Ruminal bolus for electronic identification of a ruminant

IS 2 140 237 T3

DESCRIPTION

Ruminal bolus for the electronic identification of a ruminant.

The present invention relates to a ruminal bolus for the electronic identification of ruminants. The invention was aimed more particularly, but not exclusively, at ruminants that live in a farming environment (bovines, buffaloes, sheep and goats), as well as in industrial, game or wild exploitation (reindeer and coervids and ruminants in general). The bolus can be used with animals that have a high weight (from approximately 25 kg) or of low weight (less than 25 kg), according to the variants of the invention.

A classic ruminal bolus was made up of a body that comprises an electronic data storage and exchange device, which is housed in one of the ruminant's stoomagines or pre-stomachs in order to ensure its monitoring. It is mainly used for the identification of animals, production control (fattening, milk production, control of reproduction and health status ...) or for the automation of common operations of driving these animals, such as the food, control of access to restricted areas or doors of classification corridors, etc. In a usual way, this information is provided and collected with the help of electromagnetic waves.

An electronic bolus-based identification system for ruminant herds is known from document US-A-4 262 632 comprising a transmitter that can be administered orally, such as a feed bolus, and which is optimized to be introduced into the second pre-stomach called the “red” (retócula) of a ruminant below. The device is in the form of a cylinder with a length of approximately 75 mm and a diameter of approximately 18 mm. In order to avoid any regurgitation phenomenon, it is recommended that the device have a density greater than 2 g / cm³. To this end, it is envisaged to incorporate a weight inside the bolus, in the vicinity of the data exchange device.

Other known types of boluses can indifferently lodge in the net or in the rumen (first fore-stomach).

As an example, document WO 93-A-05 648 describes a bolus of cylindrical or flat capsule shape, made of high-density resin or glass, comprising an electronic device. This bolus is also provided with a permanent visual representation system that allows the identification of the animal even when the bolus is removed from the dead animal.

Document AU-A 64 92 12 describes an apparatus for identification of an animal based on a passive transponder included in a porcelain capsule and having a density equal to or greater than 1.75 g / cm³. This system comprises a magnetic block that allows it to be held after the animal is slaughtered. The porcelain capsule was filled with a dense liquid in order to obtain the desired specific gravity to maintain the transponder in an operative position.

In other types of boluses, a long-shaped body is used, one end of which is weighted down by a metal mass in order to confer the required density and ensure that the body remains implanted in a vertical position in the rumen or the net. Said bolus is described for example in document WO-A-95

809.

Although the presence of a metalic mass makes it possible to advantageously increase the density of the bolus, it nevertheless has the following drawbacks. First, it interferes with radio frequency transmissions between the electronic device within the bolus and outside, in particular by shifting the frequency of the agreed circuits. Secondly, it is common for the stomachs of ruminants to contain, voluntarily or involuntarily, foreign bodies or magnetized pieces that tend to agglutinate against the metal piece and thus attenuate the transmission and reception signals, or generate a repulsion or expulsion. bolus.

It is found in most cases that known boluses tend, either on purpose or accidentally, to be definitively located in the rumen. Therefore, they have the disadvantage of not being able to be used successfully until after the suckling animal has developed the rumen. Their reading distance, as well as their reading efficiency, are also limited by the large size of the rumen and by the often random orientation of the electronic device used.

An object of the invention is thus to provide a high-density bolus, which allows for reduced dimensions.

ES 2 140 237 T3 and, therefore, obtain a reliable fixation in the network (second pre-stomach) of the ruminant with precise location against the left rib wall, behind the heart.

Another objective of the invention is to allow bowling in large series and at low cost.

Another more general objective of the present invention is to make it possible to obtain a bolus that does not have the drawbacks of the prior art.

These objectives are carried out according to the invention by a bolus for the identification of a ruminant, destined to be housed in the latter's network, and comprising a body that has a housing destined to contain the data exchange device (such as a electronic transponder), this bolus being characterized in that the body is made of an alumina-based material (Al2O3).

