A method of automatically milking animals and a fully automatic milking machine suitable for performing same

Abstract: In a method of automatically milking animals which are allowed to visit individually a milking parlour comprising a milking robot and an animal identification system, an animal visiting the milking parlour is milked when since the previous milking of the relevant animal at least a specific number of milkings (Q) of other animals has taken place. On the basis of at least one animal parameter a milking number (x) is allotted to each animal, which milking number (x) indicates how often the relevant animal has to be milked per unit of time. The specific number of milkings (Q) for each animal is calculated as a function of the corresponding milking number (x). As a result of the fact that the threshold value of the milking criterion depends on an individual target number for the number of milkings of the relevant animal, a desired number of milkings per unit of time can be achieved for each animal.

Description: The invention relates to a method as described in the preamble of claim 1. The invention further relates to a fully automatic milking machine which is suitable for performing said method. Such a method is known. When an animal visits the milking parlour, there is decided on the basis of a milking criterion whether or not the animal will be milked. The European patent EP-A-0 091 892 describes a system in which a cow is milked in the milking parlour, when at least a predetermined period of time has elapsed since her last milking. This has inter alia the disadvantage that mutual differences between the animals to be milked are not taken into account. Moreover it is necessary to measure each time for each animal the beginning and the end of the milking and to record these data, which requires measuring equipment that is sensitive to interference and occupies relatively much memory capacity. From the international patent WO-A-95/35028 it is known to use as a milking criterion the number of milkings of other animals since the previous milking of the relevant animal; in this situation the animal is milked when this number at least equals a specific minimum number, which may differ per animal. This milking criterion can be realized with the aid of simple and cheap means. The invention aims at working out such a method in further detail and to refine and improve same. According to the invention this is achieved by means of the measures described in the characterizing part of claim 1. As a result of the fact that the threshold value of the milking criterion depends on an individual target number for the number of milkings of the relevant animal, a desired number of milkings per unit of time can be achieved for each animal. In a preferred embodiment of the invention, the specific number of milkings is calculated in such a manner that it is proportional to the total number of milkings of all the animals per unit of time, divided by the individual milking number, multiplied by the number of milkings of the relevant animal per unit of time in a recent period of time, divided by the individual milking number. In practice it has appeared that in this manner for each animal the desired number of milkings per unit of time can be realized to a great degree of accuracy. Figure 1 is a table for cows showing horizontally as a first animal parameter P1 the anticipated milk yield per 24 hours and vertically as a second animal parameter P2 the number of days in the lactation period. In parameter P1 the cows are divided into four classes on the basis of their anticipated milk yield: from 0 to 10 kg milk per day, from 10 to 20 kg, from 20 to 40 kg and above 40 kg. In parameter P2 there are three classes: 0 - 15 lactation days, 15 - 250 lactation days and more than 250 lactation days. For the combination of the two parameters P1 and P2 there are thus defined 12 classes. The user himself can also apply other animal parameters, such as the movement activity of the animal (which can be measured inter alia by means of a pedometer known per se) and/or the animal's age and/or the animal's feed consumption and/or the health of the animals's udder (which can be measured inter alia with the aid of means for analyzing the milk). Also in this situation classes can be defined. On the basis of the reference tables and/or on the basis of empirical data, to each class a milking number x is allotted, which milking number indicates how frequently each animal in that class has to be milked. Of course the table can also be refined in such a manner that each class only comprises one cow. The table with the classes and their milking numbers is recorded in a computer which is connected to the animal identification system. The computer is adapted to adjust automatically the individual milking number x when an'animal passes to an other class. When a cow comes to the milkbox of the milking robot in order to be milked, the animal is recognized by the animal identification system. The computer calculates the milking criterion, on the basis of which there is decided whether or not the cow will be milked. She is milked when since her previous milking at least a specific number of milkings Q of other animals (a threshold value) has taken place. The specific number of milkings Q is now determined for each animal as a function of the corresponding milking number x, so that a desired number of milkings per unit of time can be achieved for the animal. For example, the threshold value Q can be calculated as follows. The total number of milkings M of all the animals per unit of time is divided by the individual milking number x and multiplied by a correction factor C: Q = C * M / x For example, a group of cows was milked totally 161 times in the past 24 hours. A specific cow has an average daily milk yield of 28 kg over the last seven days and has been in lactation for 155 days. From the table (see Figure 1) results for this cow a milking number of 2.8 milkings per 24 hours. 161 milkings divided by 2.8 is (rounded down) 57. Consequently, from a statistical point of view, this cow would have to be milked again after 57 milkings of other cows. When applying such a strict milking criterion, in order to be milked at a sufficient frequency, the cows would have to present themselves rather often at the milking robot. However, as a result of the fact that the milking behaviour of the cows is not very regular, the number 57 is still multiplied by a correction factor C ranging between 0.5 and 1.0 and amounting e.g. to 0.75. Then Q will have the value 43. In this manner it is achieved that the target number x is realized for all the cows to a lesser or greater extent. In a preferred embodiment, Q is determined as follows. The total number of milkings M of all the animals per unit of time is divided by the individual milking number x, multiplied by the number of milkings m of the relevant animal per unit of time in a recent period of time, divided by the individual milking number x, and finally multiplied by a correction factor C: Q = C * M * m / x 2 The factor m/x is thus added as an extra variable to the equation. This factor still gives a further correction, in case in a recent period of time, e.g. in the last 12 hours, a cow was milked more or less often than would have been the case on the basis of the target number x. For example, the number m can be determined by measuring the period of time that has elapsed since the last but one milking of the relevant cow and by deducing from this period of time the (fictitious) number of milkings of this cow in the last 24 hours. When the last but one milking of the relevant cow took place 11.65 hours ago, this means a fictitious number of milkings of 4.1 in the last 24 hours. This is more than the target number 2.8, so that Q is corrected by being rounded up. At a total of again 161 milkings in the last 24 hours, an individual milking number of 2.8 milkings per 24 hours and a correction factor of 0.75, Q now obtains the value 63. Hence, the cow is milked again, provided that 63 milkings of other cows have taken place since her last milking.

