IE80683B1 - Bolus for supplying biologically beneficial substances to ruminant animals - Google Patents

Description

This invention relates to a bolus for supplying ruminant animals such as cattle, » sheep, goats and deer with a biologically beneficial substance, i.e. a substance with ’ beneficial nutritional or therapeutic effects.

According to the invention there is provided a bolus which comprises a main body of naturally occurring resin having a beneficial substance uniformly dispersed therein and a pocket containing eroding material also carrying a beneficial substance, which pocket is sunk into the resin main body so that the eroding θ material contained therein is exposed to the surface of the bolus.

In order to ensure long life of the bolus in the reticulo-rumen, it is desirable either to incorporate a ballast material in the bolus or to provide the bolus with structural retention means, such as wings. Alternatively, two boluses may be joined by a flexible interconnecting piece, forming a double bolus.

In the case of a bolus incorporating a ballast material, more particularly a heavy metal or metal compound, the preferred relative proportions by weight of the constituents of the bolus are:1) resin - 3 to 70 per cent, preferably 8 to 40 per cent and most preferably about 18 per cent where trace elements and ballast are incorporated, but when a large dose of a fine powder such as zinc oxide is incorporated, then the resin presence may be 45 to 50 per cent by weight; 2) ballast - 25 to 95 per cent, preferably 50 to 85 per cent and most preferably about 70 per cent; and -23) beneficial substance - 1 to 30 per cent, preferably 3 to 25 per cent and most preferably about 12 per cent.

It is an advantage of the invention that die resin bolus with contained ballast is able ί to remain for a long period in the alimentary tract without appreciable loss by 5 erosion. Consequently, the size and density of the bolus are substantially maintained and the risk of regurgitation or passing on is greatly reduced. The contained beneficial substance(s) are released from the bolus, over the long period for which the bolus is retained in the alimentary tract, by leaching rather than bolus erosion. On the other hand, the beneficial substance(s) contained in the 1 ° pocket are released by erosion but, because the main resin body is retained, this erosion can continue until the pocket is totally consumed.

The bolus in accordance with the invention is retained in the alimentary tract for a minimum period of several weeks, and preferably up to several months. The bolus can readily be produced with a size and weight to meet this requirement.

Correct rate of release of the beneficial substance while the bolus resides in the reticulo-rumen may be ensured, if necessary, by the inclusion in the bolus main body, also uniformly dispersed therein, of a substance which dissolves relatively quickly, thereby to create a porosity in the bolus which aids release of the beneficial substance. Up to 20 per cent by weight of such a quickly dissolving substance may be incorporated.

As above-mentioned, instead of or additionally to incorporation of ballast, the bolus may be formed with retaining means such as a pair of wings or fins in order to assist retention in the reticulo-rumen, or a double bolus may be employed for ’ this purpose.

More especially, when a prolonged relatively high dosage of the beneficial -3substance is required, a double bolus may be produced, comprising two boluses of approximately normal size and weight joined, preferably at the mid-points, by a connecting piece and preferably of flexible non-toxic material, resistant to chemical or biological breakdown in the reticulo-rumen. The configuration of the interconnected parts prevents the double bolus from being passed on or being regurgitated. The double bolus is preferably administered as a unit comprising an open-ended tube, for example of cardboard, in which the two boluses are packed end-to-end, so that the tube, which quickly disintegrates in the reticulorumen, then releases the two strung together individual boluses to be retained.

A preferred resin binder for the bolus is a rosin, preferably pine rosin.

The ballast material may be constituted by iron, manganese, copper, zinc or one or more compounds thereof, but is preferably constituted by elemental zinc. Results indicate that zinc and other ballasts are not appreciably lost during the life of the bolus. The weight and density of the bolus are thus maintained, permitting prolonged retention of the bolus in the reticulo-rumen. A preferred ballast is therefore elemental zinc. , The biologically beneficial substance may be any one or more nutrients such as the trace elements selenium, cobalt, iodine, manganese, zinc and/or copper. Copper, selenium, iodine and cobalt are particularly beneficial nutrients for cattle, whilst selenium, cobalt, copper, iodine and manganese are particularly beneficial for sheep. Zinc compounds such as zinc oxide may he incorporated for control of fungal conditions such as facial eczema. Other beneficial nutrients which may be incorporated, possibly in conjunction with trace elements, are vitamins, lipids such as phospho-lipid, and amino-acids. Alternatively, however, the biologically beneficial substance may be a medicament such as an anthelmintic, antibacterial substances, growth promoters, hormones, coccidiostats and/or flukicides, again either alone or in combination with nutrients. -4When a quick release agent for creating porosity is incorporated, this is preferably constituted by potassium iodide, but other possibilities for use as a quick release ? agent are NaCl and sugar, amongst many others.

