Comparison of milking robot concepts: Lely’s Astronaut and DeLaval’s VMS

Comparison of milking robot concepts: Lely’s Astronaut and DeLaval’s VMS

Over ten years ago, Lely has determined that free cow traffic is the best system for both cows and dairy farmers. Recently, Norwegian researcher Even Landro of the Norwegian Institute for Biological Science has proven that the Lely theorem was correct. He conducted a very thorough comparison based on the study of milking frequency and yields while using free and semi-directed cow traffic (also known as the Feed First movement). In other words, the research compared milking system concepts - Astronaut by Lely and VMS by DeLaval.

The recently published study was conducted in January-February of 2009. This article provides its most important results.

Analysis of 14 herds

On the whole, 14 herds were studies, in seven of which A3 milking robots were used with free cow traffic (54,6 cows on average), while the other seven were served by VMS robots with semi-directed cow traffic (57 cows on average). In total, 819 cows took part in the milking robot experiment. Significant data per each herd were collected during three days; however, only 48 hours of these three days were devoted to analysis of the results of the experiment.

Farms that have milking robots were selected based on one criterion: the robots needs to have been in operation for over one year. This guarantees that the cows are completely used to the established traffic system.

Main results

The number of milking per each cows per day amounted to 2,9 with free cow traffic and 2,4 with semi-directed traffic respectively. These results correspond to the Lely experience, accumulated during the use of different cow traffic systems.

The average number of refusals of the milking robot under free cow traffic was 2,3 per cow per day. The average refusal time of the milking robot was 18 seconds. That means that the cows, under free traffic, spent 43,2 seconds a day on refusals. These 43 seconds provide the farmer with useful information about the efficiency of feeding and cow activity. Farm that use the semi-directed traffic system need to invest significant amounts of money into equipment, which actually causes more harm than good.

With the system of semi-directed cow traffic, the average number of passages through the selection gate was 11,6 times per cow per day, while the average number of feed station visits was 9,4 per cow per day. Judging by the results of observation, selection gates create an unnecessary narrowing of the passage, and dominant cows can block it for a long time.

The average interval between milkings was 8 hours 33 minutes under free cow traffic, and 10 hours 5 minutes under semi-directed cow traffic.

This means that use of semi-directed cow traffic makes it impossible to milk a cow three times a day.

The average duration of a visit to the milking robot was 7 minutes 11 seconds under free cow traffic, and 7 minutes 58 seconds under semi-directed cow traffic. This means that the Lely Astronaut A3 robot is 47 seconds ahead of the DeLaval VMS while milking, and the theoretical yield from an Astronaut robot is 10% higher than that of a VMS robot.

Under semi-directed cow traffic, the average duration of the cows’ being in the waiting area was 36 minutes 44 seconds. At the “worst farm” this index was 54 minutes 44 seconds on average. Therefore, for specific low-ranked cows the waiting period can last up to 2 hours.

Conclusions

The scientific study confirms what Lely has been saying for years now.

Free cow traffic:

• A larger number of milkings per cow per day
• A shorter interval between milkings
• Not necessary to lead the cow to the robot
• Higher robot efficiency
• Higher productivity
• Increase of cow health

Table 1: Average indices on various parameters under free cow traffic (FC) and semi-forced cow traffic (SFC). Average values for all animals and herds that took part in the study are provided.