Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01J—MANUFACTURE OF DAIRY PRODUCTS
  • A01J5/00—Milking machines or devices
  • A01J5/013—On-site detection of mastitis in milk
  • A01J5/0133—On-site detection of mastitis in milk by using electricity, e.g. conductivity or capacitance
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01J—MANUFACTURE OF DAIRY PRODUCTS
  • A01J5/00—Milking machines or devices
  • A01J5/013—On-site detection of mastitis in milk
  • A01J5/0134—On-site detection of mastitis in milk by using filters or decanters
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
  • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
  • G01N27/06—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a liquid
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/02—Food
  • G01N33/04—Dairy products

Definitions

• the invention relates to a method specified in the preamble of claim 1.
• the conductance signal which is derived from a conductivity measurement cell is generated, which is arranged in the flow path of the milk of a teat, is a very noisy signal. Particularly in the case of insufficient milk delivery, there are strong signal fluctuations which do not allow usable conductivity measurement. Another difficulty is that the conductivity of the milk is subject to fluctuations which are seasonal and which also depend on other factors, such as the composition of the feed. Because of the difficulties mentioned, an early detection of teat diseases on the basis of the electrical conductivity of the milk dispensed using the on-line method, that is to say immediately when the milk is taken from the animal, has only been possible with considerable uncertainties.
• the invention has for its object to provide a method of the type specified in the preamble of claim 1, which enables reliable detection of glandular inflammation on a teat directly during milk delivery.
• the conductivity signals of the individual measuring cells are first subjected to digital filtering with a signal processor, signal frequencies which are above 0.2 Hz being suppressed.
• An analog low-pass filter with such a low limit frequency cannot be implemented or can only be implemented with great effort.
• the digital signal processor is therefore used, which does a spectral analysis of it carries out supplied electrical signals, for example a Fast Fourier transform.
• low-pass filtering can be carried out using simple technical means with a very low upper limit frequency.
• the upper limit frequency does not necessarily have to be 0.2 Hz, but it can also be lower, for example 0.1 Hz.
• the conductivity signals filtered in this way are compared with one another from measuring cell to measuring cell, so that deviations in the individual teats due to illness can easily be determined.
• a teat is preferably recognized as sick when the filtered conductivity signal of the milk it delivers is above the conductivity signals of the milk delivered by the other teats by a fixed (adjustable) percentage.
• the comparison can be made in each case with the conductivity of the milk supplied by the teat whose milk has the lowest conductivity.
• the conductivity signals are further filtered by suppressing amplitude values that deviate from previous amplitude values of the same measuring cell by more than a predetermined amount. This ensures that outliers do not falsify the measurement result.
• the predetermined measure is expediently determined as a proportion or percentage of the earlier amplitude values, which are preferably the last measured amplitude values of the same measuring cell.
• the milking process is expediently divided into intervals for each teat cup, each of which has a predetermined period of time. The entire milking process thus consists of numerous time intervals of equal length, which are continuously numbered.
• a characteristic conductivity value is determined in each interval, which is evaluated and stored.
• the characteristic conductivity value is preferably the evaluable peak value that has occurred in the relevant interval, but another value, for example the mean value of this interval, can also be used as the characteristic value.
• Each of the milking processes which are carried out in the morning and evening, day after day, can differ from other milking processes over several days.
• differences in the conductance of 1000 ⁇ S / cm are noticeable within 3 days.
• the method according to the invention enables the characteristic conductivity values of the numerous intervals of a milking process to be stored and compared with the characteristic conductivity values of several previous milking processes.
• the suspicion of subclinical mastitis can always be assumed if the differential conductivity jumps up by a few hundred micro-Siemens within a few milking processes.
• the absolute level of the conductivity value is irrelevant.
• the classic case of subclinical mastitis is that milk is released from one teat with a conductivity that is 1000 or 2000 ⁇ S higher than that of the milk of the other three teats.
• the conductivity of the milk of the three healthy teats is within a range of approx. 200 to 400 ⁇ S, this can be assumed to be normal. In contrast, the conductivity of a diseased teat regularly deviates upwards by more than 1000 ⁇ S.
• the foremilk is due to the highest susceptibility to germination in the first seconds of the Milking process has a higher conductivity, which then drops quickly and in the main milking assumes a lower value in a healthy cow, which can change continuously.
• 1 is a schematic representation of the milk flow from a teat cup to a milk tank
• FIG. 2 shows a schematic representation of the measuring chamber which contains the conductivity measuring cell
• Fig. 6 shows the time course of the conductivity in a teat, in which a progressive disease is found over several days.
• Fig. 1 the teat cup 10 of a milking machine is shown which has four such teat cups.
• the teat cup 10 is attached to the teat of a cow in a known manner.
• At the outlet of the teat cup 10 there is a flow meter 11 and from this a line leads into the measuring chamber 12.
• the milk reaches the milk collector 14 via a magnetically controlled valve 13.
