My most popular post of all time is the one on farm animals. Not sure why it's so popular--maybe readers are thinking of becoming medieval farmers themselves?
Here I'd like to discuss a little more about the relationship between peasants and their animals, which, any farmer will tell you, has not changed over the centuries as much as you might have expected.
Primarily, someone who owns an animal is responsible for it. You cannot have a cow and expect it to take care of itself. It needs to be fed, guarded from predators, kept clean, and, if it is producing milk, be milked. You cannot "skip" the milking.
These days, dairy cattle may number in the hundreds at a farm (such as seen above), but a medieval peasant family would have no more than one cow, if that. There would be a close personal relationship between the family and their cow, who would of course have a name. This sounds very friendly until you realize that there would also be a close personal relationship between the family and the dung heap.
You cannot house train a cow. (Trust me on this.) The cow's barn would normally be right against the house, to make it easier to take care of the animal and to take advantage of animal warmth in the winter. Every day the straw on which the cow stood would have to be cleaned out and replaced; this is still the case. Otherwise the cow's hoofs will rot.
So a nice dung heap would be a feature of the courtyard, right outside the front door. It would just seem appropriate for the family to use the heap for their own deposits. This sounds disgusting to us in the twenty-first century, but it was often the case in the countryside up through WW I.
One of the challenges for a family was keeping the cow or ox alive through the winter, when there was little or no grass, or it was all under snow. Hay of course would be stored, but a cow can eat an awful lot of hay. And without modern mowing and baling machines, cutting hay and making sure it would stay dry until needed could be quite a challenge. (A hay shock is a way for hay to protect other hay from the rain.) The work to grow and gather food for animals meant that the peasants had less energy to grow and gather food for themselves. Modern cows are also fed corn, but there was no corn in the Middle Ages. At least cows require a less high-quality diet than do horses, which is part of the reason peasants were less likely to use horses.
For the peasants, a cow's milk was a welcome addition to the diet. Without refrigeration, however, there was no way it could be kept as fresh milk, which is why so much was made into cheese--and for that matter, medieval people were much more likely to be lactose intolerant than modern Americans, who have been drinking milk their whole lives.