Understanding VaDia Viewer data

Transcription

1 Understanding VaDia Viewer data 1. FOREWORD This document is intended to help you understand the data logged with your VaDia. It contains interesting examples of real-life VaDia recordings and a short explanation of what you see and what can be concluded. This document is written for (semi-) professionals in the dairy industry and assumes a basic knowledge and understanding of milking. This document is nr. 3 of the following 3 documents: VaDia Startup Guide VaDia Viewer User Manual Understanding VaDia Viewer data. Latest versions of these documents can be found on our website Special thanks to Odd Rønningen, Ghislain Coppejans, Johan Grolleman and the companies that allowed them to provide their valuable input. Disclaimer: this document has been carefully made by consulting milking experts. It is informative and is not intended to be complete, nor can the content be warranted for correctness and to be without errors. It is advised to be careful with making conclusions only on the basis of VaDia recordings. Understanding VaDia Viewer data v1.0 1/12

2 Contents 1. FOREWORD Changes in this document compared to previous version WHAT CAN VADIA DO FOR YOU DEFINITIONS AND BACKGROUND THEORY Teat-end vacuum fluctuations Short Milk Tube (SMT) vacuum recording Mouthpiece Chamber (MPC) vacuum recording Backspray Vacuum drop over the cluster INTERESTING EXAMPLES Comparison of liners and shells Comparison cluster/liner, take-off not working well ZOOMING IN TO INDIVIDUAL MILKINGS This is how we want it Re-attachment Insufficient preparation, bimodal milk letdown A heafer milking Pre-stimulation pulsation ZOOMING IN TO PULSATION Effect of pulsation restrictors Insufficient pulsation capacity? Changes in this document compared to previous version V1.0 is the first released version Understanding VaDia Viewer data v1.0 2/12

3 2. WHAT CAN VADIA DO FOR YOU VaDia gives you a good indication of the performance of the milking equipment, e.g. the following can be recorded and analyzed with VaDia: Average teat end vacuum with milk flow Irregular vacuum fluctuations and heavy vacuum drops that indicate insufficient vacuum capacity (vacuum reserve and under-dimensioned transport capacity) Milk flow profile per cow: - Proper preparation (fast milk release) - Over milking (no milk flow but still milking) - Duration of the end of milking delay, ACR too slow, too early, etc In many recordings VaDia gives a good milk flow indication. This suggests that accurate milk flow recording is not always necessary to obtain a good milk flow profile. Backspray (vacuum at teat end higher than vacuum in the cluster, milk and pathogens spray back into the teat end) Analyze performance of special features such as pre-stimulation pulsation settings, Duovac, milk flow commanded pulsation variation, etc. In practice these features are often of less use, even counter effect because of incorrect set-up and/or the cows react differently than expected Measure vacuum resistance (flow capacity) of a cluster Monitor the effect of adjustments to vacuum and pulsation Monitor claimed liner characteristics and improvements Verify if these liner dimensions are the most suitable for these teats Verify if vacuum drops and irregular vacuum fluctuations are according to the standard This document explains some real-life recordings so that you can recognize a normal milking and understand typical abnormalities yourself. This document is by all means not intended to be complete or list all possible causes and effects, but is intended as the starting point for your own knowledge base that will increase every time you use VaDia. Understanding VaDia Viewer data v1.0 3/12

4 3. DEFINITIONS AND BACKGROUND THEORY Mouthpiece Mouthpiece Chamber (MPC) Teat Teatcup (shell) Liner (inflation) Pulsation chamber Short Pulsation Tube (SPT) Short Milk Tube (SMT) Long Pulsation Tube (LPT) Cluster (claw-piece) Long Milk Tube (LMT) 3.1. Teat-end vacuum fluctuations Teat-end vacuum stability and pulsation setting are of major influence on the udder health. All components in the milking equipment (liner, milk tube, cluster, milk line, vacuum regulator, sanitary trap, etc.) have a dynamic vacuum behavior; the teat-end vacuum therefore is not equal to the system vacuum. Clusters are connected to the same milk line and their behavior (attachment, kick-off, etc.) influences the vacuum in the milk line and therefore in other clusters on that line. Teat-end vacuum variations can be categorized in three groups: Slow vacuum variations: Teat-end vacuum slowly differentiates from the machine vacuum. This is typically the result of transport resistance, i.e. a milk flow dependent vacuum drop between teatcup, cluster and the milkline. This can be caused by e.g. flow meters, vacuum shut-off valves, narrow tubes, not enough slope, poor reserve capacity and air leaks. Cyclic vacuum variations Caused by opening and closing of the liner. Typical norm (ISO 5707 and 6690): - alternate pulsation: ± 5 kpa - simultaneous pulsation: ± 10 kpa Note that the norm indicates that simultaneous pulsation (a.o. DairyMaster) gives more cyclic vacuum fluctuations. This is because all 4 teats get vacuum at the same time which has an effect on the cluster vacuum. In case of simultaneous pulsation VaDia Viewer assessment therefore may indicate too many irregular vacuum fluctuations. This can also happen in case of some automatic milking systems (robots). Irregular vacuum fluctuations This is caused by unintended sudden air inlet, e.g liner slips in the cluster under-test or attachment, removal or fall-off of other clusters. Putting a bucket to the milkline, overloading of the milkline and shortcoming of vacuum regulation can also result in irregular fluctuations. Understanding VaDia Viewer data v1.0 4/12