• the milk collector 14 unites in the milk collector 14 the milk flows from all four teat cups.
• the milk collector is connected to a periodically operating suction pump 15 and to a tank 16 in which the milk is collected.
• a branch line 17 leads from the valve 13 into a collector 18 for inferior milk.
• the valve 13 is switched to the milk collector 14, but it is switched to the collector 18 if germ-containing milk is detected in the associated measuring chamber 12 on the basis of an excessively high conductivity.
• the measuring chamber 12 is shown schematically in FIG. 2. It has a housing 19 with an inlet 20 i lid and an outlet 21 in the bottom. In the housing 19 there is a collecting container 22 below the inlet 20, into which the milk falls from the inlet 20. In the collecting container 22, the measuring cell 23 is arranged, which consists of an excitation coil 24 and a here coaxial receiver coil 25 or secondary coil. The two coils 24 and 25 form an ironless transformer.
• the excitation coil 24 is fed by an oscillator 26 with an excitation frequency of approximately 5 to 10 kHz.
• a the receiver coil 25 a voltage which is amplified by an amplifier 27. This voltage forms the conductivity signal.
• the conductivity signal supplied by the measuring cell 23 is fed to a multiplexer 28, which also receives the conductivity signals of the measuring cells assigned to the three other teat cups and supplies the four conductivity signals to an analog / digital converter 29 in time-multiplex mode.
• the conductivity signals are processed in digital form in the digital signal processor (DSP) 30.
• DSP digital signal processor
• the signal processor carries out a Fast Fourier analysis and a low-pass filtering or band filtering, frequencies between 0.01 and 0.1 Hz being passed through and all other frequencies being suppressed.
• amplitude filtering is carried out in the signal processor 30, and those amplitude values which deviate from the previous amplitude values of the same measuring cell by more than a predetermined amount (15%) are suppressed.
• the filtered conductivity signals represent values of a milking process are stored in a table in the RAM memory 31. Furthermore, the output signals of the signal processor 30 are fed to a further processor 32, in which they are compared with signals that have been stored in the memory 31, that is to say with conductivity signals from previous milking processes.
• the output 33 of the processor 32 supplies a signal to an alarm device 34 and to the magnet 13a of the magnetic valve 13 (FIG. 1) when milk is detected from a teat which is diseased, so that this valve is switched over to the collector 18.
• An input / output device 25 is also connected to the processor 32, on which the guide values of the current milking process can be graphically displayed on a screen, as well as the guide values of previous milking processes retrieved from the memory 31.
• the output device 35 also contains a keyboard with which the limit values and permissible proportions (percentages) for filtering and evaluating the conductance signals can be set.
• the processor 32 also receives the signal from the flow meter 11, which measures the amount of milk dispensed. If milk flows from a teat very sparsely, a signal is also generated. This flow monitoring function can also end the milking process if the signal is sent to the suction pump 15.
• the digital signal processor 30 effects the filtering out of the usable conductivity signals and the processing of these signals into a characteristic signal for each interval.
• the processor 32 carries out the administration and evaluation of the prepared characteristic conductivity values.
• the milking process consists of the phases pre-milking VG, main milking HG and post-milking NG.
• the typical time profile of the conductance of milk from a healthy teat is denoted by 36. It can be seen that the conductance is subject to strong fluctuations and is "noisy", which is due in particular to the influence of the suction surges of the suction pump 15 (FIG. 1), which are effective in the measuring chamber.
• the smoothed course of the conductance curve of milk from a diseased teat is designated by 37.
• the guide values are approximately 1000 ⁇ S / cm above curve 36.
• the entire milking process is divided into numerous intervals of 6 seconds each, which are plotted along the time axis t in FIG. 5 and which are numbered consecutively.
• a characteristic conductivity value is determined in each of these intervals. that is marked by a dot.
• the characteristic conductivity value is the peak value in the respective interval, that is to say the amplitude of a signal peak.
• curve 36 in FIG. 5 contains a pronounced region 38 of high frequency and large amplitude fluctuation. This area 38 is suppressed. There is no formation of a characteristic conductivity value determined for evaluation. The filtering does not smooth the undesired signal area, but ignores it in the evaluation.
• the digital signal processor 30 supplies the characteristic conductivity values, which are marked by dots in FIG. 5 and denoted by 39, together with the associated interval numbers to the processor 32 and the memory 31 , documented, with all characteristic conductivity values 39 with their interval numbers being stored in a table for each teat cup.
• the processor 32 compares the characteristic conductivity values of the four teat cups, interval by interval, with one another in order to be able to determine a curve of a teat which deviates from the other curves, and it also compares the curves of the current milking process with the stored curves of previous milking processes, separated by teats , the inter- valle are assigned to each other.
• the conductance k is plotted against time, the time being given in days.
• 40 is the curve of a healthy teat and 41 is the curve of a diseased teat.
• Each of the curves 40 and 41 consists of points, each of which represents a characteristic value of a milking process, for example the mean value of all characteristic values 39.
• the teat disease is determined when the value of the curve 41 is around one certain percentage (15%) deviates from the previous values of the same teat. The diseased teat is still in the early stages of the disease.

