HOW REPRO PERFORMANCE IMPACTS ROBOT UTILIZATION IN ROBOTIC MILKING

During a recent farm meeting, a nutrition consultant shared a KPI that was new to me. He said that less than 37% of the milking cows should be over 200 days in milk (DIM). 37% over 200 DIM will correlate closely to a herd average of 170 days in milk, or 60% of the herd pregnant. But the percent over 200 DIM correlates with robot usage a little more clearly than those other metrics. Repro performance can have a huge impact on robotic milking system performance. The difference between 45% over 200 DIM and 30% over 200 DIM can be over 200 pounds per robot per day. Here’s how.

Milking permission allows cows to be milked at the right time based on either milking interval or expected yield. Yield per robot is maximized at about 35 to 38 pounds per milking. Fresh cows should be milked at least 3 times per day, regardless of yield per milking. Cows that are over 200 DIM produce less milk, therefore milking permission should dictate that they are milked less frequently than their earlier lactation herd mates. If a group includes a higher percentage of cows that require less frequent milking, and the same number of cows per robot, there will be less milkings per robot. It is possible to adjust milking permission to milk late lactation cows more frequently, but more frequent milking won’t make late lactation cows produce more milk. It may take milking opportunities away from fresh cows at the time of day when the robots are busiest.

The table below shows how 65 cows per robot would be distributed at various stages of lactation for two hypothetical groups of cows – one group that is 45% greater than 200 DIM and another that is 30% greater than 200 DIM. The number of milkings for each stage of lactation is consistent with the goals above. The yields are based on benchmark values from 26,000 pound herds at each stage of lactation. The difference between the 2 scenarios is the distribution of the 65 cows over various stages of lactation.

The groups are summarized in the next table. The 65-cow group with 30% over 200 DIM had over 200 pounds more milk per robot per day, as compared to the same number of cows in the 45% group. 200 pounds per robot per day, with 8 robots is 584,000 pounds of milk per year, or $116,800 per year at $20 per hundredweight – from the same number of cows. Notice that there were fewer milkings and more idle time for the 45% group. If milking

permission is set correctly, longer lactations will result in more idle time. It would be possible to use those milkings and that idle time to milk more cows and offset some of the difference, but the extra cows would require extra feed and extra space, offsetting the added income.

Is it really possible to maintain less than 30% of the milking herd over 200 DIM? My best customer consistently maintains 29%. Keep in mind that the percent of cows over 200 DIM will vary seasonally in most herds. Remember that there is a lot of lag in this metric. It tells you about a problem you had 9-12 months ago – which may or may not have been solved.

This example illustrates how every aspect of managing your dairy impacts the performance of your robotic milking system. That’s what strategic dairy herd management consulting for better robotic milking is all about. Contact Cow Corner to learn more.