See, my cows have big heads with even bigger horns. Even though this is a big tub, only one of my cows could lick from it at a time. One would go up, lick for a few minutes, then walk off. Once that cow had returned to the herd, a different cow would go. They were literally taking turns while also maintaining distance like it was a bathroom break or something.
At one time, Patches got a brief lick before a cow had walked up. Without any head butting from the cow or any other signal, Patches just calmly strolled away. These are the same animals that kick and head butt each other when they think their portion of hay is tastier! One tub is supposed to feed fifty cows, so far it's looking good.