I have an easy way to get a cow. They are your money makers. Plant grass all over your cow field and the shopkeeper will allow you to buy both a chicken and a cow. Plant crops only near the shipping bin. Or if you have a horse, plant anywhere. On your free time go fishing. If it's a rainy day the odds are you're going to get sick. Do your chores and go to the hot springs for an hour, then go to the resturant and eat a lot. After you have done all that, go to the hospital to make sure you are okay. Even if you aren't, you will stay at the doctor's and not miss a day by being sick.