NL1035925C

NL1035925C - Determination of infectious condition in a milk gland during milking.

Info

Publication number: NL1035925C
Application number: NL1035925A
Authority: NL
Inventors: Theodorus Johannes Maria Camu; Tjerk Martin Huitema
Original assignee: Idento Operations B V
Priority date: 2008-09-12
Filing date: 2008-09-12
Publication date: 2010-03-16
Also published as: EP2334167A1; WO2010030184A1

Description

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Determination of infectious condition in a milk gland during milking.

The invention relates to a method and an apparatus for 5 determining clinical or subclinical infection in a milk gland in the udders of milking animals.

Several principles for detecting such infections rely on the presence of smaller or larger clots in the milk. Other 10 principles rely on the conductivity or acidity of the liquid, or on the temporal distribution of the supply of milk from the gland.

Modern milking machinery has to perform according to 15 established standards and practices which is based on an ability to detect infection in an animal in order that the milk delivered may be diverted from further use until the infection has subsided. For this reason it is not required that a detailed diagnosis or treatment 20 plan is the result of determining the infection, only that it precisely informs about the condition.

To this purpose it has been determined that the collection of clots on a substrate that permits the passage of all 25 other constituents of the raw milk is an efficient approach. The simplest method is visual inspection, such as it is described in US 4,385,590. The most used method of determining the presence of clots is optical,by measuring the reflection of the relatively bright clots against the 30 background,which is made to appear darker by the control of materials and illumination. However, introducing a further complication in the form of photoelectrical components into an environment that is usually considered adverse to 1035925 I 1 2 electronics entails the use of very expensive components and/or encapsulations, and the cleaning by rinsing or other CIP processes may be be subjected to limitations, thereby increasing the cleaning time.

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According to the invention a novel principle for detecting clots has been developed that eliminates the problems of the known solutions. The method is particular in that the pressure drop across the substrate is monitored to indicate 10 that infection is present. The pressure drop is directly related to the amount of clots present on the substrate, because they occlude part of the surface and so increases the flow resistance through the substrate.

15 In an advantageous embodiment of the invention the pressure across the substrate is logged and that a pattern of generally increasing pressure is used as an indicator for the presence of clots. This has the particular advantage that a range of well-known pressure measuring sensors may be 20 used.

In an advantageous embodiment of the invention the pressure is measured as the head of milk in the sensor chamber when the milk is streaming through the substrate. This has the 25 particular advantage that the level is a particularly sensitive pressure indicator, in which a 10 mm change in level approximates a pressure change of 0.001 bar.

In a further advantageous embodiment of the invention the 30 head of milk is measured as the conductivity of the milk between electrodes that are covered by the milk as it rises in the sensor chamber due to a pressure increase. This had the particular advantage that a robust and reliable signal 1 ' 3 is obtained that can directly be converted to a tabular value.

An apparatus for performing the method is particular in that 5 it comprises a sensor chamber, an inlet for milk, a substrate, an outlet for milk and milk pressure sensing means for measuring the hydrostatic milk pressure at the substrate.

10 The invention will be described in greater detail in the following with reference to the drawing, in which:

Fig. 1 shows a side view of an apparatus for performing the invention, and 15 Fig. 2 shows a section through the middle of the apparatus.

In Fig. 1, milk from one of the teat cups enters the apparatus at a milk inlet 1, and gravity will permit it to exit from a milk outlet 2. If this outlet is blocked, the 20 chamber 3 is gradually filled with the milk, and if no change in the outlet conditions occur, the milk will eventually pass through an overflow or bypass outlet 4 to be collected or otherwise disposed of.

25 The apparatus as shown consists of a top part 5 comprising the bypass outlet 4, a bottom part 6 comprising inlet 1 and outlet 2, and the chamber 3 placed in between, the whole being held together by long bolts 7a and 7b. The chamber is made as a transparent cylinder, and gaskets ensure the 30 tightness against leaks (from the inside to the outside) or contamination (from the outside to the inside).

