Just after your strawberries turn from green to light red, flood the field. You will notice a great difference in the price value when harvested. You can also do this a month before you have to harvest the field.
Place a barn enclosed by a fence then put four bales of hay and two water troughs in front of the door so that the animals cannot get out. They will stay in the best health and will not use any food. Just make sure to leave empty stalls for offspring. The position of the food and water is as follows (W indicates Water, F indicates Food, and B indicates Barn):
Rather than putting up fences for horses, cows, pigs, and/or sheep, just make ditches around their pen area. By doing this, they will not break the fences when they get too fat. None of those types of animals will cross a ditch.