Examination of ruminant animals

A method for the examination of the condition of a ruminant animal including sampling odours from at least one part of the animal with an olfactory sensor thereby to identify specific aspects of the animal condition.

This invention relates to the examination of ruminant animals and more 
particularly to the examination of the teats and general condition of 
ruminant animals kept for milk. 
The teats of a milking animal need careful attention to determine that a 
teat is clean and healthy before milk is drawn from the teat, whether by 
manual or automatic methods. The routine washing of teats before milking 
is now considered more likely to increase rather than decrease damage and 
cross-infection, particularly if the teats are generally clean. Other 
aspects of animal health also need to be examined and the time of 
presentation for milking is convenient for this. Ruminant animals not in 
milk or not kept for milk also need to be examined for general health. 
There is therefore a need for a reliable technique for the general 
examination of ruminant animals. 
It is an object of the invention to provide a technique for the examination 
of the condition and health of a ruminant animal and more particularly one 
which can be applied in milking animal husbandry whether as part of a 
manual or automatic milking regime or independently. 
According to the invention there is provided a method for the examination 
of the condition of a ruminant animal including sampling odours from at 
least one part of the animal with an olfactory sensor thereby to identify 
specific aspects of the animal condition. 
According to an aspect of the invention there is provided a method for the 
examination of a teat of a milking animal including establishing an 
examination region in the air around a teat to be examined, purging the 
region, drawing a sample of air from the region, applying the sample to a 
sensor and providing a sensor output indicative of any response of the 
sensor to said sample. 
The invention also provides an apparatus to examine a teat of a milking 
animal including an examination device to receive a said teat, means to 
purge the examination device, means to support the device with said teat 
received therein, means to draw a sample of air from around the teat 
received in the device, means to apply said sample to a sensor and means 
to supply a sensor output indicative of sensor response to said sample. 
The examination device may be an open-top vessel into which a teat can be 
inserted. The device may be a teat cup like structure. 
The purging is arranged to at least reduce the inclusion of general ambient 
air in the sample, ensuring that the sample is representative of material 
diffusing from the teat or other part of the ruminant animal or a 
substance thereon. The purging air may be used as a reference for the 
sensor before a sample is taken. Purging air may be supplied selectively 
to the top and the bottom of the device. The purging may be by a flow of 
clean air, for example from a pressure bottle. The purging and sampling 
action may be controlled by a changeover valve. The sample may be drawn by 
a piston and cylinder arrangement operated by a lead screw actuator to 
enable a precise sample size. The purge air may drawn into a sample 
chamber then expelled to purge the region by the action of the piston and 
cylinder arrangement. The purge air and sample may flow in the same 
direction. The purge air and sample may be drawn past a sensor by suction. 
The sensor is conveniently one commonly called an electronic "nose", that 
is an olfactory sensor. Such a sensor can be based on a conducting 
polymer, a metal oxide or other sensing material for olfactory purposes, 
with associated electronic signal processing circuitry. 
The sensor can be arranged to sense diffusion from the teat or another part 
of the animal or a substance thereon of organic material characteristic of 
one or more of faecal material, blood, earth, the state of the metabolic 
process and the conditions of oestrus of ketosis. 
The method and apparatus may be arranged for operation manually by an 
operator or in response to a control instruction by a robot. Such a robot 
may be part of an automatic milking apparatus. The examination may be 
applied when an animal presents for milking. The examination may be 
carried out in a milking stall before a milking apparatus is applied to a 
teat. The examination may be carried out before an animal is permitted to 
enter a milking stall. In response to a sensor output indication of teat 
condition unsuitable for milking the examined teat may be washed and again 
examined. If an animal on examination has an unsuitable teat condition it 
may be directed away from a milking stall to an area for further 
examination. 
The apparatus, where in contact with the sample, is of an inert material. 
Conveniently this is polytetrafluorethylene. 
The apparatus may be fixed to an animal stall or the like where diffusion, 
exhalation or other evacuations of the ruminant animal are present for 
examination.

Embodiments of the invention will now be described with reference to the 
accompanying drawing which is a perspective view of an apparatus according 
to the invention. 
The apparatus shown in the drawing includes an examination device in the 
form of an open-top vessel VS to receive a teat of a milking animal and 
provide around a received teat a region which can be purged by an air flow 
and from which a sample of air can be drawn. A flow connection FC is 
provided at the lower, closed, end of the vessel. The flow connection is 
controlled by a valve CV which can be selectively operated to allow entry 
of pure air through one valve port PV and to allow extraction of sample 
air via FC through another valve port SP. A pressure bottle of pure 
compressed air or other gas (so-called zero air) is connected to the port 
PV. To the other port SP a piston and cylinder arrangement is connected 
with the connection to the cylinder offset to cause swirl in flow into the 
cylinder. 