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The whole construction is designed for cleaning-in-place (CIP). The construction shown is by no means limiting for possible other embodiments of the apparatus.

5 In Fig. 2 the inside and operational parts of the apparatus are visible. Instead of passing directly from the inlet to the outlet 2 the milk passes through a substrate in the form of a mesh or filter structure 8 that is fitted tightly to the bottom part 6 at the outlet 2 by means of a 10 ring 8a. This mesh or filter is dimensioned in such a way that normal milk containing water and fat globules passes through without creating more restriction in the flow that the milk rises up into the bottom part 6.

If, however, clots are deposited on the filter 8 the 15 restriction to the flow (flow resistance) increases, because less free area is left for the flow, and the pressure to transport the milk through the filter increases. This pressure increase is directly noticeable by the rise of the milk level inside the apparatus; the pressure 20 corresponds to the height of the column of milk.

The milk level may be detected by several means, including optical means or magnetic float means, but in the present embodiment it is detected by means of measurement of the 25 conductivity between electrodes more or less covered by milk. These electrodes are thin and rod-shaped and shown at 9; they are vertically placed with connectors 10 at the top. The ends are supported by insulating means 11 to ensure that the distance between them is maintained. Suitable signal 30 processing on the measurement values will indicate the average and peak levels of the milk as well as the development in level over time.

5 A fast clotting of the filter 8 will mean a steep development in the milk level, which is detected by the control system reacting on the measurement values. This means that the milk discharged via the bypass outlet 4 will 5 be considered milk that is not useable in further dairy production and which is collected separately.

To prepare for reuse after the milking machinery has been disconnected from the udder containing the diseased milk 10 gland, the whole apparatus is flushed with warm water, in a direction preferably from the outlet 2, ensuring that all parts that have been in touch with the contaminated milk are cleaned. The filter is completely regenerated thereby, and the apparatus is ready for the next milking 15 operation. The identification code of the cow is logged and suitable treatment instituted.

In conclusion, the problem and its solution are essentially that infection in a milk gland causes milk obtained to be 20 discarded. The detection of an infection is efficiently made by observing the presence of clots in the milk. Frequently this is performed by observation of clots on a contrasting background. According to the invention the detection is performed by measuring and monitoring the resistance 25 to flow through a substrate (8) on which the clots are deposited and partly block the passage.

The foregoing description of the specific embodiments will so fully reveal the general nature of the present invention 30 that others skilled in the art can, by applying current knowledge, readily modify or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and therefore, 6 such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed 5 herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of forms without departing from the invention.

10 Thus, the expressions "means to ... " and "means for or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical, or 15 electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited functions, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying 20 out the same function can be used; and it is intended that such expressions be given their broadest interpretation.

1035925

Claims

A method for detecting an infection in a mammary gland of the udder of dairy animals during a milking operation, comprising collecting clots on a permeable substrate (8) placed in a sensor chamber (3,5,6) while milk flows through the substrate characterized in that the hydrostatic pressure drop over the substrate (8) is monitored to detect a rise in pressure as an indicator for the presence of clots.

2. Method according to claim 1, characterized in that the pressure drop over the substrate (8) is recorded and that a pattern of a generally rising pressure is used as an indicator for the presence of clots.

Method according to claim 1 or 2, characterized in that the pressure is measured as the head of the milk in the sensor chamber as the milk flows through the substrate (8).

Method according to claim 3, characterized in that the milk cup is measured as the conductivity of the milk between electrodes (9) that are covered by the milk as it rises in the sensor chamber (3) due to a pressure increase. 30 1035925

A device for performing a method according to claim 1, characterized in that the device comprises a sensor space (3,5,6), an inlet (1) for milk, a substrate, an outlet (2) for milk and 5 milk pressure recording means for measuring the hydrostatic milk pressure at the substrate (8).

Device as claimed in claim 5, characterized in that the milk pressure sensor means comprise a flow resistance-dependent milk column in the sensor chamber (3) and electrodes (9) covered by milk up to the height of the column and means for measuring the electrical conductivity between the electrodes ( 9). 1035925