solution from step 105, according to step 115 to form a wet granulation. Step 110 may be performed before, at the same time as or after step 105, provided that it is performed before step 115. Step 110 may be used to produce a large quantity of the dry blend, which may be stored and used subsequently for making a plurality of batches of compressed boluses.

Alternatively step 110 may be used to produce sufficient of the dry blend for a single batch of boluses. Step 115 is followed by drying the wet granulation according to step 120 to form a dry granulation, followed by 'sieving the dry granulation according to step 125 to from a sieved granulation, followed by adding COWP to the sieved granulation according to step 130, followed by

mixing the combination of COWP and sieved granulation to form a mixed granulation according to step 135, followed by testing the mixed granulation according to step 140. After testing, the test sample is preferably recombined with the mixed granulation. Following testing, the decision of decision point 142 is made. If the bulk density of the mixed granulation is found to be with the acceptable range, the process proceeds to step 145. If it is not found to be with the acceptable range, steps 135 and 140 are repeated until the bulk density of the mixed granulation is within the acceptable range. Once the mixed granulation is found to be within the acceptable range, the process continues with mixing a lubricant with the mixed granulation according to step 145, to form a lubricated granulation, followed by tabletting the lubricated granulation according to step 150 to form compressed COWP boluses. The compressing may be carried out at a compression of between about 0.5 and about 40 tonnes and, in particular, between 15 and 30 tonnes, preferably at about 20 tonnes.

Example 4 pilot batches were prepared using the following formula; the amount of water was varied to determine optimal granulation out come.

E310303, 15 Kg; E160703, 17.5Kg; E220703, 17.5Kg ; E240703, 17. 5Kg Copper Oxide Wire Form 70.0 % w/w Calcium Hydrogen Phosphate 12.0 % w/w Lactose Hydrous 12.8 % w/w Povidone K-90 0.5 % w/w FD&C Blue Lake Nol 0.4 % w/w Water 12.7 to 6.9 parts by weight per 100 parts of dry components Sodium Starch Glycollate 4.0 % w/w Magnesium Stearate 0.5 % w/w All percentages are presented as percentages of the dry weight of the formulation.

Method of manufacture:

1. Povidone K-90 was added to water in mixing vessel, stirred to disperse and allowed to stand until solution complete. It was then stirred until uniform.

2. Copper Oxide Wire Form was added to the mixing vessel and the resulting slurry mixed until uniform.

3. Calcium Hydrogen Phosphate, Lactose Hydrous, FD&C Blue Lake No 1 and Sodium Starch Glycollate were mixed together until uniform.

4. The premixed powders were added to the mixing vessel and mixed until a uniform wet granulation was obtained.

5. The wet granulation was transferred to wire trays lined with kraft paper and dried in an oven at 75°C for 5 to 16 hours or until dry.

6. The dried granulation was passed through a 2mm sieve.

7. The sieved granulation was returned to mixing vessel or ribbon blender and mixed until uniform.

8. A bulk density test was performed. Mixing was continued until 100g occupied less than 80 mL but not less than 70mL.

9. Magnesium Stearate was added, and mixed for 1 minute.

10. Tablets were compressed at about 20 tonnes.

Analysis: 1) Disintegration time was measured by suspending a tablet in a wire basket in 1 litre of stirred water at 37°C.

2) Assessment of fine and coarse granules was measured by sieve analysis.

Results: 12.7 parts 8.57 parts 7.48 parts 6.86 parts water water water water bulk density 1.20 1. 21 1.16 1.25 mean tablet weight 14.3g 14.4g 14. 1g tablet hardness 27. 5g 25g 27. 5g disintegration time 71 mins 52 mins 69 mins Assay (copper 101.7% LC 106.6% LC 101.2% LC oxide)

Notes: tablet hardness was measured by determining what weight was required in order to break the tablet when dropped on it. Thus greater weight corresponds to greater hardness.

- % LC refers to the percentage of the label claim There was no correlation between the amount of water used and the bulk density, or other properties shown above. The batch with the lowest water usage proved the most suitable, as that provided a more fragile granulation and a better proportion of fine and coarse granulation and provided the most control during tablet compression.

Tablets (Cue Bullets) from the above pilot batches were then used in an experimental trial to evaluate the magnitude and duration of effect of treatment with those tablets on liver copper status in adult dairy cattle.

Trial Summary In the trial, 120 mature dairy cows were used from 3 commercial dairy herds in New Zealand: 40 cows from each. Cows on each farm were paired according to liver copper levels then assigned randomly within pairs to treatment and control groups of equal size.

Treatment group cows were treated with Cue Bullets at the recommended dosage (for >300kg bodyweight) of 3 bullets, administered orally using the customised applicator.

Control group cows were left untreated.

Liver biopsies were taken from every trial cow to determine liver copper levels prior to treatment and 6,12 and 18 weeks after treatment.

