GB2448748A

GB2448748A - Milk sampling device

Info

Publication number: GB2448748A
Application number: GB0708148A
Authority: GB
Inventors: Michael Christian; George Girvan; Richard Todd
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-27
Filing date: 2007-04-27
Publication date: 2008-10-29
Also published as: GB0708148D0

Abstract

A device for extracting a milk sample from an animal. The device comprises a teat cannula 1 having a channel for receiving milk, and a connector 3 arranged to sealingly interconnect the channel in the cannula with a container 6. The pressure inside the container can be reduced in order to facilitate sample collection. The container can take the form of a tube having a self sealing membrane and the connector can take the form of needle able to pierce said membrane. The device allows milk samples to be collected in an aseptic manner. A method of using the device is also claimed.

Description

Sampling Device The present invention relates to a device for removing

samples of milk from an animal, in particular a dairy animal such as a cow, goat or sheep, and to methods for extracting milk samples using the device.

It has long been recognised that it is difficult to collect milk samples in an aseptic manner. The environment found in for example dairy sheds or around herds of dairy cows is generally highly contaminated with food and faecal material, all of which makes it hard to extract samples in an aseptic manner.

In general, up to half the samples collected from dairy cows are found to be contaminated and cannot be used for bacteriological analysis. Furthermore, contaminated samples deteriorate rapidly, frequently before being tested, in particular where tests are conducted at remote locations.

This is a problem for example in the diagnosis of bacterial mastitis and when conducting quarter cell counting, as contamination can directly affect the results in those cases.

A device for aseptic sampling is described by Vangroenweghe et al., Vet. Res. 32 (2001), 565-579, in which a sample is taken via a sterile cannula which is linked to a collection bag by way of lengthy an infusion unit. Milk infuses into the bag under gravity.

The device however, is slow and unwieldy to use, requiring either support devices or multiple handlers to use.

According to the present invention, there is provided a device for extracting a milk sample from an animal, said device comprising a teat cannula having a channel for receiving milk, and a connector arranged to sealingly interconnect the channel in the cannula with a container, said container being one in which the pressure is reduced or reducable.

By using a reduced pressure, for example a partial or complete vacuum to draw a sample through the teat cannula and into the container, asceptic samples from single quarters can be taken readily and quickly, by a single operative.

Suitably the device further comprises the container, which may be integral with the connector. Alternatively, the container may be a separate element that is for single use.

In one embodiment, the container comprises the barrel of a syringe arrangement. In this embodiment, the base of the cannula may be adapted to sealingly engage with the opening in the barrel of the syringe provided at the neck and which usually accommodates a needle, and this arrangement acts as the connector. In this embodiment, drawing down the plunger of the syringe will reduce the pressure in the barrel, thus drawing a milk sample into the barrel of the container.

Alternatively, the container comprises a sealed vacuum container, such as those sold under the trade name Vacutainer .

In this instance, the container comprises a test tube that is sealed by means of a rubber cap comprising a membrane of a "self-sealing" material, as is known in the art. The container is at least partially evacuated so that pressure within the container is reduced. Therefore, when the cap is punctured, for example by means of a needle, sample is positively drawn into the container through the needle.

In this embodiment, the connector used to interconnect the cannula with the container includes a needle which can penetrate the cap. In particular the connector comprises a support, into which the base of the cannula can be fixed. The support further includes or may accommodate a needle, projecting in the opposite direction to the cannula.

The needle and/or cannula can be connectable to the support by any suitable means, including for example, Luer locks, adhesives or screw threaded interconnections.

Caps may be provided for one or both of the needle and cannula to ensure that they remain aseptic prior to use. The caps are suitably of a rubber or plastics material and may be held in place by means of a screw thread arrangement or they may be of the snap-fit variety.

In a particular embodiment, the support is adapted to engage with a needle holder, which can fit over the cap of the container so that the needle projects through the self-sealing cap of the container. In this way, when the cannula is in position within the teat, the needle holder may be placed over the cap of the container so that the needle pierces the cap.

A sample from within the teat is then drawn through the cannula and enters the container by way of the needle.

In a particular embodiment, the cannula is provided with multiple slots or holes, which open into the central channel, so as to minimise the risk that clots within the milk sample will clog up the device and prevent it from working. However, the fact that the device utilises reduced pressure to draw sample into the container will prove useful in this respect.

The cannula itself is suitably detachable from the support and disposable, so as to minimise waste. The support and/or the needle may then be sterilised for further use.