The piston P is drivable to and fro in the cylinder C in controllable 
manner by an actuator AL. A sensor S is placed on a coupling block CB to 
be exposed to the sample drawn into the cylinder. The sensor is 
conveniently of the olfactory type, available commercially in various 
forms and commonly called an electronic "nose". An electronic circuit EC, 
connected via connector SC, is arranged to provide an indication of the 
response of the sensor at an indicator IND and over an output connection. 
The electronic circuit can also be arranged to control the valve and 
piston actuator and the operating cycle of the apparatus. Power also can 
be supplied through this connection. The exact form of the electronic 
circuit will be appropriate to the sensor used and the manner in which the 
indication is to be applied. Suitable electronic circuitry will be readily 
apparent to those skilled in the art. 
In operation the vessel is purged by a flow of air from the pressure 
bottle, either before being placed around the teat or when the teat is in 
place, the purge flow being controlled by the valve. In one arrangement 
the purge air flows through the valve into the cylinder with the piston 
withdrawn and is then sent to the vessel through the valve by operating 
the piston. A sample is then drawn from the space around the teat by 
operating the valve to connect the space to the piston and cylinder, if 
not already so-connected, and again withdrawing the piston along the 
cylinder. The offset flow connection encourages a swirl in air movement in 
the cylinder. 
The response of the sensor to the sample is derived by the electronic 
circuit and an output indication provided. After examination of a sample 
the piston and cylinder and sensor can also be purged by pure compressed 
air. A dwell time may be needed for the proper response of the sensor. The 
profile of the sensor response as the sample is drawn past may be 
significant as the proportion of material may vary during the sample flow. 
The parts of the apparatus in contact with the sample must not cause 
contamination of the sample, for example by retaining part of an earlier 
sample or by releasing material into the sample. Polytetrafluoroethylene 
(ptfe) is a suitable substance for such parts of the apparatus. 
In a specific form of the apparatus the control valve is a 3-way TEFLON 
(RTM) valve supplied by NResearch of New Jersey USA, which is operated at 
12V dc. The piston and cylinder are made from ptfe with an O-ring to seal 
the piston to the cylinder. The O-ring must not release or retain sample 
material. The piston is operated by a stepper motor lead screw actuator of 
the AIRPAX (RTM) type L92211-P2, operated at 12V dc. Such an actuator can 
provide a very precise drive of the piston at a selected speed so that the 
sample and purge volume can be accurately set. Conveniently the purge 
volume is greater than the sample volume and the cylinder is sized for the 
purge volume. 
It is important that the sample does not include air from other than the 
region around the teat. If air from outside this region is included in the 
sample false results may be obtained. The teat may bring with it stray 
"odours" and the purging action is therefore preferably carried out with 
the teat in the vessel. The vessel VS must, of course, be clean to avoid 
false results. A check may be made of the empty vessel between tests. The 
vessel could be routinely cleaned at each test. 
The apparatus can be hand-held (grip G) or supported by a shaft (H) or 
other means, for example on a milking robot such as is described in UK 
patent publication 2226941, incorporated herein by reference. 
The handling of the animal after examination is determined by the 
indication of the sensor response so as to be milked, have a cleaning 
action carried out or be directed to another area for further examination. 
In another form of the apparatus the flow route is of different form. A 
further supply of zero air as purge air is introduced at port PV' of 
additional unit ZA at and around the top of the examination device, such 
as vessel VS, into which the teat is received. In this way the drawing in 
of ambient air, with the possibility of bringing in stray odours, is 
further reduced. The flow route is now always in the same direction, as 
explained below. The flow path at the sensor S is preferably such as to 
produce a flow across the sensor rather than allow a volume of gas to 
collect around the sensor. Sensors for humidity and temperature of the 
flow are also fitted here. The piston and cylinder arrangement is operated 
to bring about the required flow rate along the flow route. It is possible 
to use suction from some external source, such as the vacuum of a milking 
apparatus (not shown), as an alternative to the piston and cylinder 
although some indication of flow rate may be needed to enable consistent 
sensor results. The lower part of the vessel VS can be openable to aid 
cleaning. It may be sufficient to line the vessel and other parts with 
ptfe. Zero air may also be selectively supplied directly to the piston and 
cylinder arrangement and extracted therefrom as a purging action. The 
exact physical form of the apparatus can be altered to suit a chosen 
component selection or other constraint as will be apparent to those 
skilled in the art and in accordance with the precautions indicated. 