Alumina has been found to have the dual advantage of providing a high density for the body while exhibiting high resistance to juices and the digestive processes of the fore-stomachs of ruminants. This material is also inexpensive and easy to use in mass production processes.

Furthermore, this material is non-magnetic and has excellent transparency at radio frequencies used for remote data exchange by means of the device housed in the body.

The alumina is preferably present in the material in an amount equal to or greater than 60% by weight. This amount can be between 75 and 99.5% by weight and preferably between 80 and 99.5% by weight.

According to a variant, which however does not constitute the object of the invention, the material comprises silica which is the majority by weight in the material. In this case, the silica can be present in the material in an amount equal to or greater than 40% by weight, preferably equal to or greater than 50% by weight, and more preferably equal to or greater than 55% by weight.

When silica is the majority, alumina is preferably present in a small amount in the material, this amount being preferably less than 10% by weight and, more preferably, less than 5% by weight.

In certain variants of the invention, the material is also based on alumina and solid, the alumina and solidifies together constituting at least 80% by weight of the composition of the material, and preferably at least 90% by weight of the composition. of the material.

To optimize the chemical composition of the material, one or more of the following compounds can be added: MgO, CaO, BaO, Na2O, K2O, Fe2O3, TiO2. These compounds may each be present in an amount between 0.1 and 2% by weight.

Advantageously, the bolus does not comprise any added metal part (apart from the electronic circuit of the data exchange device) so as to take advantage of the non-magnetic nature of the material used.

The composition of the material in the aforementioned areas makes it easy to obtain a density equal to or greater than 2.5 g / cm³. This density can also be equal to or greater than 3 g / cm³, even equal to or greater than 3.5 g / cm³.

Advantageously, the bolus is made up of a symmetrical body with a uniform distribution of the masses, so that its center of gravity and its geometrical center coincide.

In order to ensure good fixation of the bolus in the net, this first is cylindrical in shape with circular cross section, the edges of each end being chamfered or rounded. This geometry, in combination with an appropriate choice of dimensions, allows in particular to fix the bolus in the direction of the major axis of the net, obliquely and parallel to the diaphragm. This confers great stability and allows obtaining optimal and uniform electromagnetic connection conditions.

This fixation is reliably obtained when the ratio between the length and the radius of the bolus body was preferably located in an area that varied between 2: 1 and 5: 1. Advantageously, this ratio is in a range from 2.5: 1 to 4: 1.

IS 2 140 237 T3

In a preferred embodiment for a bolus intended for ruminants weighing more than about 25 kg, which can reach, for example, 1000 to 1300 kg for bulls, the length of the body is in a range of 50 to 90 mm.

When the bolus was particularly intended for ruminants weighing approximately 25 kg or less, the body length was preferably between 30 and 70 mm.

According to another advantageous characteristic of the bolus according to the present invention, the housing for the electronic data exchange device comprises a cavity accessible at one end or both opposite ends of the body. This cavity can be materialized by a blind hole in the main axis of the body or by a through hole in the main axis of the body. Once the data exchange device is in place, the hole can be closed with the help of an epoxy resin or a plastic cement resistant to the environment that prevails in the ruminant's network.

According to a variant, the mentioned hole is closed at the or each end with the help of a male part, such as a pressure screw or a self-locking rivet that can be fixed against a wall of the hole.

When the cavity is in the form of a through hole, it can be closed at each end by a self-locking rivet made up of two separate elements each having a stem portion at one end of which there is a head, the two stems being respective ones arranged so as to engage at their free ends and to lock into each other, enclosing the data exchange device between them.

This arrangement has the advantage of allowing the data exchange device to be housed before final assembly, and automaotically ensuring its precise positioning in the cavity. It also makes it possible to reduce the number of successive operations to be carried out on the body of the bolus, carrying out the placement of the device and the rivet simultaneously.

According to the preferred embodiment of the invention, the bolus also comprises a sleeve made of elaostic material intended to receive the data exchange device and which has an outer diameter that allows it to fit without play in the housing.

The present invention also refers to a process for the manufacture of a bolus as has just been described, characterized in that it comprises the steps of: preparing a mixture based on alumina (Al2O3) or desolice (SiO2); form a bolus body preform from the mixture and subject the preform to a cooking step.

