Mjölkningsstallars kapacitet : teori och praktiska studier
Milking is the task that needs most labour input in milk production. Time and motion studies are made to find work routine elements that can become more efficient. Several reports have shown that the farmers don't achieve the theoretical throughput. This paper has been initiated by Alfa Laval Agri AB to find the differences between achieved and calculated throughput and to investigate what throughput farmers reach in practise and find elements of the work routine that can be improved to achieve a higher throughput. Time and motion studies have been made on 17 farms, 12 with herringbone parlours and 5 with tandem parlours. The number of lactating cows varied from 29 to 133 cows. The milking session includes setup, milking and cleaning up. The following definitions of throughput are recommended and found in the literature. Time and motion studies usually measure the steady state throughput (TKS). This makes it possible to compare different parlours. TKS occurs when the parlour is in full operation. It does not take into account group changes, other interruptions and start and end effects. The throughput excluding setup and cleanup (PKX) includes group changes, interruptions and start and end effects. The start and end effects occur when stalls in the parlour are occupied or when all the clusters are idle. Group changes can also cause start and end effects. The throughput including setup and cleanup (PK) is the achieved throughput including all milking chores in the milking session. The milker's efficiency can be calculated from the including work routine elements during milking and is called milker's theoretical throughput (TKM). In this time and motion study PKX was 87% of TKS in both tandem and herringbone parlours. PK is 68% and 60% of TKS in herringbone and tandem parlours, respectively. The following parlour throughputs were achieved at the farms: (table) The setup time varied from 1 to 7 minutes. The cleanup time varied from 11 to 50 minutes. Scraping and washing down in the milking parlour and collecting yard took average 10 seconds per square meter in herringbone and 12 seconds per square meter in tandem parlours. The work routine elements were entry, feeding, udder preparation, attach cluster, detach cluster, strip, post treat, exit and maintenance. Some time is also spent on other work routine elements and milker idle time. The times spent on the various work routine elements are shown in table 22 and 23 for herringbone and tandem parlours respectively. One farm had in-parlour feeding, and this remarkably reduced the time spent on herding, entry and exit of cows. Other farms with short time spent on entry and exit used a sheep dog (two farms), had a good overall layout or a parlour big enough to allow the milker to work at one side while the cows entered or exited at the other side. By starting udder preparation as soon as a few cows entered the parlour, the throughput can be increased. It is important to attach the clusters as soon as possible after the entrance. Some farmers started to post treat cows closest to the exit gate, then opened the exit gate and continued with the post treat. Entry and exit times were much lower in automatic tandem parlours than in manually operated tandem parlours. Udder preparation time is effected by the cleanliness of teats, but also the placing of the equipment used and the quality of work performed. The average attach time does not differ much between farms. Five farms did not have automatic cluster removers and these farms had rather small parlours. If the milker is stripping all cows or just one cow with problem now and then influence the stripping time spent per cow. The post treatment primarily includes teat dipping or teat spraying, and it was just three farms that didn't do this. The idle time is longer in smaller parlours because of too few clusters to keep the milker busy at all times. A continuous milking routine is commonly recommended to achieve a high throughput. Most milkers left the parlour too frequently to get a continuous milking routine. The most common cause for the milker to leave the parlour was to herd cows and this could take up to 50 seconds per cow. The average herding time was 25 seconds per cow. The milking time also affect the capacity. A slow milking cow can delay the working routine for all stalls on one side in herringbone parlours, A slow milking cow just delay the work routine for one stall in the tandem parlour. In this investigation it has not been possible to measure the individual milking time. In new parlours with milk recording it is possible to measure the milking time for individual cows. The advantage of this is that grouping based on milking time is possible.
mjölkkor; mjölkningsstallar; kapacitet; teoretisk; praktisk; tidsstudier
Rapport - Sveriges lantbruksuniversitet, Institutionen för lantbruksteknik
Publisher: Institutionen för lantbruksteknik, Sveriges lantbruksuniversitet
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