A method of establishing the quality and/or composition of milk

Abstract: A method of establishing the presence of specific substances in the milk and an implement for applying same, in which method one or more sources irradiate the milk consecutively or simultaneously with radiation of different wavelengths and/or intensities and one or more receivers establish the reflected and/or absorbed radiation intensities during a period of time.

Description: The invention relates to a method of determining the quality and/or the composition of milk by means of measurements according to the preamble of claim 1. Such method is known from the document NL 1004980. This document discloses a method in which the intensity values of a number of colours in the milk are established and in which the milk is yielded from individual animals. By comparing the intensity values with the values recorded during previous milkings, the presence of specific substances, such as contaminations, is established. This method has the disadvantage that the intensity values of the milk vary to a great extent, depending on the amount of surrounding light. Moreover the results cannot be interpreted quantitatively, as only changes relative to previous milkings are recorded. The invention aims at obviating the above-mentioned drawbacks or at least minimizing same. In accordance with the invention this is achieved by the characterizing features of claim 1. In this manner the radiation intensity of the background is established. This makes it possible to correct the radiation intensities that are measured when the sources are switched on. In a preferred embodiment the periods of time for establishing the reflected radiation intensities are constant. In this manner it is achieved that the established radiation intensities can easily be compared. One or more values of one or more established reflected radiation intensities can be stored in a memory, so that the values can be compared with previously obtained values. On the basis of the values of the established radiation intensities there is determined a proportion of the values. A calibration value is formed by the progressive average of the values and/or proportions of the values obtained for a specific animal during a defined number of most recent milkings. A calibration value can also be formed by a measurement effected on a calibration means such as a transparent liquid, reference milk, a calibration rod, white paper, a white tile, rinsing liquid or water. The values can also be compared with previous calibration values. In a preferred embodiment, the values and/or proportions of values are compared, both mutually and with previous values and/or calibration values and/or proportions recorded during one or more previous measurements, and the results of this comparison process are indicated. According to an inventive feature, the results of the comparison process are displayed in such a manner that the presence and/or concentration of specific substances, such as contaminations in the milk, can be read immediately. According to a further inventive feature, a further receiver receives the radiation directly from the source, and the value obtained by the first receiver is adjusted with the aid of a value obtained by the further receiver. In this manner it is possible to establish the intensity of the radiation emitted by the source. When the source ages, which is not only relevant to radioactive sources, but also to incandescent lamps, or when the source is contaminated, the intensity of the radiation will decrease. This will affect the value of the established radiation intensity. Said value can be corrected by means of the value of the radiation intensity established by the further receiver. It is also possible to adjust one or more proportions of values by means of values obtained by the further receiver receiving the radiation directly from the source. In a preferred embodiment the source and the receiver are coupled to a periodic signal, such as a square signal or a saw-tooth signal, said receiver establishing the radiation intensity when the source has almost attained a constant intensity. By means of the periodic signal there is achieved a synchronization of the source and the receiver. First the source is switched on, whereupon the receiver establishes the radiation intensity. Many sources have a heating-up time before attaining a constant or maximum intensity. After the heating-up time has elapsed, it is possible for the receiver to establish the radiation intensity. The source can also be switched on directly by the periodic signal. According to another inventive feature, the source comprises light sources emitting radiation having one or more discrete wavelengths, which wavelengths relate to the absorption characteristic of specific substances in the milk, such as proteins or fats, and the receiver establishes the radiation intensity, and the presence and/or concentration of one or more substances in the milk is established. In this way it is achieved that the milk is irradiated with a radiation having a wavelength which is absorbed by specific substances in the milk. By comparing the intensity of the emitted radiation with the radiation established by the receiver, it is possible to establish the light absorption of a specific wavelength. Thus it is possible not only to demonstrate the presence of a specific substance, but also to determine the concentration of said substance. In accordance with an inventive feature, the measurement of the composition of the milk comprises the establishment of the presence and/or quantity of one or more of the following substances: blood, urine, excrements, contamination, Ecoli bacteria, hormones, flocks, rinsing liquid, air. All these substances can be established by measuring the reflected radiation of the source. Besides, the measurement also comprises the establishment of the fat content and/or the cell count and/or mastitis and/or colostrum and/or grass milk (milk produced after the consumption of