Chapter 2 -
After you passed the bridge and the part where there are crows everywhere. You come in a place where there is some sheep on the right. If you continue following the road you will have a bridge on the right and a path on the left. Follow the path and that will lead you a little bit backward (you should be able to see the bridge again) and you will find a cow. Just take the flower and feed the cow. YOu have to interact 2 times. 1st to get the cow to the fence (and you will get scared), 2nd to feed it and unlock the achievement.