Milking efficiency of rotary and herringbone parlours
Milking efficiency is often defined as the number of cows milked per hour, or cows milked per operator per hour. In order to achieve optimum milking efficiency, there must be successful engagement between factors that can have most impact on the milking process such as cows, equipment, and people.
Milking is a significant task and accounts for approximately 30% of a dairy farmer's daily workload. This paper will describe the times for the milking processes and milking efficiency of a subset of Irish dairy farms across both herringbone and rotary milking systems.
Farmers were chosen for inclusion in this study based on their willingness to participate in data recording, to share farm data and who were managing progressive dairy farms that are representative of future Irish dairy farms. Data were collected using both surveys and video cameras. The purpose of the survey was to generate a descriptive profile of all facilities, as well as establish the presence of automation on the farms. The cameras were used to collect empirical data from the milking process. Cameras were placed on farms for a duration of one week for two recording periods. Period 1 was from 28/07/20 - 23/10/20 and Period 2 was from 12/04/21 - 19/05/21.
The milking process was then divided into three distinct stages:
1) Set-up time – 1st cow in holding yard until 1st cluster attached;
2) Milk time – 1st cluster attached until last cow out of last row/rotation;
3) Clean-up time – hanging up of 1st cluster until hosing of facilities complete. Total process time was defined as the 1st cow in the holding yard until hosing of facilities was completed. The times presented here are an average of AM and PM milkings.
Infrastructural survey results
Herringbone: The herringbone group consisted of a sample of 17 farms. The average herd size for the herringbone group was 180 cows (range 70-364 cows). The average number of milking clusters was 20 units, (range 6-36 units). One farm had a double-up system as opposed to a swing-over system. Automatic cluster removers were installed on 81% of the farms, 41% had automatic feeders, 59% had automatic entry/exit gates, 24% had automatic backing gates and 12% had a rapid-exit system installed.
Rotary: The rotary group consisted of a sample of 10 farms. The average herd size for the rotary sample group was 425 cows, (range 275-660 cows). The average rotary farm had 50 units (range 44-64 units). Automatic cluster removers were installed on all of the farms, 70% had automatic teat sprayers installed and 60% had automatic backing gates.
Video recording results
The average total milking process time for the herringbone group was 1 hour 55 mins and 2 hour 35 mins for the rotary group. On herringbone farms, 80% of the total process time was made up of milking with 20% for set-up and cleaning. On rotary farms, 75% of the total process time was made up of milking with 25% for set-up and cleaning.
Figure 1, shows that the milking efficiency key performance indicator (KPI) of cows milked per hour was 80% higher and cows milked per operator per hour was 89% higher for rotary farms compared with herringbone farms. Litres per hour was 50% higher for rotary farms when compared with herringbone farms.
Figure 1. Milking efficiency key performance indicators for herringbone farms (on left) and rotary farms (on right)
Rotary farms had longer milking process times and higher cow throughput compared to herringbone farms. The farm-to-farm variability between herringbone and rotary systems warrants further investigation in order to identify the factors that have the largest influence on milking efficiency. The future work of this research project will seek to determine where maximum reductions in milking process time can be achieved.
This paper by Ryan Prendergast, Fergal Buckley, Michael D. Murphy and John Upton was first published in the National Dairy Conference 2022 open day book, which can be accessed here.
Also read: Improving cow flow for efficient milking