AU2003238759A1

AU2003238759A1 - Automated eostrus detection in animals

Info

Publication number: AU2003238759A1
Application number: AU2003238759A
Authority: AU
Inventors: Kylie Janet Butler; Norman Bruce Williamson
Original assignee: Massey University
Current assignee: Massey University
Priority date: 2002-06-24
Filing date: 2003-06-24
Publication date: 2004-01-06
Anticipated expiration: 2023-06-24
Also published as: NZ519743A; WO2004000158A1; AU2003238759B2

Description

WO 2004/000158 PCT/NZ2003/000129 AUTOMATED OESTRUS DETECTION IN ANIMALS FIELD OF INVENTION 5 The invention relates to a method and apparatus for automatically detecting oestrus in animals, particularly cows. BACKGROUND TO INVENTION 10 Oestrus or heat detection is one of the most important factors in determining production efficiency in an artificially-bred dairy farm. A cow will come into heat or oestrus approximately every 21 days and in order for her to become pregnant she must be bred at around this time. In herds seeking high genetic gain, the cow in oestrus must be identified properly, preferably within a 12 hour period, and separated from the herd for 15 artificial insemination. Failure to pick a cow in oestrus will result in a delay of three weeks before the cow returns to heat and therefore can be bred. The resulting calf would then be born three weeks later and the farmer or herd manager would potentially miss out on three weeks of milk production in the next season. It is therefore essential to detect heat accurately to maximise efficiency and profit on a farm. 20 It is well known that cows in a herd, when they are in heat, will permit another animal to mount them for an appreciable time but when not in oestrus (heat) will reject the mount immediately. The identification of cows in heat has been accomplished traditionally by observation, in which the cows seen to allow mounting by other cows 25 are separated from the herd for insemination. As a large percentage of mounting activity occurs at night, this causes difficulty for observation. Furthermore, observation of a herd in a paddock, yards and races often leads to difficulties in reading ear tags from a distance and remembering multiple numbers. There are also difficulties in trying to identify mounted cows in the middle of a crowded yard. 30 One method of heat detection involves tail painting in which the area of haired skin over the sacral spines and cranial coccygeal vertebrae is covered with a suitable paint. As a WO 2004/000158 PCT/NZ2003/000129 2 cow is mounted, this paint is rubbed off the hair. By visually inspecting the paint coverage on a cow's tail during milking, a fannrmer or farm manager can determine whether or not the cow is in heat. 5 Other devices are available which are glued or otherwise secured to the back of the cow over the sacral spines and which change colour when the cow is mounted due to pressure and/or friction exerted on the device. Some of these devices are designed so that a layer is partially or entirely removed from the device during mounting. 10 UK patent specification GB 2,139,117 to Lumber and US patent specification 6,467,430 to Stampe describe oestrus indicating tape that can be supplied as individual patches or alternatively in roll or sheet form. The Lumber and Stampe tape includes a layer that is partially or entirely removed from the tape during mounting. The tape described in US 6,467,430 to Stampe includes an adhesive floodcoat layer that adheres to the mounting 15 animal which causes the floodcoat layer to peel off from the tape. The Lumber tape, on the other hand, includes a facing layer of a natural or synthetic latex composition that forms a rubbery layer. The facing layer is rubbed off by the vigorous pummelling it receives during mounting. 20 In both devices, the removable part of the tape covers the entire surface area of the tape obscuring any layers positioned beneath the removable part of the tape. Also, in both forms of the tape, the dimensions of the tape as it is secured to an animal are not consistent, especially where the tape is supplied in roll or sheet form. Neither forms of tape are suitable for automation of oestrus detection. 25 Other devices are also available that are glued or secured to the back of a cow and which change colour in a manner in which a layer is not partially or entirely removed from the device during mounting. 30 US patent specification 3,942,415 to Wassilieff and Shannon, for example, describes a device which includes a sachet of coloured material which is forced along a tail section in the device by pressure caused by mounting. US patent specification 4,239,018 to WO 2004/000158 PCT/NZ2003/000129 3 Griffin and Ryden describes a device which includes an ink capsule arranged so that ink is redistributed within the device by mounting. US patent specification 5,566,679 to Herriott describes a device which has two receptacles which are fixed onto a cow's back. When the cow is mounted, the mounting motion causes liquid in the receptacles 5 to commingle so that they chemically react to emit light. US patent specification 4,696,258 to Magrath et al describes a patch formed from micro-encapsulated dye particles which are embedded in a coating. Pressure caused by mounting breaks most of the micro-capsules in the pressure area, causing the dye particles to separate and attach to abase. 10 All of the prior art techniques described above require visual inspection by a farmer or farm manager. None of the prior art techniques describe the automation of the oestrus detection process to provide an objective assessment as to whether or not a particular cow is in heat, although automated techniques are available to measure and record 15 activity (through a pedometer) and the mounting of cows using a pressure plate transducer. None of the current techniques allow the human visual checking of an automated electronic digital device as this invention does. SUMMARY OF INVENTION 20 In broad terms in one form the invention comprises an oestrus indicator patch comprising a fabric layer configured to be secured to an animal; a reflective layer secured to the fabric layer; and a non-reflective coating adhered to and partially covering the reflective layer. 25 In broad terms in another form the invention comprises a method of detecting oestrus in animals comprising the steps of securing an indicator patch to an animal in a position to be contacted by an animal mounting the animal to which the patch is secured; capturing a digital image of the animal, the image including the indicator patch; and measuring 30 the visual appearance of the indicator patch in the digital image against a visual appearance threshold.

