For training, the lids are chained up. When the calves have learnt to eat from the trough, the counterweights are filled with water. This allows the lids to float above the trough.
After around a week the weight can be reduced so the lids rest lightly on the trough.
1 Lids are hooked open for filling.
2. When calves are eating from the trough, fill both counterweight containers with water and undo the chains. The lids will now float above the trough and open at the slightest touch.
3. When the calves are lifting the lid to eat, loosen the cap on the counter balance so the water slowly drips out.
4. By the time the water has mostly dripped out, the calves will be fully trained. If the lid is still a little light to open, you can empty a little more water out.