YOu don't have to do the chicken chasing. Just finish the dialogue with the gobbo woman, that offered it and then wait, until the cub is running by you and try talking with him. You don't have to use Speak with Animals, but then, you have to roll a high animal handling check.
And you don't have to kill teh mother. You just have to encounter her, can calm her down with animal handling and she shows you the cub. You only have to see the cub officially before entering the goblin village. If you haven't killed the mother, it is implied that she was killed by goblins.