WO 2004/000158 PCT/NZ2003/000129 4 In another form in broad terms the invention comprises an oestrus detection system comprising a digital image capture device positioned to capture one or more digital images of an animal on which an indicator patch has been secured; an image selector configured to select one or more digital images from the captured digital image(s) that 5 includes an image of the indicator patch; and an image measurer configured to measure the visual appearance of the indicator patch in the selected digital image against a visual appearance threshold. BRIEF DESCRIPTION OF THE FIGURES 10 Preferred forms of the apparatus and method for automated oestrus detection will now be described with reference to the accompanying figures in which: Figure 1 shows an indicator patch of the invention secured to a cow; 15 Figure 2 shows a plan view of one preferred form indicator patch; Figure 3 shows a cross-section of the indicator patch of Figure 2; 20 Figure 4 shows a plan view of another preferred form indicator; Figure 5 shows a cross-section of the indicator patch of Figure 4; and Figure 6 is a schematic representation of digital image capture of the animal of Figure 1. 25 DETAILED DESCRIPTION OF PREFERRED FORMS Referring to Figure 1, the invention provides a responsive patch 10 which is secured to the body of an animal, for example a cow 20. Vigorous rubbing of the strip 10, for 30 example caused by mounting from another cow, causes the patch 10 to change visual appearance.