If necessary, the method further comprises a step of shaping to the final dimensions and finishing the bolus body preform after the cooking step. The cooking stage can be carried out at a temperature between 1000 C and 2500 C. However, it has been found that excellent results are obtained for the intended application when the cooking temperature is substantially equal to 1400 ° C.

In a preferred embodiment, the preform is made by extrusion and cutting the extrudate according to the general shape of the bolus body. In this case, the housing of the bolus body can be carried out by drilling before the cooking stage.

However, it is also possible to make the bolus body by a molding process, in which case the housing will be formed at the same time as the body.

Other advantages and characteristics of the invention highlight the preferred embodiments, presented only as examples, with reference to the attached drawings, in which:

FIG. 1a is a longitudinal sectional view of a bolus according to a first embodiment of the invention;

figure 1b is a sectional view taken along plane II of figure 1a;

figure 2 is a simplified view in longitudinal section of an electronic transponder suitable to be housed in the bolus of figure 1;

IS 2 140 237 T3

figure 3 is a longitudinal section view of a sleeve intended to receive the transponder of figure 2;

figure 4 is a profile view of a self-locking rivet intended to close the cavity in the bolus of figure 1;

Figure 5 is a longitudinal sectional view of a bolus according to a second embodiment of the invention,

FIG. 6 is a longitudinal sectional view of a self-locking rivet used in the embodiment of FIG. 5;

- Figure 7 is a diagram showing the location of the bolus in a ruminant,

Figure 8a is a simplified diagram of the first stages of manufacturing a bolus according to a preferred mode of the invention, and

Figure 8b is a simplified diagram of the last stages of manufacturing the bolus, in continuation of Figure 8a.

As shown in Figures 1a and 1b, the bolus 10 according to the first embodiment of the invention is presented in the form of a cylindrical capsule of circular cross section, which has chamfered edges 10a at each end.

Inside this capsule there is a cavity 12 of cylindrical shape with a circular section intended to house a data exchange device in the form of an electronic transponder 14 (figure 2). According to this first embodiment, the cavity 12 is presented in the form of a blind hole in the main axis AA 'of the capsule.

It was observed that the geomometric center and the barycenter of the capsule substantially coincide (in the sense that the capsule does not present a notable imbalance due to the presence of the cavity 12 in the form of a blind hole).

The transponder 14 used is of a known type, comprising a passive radio-frequency activated transmitter-receiver, built-in sensors that allow the identification or collection of information from the ruminant's body, and a memorization circuit that contains a programmed or programmable code. . This type of transponder was generally encapsulated in a glass or crystal cylinder.

The data exchange device 14 was housed in a sleeve of elastic material 16, such as an elastomer (Figure 3). This sleeve has an outer diameter adapted to the cavity 12 of the bolus, so that the transponder / sleeve assembly is retained therein substantially without play. Sleeve 16 has been found to confer excellent protection of transponder 14 against mechanical and thermal shock, while exhibiting good radio frequency transparency.

When the transponder 14 is in place, the blind hole is closed with the help of epoxy resin or plastic cement resistant to the environment that exists in the network.

According to a variant, the hole can be closed by a rivet 18 such as the one represented in figure 4.

It is also possible to use for this purpose a pressure screw made of plastic material, or any other known means that allows a hermetic seal and resistant to the digestive juices of the animal's net.

Figure 5 shows a bolus according to a second embodiment of the invention. It differs from the one previously described mainly by the fact that the cavity 12 is made by a through hole in the main axis AA 'of the cylinder.

According to this embodiment, the hole can also be closed by a self-locking rivet device specifically adapted to house the transponder 14, as will now be explained with reference to figure 6.

IS 2 140 237 T3

The self-locking rivet device is made up of two separate elements 21, 22 each having a stem portion 23, 24 at one end of which is a head 25, 26.

It is preferably made of plastic material of an ABS type. The two respective rods 23, 24 are arranged so that they are inserted at their free ends, opposite the head, and to lock into each other, enclosing the transponder 14 between them.

