The invention relates to a selection system to select an oestrous animal. The invention also relates to a method of selecting an oestrous animal.

The invention also relates to a shed system.

Selection systems to select an oestrous animal are known. Such known selection systems comprise detection systems which make physical contact with the animal in question in order to measure whether the animal in question is on heat, and/or detection systems which are attached to or on those animals that are expected to become oestrous in the near future.

Such a selection system is known, for example, from US patent application US 2008/0066693 which discloses a device for detecting the copulation behaviour of animals. The device concerned is attached to the male animal and records the attempts of the male animal to mount female animals. The device also records which female animals are mounted by the male animal, and in this manner the female animals that are oestrous or will become oestrous in the short term are selected. Other US patents, too, for example US 4,247,758, US 4,618,861 ,

US 5,542,431 and US 5,566,679, disclose systems which are able to demonstrate which female animal has been mounted by a male animal or by another female animal. Such systems usually comprise sensors that are sensible to pressure and that are usually attached on the back of the female animal.

A drawback of the above-described selection systems is that the systems have to be attached to or on the individual animals, which is unpleasant for the animal in question and which requires a relatively large number of selection systems, which makes the detection and selection of oestrous animals relatively costly.

The invention aims at providing a selection system to select oestrous animals, wherein disposing a measurement system on the individual animals can be avoided. The object is achieved with a selection system for selecting an oestrous animal as described in claim 1. The selection system according to claim 1 comprises a passage space to lead an animal from a first space to a second space, wherein the passage space comprises a lure for luring an oestrous animal and has sufficiently large dimensions to allow the animal to move around in the passage space, wherein the selection system comprises an identification system to identify the animal, and recording means which are configured to record and/or measure a parameter indicative of the behaviour of the animal which is moving through the passage space and to compare this parameter with a reference in order to determine whether the animal is on heat.

In the selection system according to the invention, in the passage space there is disposed a lure for luring an oestrous animal. The presence of the lure will influence the behaviour of the oestrous animal or of an animal that will become oestrous in the near future. As a result thereof, the behaviour of the oestrous animal will deviate from its usual behaviour and/or from the behaviour of the other animals of a herd. Owing to the fact that the passage space is provided with recording means to measure a parameter which is indicative of the behaviour of the animal, a deviating behaviour can be recorded and/or measured. By comparing this measured parameter with a reference, it is possible to judge whether the recorded deviating behaviour is sufficient to give an indication of whether the animal in question is oestrous or will become oestrous in the near future.

The parameter and the reference usually comprise values which describe the behaviour of the animal or from which a specific behaviour of the animal can be derived. Such parameters and references are preferably values that are capable of being measured, stored and compared with each other, so that, for example, computer systems can compare the parameters and/or reference values with each other in order to determine whether an animal is or will become oestrous. Preferably, the difference between the measured parameter and the reference is significant. This could, for example, be safeguarded by defining a difference value between the parameter and the reference. If the difference between the parameter and the reference is smaller than a minimum difference value or greater than a maximum difference value, the difference is not sufficiently significant and the animal in question will probably not be on heat. If the difference between the parameter and the reference is greater than or equal to the minimum difference value, or, preferably and, smaller than or equal to the maximum difference value, the difference is indeed significant and, in that case, the chance that the animal in question is oestrous is relatively great. Preferably, the difference value between the parameter and the reference can be set for each animal and for each parameter, in order thus to improve the reliability of the selection system. Setting the difference value could, for example, be based on earlier recordings and/or measurements of the parameter of the animal in question. The difference value could then, for example, be based on variations of earlier measured or recorded parameters. If, for example, the reference was determined in a period of time when the animal was not oestrous, the difference value between the measured parameter and the reference should be greater than the minimum difference value to indicate that the animal deviates by more than average from its normal behaviour and is, therefore, probably on heat. If, for example, the reference was determined in a period of time when the animal was oestrous, the difference value between the measured parameter and the reference should be smaller than the maximum difference value to indicate that the animal shows an oestrous behaviour within the average deviation, so that the animal may be or will soon become oestrous.

The first space, the second space and the passage space need not be covered spaces, such as a shed or parts of a shed. The spaces may also be demarcated sections of a pasture or a mix of covered spaces and pasture. The system can be integrated into the natural environment of the animals substantially without problems, so that the natural behaviour of the animals will be disturbed as little as possible and, as a result, the animal will be situated in an environment that is as much as possible true to nature. This will further improve the well-being of the animals.

The location of the lure in the passage space could, for example, be selected in such a manner that the animal has to deviate significantly from a normal walking pattern through the passage space to reach the lure, for example, in order to inspect it. As a result, the measured parameter will significantly deviate from the reference, so that the reliability of the selection system is improved. The passage space is preferably a connecting space between the first space and the second space, for example a corridor through which the animals walk from the first space to the second space. Said passage space may be provided with the selection system. The advantage of using the connecting space between the first space and the second space to select an oestrous animal from a herd is that the animals frequently make use of the connecting space, so that there is created relatively quickly a substantially standard behaviour for each animal through the connecting space. This improves the reliability of the selection system, because the "normal" behaviour of the animals through the connecting space is well known and deviations from this "normal" behaviour will clearly stand out. Such a passage space is also well known to the animals of the herd and the animals will not be extraordinarily nervous or shy when entering the passage space, which, again, improves the reliability of the selection of oestrous animals: deviating behaviour of the animals will be to a lesser extent due to the animals being nervous or shy, and to a greater extent to the animals being or not being oestrous. Finally, using the connecting space as a passage space has the advantage that hardly or no additional space is required in the sheds or pastures of a farm for the selection of the oestrous animals. The selection system can completely be integrated into the connecting space which is required anyway to move the animals from the first space to the second space.

European patent document EP 1 300 119 discloses a device for detecting a condition of heat with an animal. The known device comprises a frame to demarcate the space where the animal is present and to screen it off from the other spaces. Due to this, the animal which is present in the device is not bothered by other animals in the shed. The known device from EP 1 300 119 can only contain one animal at a time. There are also used pressure means to apply a stimulus to the animal, as a result of which the animal can and may hardly or not move in the known device. As a result thereof, the known device can detect only one animal at a time and occupies relatively much space in the sheds due to the presence of the frame.

The selection system according to the invention differs from this known device EP 1 300 119 in that the selection system of the invention comprises the passage space through which the animals are led from the first space to the second space. The passage space is dimensioned such that the animal can move around in the passage space and comprises recording means to measure a parameter indicative of the behaviour of the animal. Almost every farm has a connecting space between, for example, two parts of a shed into which the selection system can be integrated. As a result thereof, there is required hardly or no additional space for the selection system according to the invention. It is also possible for a plurality of animals to move simultaneously through the passage space and the behaviour of the plurality of animals could be recorded substantially simultaneously so that the recording time per animal will be reduced to a considerable extent. Finally, using the passage space ensures that the animal is not separated from the rest of the herd, as a result of which the animal continues to show its "normal" behaviour. The animal will continue to constitute part of the herd and will not become nervous or shy by the changing conditions of, for example, a closing frame or a pressure means such as required in the known device of EP 1 300 119.

In an embodiment of the selection system according to claim 2, the recording means are selected from a list comprising:

• the identification system to record the animal, and/or

• a further identification system to record the animal in the vicinity of the lure, and/or

• a camera system to record and/or measure the behaviour of the animal, and/or

• an image processing system in combination with the camera system to analyse the behaviour recorded and/or measured by the camera system, and/or

• a position recording system, and/or

• a measurement system to record and/or measure the walking speed, change in walking speed and/or change in walking direction of the animal through the passage space, and/or • a measurement system to measure the temperature of the animal.