In operation of the form of the apparatus just described at the beginning 
of an examination the purge supply of air or other gas, such as the 
so-called zero gas, is made available at port PV'. The piston P is 
positioned in the cylinder end close to the sensor. Before the 
introduction of a teat for examination into the vessel VS the purge supply 
at PV' is started. With the teat in place, or earlier if required, the 
valve CV is operated as above to supply zero air which, by slow movement 
of the piston along the cylinder, is drawn over the sensor S. 
When the purge is effective the valve CV is operated and the purge supply 
to the sensor replaced by the zero air and any odours from the vessel VS 
where the teat is in place. The movement of the piston is continued. This 
brings about the flow of zero air past the teat in vessel VS and draws 
odours from the teat past the sensor S so that significant odours can be 
assessed and indicated as before. 
In a further form of the apparatus a teat-cup like examination device is 
fitted with an olfactory sensor. Gas flow paths are provided to the top 
and bottom of the teat-cup like device, the flow path to the bottom of the 
device including the sensor. Zero air can be selectively supplied to each 
flow path. The top flow path conveniently discharges around the top of the 
device. Suction can be selectively applied to the flow path to the bottom 
of the device. 
In operation of this further form zero air is firstly caused to flow along 
the flow path to the bottom of the device, past the sensor, and then up 
through the device and out the open top, past a teat in place in the 
device. This zero air flow is used to calibrate the device as well as 
purge any stray odours. The zero air supply is then transferred to the 
flow path to the top of the device and suction applied to the flow path 
extending to the bottom of the device. Zero air is thus drawn past a teat 
in the device and then past the sensor for the sensor to respond to any 
odours swept along with the zero air flow past the teat. Suitable valves 
or other flow control and electronic circuit arrangements will be apparent 
to those skilled in the art having regard to the descriptions above. A 
suitable seal, operated by differential pressure, may be provided at the 
top of the device so that the purge air flow can escape, the seal being 
open, while when suction is applied the seal operates so that only zero 
air from the top flow path passes the teat and ambient air cannot enter. 
The guidance above on materials and cleaning applies to this further form 
of the apparatus. 
Reference has been made above to the nature of response by the sensor. 
Typical response by the sensor is for a significant resistance change to 
occur over a period of about ten seconds starting some five seconds after 
the flow of the sample from the space around the teat. When cow faecal 
material is present on the teat the sensor resistance change is about 
twice that when faecal material is not present. The change of the sensor 
resistance generally reduces again as the flow continues, for both clean 
and dirty teats. Relative humidity and temperature can affect the sensor 
response and these can be sensed so that the olfactory sensor response can 
be properly interpreted by the electronic circuitry. It may be necessary 
to make some "trial" runs of the apparatus before actual use to ensure 
that a proper reference condition has been established for a particular 
combination of humidity and temperature. 
It is desirable to achieve as long a life as possible from the olfactory 
sensor. These sensors can deteriorate due to contamination and can "drift" 
if sensed materials are retained. For these reasons it is desirable to 
maintain the sensor in clean air except when in use. The purge supply can 
be arranged to do this without excessive consumption. 
As described above the teat to be examined is received into a device such 
as a vessel. In another embodiment a vessel is not used and a structured 
air flow can be used to direct air which may carry significant odours from 
an area of interest of an animal to the sensing apparatus. The purge 
action can be provided by the structured flow. 
Examination of the exhaled breath from the respiratory tract of a ruminant 
can be used instead of a blood test,for certain conditions. A blood test 
involving taking a blood sample and then analysis for each animal is 
expensive and, because it is invasive, unattractive. By capturing exhaled 
breath from the nostrils of a ruminant animal and examining this for 
odours, useful information can be acquired. Purging, as mentioned above, 
is needed and any collection device needs to be a close fit to the 
nostrils of the animal. 
As the breath examination can be done regularly and frequently without 
professional intervention, such as is required for a blood test, it is 
relatively cheap and can be carried out at milking time and used as a 
control input for a milking regime control system, relating to feeding, 
milking and other aspects of the regime. 
The invention also provides general sensing of an animal condition by 
examination of a sample, such as a sample of breath, by apparatus 
including an olfactory sensor for conditions such as oestrus and ketosis. 
Appropriate modifications for the apparatus will be apparent to those 
skilled in the art. Diffusion, exhalations or other evacuations of a 
ruminant animal can also be sensed. The apparatus may be fixed to a stall 
where the breath or other odour of the animal or animal waste products is 
likely to be present, for routine testing. Various conditions of the 
animal may tested including metabolism and these tests are relevant to 
ruminants in general, whether kept for meat or milk purposes.