To this end, the stem 23 of a first 21 of the elements has the shape of a cylinder sized to be able to be inserted without play in the hole that forms the cavity 12 of the body 10 of the bolus. This rod 23 has a recess 27 in the form of a blind hole, accessible at the free end, which allows the transponder 14 to be accommodated. The bottom 27a of the blind hole is coancave so that it fits well with a first end of the transponder 14. A part 23a of the stem 23 towards the free end has a reduced section with one or more longitudinal grooves (not shown) that allow it to be coupled with the stem 24 of the second element by elasticity. This reduced section part 23a has a peripheral rib 28 on its internal surface which constitutes a part of a seaming means.

The stem 24 of the second element 22 is of circular section, dimensioned to press against the inner surface of the reduced section portion 23a of the stem of the first element 21. It has a peripheral groove 29 intended to receive the rib 28 of the first element 21 , thus forming the other part of the seaming means. The free end of the stem 24 of the second element 22 has a recess 24a in the axial direction that can engage with the second end of the transponder 14.

The set of the two elements 21, 22 is configured in such a way that when the rib 28 of the first element is inserted in the groove 29 of the second element, the internal faces 25a, 26a of the respective heads are separated by a distance corresponding to the length bolus body 10. This arrangement is made by the fact that the stem 23 of the first element has the same length as the body of the bolus; its end then abuts against the internal face 26a of the head of the second element when the self-locking rivet is in the latching position. On the other hand, the respective positions of the bottom 27a of the blind hole in the first element 21 of the bottom of the gap 24a in the second element 22, when these elements are coupled, are determined so that the transponder 14 is housed without play in the direction of the bolus, and in the geometrical center of the latter.

When the transponder 14 is mounted on the body 10 of the bolus, this first is in principle inserted into the blind hole 27 formed in the first element 21 of the self-locking rivet. This operation can be carried out outside the body of the bolus, which makes it possible to reduce the number of successive operations in the latter.

Once the transponder 14 is retained in the first element 21, it is inserted at one end into the through hole 12 of the bolus body. The second element 22 of the self-locking rivet is then inserted through the other end of the bolus body and a force is applied between the respective heads 25, 26 until the rib 28 has been snapped onto the groove 29. The rivet is then locked with the inner faces 25a, 26a of the heads abutting against the respective faces of the bolus body.

It will be noted that, in this second embodiment, the heads 25, 26 can cover the entire surface of the faces of the body 10 and have a bulged outer surface. In this case, the edges of the body 10 are devoid of chamfering.

The particular choice for the composition of the bolus body material, whether based on alumina or silica, will depend on several factors: manufacturing procedure, desired density, bolus dimensions, etc ..., which make it necessary to intervene in particular the weight and type of ruminant for which the bolus is intended.

For many cases, a material comprising about 80% by weight alumina and 15% by weight salty (SiO2) can be envisaged.

The complement, in percentage by weight, may be distributed with the aid of 0.1 to 2% by weight among the following products: MgO, CaO, BaO, Na2O, K2O, Fe2O3 and TiO2. Of course, only one or a group of these mentioned products can be used, adapting the quantities.

With this composition, the material can have a density greater than 3.2 g / cm³.

IS 2 140 237 T3

The porosity of said alumina-based material (Al₂OR₃) and / or silica (SiO₂) high density is negligible.

Three specific examples of high alumina material composition having the above general characteristics will now be presented.

Example 1

Composition of the alumina-based material that forms the body of the bolus, which has a specific gravity of 3.2 g / cm³

<td>Constituent</td><td>ALO3</td><td>SiO2</td><td>MgO</td><td>CaO</td><td>Beam</td><td>Na2O</td><td>K2O</td><td>^Faith2^OR3</td><td>TiO2</td><td>Others</td>

<td>% in weigh</td><td> 80,6</td><td> 15,1</td><td> 1,1</td><td> 0,9</td><td> 0,8</td><td> 0,6</td><td> 0,5</td><td> 0,2</td><td> 0,2</td><td> &lt; 0,1</td>

A bolus has been made from this composition according to the first and second modes of realization. Its characteristics are summarized in table 1.