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• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Biochemistry (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Environmental Sciences (AREA)
• Pathology (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Animal Husbandry (AREA)
• General Health & Medical Sciences (AREA)
• Food Science & Technology (AREA)
• Immunology (AREA)
• Medicinal Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
• Feed For Specific Animals (AREA)
• Investigating Or Analysing Biological Materials (AREA)
• Fodder In General (AREA)
• Feeding And Watering For Cattle Raising And Animal Husbandry (AREA)
• External Artificial Organs (AREA)

Priority Applications (2)

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Publications (1)

Family

ID=6401703

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Citations (3)

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• 1990
  • 1990-03-08 DE DE4007327A patent/DE4007327C1/de not_active Expired - Lifetime
• 1991
  • 1991-02-27 DE DE59103916T patent/DE59103916D1/de not_active Expired - Fee Related
  • 1991-02-27 WO PCT/EP1991/000364 patent/WO1991014179A1/de not_active Ceased
  • 1991-02-27 ES ES91905030T patent/ES2066426T3/es not_active Expired - Lifetime
  • 1991-02-27 EP EP91905030A patent/EP0518907B1/de not_active Expired - Lifetime
  • 1991-02-27 AT AT91905030T patent/ATE115725T1/de not_active IP Right Cessation
  • 1991-02-27 DK DK91905030.2T patent/DK0518907T3/da active
  • 1991-03-06 WO PCT/EP1991/000415 patent/WO1991013543A1/de not_active Ceased
  • 1991-03-07 PT PT96972A patent/PT96972B/pt not_active IP Right Cessation

Patent Citations (3)

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