Part 2 suggested 2 similar rules of thumb for balancing the bunk and the pellet in free flow barns. One suggestion was to balance the bunk to support 15 pounds less milk than the herd average. The other was to balance for 80% of herd average. Those are more guidelines than actual rules. Part 3 covers 2 more questions. How do you tell if the bunk and pellet are balanced correctly? And what do you do if they are not?
When bunk and pellet are not balanced correctly, the first complaint is usually too many fetch cows. There are some other things to rule out before rebalancing the bunk. Are the robots overstocked? If the robots are overstocked, more fetching will be needed – especially timid cows that shy away from a busy robot. Are there a lot of late lactation cows? Cows that have been milking for a long time will become fetch cows – especially if milk production has dropped. Is feed consistently available at the bunk? If cows are out of PMR for several hours every day they will come to the robot in groups and those that don’t get a chance to be milked with the rest will become fetch cows. If the answer to all of these questions is no, the next step is to evaluate the rejections or refusals.
A refusal is Lely’s term for a cow being released from the robot because she does not have milking permission. DeLaval calls it a rejection. Either way, an average of at least 1 refusal per cow per day, ensures that the average cow is coming to the robot frequently enough for the desired number of milkings.
If milkings are low, and refusals are less than 1 per cow per day, balancing the bunk and PMR can help. Remove energy from the PMR and replace it with energy from the pellet. Milking frequency and duration can limit the amount of pellet that a cow can eat. As that limit is approached, it may not be possible to replace energy in the bunk by feeding more pellets. It may be necessary to reformulate the pellet to be more energy dense so cows get more energy from the same amount of pellet. One way or another, the energy removed from the bunk must be replaced with energy from the pellet. Cows usually respond quickly to adjusting the balance between the bunk and the pellet. Results should be evident in 2 to 7 days.
Take a different approach if milkings are low, and refusals are greater than 1.5 per cow per day. In this case, the barn is moving, and the bunk and the pellet are balanced. Adjusting milking permission will allow more of a cow’s trips to the robot to be captured for milking.
There are many factors involved in maintaining cow flow in free-flow barns. First, make sure system settings, cow health, and activity in the barn and at the bunk are not limiting. If all of those are in order, gradually remove energy from the bunk and replace it with energy at the robot.