WO 2004/000158 PCT/NZ2003/000129 5 In one form of the invention, the patch 10 comprises a reflective strip which is painted with a substantially non-reflective paint. The paint is preferably selected so that it will be at least partly rubbed off the reflective strip during mounting activity, exposing areas of the reflective strip beneath the paint. 5 To secure the patch 10 to a cow 20, the cow is preferably brushed over the sacral spines and tail head area, indicated generally at 30 to remove loose hair and debris. A suitable adhesive is applied to the underside of the patch 10 and preferably to the cow and the patch then secured to the back of the cow 20 as shown in Figure 1. 10 It is preferable to place the patch 10 directly over the sacral spines in the mid-line at the most prominent point between a line joimng the tuber coxae indicated at 40 and 50 at the front and the cranial tail head 60 at the back. Positioning the patch 10 in this way leads to reduced movement and wrinkling of the strip from tail movement and reduces 15 the amount of paint lost through everyday wear and tear, and to maximising the amount of rubbing and removal of non-reflective coating that occurs at mounting. In some circumstances, it may be necessary to reapply new strips to mated cows, particularly in spring where a hairy coat that is moulting may cause problems with patch adherence and strips will also require replacement after they are activated by mounting. 20 Figure 2 illustrates a plan view of one preferred form indicator patch in accordance with the invention. The patch 200 includes a reflective layer 202 and a non-reflective coating 204 adhered to and partially covering the reflective layer 202. 25 The non-reflective coating 204 only partially covers the reflective layer 202. In one form both the non-reflective coating 204 and the reflective layer 202 are generally rectangular in shape. The non-reflective coating 204 is sized and positioned to leave a generally rectangular area at one end and preferably both ends of the reflective layer 202 not covered by the non-reflective coating 204. 30 The preferred non-reflective coating 204 (such as paint) is durable so that minimal scratching occurs, it is stretchable so that cracking does not occur with movement, and it WO 2004/000158 PCT/NZ2003/000129 6 adheres well to the reflective tape so that peeling does not occur. It is also preferable to use a matt finish, thereby reducing the amount of reflection off the paint, enabling greater accuracy in error calculations as will be described below. The preferred colour of the non-reflective coating 204 is black. 5 The non-reflective coating 204 is formed from a suitable material so that it can be scraped or rubbed off the patch 200 through friction caused by a mounting animal. It is not intended that the non-reflective coating 204 adheres to the mounting animal in a way that causes the non-reflective coating to peel off from the indicator patch. The non 10 reflective coating 204 is designed to be at least partly removed from the indicator patch due to friction rather than adherence to the mounting animal. Figure 3 illustrates the indicator patch 200 in cross-section. The patch 200 includes a fabric layer 206 to which the reflective layer 202 is secured. The reflective layer 202 15 and the fabric layer 206 are generally rectangular and have substantially the same surface area. It is envisaged that a suitable product such as 3M Scotchlite 9920 reflective material be used that includes both the reflective layer 202 and the fabric layer 206. 20 The fabric layer 206 is configured to be secured to the animal. The fabric layer 206 could have an adhesive layer 208 attached to the fabric layer 206. Where the adhesive layer 208 is pre-applied to the fabric 206 in this way, the patch 200 could include a cover layer 210 releasably attached to the adhesive layer 208 attached to the fabric layer 206. 25 Alternatively, it is envisaged that the user could simply apply a suitable adhesive to fabric layer 206 prior to securing the patch 200 to the animal. This arrangement would not require an adhesive layer 208 nor cover layer 210. 30 Figure 4 shows a plan view of another preferred form indicator patch 400. The patch 400 includes a reflective layer 402 and a non-reflective coating 404 equivalent to the reflective layer 202 and the non-reflective coating 204 respectively from Figures 2 and WO 2004/000158 PCT/NZ2003/000129 7 3. Where patch 400 differs from patch 200 is that patch 400 includes a border layer 406. As will be apparent from Figure 4, the border layer 406 has a larger surface area than the reflective layer 402 and non-reflective coating 404, and could be sized and positioned so that the border layer 406 frames the reflective layer 402. 5 Figure 5 illustrates a cross-section of patch 400. The patch includes a fabric layer 408 similar to the fabric layer 206 from Figures 2 and 3. The patch 400 could include an adhesive layer 410 in the form of a glue affixing strip securing the fabric layer 408 to the border layer 406. The border layer 406 is preferably formed of a suitable flexible 10 material such as fabric backing. The patch 400 could also include an adhesive layer 412 similar to adhesive layer 208 from Figures 2 and 3, and a cover layer 414 similar to cover layer 210 from Figures 2 and 3 releasably attached to the adhesive layer 412. 15 The dimensions of each indicator patch are preferably 150 x 50mm. It is envisaged that the specific dimensions of the strip could be varied slightly. Where the indicator patches are sold as a plurality of patches in a particular package, it is anticipated that the indicator patches sold in that package will be of substantially the same size and shape. 20 Having a consistent size and shape facilitates automatic processing of the indicator patches, as will be described below. The portions of reflective layer 202 and 402 not covered by the non-reflective coating assist automatic reading of the indicator patches as they provide a reflective reference 25 band at one or both ends of the indicator patch. Similarly, the border layer 406 assists automation, particularly where the border layer 406 is in a dark colour as it facilitates distinguishing between light coloured patches of hair on the animal and the reflective portions of the indicator patch, as will be described below. 30 Automated image analysis of the patch 10 is now described with reference to Figure 6. In one form, an image capture device 600 is mounted as shown, such as in a rotary cow milking shed, so that cows rotated around the shed pass under the image capture device.

