AU677499B2

AU677499B2 - Mechanical milking process

Info

Publication number: AU677499B2
Application number: AU14539/95A
Authority: AU
Inventors: Goswin Haver; Bernhard Schulze Wartenhorst
Original assignee: Westfalia Separator GmbH
Current assignee: GEA Mechanical Equipment GmbH
Priority date: 1994-03-02
Filing date: 1995-01-24
Publication date: 1997-04-24
Anticipated expiration: 2015-01-24
Also published as: AU1453995A; EP0748155A1; BR9506923A; JPH09509575A; WO1995023501A1; CA2184605A1; DE4406741A1; IL112801A0; ATE168526T1; EP0748155B1; PL315839A1; NO963636D0; DE4406741C2; NO963636L

Abstract

Before the main milking phase there is a mechanical stimulation phase divided into a pre-stimulation phase in which no significant quantity of milk is yet extracted and a subsequent control phase in which the change in the pressure cycle in the intermediate space in the udder cup reduces the intensity of the pressure exerted on the udder by the cup rubber in such a way that milk is extracted. The main milking phase starts as soon as the flow of milk exceeds a predetermined threshold which is selected so that adequate stimulation of the beasts is ensured and over-stimulation is prevented.

Description

Mechanical milking process The invention concerns a mechanical milking process, wherein for the extraction of milk in the inner space of an udder cup placed onto the udder a predetermined vacuum is applied and a pulsation of a cup rubber is carried out with a predetermined frequency and force by means of alternately ventilating and evacuating an intermediate space in the udder cup and with the udder cup in place in a stimulation phase for a predetermined time before the main milking phase the maximum pulse vacuum is reduced and this has a stimulating effect on the udder.

Such a process is known, for example, from DE 30 47 579 C2, where the duration of the stimulation is determined by a preselected time. The result of the stimulation phase cannot be checked in this case. Since, however, each kind of milking animal and each animal reacts differently depending from the lactation state, in this case one can deal only with a compromise for all animals. It has been established in the practice, that these processes could lead to negative reactions in the animals due to overstimulation. These phenomena is particularly evident at the beginning of the lactation by the animal or when the milker by manually stimulating the udder during pre-milking and the cleaning of the udder lets the udder of the animals be affected by the mechanical stimulation time without shortening it. These too long a stimulation times lead then to a disturbing milk delivery behaviour of the animals.

A similar problem occurs at the end of the lactation of the animals in case of a too short a stimulation phase. In this phase the need for stimulation by the animals is greater, so that a longer stimulation time is necessary to achieve a good milk extraction and short milking times.

From DE 36 21 666 C2 a mechanical milking process is already known, wherein the stimulation time is set in accordance with the lactation stage of the animals. However, in this case too the setting is a fixed one, which does not take into V!AL4.

consideration the individual need for stimulation by the individual animal and the manual stimulation carried out by the milker.

The object of the invention is to produce a method with which the individual need to stimulate the animal is taken into consideration.

This objective is achieved by that the stimulation phase is divided into a pre-stimulation phase, in which no significant quantity of milk is yet extracted, and a following control phase, in which by altering the progress of the pressure in the intermediate space of the udder cup the intensity of the pressure on the udder by the cup rubber is reduced so that an extraction of the milk is carried out and the main milking phase commences as soon as the milk flow exceeds a specified threshold value.

The duration of the pre-stimulation phase is to be selected so, that an overstimulation of the animals to be milked is reliably prevented. In this phase the stimulation can be carried out in the known manner. In the subsequent control phase the clamping pressure of the cup rubber on the udder of the animals is reduced, without changing the character of the stimulation phase. By this an extraction of the milk is possible in combination with an increasing inner pressure of the udder. The increasing intensity of the milk flow is in this case an indication of the achieved stimulation and makes it feasible to determine the duration of individual stimulation.

It is definitely not enough to change to the normal milking rhythm after the pre-stimulation phase is finished and then measure the intensity of the milk flow, because due to the subsequent complete opening of the cup rubber the lactiferous duct of the udder opens as the result of the existing vacuum and this results in the unhindered extraction of milk from the stored milk present in the udder. At the same time animals, which are easy to milk and have very easily opening closing 2 'K 7* iu\ I 'P C'IA muscles of the udder, have in a short while a milk flow of over 2 kg/min, despite the lack of readiness for the milk. In any case, the milk flow collapses after a short while and therefore this is not suitable as an indicator for the result of the stimulation phase.

In case of an advantageous development the progress of the pressure is changed by prolonging the ventilating phase of the intermediate space of the udder cup. The duration of the ventilating phase is to be chosen so that the intensity and the magnitude of the pressure building up in the intermediate space of the udder cup would differ considerably from the values effective in the pre-stimulation. By virtue of this in the control phase a smaller pressure will act via the cup rubber on the tip of the udder, due to which in case of adequate internal pressure of the udder the natural resisting force of the closing muscle of the udder can be overcome and thus the milk will reach the milking machine. When the prior specified milk flow is exceeded, the stimulation phase ends and the main milking phase will commence.

In case of a further advantageous development the ventilating phase is chosen so, that the evacuation of the intermediate phase of the udder cup takes place immediately after reaching the atmospheric pressure. Therefore the full pressure acts only for a very short while on the udder, due to which the udder during the entire pulsation is subjected mainly to a smaller pressure, so that milk can be extracted already during this time.

The extraction of the milk can be also facilitated by that the duration of the ventilating phase prevents the reaching of the atmospheric pressure.

The duration of the pre-stimulation phase should be at least sec. During this time a stimulation is carried out, causing the pouring out of the oxytocin up to the threshold value of the individual animal. Only then can the control phase commence and t -I following it the milking. Otherwise there is the danger that due to an internal pressure of the udder an irrelevant value of the milk flow will be measured, which, however, does not yet mean a readiness of the animal to be milked. If the prestimulation had already been carried out adequately manually by the milker, the mechanical control phase can commence immediately.

To avoid an overstimulation in any case, the duration of the pre-stimulation phase must be 35 sec. maximum.

As very easily milked animals reach a certain milk flow intensity already without adequate stimulation, a threshold value of minimum 300 mL/min has proved itself for the milk flow. It could be advantageous to increase the threshold value to a minimum of 500 mL/min. This depends, inter alia, from the differently equipped milking stations, e.g. whether the milking hoses are situated high or low.

The duration of the entire stimulation phase should be limited in time to prevent a disadvantageous long stimulation phase in case the threshold value is not reached.

The affect of the process according to the invention is explained in detail based on the drawing. Shown is in: Fig.l the progress of the pressure in the pre-stimulation phase, Fig.2 the progress of the pressure in the control phase with atmospheric pressure, Fig.3 the progress of the pressure in the control phase without atmospheric pressure.

In Figs.l to 3 the progress of the vacuum "Pu" is shown in the intermediate spaces of the udder cup as the function of time I -PI As it can be seen from Fig.l, a pulse cycle in the prestimulation phase consists of the evacuation phase suction phase ventilating phase and pressure phase The pressure phase is in this case clearly evident. Therefore the cup rubber hardly opens, so that no milk is extracted. The strived for stimulation of the animals is carried out by a high number of pulsation.

The progress of the pressure in the control phase according to Fig.2 differs from the stimulation phase by the prolongation of the ventilation phase to a value, by which the time for the pressure phase will be strongly reduced. Due to this the atmospheric pressure is reached for a short while only. This leads to a longer opening of the cup rubber, so that the desired milk flow will he achieved.

If, according to Fig.3, the ventilation phase is extended longer, the pressure phase will be omitted and the atmospheric pressure will not be reached. The pressure on the udder is thus considerably reduced and the extraction of the milk is facilitated.

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Claims

1. A mechanical milking process, wherein for the extraction of milk in the inner space of an udder cup placed onto the udder a predetermined vacuum is applied and a pulsation of a cup rubber is carried out with a predetermined frequex,-y and force by means of alternately ventilating and evacuating an intermediate space in the udder cup and with the udder cup in place in a stimulation phase for a predetermined time before the main milking phase the maximum pulse vacuum is reduced and this has a stimulating effect on the udder, characterised in that the stimulation phase is divided into a pre-stimulation phase, in which no significant quantity of milk is yet extracted, and a following control phase, in which by altering the progress of the pressure in the intermediate space of the udder cup the intensity of the pressure on the udder by the cup rubber is reduced so that an extraction of the milk is carried out and the main milking phase commences as soon as the milk flow exceeds a specified threshold value.

2. A process according to claim i, characterised in that the progress of the pressure is changed by prolonging the ventilating phase of the intermediate space of the udder cup.

3. A process according to claim 2, characterised in that the prolongation of the ventilating phase results in the immediate evacuation of the intermediate phase of the udder cup after reaching the atmospheric pressure.

4. A process according to claim 2, characterised in that the prolongation of the ventilating phase results in a renewed evacuation of the intermediate phase of the udder cup before reaching the atmospheric pressure.

A process according to any one of the claims 1 to 4, characterised in that the duration of the pre-stimulation phase is at least 20 sec. 6 IS r -s

6. A process according to any one of the claims 1 to 4, characte" sed in that the duration of the pre-stimulation phase i sec. maximum.

7. A process according to any one of the claims 1 to 6, characterised in that the threshold value for the milk flow is 300 mL/min minimum.

8. A process according to any one of the claims 1 to 7, characterised in that the entire stimulation phase is limited in time. -I s.A