Study Design A total of 120 adult dairy cows from 3-4 herds in the Waiuku district were included in the study based on a known history of copper deficiency or low copper status. The study began shortly after calving. The study cows in each herd were divided into a treatment and control group of equal size. Group allocation was conducted randomly within replicates of cows grouped by initial liver copper level and where possible age. Cue Bullets were administered at the recommended dose rate to the treatment group, and the control group was untreated. Liver biopsy was conducted initially and every 6 weeks throughout the study for copper analysis.

Materials & Methods Study Subjects Within each herd, healthy adult cows were randomly selected for inclusion in the study.

Study cows had not received injectable copper in the previous 3 months, oral copper boluses in the previous 6 months or oral copper drenching in the previous month, and received no copper supplementation during the study other than that prescribed in the protocol. The study cows were managed together with the rest of the herd according to routine management practices for the herd.

At the commencement of the study, all selected cows were individually identified, underwent a clinical examination to ensure good health and liver biopsy samples were collected. The study cows were paired according to their initial copper level and where possible their age. Within pairs, cows were randomly allocated to the treatment and control groups.

Treatments Cue Bullets used in the study were the marketed product, manufactured and supplied by Parnell Laboratories. Cue Bullets were administered to the treatment group according to label directions, as follows: Treatment Group: 1 bullet per 100kg bodyweight; over 300kg bodyweight: 3 bullets. Administered orally using the bolus applicator provided.

. Control Group: No treatment Liver Biopsy Liver biopsies were conducted on all study cows. Where possible samples were taken from approximately the same area of the liver each time and were ideally >100mg fresh weight. If scar tissue was apparent in the sample at biopsy a further sample was taken immediately. Liver samples were as free of blood as possible were submitted to the laboratory for copper analysis.

Key to Trial Data: W, H and P represent the 3 different herds (i. e. 3 different farms) in the trial.

Allocation: T-treatment group, C-control group.

Biopsy results are expressed as, umol copper/kg of liver tissue.

Trial Data: The results of the trial are shown in Tables 1 and 2 below. The data in Table 1 is shown graphically in Fig. 3 and the data in Table 2 is shown graphically in Fig. 4.

Table 1: data for individual herds Trial Farm Age Calving Pre-Biopsy Biopsy Biopsy Biopsy Date treatment 6wks 12 wks 18wks 24wks Biopsy WC average 300 237 159 134 138.0 WT average 243 306 239 206 216.2 HC average 5. 619048 11/08/2003 596 412 499 630 705 HT average 6.095238 14/08/2003 604 1111 1170 1306 1344 PC average 5 28/07/2003 278 191 144 224 187 PT average 4. 142857 01/08/2003 266 466 415 490 488 Table 2: average values over all herds Trial Age Calving Pre-Biopsy Biopsy Biopsy Biopsy Farm Date treatment 6wks 12 wks 18wks 24 wks Biopsy Total C average 5.309524 04/08/2003 393 283 271 334 356 Total T average 5. 119048 07/08/2003 373 e 653 617 681 694 Results: From the data in Tables 1 and 2, it can be seen that the treatment in the trial increases the liver copper levels in all herds relative to the control animals.

Efficacv of orraulations ofCUE bullets Mean liver copper levels across all farms are shown in Table 2 and depicted in Figure 4.

Prior to treatment, the average copper levels were similar in both groups. The copper

levels were substantially higher in the treatment group at all time points following application of the CUE bullets. Of particular significance were the results at weeks 6 and 12. A decline in average copper levels was seen in the control group during the initial 12 weeks of the trial whereas the levels in the treatment group increased substantially over the same period. By week 24,13/24 cows in the control group on farm W had liver copper levels less than 95umol/kg, which is approaching a dangerously low level. All of the cows in the treatment group had highly acceptable copper levels. Accordingly the trial was terminated on this farm and all of the control cattle were treated with a copper supplement.

From the mean liver levels, there was a positive effect of treatment on liver copper levels across all farms. Across all farms, RMANOVA analysis demonstrated that the effects of treatment group, time and treatment group x time were significant, p<0.01 for all three parameters, indicating a significant elevation in liver copper levels was achieved by treatment.

Two further biopsies were carried out on farms P and H at weeks 33 and 39 post treatment. Statistically significant elevations in liver copper levels persisted on these properties throughout the extended trial period based on the combined trial group analysis (see Figure 5). By week 39,13/20 cows in the control group on farm P had liver levels less than 95umol/kg. The trial was terminated at this time and the animals in the control group on farm P were treated with a copper supplement. These data clearly demonstrate that supplementation with a solid copper bolus significantly elevated liver copper levels for periods of at least 39 weeks and probably beyond. The full potential advantage of the application of CUE bullets could not be demonstrated as a substantial proportion of the non-treated control cows had dangerously low liver copper levels which resulted in the trials being terminated.

The individual farm data is shown in Table 1. Control groups on all farms showed a decrease in liver copper level between-1 (pre-treatment) and 6 weeks compared to a rise in all treatment groups over the same period. From the week 6 biopsy data, the liver copper level of the treatment groups remained elevated above the liver copper level of the control groups out to the end of the study on all farms.