WO 2004/000158 PCT/NZ2003/000129 8 The image capture device 600 could be mounted in a herringbone dairy shed or race, or an automated milking or feeding unit. In one form the image capture device 600 could comprise a digital camera interfaced to a processing device, for example a workstation 602 further comprising a data memory 604 and a data processor 606. The workstation 5 602 is preferably interfaced to secondary storage 608, for example a hard drive or optical drive for storing images. In one form the digital camera 600 could be arranged to capture successive digital images every few seconds, depending on the speed of rotation of the platform or 10 passage of cows. This series of images is then transferred to the workstation 602 for further processing. Image processing software installed and operating on the workstation 602 identifies and selects those images of each cow which include the patch 10. Images which do not include the patch 10, or do not include a good image of the patch 10, are discarded. 15 Alternatively, the image capture device 600 could comprise a camera arranged to capture an animated sequence of each cow passing under the camera 600. Frame grabbing software would identify those frames of the animated sequence which include a patch 10 and store those frames in secondary storage 608 for processing. 20 It is also envisaged that the camera 600 could include or be interfaced to motion sensors so that images are captured of cows when they pass under the camera. Alternatively, the camera could be interfaced to a timing reset device which is set to capture an image as a cow rotates around a rotary milking shed, for example using a reflective spot or 25 similar. A light source 610 is preferably also mounted in the same manner as the digital camera and arranged so that illuminating light 612 is directed downwardly toward the cow 20 and patch 10. Light reflected from the cow and patch 10 as shown at 614 is then 30 captured by camera 600. As cows are mounted, paint is rubbed off exposing a greater area of reflective material beneath the paint. A patch 10 which has had a large area of paint rubbed off will reflect a large amount of light from the light source 610. The WO 2004/000158 PCT/NZ2003/000129 9 digital image of this patch 10 will have a greater intensity and have a greater reflective area than an image of a patch from which the paint has not been rubbed off. Preferred form patch 400 from Figures 4 and 5 has a black border around its edges 5 providing a consistent background. Without such a border, when a large percentage of the paint is removed from a patch 10, the contrast between a white patch of hair, for example on a Friesian cow and the bright reflection of the patch 10 may appear similar when using a camera with an automatic aperture. The patch 10 could blend in with the cow 20, making it difficult to determine the outline of the patch. 10 In one form, the digital camera 600 could have a variable aperture which could be adjusted to the appropriate level of light intensity in the shed. Each patch 10 could then appear much brighter than any natural markings on the cow 20, enabling the camera or image processing software to differentiate between different levels of brightness or 15 intensity. This adjustment will generally work consistently with each patch. Where an illuminating light source 610 is used, the invention can determine whether or not a particular digital image includes an image of a patch 10 by selecting image objects in a digital image above a threshold of light intensity, to recognise the reference area or 20 border at one end or both ends of each patch. If the appropriate level of light intensity is recognised in a digital image, the invention calculates the exposed area as a proportion of total patch area, using the unpainted reflective reference band(s) at the end(s) of the patch as a reference for the outline, thus giving total area outline. 25 An advantage in calculating area as a proportion of total patch area instead of a value in mm 2 , is that the camera 600 does not have to be callibrated for height above the cow 20 for each patch, because an area ratio is correct for cows of varying heights. In this way, the system automatically calibrates indicator patches regardless of camera height above the animal, or the height of the animal within the working range. 30 WO 2004/000158 PCT/NZ2003/000129 10 Each patch 10 preferably has a threshold exposed : not exposed reflective material ratio value specific for each shed and/or farm, and if this ratio value of a patch is exceeded, the cow on which the patch is secured will be identified as being on heat. 5 It is also an advantage if the camera 600 is arranged to be accurate through a range of cow heights, for example 1.15 metres to 1.5 metres. Taller animals will decrease the distance between the camera 600 and the patch 10, causing greater distortion in the digital image. To minimise this effect, the digital camera is preferably mounted a sufficient distance from the patch 10, but is focussed to magnify the image of the patch, 10 thereby enabling high accuracy in area calculation. In one form, the reference bands at each end of the patch reveal the current width of the patch, enabling calculations of area to take into account the degree of curvature given to the patch while it is adhered to the cow, thereby making area calculations as accurate as 15 possible. The camera 600 is preferably also set at a sufficient angle that minimises distortion and is adjusted for a range of light intensities so that lighting of the shed, and lighting caused by the light source 610, can be taken into account. 20 In some circumstances, it is possible that dirt and/or manure may be deposited on a patch 10. As such contaminants are non-reflective, this may affect the intensity of the resulting digital image. Dirt, mostly manure, can be splattered onto a patch 10, especially on smaller cows in a crowded dairy yard at milking. The contaminants may 25 either be added to the paint area during calculation and taken as an error, or added to the reflective area and taken as an error, or identified and discounted from either area. How contaminants are treated will depend on the magnitude of the error measured through field testing. 30 The apparatus shown in Figure 6, for example the digital camera 600, workstation 602 and secondary storage 608 could be implemented as a single unit, or as a combination of networked components. It is also envisaged that image processing software for WO 2004/000158 PCT/NZ2003/000129 11 processing digital images could be implemented as a programmed microprocessor or could be programmed in a suitable programming language and stored on secondary storage 608 and/or workstation 602 or equivalent. Examples of such software include ImageTool tm or VIPS t n software or modifications. 5 It is envisaged that the apparatus shown in Figure 6 will work in combination with animal identification so that the result of imaging a particular animal can be linked to that specific animal. In one form the animal could be identified by an electronic ear tag, a subcutaneous transponder identifier, an intraruminal transponder, a retinal 10 identification system, or other biometric digital identification apparatus. The detection of oestrus or detection of no oestrus could be recorded for each animal in a database using a suitable animal identifier. Alternatively, the apparatus shown in Figure 6 could be set up in association with an 15 automatic drafting system. If a particular animal is detected as being in oestrus, the automatic drafting system opens a gate enabling the animal to pass through the open gate into an enclosure. An animal that is not in oestrus, on the other hand, could trigger another gate to open enabling the animal to pass through that open gate to an enclosure different from the first enclosure or allow the animal to exit the enclosure area. 20 The invention is particularly suitable for automatically detecting oestrus in cows due to the particular behaviour of cows toward each other during oestrus. It is envisaged that the invention could also be used to automatically detect natural mating activity between cows and bulls, and to detect mating activity in other high value farmed manummals for 25 example deer, Llama and Alpaca. It is also envisaged that the automated method described above could be used in conjunction with a visual inspection programme. The foregoing describes the invention including preferred forms thereof. Alterations and modifications as will be obvious to those skilled in the art are intended to be 30 incorporated within the scope hereof as defined by the accompanying claims.