The identification system is, for example, used to provide animals access to the passage space, for example, by means of an entrance gate that records which animals are allowed to pass through. Such an identification system could, for example, comprise RFID labels or optical labels to identify the individual animals. The identification system could, for example; comprise a number of measurement positions in the passage space where the presence of a specific animal is measured. The period of time between the various measurement positions could be used as a parameter. By disposing the lure at a specific position in the passage space, a deviation in the period of time between two measurement positions in the vicinity of the lure could, for example, be an indication that the animal is on heat because the animal will need time to inspect the lure. The passage space could also comprise an additional identification system with, for example, a very limited range, so that only animals in the immediate vicinity of the lure are identified by the additional identification system, while animals that follow the customary route through the passage space are not recorded by the additional identification system. The recording means could, for example, comprise a camera system to show the movement of the animals through the passage space or to record it and display it later. By observing the displacement of the animals from the first space to the second space through the passage space, deviating behaviour of a specific animal can be recorded due to the presence of the lure. Especially when a herd is displaced, the animal will preferably behave in conformity with the rest of the herd. Due to the presence of the lure the animal would behave differently from the rest of the herd, which is relatively easy to record. The camera could also be provided with an image processing system. Such an image processing system could, for example, analyse the behaviour of the herd and identify individual animals that behave differently and are possibly oestrous or will become oestrous in the near future.

The recording means of the selection system could also comprise a position recording system for accurately recording the position of individual animals in the herd. This position recording could take place per unit of time and would make it possible to determine in a relatively simple manner a speed, change in speed, direction of movement and change in direction of movement. Such position recording systems comprise, for example, known Global Positioning System sensors (in what follows also designated as GPS sensors) for accurately determining the position of an animal in question. The recording means of the selection system could also comprise other measurement devices for recording the walking speed, walking direction, change in walking speed and/or change in walking direction of the various animals. It is possible to analyse from these parameters whether an animal shows deviating behaviour in the vicinity of the lure. This could be a clear indicator that the animal in question is or is going to be oestrous. Such recording means could, for example, comprise speed detectors to measure the walking speed and/or changes in the walking speed of the animals or, for example, step counters. The temperature of the animal, too, may be an indicator of whether or not the animal is oestrous. Therefore, the recording means could also comprise a temperature sensor, for example an infrared camera.

In an embodiment of the assembly according to claim 3, the parameter is selected from a list comprising: • a period of time during which an animal is present in the passage space,

• a speed at which the animal is moving through the passage space,

• a speed variation of the animal while the animal is moving through the passage space,

• a direction of movement of the animal while the animal is moving in the passage space,

• a variation in the direction of movement of the animal while the animal is moving through the passage space,

• a recording of the animal by the further identification system,

• a temperature of the animal. The period of time an animal spends in the passage space and an average speed at which the animal moves through the passage space are relatively simple to measure by, for example, arranging measurement positions of an identification system at the entrance and exit of the passage space. It will, for example, be possible to measure a speed variation by substantially continuously measuring the speed of an animal while it is moving through the passage space. For such a measurement almost every measurement device for measuring the walking speed of an animal could be used, including the GPS sensor. Such parameters are also relatively simple to be processed by a computer in order further to automate the recording of deviating behaviour. The measured speed could, for example, be compared with a reference and, in the case of a deviation of the parameter with respect to the reference, which deviation has a value greater than or equal to the minimum difference value, the animal in question could be designated as possibly oestrous or oestrous in the near future.

The recording of the animal by the further identification system, too, can serve as a parameter to determine whether the animal which has been identified by the additional identification system may be or will soon become oestrous. When the animal is frequently recorded at the further identification system, it will have interest in the lure and there is a great chance that the animal is or is going to be oestrous.

In an embodiment of the assembly according to claim 4, the reference is selected from a list comprising: • an earlier recording and/or measurement of the parameter of the animal, and/or

• an average of earlier recordings and/or measurements of the parameter of the animal, and/or

• an average of earlier recordings and/or measurements of the parameter of other animals, and/or

• earlier behaviour of the animal when the animal was known to be on heat.

In such a selection system the history of a relevant parameter is, for example, used to determine the reference. Such a history based reference could, for example, comprise an average of the historic values of all animals from a herd or, alternatively, the reference could be animal-specific and thus be based on the history of one of the animals of the herd. In this case, for example, behaviour during a period in which the animal was known to be oestrous could not be used in order not to disturb the reference. By using historic values of an animal in question the reference is made specific for the animal in question and errors in recording are reduced.

The period over which historic values are averaged to determine the reference could, for example, be limited in order to implement, for example, trend changes in the behaviour of a herd or a specific animal into the reference. This is to further improve the accuracy of selecting an oestrous animal from a herd.

Alternatively, the behaviour of the animal when it was known to be on heat could, of course, be used as a reference. In such a case an animal would possibly be on heat if the parameter of the animal in question is relatively close to the reference. The animal would probably be on heat if the difference between the parameter and the reference is smaller than a maximum difference value.

In an embodiment of the assembly according to claim 5, the earlier recording and/or measurement of the parameter comprises a recording and/or measurement without the lure in the passage space and/or wherein an average of earlier recordings and/or measurements of the parameter comprise recordings and/or measurements without the lure in the passage space. As a result thereof, the effect of the lure on the herd and/or on individual animals of the herd can be determined relatively accurately so that the accuracy of the selection system is improved.

In an embodiment of the assembly according to claim 6, the lure comprises at least one of the following elements:

• an artificial odorant, • oestrous mucus,

• sperm,

• in operation, a male animal.

An advantage of using artificial odorants is that they are relatively simple to obtain. Oestrous mucus of congeners, too, is observed by oestrous animals or animals that will soon become oestrous, as a result of which the behaviour of these animals will change in the vicinity of the oestrous mucus. An advantage of using a male animal as a lure is that not only the behaviour of the animals of the herd is influenced to select oestrous animals, but that the presence of the male animal can also lead to natural insemination of the oestrous animal. For this purpose, the oestrous animal that has interest in the male animal would, for example, remain in the passage space so that the two animals can be separated for a certain period of time from the rest of the herd. This separation could be recorded by the identification system so that the natural insemination of the animal can be recorded. In an embodiment of the assembly according to claim 7, wherein, in operation, the lure is a male animal, and wherein the selection system is configured to record a second parameter indicative of the behaviour of the male animal which can move through the passage space. The behaviour of the male animal which is moving through the space can be indicative, too, of one of the animals of the herd being or not being on heat. The male animal could in that case, for example, move freely through the passage space and because the male animal will probably spend more than average attention to oestrous animals, this could used to select the oestrous animals. In such a system, the male animal and any animal from the herd could, for example, comprise a GPS sensor, so that the GPS sensor of the male animal "indicates" the oestrous animals or animals that will soon become oestrous by, for example, spending more than average attention to these animals of the herd. In this case, too, the update of a reference and a minimum or maximum difference value for the behaviour of the male animal could improve the selection of the selection system.

In an embodiment of the assembly according to claim 8, the selection system comprises a third space which is in contact with the passage space and wherein, in operation, a male animal can be present as a lure. The oestrous animal could, for example, walk to the third space and the period of time spent by the oestrous animal in the third space could, for example, be recorded. Such a third space could be used to separate animals so that natural insemination can take place during the so-called co-pasturing of the male animal with an oestrous animal. The recording of which oestrous animal has walked to the third space and the recording of the period of time the oestrous animal has spent in the third space could be used to record natural insemination. In the third space there could be provided, if desired, additional recording means to record natural insemination of the oestrous animal.

The third space, too, need not be a covered space such as a shed or a part of a shed. The third space may also be a demarcated section of a pasture or a mix of covered space and pasture.

In an embodiment of the assembly according to claim 9, a passageway between the third space and the passage space is closed by means of an entrance gate and the selection system is configured to allow an animal access to the third space depending on the recorded and/or measured parameter of the animal in question. In such a system, for example, only animals that may be oestrous or will soon become oestrous could be allowed access to the third space. The selection system could, for example, on the basis of measured parameters of one of the animals of the herd and on the basis of comparing the measured parameters with a reference, give an indication of whether the animal in question may be or will soon be oestrous. Following the selection of such an animal by the selection system the possibly oestrous animal could receive a specific label that indicates that the animal is possibly oestrous. This specific label could, for example, comprise a software design label that could be used in a control system for cattle management. Subsequently, the selection system or the control system could control the entrance gate to the third space and allow access to the third space only to the animals that may be oestrous. It is again possible to record which oestrous animal has walked to the third space and to record the period of time the oestrous animal has spent in the third space as an indicator of recording natural insemination.

The entrance gate to the third space also offers the possibility of preventing specific animals which, for example, are related to the male animal, from being admitted to the third space.

In an embodiment of the assembly according to claim 10, the passage space allows access to a plurality of third spaces closed by means of an entrance gate and which can each comprise a male animal, and wherein the selection system is configured to selectively allow an animal access to one of the third spaces. In such a system, an oestrous animal that is related to the one male animal could, for example, only be allowed access to another male animal. The invention also relates to a method of selecting an oestrous animal, wherein the method comprises the steps of:

• disposing a lure for luring the oestrous animal into a passage space, wherein the passage space is configured to lead an animal from a first space to a second space and wherein the passage space has sufficiently large dimensions to allow the animal to move around in the passage space,

• allowing the animal access to the passage space, • recording and/or measuring a parameter indicative of the behaviour of the animal which is moving through the passage space, and

• comparing the recorded and/or measured parameter with a reference in order to determine whether the animal is on heat. In an embodiment of the method according to claim 12, the step of disposing the lure comprises:

• disposing an artificial odorant in the passage space, or

• disposing oestrous mucus in the passage space, or

• disposing sperm in the passage space, or • disposing a male animal in the passage space, or

• leading the male animal to a third space which is in contact with the passage space.

In an embodiment of the method according to claim 13, the step of recording and/or measuring a parameter comprises: • recording and/or measuring a period of time during which an animal is present in the passage space, and/or

• recording and/or measuring a speed at which the animal is moving through the passage space, and/or

• recording and/or measuring a speed variation of the animal while the animal is moving through the passage space, and/or

• recording and/or measuring a direction of movement of the animal while it is moving in the passage space, and/or

• recording and/or measuring a variation in direction of movement of the animal while the animal is moving through the passage space, and/or • recording and/or measuring a recording of the animal by a further identification system, and/or

• recording and/or measuring a temperature of the animal.

In an embodiment of the method according to claim 14, the passage space comprises an entrance gate to allow access to a third space, wherein the male animal can be present in the third space; the method also comprises the step of: allowing the animal access to the third space, depending on the recorded and/or measured parameter of the animal in question. In an embodiment of the method according to claim 15, the passage space allows access to a plurality of third spaces which can each contain a male animal and which can each be closed by means of an entrance gate, wherein the step of allowing access to the third space also comprises: • selectively allowing the animal access to one of the third spaces.

Such a method can again be used to prevent, for example, an oestrous animal that is related to a bull, from being inseminated by the bull in question.

The invention also relates to a shed system, wherein the shed system comprises a first space and a second space and comprises a selection system according to the invention.

These and other aspects of the invention will be clarified by and explained with reference to embodiments described below. Figure 1 shows schematically an embodiment of a selection system according to the invention,

Figure 2 shows schematically an embodiment of a selection system according to the invention, wherein the lure is a male animal.

Figure 3 shows schematically an embodiment of a selection system according to the invention, wherein the selection system comprises a third space and wherein the male animal is present in the third space, and

Figure 4 shows a flow diagram which indicates steps of the method of selecting an oestrous animal.

The figures are schematic and are not drawn to scale. Some dimensions are exaggeratedly increased for illustrative purposes. Identical elements in the drawings are, as far as possible, denoted by the same reference numerals.

Figure 1 shows schematically an embodiment of a selection system 10 according to the invention. The selection system 10 as shown in Figure 1 comprises a passage space 30 to lead an animal 20,...28 from a first space 40 to a second space 50. The first space 40 and the second space 50 could, for example, be closed parts of a shed, or two different sheds or closed sections of a pasture. The passage space 30 forms the connection between the first space 40 and the second space 50 and is dimensioned in such a manner that the animal 20,...28 can move around in the passage space 30. The passage space 30 further comprises a lure 60 for luring an oestrous animal 20. An animal 20 which is or will soon be oestrous will be interested in the lure 60 and be willing to take a look at it or inspect it. Owing to the fact that the selection system 10 also comprises an identification system 70, 72 for identifying the animal 20,...28, the selection system 10 records which animal 20,...28 is present in the passage space 30. The selection system 10 also comprises recording means 70, 72, 170, 172; 174 for recording and/or measuring a parameter which is indicative of the behaviour of the animal 20,...28 which is moving through the passage space 30. By comparing this measured parameter with a reference, it is possible to determine whether the animal 20,...28 is on heat.

The presence of the lure 60 will influence the behaviour of the oestrous animal 20 or of an animal 20 that will become oestrous in the near future. As a result thereof, the behaviour of the oestrous animal 20 will deviate from its usual behaviour and/or from the behaviour of the other animals 21 ,...28 of a herd 20,...28. Owing to the fact that the passage space 30 is provided with recording means 70, 72, 170, 172; 174 for measuring the parameter which is indicative of the behaviour of the animal 20, ...28, a deviating behaviour can be recorded and/or measured by comparing this measured parameter with the reference.

The parameter and reference are preferably values that are capable of being measured, stored and compared with each other, so that, for example, computer systems can compare the parameters and/or reference values with each other to determine whether an animal 20,...28 is or will become oestrous. The difference between the measured parameter and the reference is preferably significant, for example, by defining a minimum or maximum difference value. Preferably, the difference value between the parameter and the reference can be set for each animal and for each parameter, in order thus to improve the reliability of the selection system.

The lure could, for example, be artificial odorant 60, oestrous mucus 60 or sperm 60, offered at a specific location within the passage space 30. The location of the lure 60 in the passage space 30 could, for example, be selected in such a manner that the oestrous animal 20 has to deviate significantly from a normal walking pattern to inspect the lure 60.

The passage space 30 is preferably a connecting space between the first space 40 and the second space 50, for example a corridor 30 through which the animals 20,...28 walk from the first space 40 to the second space 50. The advantage of using the connecting space 30 is that the animals 20,...28 frequently make use of the connecting space 30, so that there is created relatively quickly a substantially standard behaviour for each animal 20,...28 through the connecting space 30. This improves the reliability of the selection system 10, because the "normal" behaviour of the animals 20, ...28 through the connecting space 30 is well known and deviations from this "normal" behaviour will clearly stand out. Such a connecting space 30 is also well known to the animals 20,...28, so that they will feel at ease and will not be extraordinarily nervous or shy. Finally, the advantage of using the connecting space 30 as a passage space 30 in the selection system 10 is that hardly or no extra space is required in the sheds or pastures of a farm.

The recording means 70, 72, 170, 172, 174 could, for example, comprise an identification system 70, 72 for identifying the animals 20,...28 which enter and/or leave the passage space 30. Such an identification system 70, 72 is denoted in Figure 1 by antennas 70, 72 which schematically show wireless identification systems 70, 72, such as so-called RFIDs (Radio Frequency IDentification). However, other identification systems 70, 72, such as optical identification systems 70, 72, are also possible. The recording means 70, 72, 170, 172, 174 could also comprise a further identification system 170 for recording the animal 20,...28 in the vicinity of the lure 60. Here, it is possible, for example, to limit the range of the further identification system 170 in such a manner that only animals 20 that deviate from the normal walking pattern through the passage space 30 are identified. The recording means 70, 72, 170, 172, 174 could also comprise a camera system 172 with or without image processing system 174. The recording systems 70, 72, 170, 172, 174 could also comprise a position recording system (not shown), such as a system that is able to determine the position of individual animals 20,...28 with the aid of the Global Positioning System. The recording system 70, 72, 170, 172, 174 could also comprise a measurement system 176 which is able to determine the walking speed, walking direction, change in walking speed and/or change in walking direction of an animal 2O ₁ ...28. By means of this it is also possible to determine a deviating behaviour of an oestrous animal 20 with respect to a reference in order to determine whether an animal is or will soon become oestrous. The parameter could, for example, comprise a period of time spent by an animal 20,...28 in the passage space 30, and/or a speed at which and/or direction of movement in which the animal 20,...28 is moving through the passage space 30. This measured period of time, speed or direction of movement should, for example, differ by more than a difference value from a reference value to give an indication of whether the animal 20,...28 is on heat. The parameter could, for example, also comprise a speed variation or variation in the direction of movement that gives an indication of whether or not an animal 20,...28 is on heat. These parameters are relatively simple to measure and relatively simple to compare with each other in order to determine whether the recorded parameter significantly deviates from the reference.

The recording of the animal 20 by the further identification system 170 can serve, too, as a parameter to determine whether the identified animal is possibly oestrous. If the animal 20 is frequently recorded at the further identification system 170, it will have interest in the lure 60 and there is a great chance that the animal 20 is or is going to be oestrous.

The reference could, for example, comprise an earlier recording and/or measurement of the parameter of the animal, 20,...28, and/or an average of earlier recordings and/or measurements of the parameter. This earlier recording of the parameter, could, for example comprise a recording of the parameter while the animal 20,...28 was not oestrous or would not soon become oestrous. If the now recorded parameter deviates by more than the minimum difference value from such a reference, there is a chance that the animal is on heat. If the earlier recording of the parameter for determining the reference, for example, took place when the animal 20,...28 was or would soon become oestrous, a deviation of the now measured parameter which is greater than a maximum difference value would indicate that probably the animal is not or will not soon become oestrous. In such a selection system 10, the history of a relevant parameter is, for example, used to determine the reference. Such historic values could comprise values of all animals 2O ₁ ...28 from a herd 20,...28, or, alternatively, the historic values could be animal-specific and thus be based on the history of one of the animals 20,...28 of the herd 20,...28.

Figure 2 shows schematically an embodiment of a selection system 12 according to the invention, wherein the lure 65 is a male animal 65. Elements of a selection system 12 as shown in Figure 2 that are identical or play a comparable role as elements from Figure 1 , have the same reference numerals and will not be elucidated in the description of Figure 2. The male animal 65 could, for example, also move fairly freely through the passage space 30. In this case, a second parameter could be recorded and/or measured, the second parameter being indicative of the behaviour of the male animal 65 which is moving through the passage space 30. The behaviour of the male animal 65, too, may be indicative of one of the animals 20, ...28 of the herd 20,...28 being or not being oestrous. The male animal 65 could then, for example, be able to move freely through the passage space 30, but not be able to leave the passage space 30. Owing to the fact that the male animal 65 probably spends more than average attention to an oestrous animal 20, this could be used to select the oestrous animal 20 from the herd 20,...28.

Figure 3 shows schematically an embodiment of a selection system 14 according to the invention, wherein the selection system comprises a third space 80, 82 and wherein the male animal 65, 66 is present in the third space 80, 82. Here again, elements of a selection system 12 as shown in Figures 1 and 2 that are identical or play a comparable role as elements from Figure 1 , have the same reference numerals and will not be elucidated in the description of Figure 3. In the selection system 14 as shown in Figure 3, the male animal 65, 66 is present in the third space 80, 82 which is in connection with the passage space 30. The oestrous animal 20 could, for example, walk to the third space 80, 82 and the period of time spent by the oestrous animal 20 in the third space 80, 82 could, for example, be recorded. The third space 80, 82, too, need not be a covered space such as a shed or a part of a shed. The third space 80, 82 may also be a demarcated section of a pasture or a mix of covered space and pasture. In the embodiment of the selection system 14 as shown in Figure 3, the selection system 14 comprises two third spaces 80, 82, each closed by means of an entrance gate 90, 92. The further identification system 170 is used as a selection system to allow an animal 20,...28 access to the third spaces 80, 82, depending on the recorded and/or measured parameter of the animal 20,...28 in question. Thus, for example, the further identification system 170 would only allow oestrous animals access to the third space 80, 82. The entrance gate 90, 92 to the third space 80, 82 also offers the possibility of preventing specific animals 20,...28 that are, for example, related to the male animal 65, 66, from being allowed access to the third space 80, 82 where the related male animal 65, 66 is present.

Figure 4 shows a flow diagram which indicates steps of the method of selecting an oestrous animal 20 from a herd 20,...28.. A first step 200 in the flow diagram comprises disposing the lure 60; 65, 66 in the passage space 30. Disposing the lure 60; 65, 66 comprises disposing an artificial odorant 60, oestrous mucus 60, sperm 60 in the passage space 30, or leading a male animal 65, 66 to the passage space 30, or leading the male animal 65, 66 to a third space 80, 82 which is in contact with the passage space 30. A next step 210 in the flow diagram comprises leading the animals

20,...28 or leading individual animals 20;...28 through the passage space 30.

Subsequently, in step 220, the animals 20,...28 which walk or have walked through the passage space 30 are recorded with the aid of an identification system 70, 72. As it is now known which animals 20,...28 are present in the passage space 30, a parameter of each of the animals 20, ...28 will be recorded or be measured in a next step 230 of the flow diagram. The step 230 of recording and/or measuring a parameter could, for example, comprise recording and/or measuring a period of time spent by an animal 20,...28 in the passage space 30, and/or recording and/or measuring a speed at which and/or a direction of movement in which the animal 20,...28 is moving through the passage space 30. The step 230 of recording and/or measuring a parameter could, for example, also comprise recording and/or measuring a speed variation and/or a variation of the direction of movement of the animal 20,...28, while it is moving through the passage space 30. The step 230 of recording and/or measuring a parameter could, for example, also comprise recording and/or measuring a recording of the animal 20,...28 by an additional identification system 170. Subsequently, in step 240, the recorded and/or measured parameter is compared with a reference in order to determine whether the animal 20, ...28 is or will soon become oestrous. In this step 240, it will be looked at whether the parameter significantly deviates from the reference. If, for example, the parameter deviates by more than the minimum difference value from the reference, the measured deviation of the behaviour is considered as significant. In such a case, the animal 20 is designated as possibly oestrous.

Step 250 in the flow diagram looks at the result of the comparison step 240. If the result of the comparison step 240 is that the animal 20,...28 is possibly oestrous, the animal will be recorded in step 260. The recording step

260 comprises inputting an indication of whether the animal in question 20,...28 is possibly oestrous into an animal-specific file in a cattle management system

(not shown). If the result of the comparison step 240 is that the animal 20,...28 is probably not oestrous, no action will be taken. Alternatively, in such a case, the recorded and/or measured parameter could be added in an algorithm for determining a reference of the animal 20,...28 in question.

In an alternative embodiment (not shown), the fact that an animal 20,...28 is possibly not oestrous could, of course, also be recorded in contrast with the described embodiment in which the fact that the animal 20,...28 is possibly oestrous is recorded.

Subsequently, it is looked at whether the last animal 20,...28 has walked through the passage space 30 in step 270. When the last animal 20, ...28 has walked through the passage space 30, the flow diagram ends with step 300. When a parameter of all animals has not yet been recorded and/or measured, the steps of the flow diagram are repeated from step 210 and the next animal is led through the passage space 30.

Alternatively, it is, of course, also possible for a plurality of animals

20,...28 to move through the passage space 30 and the selection system 10,

12, 14 is able to determine the parameters of the various animals 20,...28 in sequence or simultaneously and to compare them with a general reference or with the individual references of the various animals 20,...28.

The flow diagram of Figure 4 still comprises additional steps 280, 290, 295 which can possibly selectively allow an oestrous animal 20 access to a third space 80, 82. The step 280 compares the data of the oestrous animal 20 in question with the data of a male animal 65, 66 which is present in the third space 80, 82 where the oestrous animal 20 in question is walking to. If the male animal 65 in question in the third space 80, 82 is related to the oestrous animal 20, access to the relevant third space 80, 82 is refused and the oestrous animal 20 could allowed access to a next third space 82, 80 in step 295. If the male animal 65 and the oestrous animal 20 in question are not related to each other, the oestrous animal 20 is allowed access to the third space 80, 82 in step 290.

The above-described selection system 10 and methods of selecting an oestrous animal 20 according to the invention can be designed both in hardware and in software. Especially the method steps as described above can be programmed and executed by a suitable control device such as a suitable microprocessor.

It should be noted that the aforementioned embodiments describe and do not limit the invention, and that it is possible for the person skilled in the art to design many alternative embodiments without essentially deviating from the accompanying claims.

Reference numerals which are added in brackets in the claims must not be regarded as limitations in the claims. The use of the verb "comprise" and its conjugations does not exclude the existence of elements or steps other than those specified in the claims. The article "a" preceding an element or step does not exclude the existence of a multiplicity of such elements or steps. A plurality of means listed in a device claim may be implemented in one and the same device. The sole fact that specific measures are listed in different dependent claims does not indicate that a combination of these measures is not advantageous.