grass). In a preferred embodiment, the measurements are effected on milk yielded from individual animals. In this manner it is possible to check the quality of the milk of an individual animal. When the animal is on heat, or is in a bad condition, e.g. due to illness, this can be detected in time. The measurements can also be effected on milk yielded from separate udder quarters. The values and/or proportions of values can be compared mutually as well as with previous values and/or values obtained from different udder quarters, and the results of this comparison process can be indicated. In this manner it is possible for example to separate in time milk containing blood or pus yielded from an udder quarter before this milk is mixed with milk yielded from the other quarters. According to a further inventive feature, one or more measurements are effected when the flow sensor indicates that the milk is flowing. In this manner it is achieved that measurements are effected during milking. In a preferred embodiment, the source comprises light sources which irradiate the milk consecutively or simultaneously with red-coloured, green-coloured, blue-coloured light, and which are switched off consecutively or simultaneously. According to a further inventive feature, the proportions RG, RB and GB of the established radiation intensities are calculated as RG=(r-a)/(g-a), RB=(r-a)/(b-a), GB=(g-a)/(b-a), r being the established radiation intensity during irradiation of the milk by a source of red-coloured light, g being the established radiation intensity during irradiation of the milk by a source of green-coloured light, b being the established radiation intensity during irradiation of the milk by a source of blue-coloured light and a being the established radiation intensity during the period of time when the light sources are switched off. The proportions RG, RB and GB can be multiplied by correction factors depending on the calibration values. These calibration values can be based on measurements effected on reference liquids. The proportions can also be multiplied by the values of the radiation intensities established by the further receiver receiving the radiation directly from the light source. In a further embodiment the feeding of an animal is established on the basis of a measurement effected on the milk. By measuring the milk there can be established that for example the colour green has a rather high intensity. This is an indication that the animal has consumed grass instead of the usual portion of concentrate. The invention will now be explained in further detail with reference to the accompanying drawings, in which Figure 1 shows a milking system provided with the colour measuring system; Figure 2 shows a milk line on which there is disposed a sensor; Figure 3 shows an embodiment of the sensor not in accordance with the invention, and Figure 4 shows another embodiment of the sensor. Figure 1 shows four teat cups 1 to be connected to the teats of an animal to be milked, the milk lines 2 of said teat cups 1 debouching into a milk glass 3. To the milk glass 3 there is further connected a vacuum line 15 for the purpose of applying a vacuum in the milk glass 3 itself, in the milk lines 2 and in the teat cups 1, said vacuum being required to keep the teat cups connected to the teats of the animal, to milk and to separate the milk and the air present therein from each other. From the milk glass 3 the milk obtained is discharged, via a valve 4, a pump 5, a non-return valve 6 and a three-way valve 7, through a line 8, to a (non-shown) milk tank. In the figure there is further indicated a colour measuring system 9 comprising a processing unit 10 to which four colour sensors 11 are connected. These sensors 11 are preferably disposed on the milk lines 2 of the individual teat cups 1. In other embodiments the sensors 11 may also be disposed in the milk glass 11", in the milk, or in an overflow reservoir 14. The processing unit records the values measured by the sensor. These measured values can be passed to a computer 12 for being processed further. Figure 2 shows a sensor 11 which is included in a milk line 2. The sensor 11 consists of a light source 16 and a receiver 17, disposed together in a housing 19. The receiver 17 is provided with screening means, so that only the light from the light source 16 reflected by the milk is received by the receiver 17. The housing 19 is preferably designed such that the light source and the receiver are screened from surrounding light. In a preferred embodiment the light source is a multicolour LED by means of which the milk can be irradiated with different colours of light. The LED can be activated by means of a periodic signal, such as a square signal or a saw-tooth signal. The receiver can also be coupled to this signal, so that both the source and the receiver are synchronized. Each time when the source attains a constant intensity, the reflected and/or absorbed amount of radiation is established by the receiver. Figure 3 shows a sensor not in accordance with the invention in an arrangement in which the receiver 17 is located opposite the source 16. In this case the quality of the milk is measured by means of the absorption of radiation of different wavelengths. In this situation the absorbed quantity of light of specific wavelengths is a measure for the presence and/or concentration of specific substances in the milk. Both the source and the receiver are accommodated in a separate housing. Figure 4 finally shows an alternative embodiment in which a further receiver 18 is disposed in the sensor, which further receiver 18 measures the radiation directly from the source. In this manner the intensity of the radiation emitted by the source can be established. When the source ages, or when the source is contaminated, the intensity of the radiation will decrease. This will affect the value of the established radiation intensity. Said value can be corrected by means of the value of the radiation intensity established by the further receiver.