Claims: A method of automatically milking animals, such as cows, which are allowed to move freely in an area intended therefor and to visit individually a milking parlour comprising a fully automatic milking machine or milking robot and an animal identification system, in which method an animal is milked during a visit to the milking parlour when since the previous milking of the relevant animal at least a specific number of milkings (Q) of other animals has taken place, characterized in that , on the basis of at least one animal parameter there is allotted to each animal a milking number (x) indicating how often the relevant animal has to be milked per unit of time, while the specific number of milkings (Q) is calculated for each animal as a function of the corresponding milking number (x). A method as claimed in claim 1, characterized in that the animal's milk yield per unit of time is used as an animal parameter. A method as claimed in claim 1 or 2, characterized in that the stage of the lactation period in which the animal is, is used as an animal parameter. A method as claimed in any one of claims 1 - 3, characterized in that the animal's age is used as an animal parameter. A method as claimed in any one of claims 1 - 4, characterized in that the movement activity of the animal is used as an animal parameter. A method as claimed in claim 5, characterized in that the movement activity is measured by means of a pedometer. A method as claimed in any one of claims 1 - 6, characterized in that the feed consumption of the animal is used as an animal parameter. A method as claimed in any one of claims 1 - 7, characterized in that the health of the animal's udder is used as an animal parameter. A method as claimed in any one of claims 1 - 8, characterized in that the choice of the animal parameters used can be adjusted by the user. A method as claimed in any one of claims 1 - 9, characterized in that in each animal parameter used each animal is classified. A method as claimed in any one of claims 1 - 10, characterized in that , when an animal passes to an other class, the individual milking number (x) is adjusted automatically. A method as claimed in any one of claims 1 - 11, characterized in that the specific number of milkings (Q) is calculated in such a manner that it is proportional to the total number of milkings (M) of all the animals per unit of time. A method as claimed in claim 12, characterized in that the specific number of milkings (Q) is calculated in such a manner that it is proportional to the total number of milkings (M) of all the animals per unit of time, divided by the individual number of milkings (x). A method as claimed in any one of claims 1 - 13, characterized in that the specific number of milkings (Q) is calculated in such a manner that it is proportional to the number of milkings (m) of the relevant animal per unit of time in a recent period of time. A method as claimed in any one of claims 1 - 14, characterized in that the specific number of milkings (Q) is calculated in such a manner that it is proportional to the number of milkings (M) of all the animals per unit of time, divided by the individual number of milkings (x), multiplied by the number of milkings (m) of the relevant animal per unit of time in a recent period of time, divided by the individual milking number (x). A method as claimed in claim 13 or 15, characterized in that as a proportionality factor there is used a correction factor (C) ranging between 0.5 and 1.0. A fully automatic milking machine or milking robot comprising an animal identification system and a computer connected thereto characterized in that said milking machine or milking robot is suitable for performing the method as claimed in any one of claims 1 - 16.

Inventors: VAN DEN BERG KAREL, VAN DER LELY ALEXANDER, VAN OVERVELD CORNELIS JOHANNES, VAN DEN BERG, KAREL, VAN DER LELY, ALEXANDER, VAN OVERVELD, CORNELIS JOHANNES MARIA
Applicants: MAASLAND NV, MAASLAND N.V.
Application year: 1999
Main classification: A01J5
IPC codes: A01J5, A01J7