TABLE 1

Set of bolus characteristics according to the first or second mode of implementation

- Shape and dimensions • Cylindrical with flattened end edges • Weight between 65 and 70 g • Length = 69 mm, diameter = 20 mm • Cylindrical hole (blind hole): length = 45 mm, diameter = 6.5 mm • Cylindrical hole (through hole): diameter 8 mm

- Physical characteristics of the material:

• Rich in white alumina • Porosity (%) = 0 • Specific weight (g / cm³)&gt; 3,2 • Dielectric stiffness (kV / mm)&gt; 10 • Thermal shock&gt; 140 ^ C • Thermal conductivity from 20 to 100 ^ C (w / mkg) = 10-16 • Coefficient of linear expansion at 600 ^ C ( microns) = 6-8 • Bending strength (MPa)&gt; 200

Example 2

Composition of the alumina-based material that makes up the body of the bolus, which has a specific gravity of 3.5 g / cm³

<td>Constituent</td><td>ALO3</td><td>SiO2</td><td>MgO</td><td>CaO</td><td>Beam</td><td>Na2O</td><td>K2O</td><td>^Faith2^OR3</td><td>TiO2</td><td>Others</td>

<td>% in weigh</td><td> 95,0</td><td> 3,0</td><td> 0,6</td><td> 0,5</td><td> 0,2</td><td> 0,2</td><td> 0,2</td><td> 0,1</td><td> 0,1</td><td> &lt; 0,1</td>

Example 3

Composition of the alumina-based material that forms the body of the bolus, which has a specific gravity&gt; 3.8 g / cm³

<td>Constituent</td><td>ALO3</td><td>SiO2</td><td>MgO</td><td>CaO</td><td>Others</td>

<td>% in weigh</td><td> 99,0</td><td> 0,5</td><td> 0,2</td><td> 0,2</td><td> &lt; 0,1</td>

IS 2 140 237 T3

The material of Examples 2 and 3 is particularly adapted to small ruminants, weighing less than about 25 kg, such as young lambs or goats. It is thus possible to obtain a bolus having the general shape according to the first and second embodiments, having a mass greater than 45 g, and even 65 g with relatively small dimensions (for example 55mmx15mm or 60mmx17mm).

Following a variant, which however does not constitute the object of the invention, the material that constitutes the body of the bolus is based on silica (SiO₂). In this case, the alumina content can be very low, being for example less than 10% and even less than 5% by weight.

This silica-based composition is usable in particular for boluses of relatively large dimensions, for example greater than 65 mm x 20 mm, intended for high-weight ruminants (cattle, buffalo).

An example of such a material, used to make a 75mm x 20mm bolus is given below.

Example 4

Composition of the silica-based material that forms the body of the bolus, which has a specific gravity of

2.8 g / cm³

<td>Constituent</td><td>Λ ^ Θβ</td><td>SiO2</td><td>MgO</td><td>CaO</td><td>Beam</td><td>Na2O</td><td>K2O</td><td>^Faith2^OR3</td><td>TiO2</td><td>P₂OR₃ Others</td>

<td>% in weigh</td><td> 3,1</td><td> 60</td><td> 28,0</td><td> 0,7</td><td> 6,6</td><td> 0,2</td><td> 0,4</td><td> 0,5</td><td> 0,2</td><td> 0,1 &lt; 0,1</td>

It will be noted that it is preferable to supplement the silica content with another compound, such as MgO or analog, so that the silica and this other set together constitute at least 70%, even 80%, or even more than 85% by weight. of the material.

The characteristics of density, in general, and of dimensions given in the aforementioned examples allow the bolus to remain permanently in the ruminant network, and this in the direction of the major axis of the network (oblique position), as shown in the figure 7.

The use of a material based on alumina or high-density silica for the creation of the bolus body makes it possible to obtain optimized dimensions for oral administration to numerous species of ruminant animals of any age.

When the boluses follow the first and second modes of execution presented, they are very particularly configured for use with ruminants weighing more than 25 kg, the esophagus is sufficiently developed to allow the capsule to be lowered, from its introduction into the posterior part of the animal's mouth (close to the glottis) until it is permanently located in the ruminant network (figure 7).