Claims: A method of determining the quality and/or the composition of milk by means of measurements, in which method: a source irradiates the milk consecutively with radiation of different wavelengths, while, during at least part of the time when the source is switched on, a receiver establishes reflected radiation intensities during a period of time; the values of the thus obtained radiation intensities are stored in a memory; the values are compared mutually as well as with previous values recorded during a previous measurement; and that the results of this comparison process are indicated, characterized in that during a measurement the source is switched off, while, during at least part of the time when the source is switched off, the receiver establishes reflected radiation intensities during a period of time; in that the values of the thus obtained radiation intensities are stored as background values in a memory; in that the background values are incorporated in the values obtained during the period of time when the source is switched on; and in that the values adjusted by the background values are stored in a memory. A method as claimed in claim 1, characterized in that a proportion of the values and/or background values are determined. A method as claimed in claim 1 or 2, characterized in that a calibration value is formed by the progressive average of the values and/or proportions of values obtained for a specific animal during a defined number of most recent milkings. A method as claimed in any one of claims 1 to 3, characterized in that a calibration value is formed by a measurement effected on a calibration means such as a transparent liquid, reference milk, a calibration rod, rinsing liquid or water. A method as claimed in claim 3 or 4, characterized in that the values are compared with previous calibration values. A method as claimed in any one of claims 1 to 5, characterized in that the values and/or proportions of values are compared, both mutually and with previous values and/or calibration values and/or proportions recorded during one or more previous measurements, and the results of this comparison process are indicated. A method as claimed in claim 6, characterized in that the results of the comparison process are displayed in such a manner that the presence and/or concentration of specific substances, such as contaminations in the milk, can be read immediately. A method as claimed in any one of claims 1 to 7, characterized in that a further receiver receives the radiation directly from the source, and the value obtained by the first receiver is adjusted with the aid of a value obtained by the further receiver. A method as claimed in claim 8, characterized in that one or more proportions are adjusted by means of values obtained by the further receiver receiving the radiation directly from the source. A method as claimed in any one of claims 1 to 9, characterized in that the source and the receiver are coupled to a periodic signal, such as a square signal or a saw-tooth signal, said receiver establishing the radiation intensity when the source has almost attained a constant intensity. A method as claimed in any one of claims 1 to 10, characterized in that the source comprises light sources emitting radiation having one or more discrete wavelengths, which wavelengths relate to the absorption characteristic of specific substances in the milk, such as proteins or fats, that the receiver establishes the radiation intensity, that the presence and/or concentration of one or more substances in the milk is established. A method as claimed in any one of claims 1 to 11, characterized in that the measurement of the composition of the milk comprises the establishment of the presence and/or quantity of one or more of the following substances: blood, urine, excrements, contamination, Ecoli bacteria, hormones, flocks, rinsing liquid, air. A method as claimed in any one of claims 1 to 12, characterized in that the measurement of the composition of the milk comprises the establishment of the fat content and/or the cell count and/or mastitis and/or colostrum and/or grass milk (milk produced after the consumption of grass). A method as claimed in any one of claims 1 to 13, characterized in that the measurements are effected on milk yielded from individual animals. A method as claimed in any one of claims 1 to 14, characterized in that the measurements are effected on milk yielded from separate udder quarters. A method as claimed in any one of claims 1 to 15, characterized in that the values and/or proportions of values are compared mutually as well as with previous values and/or values obtained from different udder quarters, and the results of this comparison process are indicated. A method as claimed in any one of claims 1 to 16, characterized in that one or more measurements are effected when a flow sensor indicates that the milk is flowing. A method as claimed in any one of claims 1 to 17, characterized in that the source comprises light sources which irradiate the milk consecutively or simultaneously with red-coloured, green-coloured, blue-coloured light, and which are switched off consecutively or simultaneously. A method as claimed in claim 18, characterized in that the proportions RG, RB and GB of the established radiation intensities are calculated as RG=(r-a)/(g-a), RB=(r-a)/(b-a), GB=(g-a)/(b-a), r being the established radiation intensity during irradiation of the milk by a source of red-coloured light, g being the established radiation intensity during irradiation of the milk a source of green-coloured light, b being the established radiation intensity during irradiation of the milk by a source of blue-coloured light and a being the established radiation intensity during the period of time when the light sources are switched off. A method as claimed in claim 19, characterized in that the proportions RG, RB and GB are multiplied by correction factors depending on the calibration values. A method as claimed in any one of claims 1 - 20, characterized in that the feeding of an animal is established on the basis of a measurement on the milk.

Inventors: VAN DEN BERG KAREL, VAN LIER WILHELMUS JOHANNES AD, VIJVERBERG HELENA GERALDA MARI, VAN DEN BERG, KAREL, VAN LIER, WILHELMUS JOHANNES ADRIANUS, VIJVERBERG, HELENA GERALDA MARIA
Applicants: MAASLAND NV, MAASLAND N.V.
Application year: 1999
Main classification: A01J5
IPC codes: G01N33, A01J11, A01J5, G01N21