RMNOVA demonstrated statistically significant differences for the three parameters treatment group, time and treatment group x time interaction for both farms H and P. The p values for farm H data were all <0.01 all three parameters whereas the p values for farm

P were <0.02, <0. 01 and <0.01 for the respective parameters. This indicates significant positive effects of treating cattle with a solid copper bolus.

Results for farm W were less clearly defined. It is clear in retrospect that in order to demonstrate significant differences in all parameter, group sizes needed to be increased.

The results were significantly different with the time and treatment group x time parameters (p<0.01) but not for treatment group alone. This suggests that the elevation seen in the treatment group was genuine but not large enough fro significance to be demonstrated with the numbers of animals present. Some unique farm factors contributed to this result.

Ease of administration Of particular significance to this application was that all farmers involved in the administration of the solid copper bolus commented on the ease of administration and the resilience of the boluses toward moisture. A major objective of the formulation protocol was to produce a product with the desirable characteristics of not becoming sticky and difficult to handle as a consequence of becoming wet following interactions with cattle saliva and/or rain, and it is clear from the responses of the farmers involved in this trial that that objective has been satisfactorily achieved.

At the same time, it was vital that the resultant formulation did not disintegrate upon encountering moisture as a consequence of interaction with moisture which would again make the accurate administration of the required doses to the cattle difficult or impossible to achieve. The reactions and the experience of the farmers involved in this trial clearly demonstrate that this objective has again been successfully achieved as a consequence of the formulation protocol.

Of critical importance to the success of the project was to achieve the above objectives with a formulation that would not disintegrate and/or become sticky prior to delivery but would dissolve following delivery to the rumen releasing the encapsulate copper in such a form that it would be biologically available to the cattle in biologically relevant doses sufficient to supplement the copper in deficient cattle but not at doses so high that toxicity would be encountered. It is clear from the results of the trial that the combination of these conflicting objectives has been successfully achieved by the formulation disclosed herein.

Indeed, detailed analysis of the individual cattle data indicates that cows with severely depleted liver copper reserves benefited more than those with higher liver reserves. If the

treated cattle are divided into two groups: those with initial liver copper levels <50umol/kg and those with initial liver copper levels >50umol/kg ; it is clear that those with the lower initial liver copper levels benefited from the administration of CUE bullets more than the cows with the higher initial liver copper levels. This initially paradoxical observation is very surprising and is difficult to explain. However it does demonstrate that the formulation and delivery of copper in this form may have added advantages that have not been anticipated, particularly for deficient cattle.

The benefits gained by the administration of CUE bullets to cattle in different properties varied considerably between the properties. This may appear surprising at first, particularly as the properties were relatively close together (ca 10km in two cases).

Those familiar with copper deficiencies in cattle will know that this is often encountered and is due to a variety of factors that have been thoroughly investigated. Of particular relevance are the soil copper levels. Pasture copper is in the marginal range at 5mg/kg of soil. Pasture copper levels of 4 mg/kg or less can cause a simple copper deficiency in cattle. Furthermore, the presence in the soil of various inhibitors to the uptake of copper can affect the levels of copper in animals. Among the well-known inhibitory substances in this category are iron and molybdenum. Other factors such as metabolic stresses as a result of, for example, lactation and pregnancy can impose burdens on the animals that are reflected in variations in liver copper levels. It is clear from the results of the trial that a range of dietary and potentially other factors can interfere with the absorption of copper, not only from the environment but also from copper boluses. Timing of the supplement would appear to be a critical factor to optimise the absorption of the copper supplement.

Administration of the copper bolus at a time when dietary inhibitors are at a low level is likely to give a better elevation in copper level.

While it was not possible to demonstrate conclusively the duration of treatment effect in this trial, as the copper levels in control cows dropped to dangerous levels, it is clear from the results that the copper levels remained higher in the treated animals for a period of at least 24 weeks on all farms and at least 39 weeks on two of the three farms. The trial did not address whether the duration of effect of copper administration is sufficient to ensure cattle remain copper sufficient over the entire dry and early lactation periods.

Since the present discovery was made, more than 76,000 tablets (CUE bullets) have been used to dose cattle under a diverse range of weather conditions including heavy rain and conditions of high humidity over a period exceeding 12 months in many locations

throughout New Zealand. During this period, there have been no reports of any difficulties being encountered such as tablets becoming sticky and thereby difficult to conveniently administer to animals or tablets disintegrating and thereby difficult to administer the required doses accurately to animals. This experience attests to the utility of the present invention in successfully generating a product that is capable of delivering copper to cattle while avoiding the difficulties encountered by users of products currently on the market, which are largely encased in gelatin and suffer the considerable disadvantage of becoming sticky and aggregating when encountering water present in the saliva of cattle, rain and similar water sources present in the field.