5 3.2. Short Milk Tube (SMT) vacuum recording The SMT vacuum is a good indication of the teat-end vacuum. The SMT vacuum is also an indicator of milk-flow. This is based on the common mechanism that vacuum level decreases when milk flow increases Mouthpiece Chamber (MPC) vacuum recording MPC vacuum helps keeping the teatcup stable on the teat. Too low MPC-vacuum increases the risk of liner slips and fall-offs, while too high MPC-vacuum causes trauma to the teat. MPC-vacuum variations can indicate air being sucked-in (liner-squeak and slip) and can indicate that a liner must be selected that is more suitable for the teats in the herd. A sudden change in the MPC-vacuum occurs when milk flow from the teat stops; this is used to decide the time of start overmilking of the teat Backspray Backspray of milk happens when the teat-end vacuum is higher than the cluster vacuum. This is caused by the liner movement, which causes volume changes under the teat. Backspray is a known cause of mastitis because pathogens can spray with the milk into the teat-end. Backspray can be recorded by measuring SMT at the same time at two points: close to the teat-cup and close to the cluster (or in the LMT) Vacuum drop over the cluster The milk should flow from the teat to the milk line as fast and smooth as possible without turbulence. This is significantly influenced by the vacuum resistance (drop) of the cluster. Vacuum drop can be recorded by measuring SMT and LMT at the same time. Understanding VaDia Viewer data v1.0 5/12

6 4. INTERESTING EXAMPLES 4.1. Comparison of liners and shells Below table lists a report of a milking with series 1 having different liners and shells than series 2. Interesting differences are recorded in machine-on-time, overmilking, teat-end vacuum and mouthpiece vacuum. MPC vacuum in series 2 is lower and better than series 1, which is too high, causing congestion. Understanding VaDia Viewer data v1.0 6/12

7 4.2. Comparison cluster/liner, take-off not working well Below table lists a report of a milking with series 1 from a different cluster/liner than series 2 (both simultaneous pulsation). Here interesting differences are recorded in cyclic vacuum fluctuations. Which cluster/liner combination would you want? Later the farmer mentioned that he had the idea that the take-off setting of series 2 was not so good. Not so good was here about 1:30 minutes overmilking! 1:30 Understanding VaDia Viewer data v1.0 7/12

8 5. ZOOMING IN TO INDIVIDUAL MILKINGS Below is a nice example of a normal individual milking assessment. Please refer to chapter 6 of the VaDia Viewer manual about definitions of milking phases and calculation methods or go to: Further explanations and examples assume this basic knowledge. SMT (red circle below) indicates significant milk flow, this is the peak flow period This is how we want it Below two images are of the same cow recording (cow 02). Immediate milk release, fast milking, no overmilking. Chan 1 = SPT, Chan 2 = SMT, Chan 3 = MPC1, Chan 4 = MPC2 Understanding VaDia Viewer data v1.0 8/12

9 5.2. Re-attachment The large SMT variation in below picture is typical for simultaneous pulsation. But such a reattachment (kick-off?) sure won t feel nice for the cow Insufficient preparation, bimodal milk letdown Below we can see that SMT vacuum fluctuations increase with increasing milk flow on a cow with bimodal milk letdown. First the cisternae milk is released, then the flow stops (insufficient preparation) until the alveolar milk is released. A sudden large drop in SMT vacuum is probably caused by a liner slip and teatcup repositioning on the teat. Changes in the MPC vacuum fluctuations coincide with changes in SMT fluctuations, and denote the end of milk flow from the relevant teat. Understanding VaDia Viewer data v1.0 9/12

10 5.4. A heafer milking The MPC vacuum is identical to SMT vacuum. This happens when the teat is not entering the liner barrel. In this setting the teat is milked without pulsation, i.e. with constant vacuum on the whole teat without any massage from the liner Pre-stimulation pulsation Chan1 = SPT, Chan2 = SMT. Red circle: pulsation goes to stimulation mode in the beginning of the milking. Chan1 Chan2 Graphics: VaDia by BioControl :27: :29:12 16:30:38 16:32:05 16:33:31 16:34:57 16:36:24 Understanding VaDia Viewer data v1.0 10/12

11 6. ZOOMING IN TO PULSATION Even though the timing of the pulsation phases is not accurately indicated, the recording is accurate enough to give valuable information Effect of pulsation restrictors Below top picture is of pulsation without restriction, bottom picture is with restriction. Understanding VaDia Viewer data v1.0 11/12

12 6.2. Insufficient pulsation capacity? The ripple on the pulsation in below picture causes a variation in the teat-end vacuum. This vibration during the B-phase can be irritating for cows and make them nervous. This seems to be caused by oscillations in the vacuum system, about 12 Hz. This may be a problem, but this can only be concluded when the explanation is found. Understanding VaDia Viewer data v1.0 12/12