All the calves are in the process of being weaned from their mothers. Weaning calves can be a stressful time for both calf and cow, so we utilize a method called fence-line weaning to try to reduce that stress! In this method, cows and calves share a fence where they can see each other and touch noses, but the calves can't nurse. This allows for a more gradual transition towards independence for the calves as opposed to abrupt separation. Weaning calves allows the cows to stop producing milk (which uses a lot of the cow's energy!) and encourages the calves to meet their nutritional needs through hay/grass and water.
Here is an article from progressive cattle on fence-line weaning: