Analysis of meat characteristics in animals or carcasses is an important concern in the meat industry. The quality of an animal's meat, for example in terms of its fat or lean content, will usually determine the market price which the animal or carcass will fetch. For example, abattoirs often buy live animals at a price which is dependent upon the estimated "fat content" of each animal, or the estimated average "fat content" of each animal in the herd or flock, for example.

Various ways of estimating meat characteristics, in particular fat content in live animals are known. The oldest, traditional way involves a "hands-on" examination following which the farmer or buyer guesses the animal's fat content based on his or her own personal knowledge and experience. This is a rather random technique which can result in highly inaccurate estimates of fat content.

Ultrasonic scanning apparatus has also been used in the past.

An ultrasonic probe is held against a live animal so as to obtain an ultrasound image or "scan" of the animal, or at least a portion thereof, on an electronic screen or display unit linked to the probe. The operator then often guesses the fat content (or other meat characteristic of interest) from the features shown on the ultrasound image or scan (again based on his or her own personal knowledge and experience), or carries out manual calculations involving the use of predetermined "look-up" tables for comparing with the scanned image of the animal. These methods are again prone to inaccuracies, due to the heavy reliance on personal judgement, and/or are relatively time consuming. Moreover another significant problem arises due to the difficulty in obtaining accurate and consistent measurements from a live animal which tends to move about while the scan is carried out.

The inherent problem for the industry, and in particular owners and sellers of live animals such as sheep/lambs, is that the actual quality of an animal's meat, for example its fat content, cannot be known until the animal is slaughtered and the meat is examined. By this time the animal has already been sold e.g. to the abattoir at a price based on the, often inaccurate, estimated fat content of the animal.

In the UK, the Meat and Livestock Commission (UK) has introduced an official grading scheme for fat classification of animals (or carcasses) in order to provide a universal standard for grading sheep, namely lambs, according to the fat content of their meat. This is another reason why it is important to be able to measure, or estimate, "fat content" accurately and consistently.

It is an aim of the present invention to avoid or minimise one or more of the foregoing disadvantages associated with the prior art.

According to a first aspect the present invention provides apparatus suitable for use in analysing a live animal, the apparatus comprising ultrasound imaging means, and constraining means formed and arranged for engaging the trunk of the animal in a substantially immobile position, said ultrasound imaging means having a probe portion disposable, in use of the apparatus, in contact with a substantially immobilised portion of the animal for obtaining an ultrasound image thereof, and output means for providing ultrasound image data from said ultrasound imaging means, in use of the

apparatus, to at least one of: ultrasound image data analyser means and image display means.

One advantage of the apparatus according to the present invention is that the trunk of the animal is held in a substantially immobile position while an ultrasound image is obtained. Several animals may be analysed in succession using the apparatus, each animal's trunk being held in a substantially immobile position while the required ultrasound image is obtained. This enables an accurate ultrasound image and highly repeatable results to be obtained.

The apparatus is preferably provided as a mobile unit. The ultrasound imaging means, the constraining means and the output means may be mounted on platform means having wheels.

Alternatively, the apparatus may be mounted in a vehicle, or other mobile unit having wheels, such as a trailer. By providing the apparatus as a mobile unit, animals may be analysed at any convenient location. Moreover, this allows the apparatus to be used at more than one location per day, for example.

The apparatus conveniently further includes image display means for displaying the ultrasound image of said portion of the animal as a visual image.

Preferably the apparatus further includes ultrasound image data analyser means for analysing the ultrasound image obtained of said portion of the animal, so as to evaluate a nominated characteristic of the animal, preferably the fat content of the animal. Conveniently the analyser means is adapted to grade the animal, preferably according to its fat content. The apparatus may further include display means for displaying the grade for the animal. Said display means may comprise the image display means for displaying the ultrasound image, where provided.

An advantage of the above-mentioned features is that the apparatus produces a grade for the animal, which grade is displayed to an operator. This avoids the need for any operator input, which could introduce human error and/or inaccuracies, and also enables a grade for the animal to be rapidly obtained. Thus the apparatus enables accurate and consistent grading of an animal, or a successive number of animals, to be achieved at a relatively quick rate.

The constraining means is preferably formed and arranged to support the weight of the animal, when the trunk of the animal is engaged in said substantially immobilised position.

Advantageously, the constraining means is formed and arranged to engage the animal in a predetermined position. Thus, where a plurality of animals are to be analysed, and/or graded, each animal is engaged in substantially the same position by the constraining means thereby to facilitate disposal of the ultrasound imaging means probe portion in proximity to the animal portion to be analysed.

The constraining means advantageously is incorporated in conveyor means. Conveniently there is used a conveyor means with an endless elongate conveyor belt means disposed, within an animal engaging reach, in a generally wedge-shaped arrangement having two sloped side portions converging downwardly to a gap or slot disposed at the thin end of the wedge-shape of the arrangement. The sloped side portions are formed and arranged for supporting the trunk of the animal.

The animal engaging reach of the conveyor belt means is preferably disposed in a substantially horizontally extending manner, or a gently inclined manner, in the direction of travel of said reach of the conveyor belt means. Preferably, the region above the sloped side portions is substantially open to facilitate access from above to an animal engaged therein. In use of the apparatus, an animal to be graded, for example a lamb, is fed into the apparatus at a first, receiving end of the conveyor belt means. The dimensions of the wedge-shaped conveyor belt means arrangement are designed

to be such that the legs of the animal fall through the gap or slot therein while the body of the animal is wedged between the sides of the wedge-shape of the belt means. Thus, the animal trunk is suspended in the belt means, substantially motionless, with the animal unable to gain any leverage with its feet. This provides an ideal opportunity for an operator, positioned adjacent the conveyor belt means, to access a predetermined portion of the animal with the probe portion of the imaging means so as to obtain the desired ultrasound image.

Preferably the constraining means is formed and arranged so that the animal is capable of only very small, if any, movement of its trunk even when the animal is moving its legs and/or head. Desirably the ultrasound imaging means is designed to obtain the ultrasound image of said substantially immobile portion of the animal substantially instantaneously, preferably within a few seconds or less, whereby any small movement(s) of the animal while it is engaged by the constraining means has substantially no effect on the ultrasound image which is obtained.

The probe portion of the ultrasound imaging means preferably comprises a contact surface for disposing against the skin of the animal whereby an ultrasound image of the desired portion of the animal may be obtained. Advantageously, a lubricant may be used between the contact surface of the probe and the animal's skin to enhance the contact, and hence the ultrasonic coupling therebetween.

The output means may simply comprise data transfer means, for example in the form of an electrical cable and/or signal processing means, coupled directly between the ultrasound imaging means and an image display means of the apparatus, for enabling the ultrasound image to be displayed in the form of a visual image for viewing by a human operator who views the image and evaluates it using his/her own resources.

The output means may comprise image capture means, preferably in the form of a frame grabber, coupled between the ultrasound imaging means and an image display means of the apparatus, for capturing a "frozen" ultrasonic image of the portion of the animal being analysed, which frozen image may then be displayed on the image display means.

The image capture means, where provided, may alternatively or additionally be coupled between the ultrasound imaging means and analyser means provided in the apparatus. The analyser means may advantageously comprise image processing means for analysing the ultrasound image. The image processing means may comprise a microprocessor programmed to analyse the image, or suitable image processing software provided for use with a microprocessor, for this purpose.

The analyser means may be adapted to analyse an electronic ultrasound image i.e. ultrasound image data from the ultrasound imaging means representing an ultrasound image of said portion of the animal being analysed, without the ultrasound image being displayed. The image data to be analysed may be stored, at least temporarily, in a memory means in the apparatus prior to analysis. Alternatively, the analyser means may be adapted to analyse the data on-the-fly.

The conveyor belt means is preferably driven by motor drive means. Motor control means may be provided for controlling the speed of the motor drive means so as to enable the speed of the conveyor belt means to be controlled and/or varied.

The control means may include pause control means for enabling the conveyor belt means to be halted temporarily while an ultrasound reading, or scan, of an animal engaged therein is carried out.

Where the constraining means comprises conveyor belt means, the apparatus preferably also includes ramps for disposal adjacent first and second ends of the conveyor belt means so as to extend between the ground and said conveyor belt means.

In this manner, animals can be fed onto and off the conveyor belt means via the ramps. The ramps may be formed and arranged for dismantling or folding away when the apparatus is not in use. The ramps may be in the form of additional conveyor means which may be similar to said afore-described conveyor belt means, formed and arranged for conveying animals from the ground up into, and down from, said conveyor belt means.

Where the apparatus is being used for grading a large number of animals, the animals can be fed into the apparatus via ramp means provided with side wall means converging towards the ramp end adjacent the receiving end of the conveyor belt means, for funnelling the animals in towards the conveyor belt means so that only one animal at a time can enter the receiving end of the conveyor belt means. Once the scan has been completed, the animal travels in the conveyor belt means to an exit end of the belt means where the animal is released.

Where the apparatus is intended for use in grading fat content of sheep, the analyser means is preferably adapted to grade the sheep or lamb in terms of "back-fat". This is a term commonly used in estimating or grading the fat content of a sheep or lamb according to the depth of a fat layer which runs along the animal's back.

Where the analyser means is provided in a microprocessor, the microprocessor may be programmed to calculate the fat content of the animal in terms of a percentage fat content. The grade for the animal may simply comprise said percentage fat content. Preferably, though, the analyser means is adapted to produce a grade for the animal according to a predetermined grading scale which may, for example, consist of a plurality of grades each of which represents a particular range of percentage fat contents. For example, the grading scale may start at 1 for the lowest fat content (i.e. very lean), going up to 4 for the highest fat content.

The apparatus may further include weighing means for weighing each animal which is conveyed through the apparatus. The weighing means may conveniently comprise a weighing station disposed at said second end of the conveyor means.

Alternatively, or additionally there may be a weighing means disposed at the first end of the conveyor means.

A gating system may also be provided in the apparatus for controlling the direction in which each animal leaves the apparatus. For example, separate or divided ramp means may be provided at the second end of the conveyor means and the gating system may include an automatically controlled gate for controlling access to said ramp means so that animals may be guided into a plurality of respective, separated containing pens or areas according to a grade allocated to the animal, which grade may, for example, be dependent upon the animal's measured weight (where a weighing means is provided in the apparatus).

According to another aspect the invention provides a method of analysing live animals, the method comprising the steps of: feeding a live animal into constraining means formed and arranged to engage the trunk of the animal in a substantially immobile position; obtaining an ultrasound image of a substantially immobilised portion of the animal by disposing a probe portion of an ultrasound imaging apparatus in contact with the substantially immobilised portion of the animal while the trunk of the animal is held in said substantially immobile position; and outputting ultrasound image data from the ultrasound imaging means, in use of the apparatus, to at least one of: ultrasound image data analyser means and image display means.

Preferably the method further includes the step of displaying the ultrasound image of said portion of the animal in a visual format.

Advantageously, the method further includes the step of analysing the ultrasound image of said portion of the animal, preferably automatically, so as to obtain a grade for the animal in accordance with predetermined criteria. Preferably the method also includes displaying said grade obtained for the animal on a display means.

The method may include obtaining a grade for the animal in accordance with a predetermined fat classification system.

The method is preferably used for grading sheep or lambs, according to their fat content. For example, the method may include obtaining a back-fat grade for the sheep or lamb, said grade preferably being one of a predetermined range of grades set by an official body, such as, for example, the Meat and Livestock Commission (UK).

Where the method is used for grading lambs (or sheep) according to their fat content, the portion of the lamb or sheep from which the ultrasound image is obtained is, preferably, the portion of the lamb where the lumbar vertebrae meet the ribs on the lamb's back, preferably where the first two lumbar vertebrae meet the last rib of the lamb.

This has been found to provide ultrasound images from which consistent and accurate back-fat grades may be obtained for the lambs.

In yet another aspect the invention provides a method of analysing, and/or grading, a plurality of live animals, the method comprising the above-described steps for analysing and/or grading a first one of the animals, and further including the steps of releasing the first animal from said constraining means and repeating the above-described steps for a second one of the animals, and so on until all the animals have been analysed and/or graded.

The second animal may be fed into said constraining means before, or while, the first animal is exiting therefrom.

The process whereby a live animal to be scanned using the ultrasonic probe must be first restrained, and the person carrying out the scanning must apply a small amount of lubricant to a portion of the animal's skin to be scanned and then bring the ultrasonic probe into contact with said lubricated portion of the skin and scan that portion of the animal, has disadvantages. Problems with this procedure are that it is time consuming, particularly where, for example, the animal is a sheep with a thick woolly coat which must be parted in order to reveal the portion of skin to be lubricated. Also, if the animal were being restrained by a person, rather than mechanical means, the procedure would normally require two people i.e. one to restrain the sheep and one to carry out the lubrication and scanning process. A further problem is that it may be difficult for the person operating the scanner to identify and scan the same portion of each animal, thus leading to inconsistencies with the scanning results obtained for different animals. This is a significant problem where the results of the scanning process are being used to grade the animals e.g. according to their fat content, since as afore-mentioned, consistency of grading is of particular importance.

According to another aspect of the present invention there is provided a hand-held probe unit for use in scanning at least a portion of a live animal, the probe unit comprising a body mounting an ultrasonic scanning probe with a scanning head of the probe disposed in a sole portion of the probe unit, the probe unit having a nose portion at a leading end of the sole portion, forward of the probe scanning head, for parting the fleece or hair of an animal to be scanned, the body being provided with conduit means extending between a lubricant supply inlet means and a lubricant outlet means in the sole portion of the probe unit and forward of the probe scanning

head, and said body having a hand grip portion whereby, in use, a user may hold the probe unit in contact with the animal's body and drive it thereover parting the fleece or hair, bringing the sole portion substantially into contact with the skin of the animal, applying lubricant to the skin via said conduit means, and drawing the probe scanning head over the lubricated skin.

An advantage of the hand-held probe unit is that the user may part the animal's fleece or hair, apply the lubricant to the animal's skin, and scan the lubricated portion of the animal, in a single motion i.e. as the probe unit is driven along the animal's body, in contact therewith, by the user.

In use of the probe unit the lubricant inlet means is preferably connected to a lubricant supply and injection means (external to the probe unit) including a reservoir of lubricant, and the scanning probe is preferably connected to ultrasound imaging means (preferably also external to the probe unit) including ultrasound generating and receiving means and/or ultrasound imaging means and/or ultrasound image processing means.

Advantageously, the probe unit further includes a manually operable trigger means formed and arranged for triggering the injection of lubricant into the hollow channel of the housing via the lubricant inlet means, so as to cause lubricant to be expelled from the outlet means, onto the animal's skin. Said trigger means may, for example, be formed and arranged for opening a valve means provided in the lubricant inlet means of the probe unit, for example, by depression of the trigger means by a user.

The probe unit may additionally be provided with a positioning device for assisting a user in the positioning of the scanning head of the scanning probe on the animal's body, in use of the probe unit. The positioning device may comprise spacer means, conveniently in the form of at least one

substantially rigid member extending outwardly from one side of the probe unit and comprising a generally arc-shaped or concave portion at its free end for engaging (loosely) with the spine or backbone of the animal, or alternatively with a rib of the animal. For example, the or each said substantially rigid member may be of a predetermined length such that, in use of the probe unit, the arc-shaped member(s) may be positioned over the backbone of the animal, whereby the scanning head mounted in the body of the probe unit is spaced a predetermined distance from the animal's backbone and travels forwardly, generally parallel to the backbone, during the scanning operation. This has the advantage that a desired portion of the animal may be located and scanned accurately and speedily, and where a number of animals are being scanned, the same portion of the body of each animal for scanning may be easily and speedily located using the spacer means. Alternatively, the or each said substantially rigid member may be of a predetermined length such that, in use of the probe unit, the arc-shaped member(s) may be positioned over a rib of the animal, whereby, during scanning, the scanning probe travels over the animal's side, moving generally parallel to the rib of the animal.

According to another aspect of the invention we provide ultrasound scanning apparatus comprising a hand-held probe unit as afore-described, lubricant supply and injection means for injecting lubricant into the conduit means of the hand- held probe unit, and ultrasound imaging means for connection to the scanning probe in the probe unit. The ultrasound imaging means preferably includes ultrasound generating and receiving means and image display means, and may optionally further include image processing means.

The hand-held probe unit preferably comprises said probe portion of the apparatus according to the above-described first aspect of the invention. In this manner, according to yet another aspect of the invention, we provide apparatus for use in analysing a live animal, the apparatus comprising the

afore-described ultrasound scanning apparatus incorporating said hand-held probe unit, and constraining means formed and arranged for engaging the trunk of the animal in a substantially immobile position, whereby a user may hold the hand-held probe unit in contact with a substantially immobilised portion of the animal and drive it therealong so as to obtain an ultrasound image thereof.

The lubricant supply and injection means may comprise a pressurised bottle of lubricant and a conduit means for connecting said bottle of lubricant to the lubricant supply inlet means of the housing.

The image display means may be visually calibrated for grading an animal according to the depth of a fat layer present in the scanned ultrasound image of the animal obtained using the scanning apparatus.

Preferred embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings in which:- Fig.l is a side view of a grading apparatus according to a preferred embodiment of the invention, showing three lambs in the apparatus; Fig.2 is a partial end view of the apparatus of Fig.l, an end ramp having been removed for clarity; Fig.3 is a similar view to that of Fig.2, showing a lamb supported within a conveyor belt arrangement of the apparatus; Fig.4 is a schematic diagram showing the electrical arrangement of various parts of the apparatus; and Fig.5 is a schematic illustration of a typical ultrasound image of back-fat in a lamb; Fig.6 is a schematic representation of an ultrasound image obtained by scanning a lamb, as viewed on a display screen according to a scanning apparatus of the invention; Fig.7 is a schematic side view of part of an alternative embodiment of the invention;

Fig.8 is a perspective end view of a conveyor belt arrangement used in another embodiment of the invention; Fig.9 is a side view of a hand-held probe unit according to a preferred embodiment of the invention; Fig.lO is a block diagram illustrating schematically an ultrasound scanning apparatus according to one embodiment of the invention; Fig.ll(a) is a plan view of a further embodiment a hand-held probe unit according to the invention; and Fig.ll(b) is a detail side view of a portion of the unit of Fig.ll(a).

Fig.l shows a mobile unit 1 for use in the grading of sheep or lambs 2, specifically for grading them according to their "back-fat". The mobile unit 1 comprises lamb constraining means in the form of a conveyor belt arrangement 3 for engaging at least one lamb 2 within an engaging reach 3a thereof so as to substantially immobilise the trunk of the lamb while a portion of the lamb is scanned by an ultrasonic scanning probe 4 operated by a human operator (not shown).

The conveyor belt arrangement 3 is mounted on elongate supporting elements 5,6 which, in turn, are mounted on a platform 7. The platform is supported on four wheels (only two shown) 8,9. A seat 11 is provided on the platform 7 for the (optional use of the) operator.

The ultrasonic scanning probe 4 is part of an ultrasound imaging system provided in the mobile unit 1. The system also includes a generating and receiving unit 10 for sending and receiving electrical signals to and from the scanning probe 4. As shown schematically in Fig.4, the generating and receiving unit 10 is also connected to a frame grabber 12 which is connected to a microprocessor 14. The frame grabber can, in practice, be incorporated in a personal computer 15 including the microprocessor 14. The microprocessor is also connected to a Visual Display Unit (VDU) 16 of the personal computer.

Two ramps 17,18 are provided, a first one 17 at a receiving end 19 of the conveyor belt arrangement (which is of generally elongate form), and the second one 18 at an exit end 20 of the conveyor belt arrangement 3. The ramps extend between the ground G and the receiving and exit ends 19,20 respectively and each comprise a base 21 and two relatively high sides 22 for preventing sheep falling off the ramp as they walk up it, in use of the apparatus.

Figs.2 and 3 show partial end views of the apparatus, at the receiving end 19 of the conveyor belt arrangement 3, (the respective ramp 17 being omitted for clarity) and showing the belt arrangement with and without a lamb 2 engaged therein, respectively. As illustrated in Figs.l and 2, the conveyor belt system 3 comprises two endless belts 23,24 disposed in a generally wedge-shaped arrangement, the two belts being supported on rollers (not shown) mounted on the elongate supports 5,6 on the platform 7 and/or mounted on generally vertical side walls 27,28 mounted on the supports 5,6 respectively. The engaging reach 3a of the arrangement extends substantially horizontally in the direction of travel (indicated by arrows shown in Fig. 1) of the belts 23,24. The belts are arranged in opposed sloping relationship so as to converge towards each other in the downward direction, forming the narrow end of the wedge-shape. In the end view of Fig.2 the belts 23,24 thus form a substantially V-shaped arrangement. The belts 23,24 do not meet, however, but terminate in a gap 25 at the narrow end of the wedge-shape, the gap 25 extending substantially along the length of the conveyor belt arrangement 3.

The endless belts 23,24 are driven by drive means in the form of drive wheels or rollers (not shown) powered by an electric motor 13, indicated schematically in Fig.4. The speed of the motor can be controlled by the operator by means of a control unit 30 which is itself linked to the microprocessor 14, thus enabling the operator to control the speed of the motor 13, and hence the conveyor belts 23,24, using the computer 15. In

another possible embodiment, the operation of the motor is entirely independent from the microprocessor, the speed of the motor being controlled directly by an operator.

In use of the apparatus, the motor 13 is switched on so as to drive the endless belts 23,24. Lambs 2 are fed up the first ramp 17, preferably one at a time, towards the receiving end 19 of the conveyor belt arrangement 3. The upper end of this ramp 17 is arranged so as to be more or less level with upper surfaces 32,33 of the two supporting elements 5,6 mounted on the platform 7 so that a lamb 2, reaching the receiving end 19 of the conveyor belt arrangement 3, walks forward so as to be received between the two belts 23,24, while finding its legs and feet 32 fall through the gap 25 between the belts, as illustrated in Fig. 3. The trunk 34 of the lamb is gripped and supported by the belts 23,24 so that the lamb is carried along in the belts towards the operator who is disposed adjacent the conveyor belt arrangement, ready to scan a desired portion of the lamb's back with the ultrasonic scanning probe 4. The lamb is immobilised in the belt arrangement 3, unable to gain any leverage with its feet, and thus it is relatively easy for the operator to scan the desired portion of the lamb.

The scanning probe 4 has a contact surface designed to be brought into physical contact with the skin of the animal to be analysed. In the preferred embodiment, the contact surface of the probe is approximately 8cm in length so that a portion of the approximately 8cm length along the lamb's back will receive and reflect a scanning beam of ultrasonic waves emitted from the probe, the reflected ultrasound also being received by the probe 4.

It has been found that where the lamb is to be graded according to its back-fat grade, the best results are achieved when the probe 4 is brought into contact with that portion of the lamb located between the last rib of the lamb and its first two lumbar vertebrae. To improve contact

between the probe and the lamb's skin, the lamb's wool is parted and a small amount of liquid paraffin is applied to the skin prior to application of the probe contact surface.

The frame grabber 12 captures or "grabs" an image, "frozen in time", of the chosen portion ultrasonically scanned by the probe 4. (The grabbed image is temporarily recorded in the frame grabber until such time as another image is grabbed, the next image overwriting the first etc.) The microprocessor is programmed to receive an incoming digital image from the frame grabber 12 and display the grabbed image, in digital format, on the VDU 16. The microprocessor incorporates image processing means for processing the grabbed image so as to determine the back-fat content of the lamb and to automatically calculate a back-fat grade for the lamb. This can be done in various ways, the preferred way being to measure the average value of the depth 6 of a layer of fat normally seen in the grabbed image of any given lamb, such as that seen in the schematic illustration of a typical such ultrasound image shown in Fig.5, and to grade the lamb accordingly, the microprocessor having been pre-programmed with a series of grades corresponding to pre-determined ranges of average depths of this fat line. The calculated grade for the lamb is subsequently displayed on the VDU for the operator to see. The width of the back-fat line can be calculated using any one of several known image processing techniques e.g. grey-scale analyser, fuzzy processing and/or pattern recognition. As shown in Fig.5, the ultrasound image typically obtained of the scanned portion of the animal consists of three layers: firstly, a layer 40 of fat, below which is a layer 42 of muscle, below which is a layer 44 of general animal tissue.

In a preferred embodiment of the invention the microprocessor is programmed to grade the lambs according to the standard grading system introduced by the Meat and Livestock Commission (UK), the lambs thus each being accorded a grade of 1 (the leanest), 2, 3L, 3H, 4L, or 4H (the fattest).

Once a lamb 2 has been graded it is carried along by the belts 23,24 to the exit end 20 of the belt arrangement where the lamb gains footing on the edge of the second ramp 18 and is able to walk down this ramp. The apparatus may be used for grading several lambs, for example a few hundred, in succession, the lambs being graded one by one. As one lamb is being scanned, another can be fed up the first ramp 17 and/or into the conveyor belts, and another can be leaving the exit end of the belt arrangement 3. In the preferred embodiment, up to three lambs may be held in the conveyor belt arrangement at any one time. The speed at which the lambs are scanned, and thus graded, is determined by the speed at which the lambs 2 are brought up to the operator for scanning. This can be controlled via the control unit 30 linked to the microprocessor. The operator can decrease or increase the speed of travel of the endless belts 23,24 as desired. Motor on/off control is also provided so as to enable the operator to stop the belts 23,24 temporarily, while the ultrasound image for each lamb is captured. For this purpose a foot pedal (not shown) is provided by means of which the operator can control the on/off of the motor 13 driving the conveyor belts 23,24. In the preferred embodiment the foot pedal is linked to, or incorporated in, the control unit 30.

The sides 22 of at least the first ramp 17 may be of converging or funnelled configuration so as to allow several lambs to ascend the ramp up to the platform 7 at a time, but to allow only one lamb at a time to enter the receiving end 19 of the belt arrangement 3.

The ramps 17,18 are detachable so that they can be dismantled from the apparatus for storage or transportation purposes.

Alternatively the ramps may be collapsible or foldable for easy transportation of the apparatus.

Using the above-described technique and apparatus it is envisaged that in the region of up to one thousand five hundred lambs can be graded per hour i.e. 2.4 seconds per lamb. The apparatus has been found to achieve accurate and consistent grades for the lambs. Previously, using the old, known techniques and apparatus, only a maximum of perhaps 100 lambs per hour was possible and/or only speculative, inaccurate and/or inconsistent grading was ever achieved.

It will be appreciated that various modifications to the above-described embodiments are possible without departing from the scope of the invention. For example, the apparatus may be adapted for grading the lambs according to one or more characteristics of the lambs other than back-fat, as long as an appropriate portion of the lamb can be imaged while the lamb is supported in the conveyor belt arrangement. Moreover, the apparatus could be designed for use in grading other animals, such as, for example, cattle or pigs. This would require the conveyor belt arrangement 3 to be dimensioned for engaging the trunk of, for example a cow, or a pig, therein in a similar manner to the way in which the trunk 34 of the lamb is supported in Fig. 3.

The apparatus can be loaded into a truck or trailer for transporting to a location where grading is to take place e.g. an abattoir. Instead of a platform 7, the apparatus may be permanently incorporated in, for example, a truck or a trailer.

Also, the apparatus could be in the form of a more or less permanent installation, in which case the conveyor belt arrangement would be mounted directly on the floor or ground 30. Moreover, the scanning probe 4 could be built into the apparatus so as to be appropriately placed for capturing an ultrasound image of the desired portion of each lamb or other animal automatically while it is engaged in the conveyor belt arrangement. The scanning probe 4 could even be built into,

or mounted on, a robotic arm arrangement which is programmed to obtain the desired ultrasound images.

The endless belts 23,24 may alternatively be driven by other means than an electric motor. For example they may be driven by hydraulics.

In a simpler embodiment of the invention, the apparatus may be used simply to display an ultrasound image of a scanned portion of the animal without performing any computerised analysis of the image. This may be useful where an operator merely wishes to observe a given characteristic of the animal(s) for breeding and/or genetic modelling purposes. In this embodiment the apparatus need not include any image processing software for analysing the ultrasound images.

Alternatively, in another possible embodiment, the ultrasound image is not visually displayed, the microprocessor being programmed only to analyse incoming ultrasonic image data signals from the frame grabber representing the imaged portion of the animal.

In an alternative embodiment of the apparatus, the ramps 17,18 may be replaced by extensions to the conveyor belt arrangement (or separate, additional conveyor belt arrangements) at the receiving and exit ends 19,20 thereof, so that each animal is received directly into the moving conveyor, from the ground G at the receiving end 19 of the system. This may be advantageous where the animals to be scanned are reluctant to walk up a ramp e.g. it is very difficult to get pigs to walk up a ramp. The conveyor belt extensions may be raised or lowered by means of hydraulic arms connected between the platform 7 (of the mobile apparatus) and each conveyor belt extension. In this manner, the free end of each conveyor belt extension can be raised off the ground when the apparatus is travelling and lowered on to the ground when in working use.

In any of the above-described embodiments, the apparatus may further include a weighing area, for weighing the animals either before or after they are scanned. A possible such system 60 is illustrated in part in Fig.7 which shows a platform 62 on wheels 64 and having a weigh station 66 incorporated therein. Animals 65 are conveyed into the weighing station 66 by a first conveyor section 68 having an upper end 69 mounted to the weigh station 66 fixed to the platform 62 and a free end 71 which is lowered to the ground G in use of the apparatus. As shown, a hydraulic arm 72 is provided between the platform 62 and the conveyor section 68 for raising/lowering the free end 71 thereof. This first conveyor section is of similar construction to the conveyor arrangement illustrated in Figs.2 and 3. At the upper end 69, the animal being conveyed exits the conveyor section and enters the weigh station 66 which consists of two vertical side walls (only one seen in side view in Fig.7) each formed by a series of parallel rollers 74, between which side walls the animal walks forwardly. The rollers 74 are not driven but are freely rotatable. The two side walls formed by the rollers are spaced apart by a predetermined distance which is such that the animals' sides tend to brush against the rollers. The floor of the weigh station 66 comprises a weighing platform 75 under which electronic weigh cells 76 are provided. The weigh cells are linked to the microprocessor which is programmed to store and/or display on the VDU 16 (not shown) the measured weight of each animal which is weighed. At the end of. the weigh station 66 the animal enters the upper end of a second conveyor section 78 (similar to the first conveyor section 68), via which the animal is conveyed back down to the ground G. The ultrasound scanning operation on the animal may be carried out either while the animal is in the first, or the second conveyor section, using the apparatus afore-described in this connection (the scanning probe 4, and ultrasound imaging and analysing apparatus has been omitted from Fig.7 for clarity).

In a further possible embodiment, the apparatus may comprise a tandem conveyor belt arrangement providing two wedge- shaped, generally horizontally extending conveyor belt channels like that of Figs.2 and 3, in which individual lambs or sheep may be conveyed, allowing an even faster rate of scanning to be achieved. In this embodiment two operators may work simultaneously to scan animals at twice the rate. In order to achieve this, the system thus includes two scanning probes 4, or hand-held scanning units 81, each linked to a respective ultrasound image display screen. Each display screen would either be visually calibrated as described above, or linked to image processing means for analysing the image and calculating a grade for each animal.

A weigh station 66, or respective weigh stations, as afore- described in relation to Fig.7 may also be incorporated at the exit ends 20 of the two conveyor belt arrangements, for weighing each animal after it has been graded for fat content before the animal leaves the apparatus. A further possible modification of this latter described system would be to have two or more exit ramps, or exit conveyor sections, (or a single, sub-divided ramp or conveyor section) at the exit end(s) of the weigh station(s), each leading down into a different area. Each said area may be designated to contain animals having a weight falling within a respective band of at least two pre-determined weighting bands. An electronically controlled gating system is incorporated at the exit ends 20 of the two conveyor arrangements. The gating system would comprise a pivoting or sliding gate which may be moved to different positions so as to only allow an animal leaving the weigh station(s) to enter the exit ramp or conveyor section leading to an appropriate one of said designated areas according to its measured weight. This may be achieved by linking the gating system electronically to the grading and weighing system microprocessor, which is programmed to move the gate into one of two or more possible positions depending on the measured weight of the animal most recently weighed. In the preferred embodiment of this

system, the apparatus is designed to divide or "draft" the scanned and weighed sheep into three different areas corresponding to three different weighting categories.

It will be appreciated that such a gating system may be incorporated in any of the afore-described embodiments of the invention, to separate out e.g. lambs/sheep according to their different weights, where a weigh station is provided, or according to their different back-fat grades. Thus, for example, in the system of Fig.l a gating system may be employed at the exit end 20 of the conveyor belt arrangement 3, with three or more exit ramps 18 being disposed beyond the gating system, leading down to separated animal containing areas. Similarly, such a weigh station may be incorporated before the entrance end(s) of the or each conveyor arrangement and a suitable gating system employed to draft out sheep below (or alternatively, above) a certain weight which sheep need not be scanned, and allow only those sheep which are to be scanned to enter the conveyor arrangement.

In another possible embodiment the conveyor belt arrangement is simply provided as a relatively small, portable unit, the animal engaging reach 3a thereof being only long enough to engage a single animal (e.g. lamb) therein at a time. Such a portable unit 3' is illustrated in Fig.8. The endless conveyor belts are mounted in a metal frame 4' having four lower corner portions 5',6',7',8'. The frame 4' is provided with at least two handles 9',10' for enabling a user to easily lift and carry the unit to a desired position. The conveyor belts defining the animal engaging reach 3a' of the unit are driven by two power motors 15',16' mounted to the frame 4'. Each of the four lower corner portions of the frame 4' has a weighing means in the form of a weighing foot 11',12',13',14' attached thereto. The weighing feet are linked to a central processing unit (not shown) which is programmed to subtract the predetermined weight of the empty unit from the total weight measured by the weighing feet when the unit has a lamb L engaged therein (as shown in Fig.8), so

as to calculate the weight of the lamb. The unit is simply rested on the ground or floor G at the desired location where scanning work is to be carried out. The ultrasound scanning of the lamb can be easily carried out by the operator while the lamb is engaged in the unit, similarly to in the other described embodiments. The ultrasound scanning equipment may be incorporated in, or attached to, the portable unit itself, but more preferably this equipment will be separate from the portable unit. The portable unit is designed to fit easily in a truck or other transport vehicle, for easy transport (with the scanning equipment) from one working location to another.

Alternatively, the unit may be resting on a mobile platform or trailer, with the weighing feet 11',12',13',14' resting on the platform (or floor of the trailer).

Fig.9 shows a hand-held probe unit 81 according to another claimed aspect of the invention. The unit 81 comprises a body 82 in which a scanning probe 84 is mounted. The scanning probe 84 has a scanning head 83 disposed in a sole portion 85 of the probe unit 81 so that the scanning head will be brought into contact with an animal's body when the sole portion 85 of the unit 81 is brought into contact with the animal's body. The body 82 is generally foot-shaped with a toe or "nose" portion 86 at a leading end of the sole portion 85, forward of the scanning probe 84. An upstanding portion 93 of the body 82, above a trailing end of the sole portion 85, provides a hand-grip for a user. The sole portion 85 tapers forwardly to a narrow point at the forwardmost tip 91 of the nose portion 86 which is shaped so as to part the fleece of hair of an animal when the sole portion of the body 82 is driven along the body of an animal, in contact therewith, by a user. To optimise the fleece parting action the nose portion 86 is tapered in both the horizontal and vertical cross-sectional planes thereof, the tip 91 of the nose portion thus being elevated slightly above the level of the rest of the sole portion of the unit 81, as shown in Fig.9. A conduit 87 in the body 82 of the unit extends between an inlet 88 in an upper end 89 of the body 82, and an

outlet 90 in the sole portion 85. A lubricating substance, conveniently in the form of a gel, may be applied directly to the animal's skin via the outlet 90 in the sole portion 85 by injecting it into the inlet 88 during use of the probe unit 81. The outlet 90 is located between the probe scanning head 83 and the nose portion 86 so that, as the probe unit 81 is driven forwardly along the animal's body (in the direction indicated by arrow F) the nose portion parts the fleece/hair, the gel is applied to the animal's skin, and the scanning probe scans the lubricated skin, all in one motion.

Injection of the lubricant may be controlled by a trigger 92 provided in the unit 81 and linked to a lubricant reservoir and injection means 94 external to the probe unit 81, as shown schematically in Fig. 10. The fluid reservoir 94 is connected to the inlet 88 of the probe unit 81 by means of a conduit 95. The reservoir is a pressurised container of lubricant the injection of which into the probe unit is controlled by a valve 96 (e.g. a spring loaded valve) in the inlet 88 of the probe unit body 82, opening/closing of the valve being controllable by the trigger 92 on the unit 81, the trigger 92 being mechanically linked to the valve in the inlet 88. The scanning probe 84 is electrically linked (via leads 97), in use, to an ultrasound imaging means (external to the probe unit 81) comprising ultrasound generating and receiving equipment 100 linked to an ultrasound image display unit 101 having a visual display screen 102, as indicated schematically in Fig.10. In another embodiment the trigger 92 may instead be provided in a lubricant infeeder(linked to the reservoir 94) connected to the lubricant inlet 88 which is in this case located in the lower "foot"portion of the body 2.

Fig. ll(a) shows a further possible embodiment of a hand-held probe unit 81 according to the invention. Where the probe unit is being used for scanning sheep or lambs to obtain ultrasound data from which the sheep can be graded according to their fat content, it has been found that accurate and consistent fat gradings may be obtained by scanning that

portion of the lamb's body which is where the lumbar vertebrae meet the ribs on the lamb's back, preferably where the first two lumbar vertebrae meet the last rib of the lamb.

In order to assist the user in correctly locating and scanning this portion of the lamb, the hand-held probe unit may have two spacer rods 104,106 integrally attached, or mechanically or adhesively fixed, thereto and having arched or cupped free end portions 105,107 (one of which is shown in detail in Fig.ll(b)) designed to sit on the spine or backbone S of the animal and slide therealong during scanning of the desired portion of the lamb's back, thus ensuring that the scanning head of the probe unit follows a continuous, generally linear scanning path along the lamb's back, generally parallel to the lamb's backbone, and at a predetermined lateral distance therefrom which is the same for each sheep being scanned. Alternatively the spacer rods may be used to follow the path of a chosen rib of the lamb, so that the scanning head of the probe unit travels over one of the lamb's sides during the scanning process. Where scanning is carried out in this manner, the length of the spacer rods 104,106 and/or the configuration of the arched end portions 105,107 thereof may be specifically designed for this purpose.

The body 82 of the unit 81 may conveniently be formed in a metal material. The body (or at least the nose portion thereof) can then be sprayed or otherwise coated in a low- friction material plastics material so as to reduce frictional resistance when the nose portion is driven through the animal's fleece/hair. Alternatively, the body 82 could be moulded from a plastics material, preferably having low- friction characteristics. The spacer rods 104,106 may be made from a rigid plastics material and may be permanently or removably fixed to the body 82 of the unit 81. The size of the acute angle cp of the tapered nose portion, in the horizontal plane thereof, is approximately 15 to 30 degrees (see Fig.ll(a)).

The afore-described hand-held probe unit may be used in conjunction with the apparatus of Figs.4 and 5, in place of the basic scanning probe 4 indicated schematically in Fig.4.

In a further embodiment of the invention, the apparatus incorporating the hand-held probe unit 81 of Fig.9, or scanning probe 4 of Fig.l, may be used simply to obtain a live ultrasound image of a scanned portion of the animal without performing any computerised analysis of the image.

The output from the scanning probe may simply be displayed as a live ultrasound image on a screen 102 of an ultrasound image display unit 101, as illustrated by Fig.10. Grading of the animal may be achieved by means of a marking system applied to the screen 102 on which the live image is displayed, in order to calibrate the screen. This is illustrated by Fig.6. The marking system consists of a number of parallel horizontal lines applied to the screen (e.g.

painted or printed onto the outer surface of the screen) at predetermined spacing widths from each other, so as to define grading bands corresponding to different depths of the fat layer in the lamb. Since the ultrasound image obtained using the scanning probe is generally in a layered format, the fat, muscle and tissue layers (150,152,154) of the animal appearing as adjacent, generally horizontal layers on the screen, an operator may immediately see which grading band the animal falls into by observing which band a lower edge of the fat layer extends into (or alternatively how many bands the fat layer extends over). Fig.6 which shows a four band grading scheme (Bands 1,2,3,&4) defined by lines A,B,C and D on the image display screen 102, in which the depth 5 of the fat layer 150 in the scanned image is such that a lower edge thereof lies between grading lines B and C on the screen, thus indicating that the animal should be graded as "Band 4'.

This technique offers some advantages since it increases the rate at which animals e.g. sheep may be scanned and graded.

Use of the hand-held probe unit 81 further improves the consistency and accuracy of the ultrasound images obtained by the user.