MANAGING PMR TO OPTIMIZE ROBOTIC MILKING TRAFFIC

There is no doubt that the relationship between the energy fed in the bunk and the energy fed in the robot is critical to maintaining cow flow – especially in free flow robotic milking systems. Occasionally I get a call from a farmer or nutritionist pointing out that they have reviewed and adjusted the ration, but cow traffic has not changed. Maybe energy balance is not the problem. If energy balance is the problem, a change in the PMR should be expected to change cow behavior in a matter of days. If it does not, it is a good idea to determine how closely the diet the cows are eating matches the diet that was formulated. Problems with mixing, delivery, and sorting, can each affect the balance between the robot feed and the PMR. We have a few tools to evaluate.

Mixing

Begin with a review of the feed software and/or mixing practices. Watch the bunker facing

and blending of ingredients. Bagged forage is more difficult to blend, and harvest variation can be more significant. Observe the mixing process to be sure that ingredients are added in the right order for the equipment being used. Evaluate the inventory to make sure feed is disappearing at the expected rate. If a truck scale is available, use it to verify the accuracy of the mixer scale. Consider analyzing a sample of the PMR, as delivered to the bunk, to make sure it has the expected nutrient content.

Delivery

Mixing and delivery are closely related. Either will be affected by the condition, and setup, of the PMR mixer. Use a shaker box to determine whether feed is mixed and delivered accurately. Take several samples along the length of the bunk, right after feed is delivered. Shake each sample separately to determine whether the feed is uniform from the beginning of the load to the end. If it is not, go back to the mixing process, and check for worn or dull mixer parts.

Sorting

A shaker box can also be used to evaluate sorting, Compare a sample of freshly mixed PMR to the refusals from the previous day. The greater the difference, the more likely that cows are sorting to avoid longer, coarser particles in the PMR. A little sorting can create a big difference between the PMR cows are supposed to eat and what they actually eat.

There are resources available if you need help. Some suppliers offer a complete PMR audit which even includes using a video camera to observe the batch as it moves in the mixer.

It’s also important to verify the accuracy of feed delivery in the robot. First, compare the amount of feed the robot allows to the amount that cows actually eat. Then calibrate the feed dispenser on the robot to make sure it is dispensing accurately. Observe the calibration sample for clumps, mold, and fines. Finally, watch the feeder to make sure that feed is dispensed when the auger turns.

All of these steps can be important parts of troubleshooting cow flow problems in the barn. Better yet, consider adding them to a semi-annual protocol to prevent problems of catch them sooner before performance is affected. Combine the PMR audit with a Cow Corner Robotic Dairy Performance Audit to eliminate bottlenecks from the whole system.