Thus in a further aspect, the invention provides a connector adapted for use in the device as described above. Cannulae specifically adapted for attachment to the connector may also be novel, and those with such specific adaptations form a further aspect of the invention.

Samples taken using the device described above are suitable for use in a variety of milk testing including quarter cell counting and bacteriology, and in particular in the diagnosis of mastitis.

They may be use to extract milk samples from any suitable animal including for example, cows, sheep, goats, camelids or equidae.

In a further embodiment, the invention provides a method for extracting a sample of milk from an animal, said method comprising inserting a cannula of a device as described above into the teat of said animal, if necessary, interconnecting the cannula with the container by way of the connector, and drawing sample into the container.

Where the cannula is integral with the container, for example in the form of a syringe, there will be no need to specifically interconnect the cannula with the container after insertion.

It is merely necessary to draw out the plunger of the syringe so that the sample is sucked into the barrel of the syringe.

Where the container is of the Vacutainer type, insertion of a needle in the support through the cap is necessary to effect the interconnection and to ensure that the drawing down occurs.

The invention will now be particularly described by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 is a perspective schematic view of a device embodying the invention; Figure 2 is a side section through of the device of Figure 1; Figure 3 is an enlarged view of a cannula of the device; and Figure 4 illustrates an alternative embodiment of a device of the invention.

The device (Fig. 1) comprises a teat cannula (1) which is fixed to a support (2) . The support (2) further comprises a needle (3) which is in fluid communication with a central channel (4) in the cannula (1) and which extends in the opposite direction to the cannula (1).

The support (2) is attachable to a needle holder (5) for example by means of a screw thread arrangement (not shown).

In this instance, the container comprises a tube (6) which is at least partially evacuated, and which is sealed by means of a cap (7) . The cap (7) includes a self-sealing membrane (not shown), which extends across a central aperture.

In use, the cannula (1) is inserted into the teat of an animal such as a cow, sheep or goat. The needle (3) is then pushed through the membrane of the cap (7) into the tube (6) . The reduced pressure within the tube (6) then draws a milk sample down from the teat, through the cannula (1) and needle (3), into the container (6).

When the sample has been taken, the cannula (1) may be removed from the teat and the needle (3) extracted from the cap (7).

On withdrawal of the needle (3), the self-sealing membrane within the cap (7) immediately reseals the container (6), thus isolating it from the environment and ensuring the integrity and sterility of the sample.

Where possible, the cannula may be detached from the support and discarded. The support (2) and or the needle holder (5) may then be reused.

Figure 3 shows an enlarged view of a particular form of a cannula (1) which may be used in the invention. The cannula includes not only a central channel (4) but a number of laterally arranged slots or holes (B) which feed into the channel (4). I0

The channel (4) opens at the lower end into a needle (3) (although in this Figure, the connector is not shown), which may be used to pierce a self-sealing membrane (9) of an evacuated tube (10). The support and needle holder (2,5) in this instance are shown schematically.

An alternative embodiment of the device is illustrated in Figure 4. In this case, the cannula (1) with the transverse holes (8) is fitted into the open neck (11) of a syringe (12) When the plunger (14) of the syringe (11) is withdrawn in the direction of the arrow, a partial vacuum is induced in the barrel (13) of the syringe drawing milk through the cannula (1) and directly into the barrel (13), from where it may be transferred to a sterile container for testing.

In each case, sterile milk samples can be obtained easily and rapidly.

Claims

Claims 1. A device for extracting a milk sample from an animal, said

device comprising a teat cannula having a channel for receiving milk, and a connector arranged to sealingly interconnect the channel in the cannula with a container, said container being one in which the pressure is reduced or reducable.
2. A device according to claim 1 further comprising the container.
3. A device according to claim 1 or claim 2 wherein the container is a vessel which is at least partially evacuated and sealed by means of a self-sealing cap, and wherein the connector includes a needle in fluid contact with the channel of the cannula and being able to pierce said cap.
4. A device according to any one of the preceding claims wherein the cannula is detachable from the connector.
5. A device according to claim 2 wherein the container is barrel of a syringe arrangement and a base of the cannula sealingly engages with an opening in the barrel of the syringe.
6. A connector adapted to sealingly interconnect a teat cannula and a container, for use in the device according to claim 1.
7. A teat cannula adapted for attachment to a connector of claim 6.
8. A method for extracting a sample of milk front. an animal, said method comprising inserting a cannula of a device according to any one of claims 1 to 6 into the teat of said animal, if necessary, interconnecting the cannula with the container, and drawing sample into the container.