Claims

1. An oestrus indicator patch comprising: a fabric layer configured to be secured to an animal; 5 a reflective layer secured to the fabric layer; and a non-reflective coating adhered to and partially covering the reflective layer.

2. An oestrus indicator patch as claimed in claim 1 wherein the fabric layer and the reflective layer are generally rectangular and have substantially the same surface area. 10

3. An oestrus indicator patch as claimed in claim 2 wherein the non-reflective coating is sized and positioned so that a generally rectangular area at one end of the reflective layer is not covered by the non-reflective coating. 15

4. An oestrus indicator patch as claimed in claim 2 wherein the non-reflective coating is sized and positioned so that respective generally rectangular areas at both ends of the reflective layer are not covered by the non-reflective coating.

5. An oestrus indicator patch as claimed in any one of the preceding claims 20 wherein the non-reflective coating comprises a black matt paint layer.

6. An oestrus indicator patch as claimed in any one of the preceding claims further comprising an adhesive layer attached to the fabric layer to attach the patch to the animal. 25

7. An oestrus indicator patch as claimed in claim 6 further comprising a cover layer releasably attached to the adhesive layer.

8. An oestrus indicator patch as claimed in any one of claims 1 to 5 further 30 comprising a border layer secured to the fabric layer, the border layer having a larger surface area than the fabric layer. WO 2004/000158 PCT/NZ2003/000129 13

9. An oestrus indicator patch as claimed in claim 8 wherein the border layer is sized and positioned so that the border layer frames the reflective layer.

10. An oestrus indicator patch as claimed in claim 8 or claim 9 wherein the border 5 layer has a colour contrasting to the reflective layer.

11. An oestrus indicator patch as claimed in any one of claims 8 to 10 wherein the border layer is substantially the same colour as the non-reflective coating. 10

12. An oestrus indicator patch as claimed in any one of claims 8 to 11 further comprising an adhesive layer attached to the border layer to attach the patch to the animal.

13. An oestrus indicator patch as claimed in claim 12 further comprising a cover 15 layer releasably attached to the adhesive layer.

14. A method of detecting oestrus in animals comprising the steps of: securing an indicator patch to an animal in a position to be contacted by an animal mounting the animal to which the patch is secured; 20 capturing a digital image of the animal, the image including the indicator patch; and measuring the visual appearance of the indicator patch in the digital image against a visual appearance threshold. 25

15. A method of detecting oestrus in animals as claimed in claim 14 wherein the indicator patch includes a reflective layer and a non-reflective coating adhered to and partially covering the reflective layer, the non-reflective coating arranged to be rubbed off the reflective layer during mounting activity. 30

16. A method of detecting oestrus in animals as claimed in claim 14 or claim 15 further comprising the step of directing a light source toward the indicator patch while capturing the digital image. WO 2004/000158 PCT/NZ2003/000129 14

17. A method of detecting oestrus in animals as claimed in claim 16 wherein the step of measuring the visual appearance of the indicator patch comprises the step of measuring the light intensity of the patch in the digital image against a threshold light 5 intensity.

18. An oestrus detection system comprising: a digital image capture device positioned to capture one or more digital images of an animal on which an indicator patch has been secured; 10 an image selector configured to select one or more digital images from the captured digital image(s) that includes an image of the indicator patch; and an image measurer configured to measure the visual appearance of the indicator patch in the selected digital image against a visual appearance threshold.