An example of one particular formulation of bolus main body in accordance with 5 the invention is as follows:- Material WeighiJn£pq?Q.rated Zinc 74.77 g Rosin 18.58 g Potassium iodide 1.31 g Calcium iodate 6.15 g Sodium selenite 0.85 g Cobalt carbonate 1.41 g Total weight of bolus 103.01 g This formulation is suitable for cattle, for which an overall weight of bolus in the range 30 to 170 g, preferably 50 to 150 g, typically about 100 g, is most suitable. A bolus for sheep, which would generally have a different formulation, would normally have an overall weight in the range 5 to 35 g, preferably 7 to 25 g, typically about 15 g. A bolus for a calf would typically have a weight of 5 to 120 g, preferably 20 to 80 g, most preferably about 50 g. a trial has been carried out in respect of iodine retention in the case of a test bolus of the following formulation: Iron:- 30 g, Pine rosin:- 5.7 g, Potassium iodide:2.35 g, with the following results:-5Blood Iodine Content Start 1 week 3 weeks 5 weeks Control animal 13.9 30.6 16.3 19.3 Test animal given bolus 11.1 302.0 126.3 87.8 Other trials have been carried out with the following boluses, in order to test release rates of the benficial elements incorporated:- Zn (ballast) 75.3 g Rosin (pine) 18.0 g Potassium iodide 3.01 g Cobalt carbonate 0.39 g Sodium selenite 0.12 g Release rates of elements from the bolus (in percentages released) days MDR 42 days MDR Se 19.57 0.98 8.70 0.21 Co 45.95 2.30 38.26 0.91 I 28.41 1.42 91.15 2.17 Zn no release detected where MDR represents the mean daily rate release percentage.

This test shows, as do the further results which follow, that a satisfactory release -6rate is achieved for all the biologically beneficial trace elements without any substantial release of the ballast, which would disadvantageously indicate disintegration of the bolus.

Zinc 71.01 g Rosin (pine) 18.30 g Sodium selenite 0.17 g Cobalt carbonate 1-08 g Potassium iodide 5.12 g Release rates of elements from the bolus MPR 42 davs MPR Se 16.67 0.83 39.39 0.94 Co 78.49 3.92 62.71 1.49 I 21.87 1.09 19.80 0.47 Zn no release detected , The bolus also has an eroding portion, achieved by means of a pocket sunk into the bolus and containing an eroding material exposed to the bolus surface, said pocket material also incorporating one or more biologically beneficial substances as hereinbefore exemplified. Continual release of the substances contained in this eroding material contained in the pocket is not terminated by regurgitation or 20 passing on of the reducing eroding material because this is retained within the body of the bolus which does not substantially erode.

Claims (16)

1. A bolus for supplying ruminant animals with a biologically beneficial substance, comprising a main body of naturally occuring resin having a beneficial substance uniformly dispersed therein and a pocket containing eroding material also 5 carrying a beneficial substance, which pocket is sunk into the resin main body so that the eroding material contained therein is exposed to the surface of the bolus.

2. A bolus according to claim 1, wherein the bolus is adapted for prolonged retention in the reticulo-rumen by means of wings extending from the surface of the bolus. 10

3. A bolus according to claim 1, wherein the bolus is adapted for prolonged retention in the reticulo-rumen by means of a flexible interconnecting piece joining two bolus bodies.

4. A bolus according to claim 3, wherein the two bolus bodies are packed in a tube which rapidly disintegrates in use. 15

5. A bolus according to any of claims 2 to 4, comprising a main body having 370% by weight resin.

6. A bolus according to claim 5, comprising 8-40% by weight resin.

7. A bolus according to claim 5, comprising 45-50% by weight resin.

8. A bolus according to claim 1, wherein a ballast is also incorporated in die 20 resin body to ensure long life in the reticulo-rumen. -89.

A bolus according to claim 8, wherein the ballast is constituted by a heavy metal or metal compound. f

10. A bolus according to claim 9, wherein the ballast is constituted by i elementary zinc.

5.

11. A bolus according to claim 9 or claim 10, comprising a main body having 3 to 70% by weight resin, 25 to 95% by weight ballast and 1 to 25% by weight beneficial substance.

12. A bolus according to claim 11, comprising 8 to 40% by weight resin, 50 to 85% by weight ballast and 3 to 25% by weight beneficial substance. 1 θ

13. A bolus according to any of claims 1 to 12, incorporating a fast dissolving substance uniformly dispersed in the resin body, thereby in use to create porosity of the bolus main body.

14. A bolus according to any of claims 1 to 13, wherein the resin is constituted by a rosin. 15

15. A bolus according to claim 14, wherein the rosin is a pine rosin.

16. A bolus according to any of claims 1 to 15, wherein the beneficial substances carried by the bolus are compounds of iodine, selenium and cobalt.