Due to its relatively restricted dimensions, the bolus can be administered with the aid of a simple drug gun that is commonly used by breeders.

Its conception and characteristics prevent the capsule from being definitively placed in the rumen of the animal, the first fore-stomach of ruminants and mine bulky (when food movements take place during digestion and rumination). It can also be regurgitated into the mouth or pass to the posterior parts of the digestive system of ruminants (book, third pre-stomach).

The bolus conception and the characteristics of alumina or silica allow the use of a single and unique type of capsule for all ruminant species, whatever their age, as long as they have an adequate weight. It is therefore not necessary to wait for the development of the rumen, as was normally the case with age at the end of the lactation period, because the capsule is placed in a fixed position only in the network.

The permanent location of the capsule in the network allows avoiding erraitic movements in the rumen. Indeed, in the latter case, the significant volume of the rumen reduces the possibilities of locating the capsule with respect to the network. The significant volume of the rumen also decreases the

ES 2 140 237 T3 efficiency as well as the reading distance of the electronic system arranged in the capsule.

The small size of the network, its contractile characteristics, as well as the longitudinal arrangement of its muscle fibers in the anteroposterior direction allow a fixed orientation of the same type of the capsule and the data exchange device. This orientation increases the possible reading distance in the cranial-caudal (longitudinal) axis of the animal and decreases it in its costal (transverse) axis. In this way, the reading efficiency is increased when the animal approaches the reading point and the chances of confusion with neighboring animals are reduced.

The main steps in the manufacture of the bolus according to a preferred embodiment of the present invention would now be described with reference to Figures 8a and 8b.

In the first place (figure 8a), a mixture of the constituents of the material based on alumina or silica that must constitute the body of the bolus is prepared in a tank 30. These base constituents are led to the tank through respective conduits 32 to allow a continuous process to be carried out.

The tank 30 comprises stirring means 34 and possibly heating means (not shown) to ensure the material an optimum consistency and mixing in view of an extrusion.

The material is withdrawn from the base of the tub and led along a conduit 36 ​​that leads to an extruder 38. E^í It is equipped with an extrusion head 40 in the form of a simple hole having an outlet section corresponding to the section of the bolus body. At the exit of the extrusion head, the material appears as a solid and continuous cylinder 42, suspended vertically from it. This cylinder is deposited on a moving belt 44 that evolves on a horizontal plane towards different manufacturing stations.

Once on the treadmill 44, the cylinder of material 42 passes to a station 46 to undergo a cut into cylindrical bars 42a of length corresponding substantially to that of the finished product. In the example, this station 46 comprises an oscillating blade 46a at a frequency adapted to the speed of the treadmill 44.

The bars 42a are then put upright and pass from a drilling station 48 (figure 8b) to make a through hole in the axial direction of the body, this hole corresponding to the housing 12 according to the first embodiment. (In the case of manufacturing the bolus body according to the second embodiment, the drilling is interrupted before passing through the two ends, in order to make the blind hole).

The bars then pass to a first chamfered edge forming station 10a operating at one of the ends of the bar 42a. After this operation, the bars are turned and pass to a second chamfered edge formation station 50b, identical to the first, from where they exit with chamfers 10a at each end according to the first or second embodiment. At the end of these operations, a body preform is obtained whose dimensions roughly correspond to that of the final object.

The preform then passes to a cook station 52 where it undergoes a cook for a predetermined time. The cooking temperature is variable depending on the specific composition of the material and the desired mechanical properties. In general, this temperature can be in a zone between 1000 ° C and 2500 ° C. For the composition of the material specified in the example (table 1), as well as for some variants of this, it has been found that a cooking temperature of 1400 ° C is preferable.

At the end of cooking, the preform is hardened and its dimensions stabilized. It then passes to a last grinding station 54 (or set of stations) to obtain the final dimensions of the bolus. In the example, the preform after firing is subjected to a re-spinning (position 52) to ensure the precise dimensioning of the housing, in order to obtain a good closure with a self-locking rivet or a press screw.