The cow is central to all of the products that we develop. This also applies to the design of the Lely Astronaut. Keeping the cow in mind led to free cow traffic. This is the basis of the automatic milking system and the most natural way possible to milk.

Natural milking and free cow traffic are not only about the cow’s freedom to choose when to eat, drink, rest or be milked. They are also about the cow’s well-being and degree of comfort during milking. The I-flow concept contributes to these in many different ways.

Natural behavior

Free to walk in

Cows dislike obstacles. The Astronaut’s straight route -- the I-flow -- offers unhindered entry, leading cows more easily to their milking turn. As a result, the number of times the cow is milked and the milk yield both increase.

Contact with other cows during milking

Cows are sociable creatures. They are herd animals and prefer to stay with the group. The straight route and the open construction of the cow box ensure that the cow and the group are never out of sight of each other. The natural interaction prevents stress during milking, and a stress-free cow is a productive cow. The cows let down their milk and the milking is quicker, increasing yield. 

Lely’s research shows that the milking time per cow is reduced by 4% in the case of Astronaut robots with I-flow compared to previous models without the straight route.

Increased milk yield

The I-flow concept and the spacious and open construction of the cow box promote cows’ natural behavior. Cows feel safe and have enough room to move during milking, as the robot arm effortlessly follows their movements. Because of this freedom, cows adjust quickly and the frequency with which they are milked soon increases.


Average milkings

per cow / day

Average rejections

per cow / day

Average lbs. milk

per cow / day

K-flow (Astronaut A3) 2.67 2.38 60.64
I-flow (Astronaut A4) 2.76 3.12 62.66
Difference in percentage +3.37% 31.09% 3.49%



Producing high-quality milk requires time and care, and healthy and comfortable cows. It requires making the right choices that fit with you and your goals. Our solutions for automatic milking help you make the right decisions for attaining these goals.