A word of advise to pig farmers who have pigs with the Porcine Epidemic Diarrhea virus, or those farming with pigs near the areas where the infection has been found. Feed your pigs garlic to help them through this outbreak, without having to resort to killing them. What a tragedy it is to kill so many animals needlessly.
The thing is, we humans have forgotten our instincts, and as such we have also forgotten that animals are much more instinctive than we are. I lived on an acreage and I had about 250 chickens running around free-range. I had tried to grow garlic, but I never could get one to grow because the chickens picked all the cloves out of the ground. I had sheep and I once fed them kelp as a vitamin/mineral supplement. You would think, what do sheep know of kelp, it is an ocean seaweed, but after I had fed the kelp to them they would almost knock me over when I attempted to go into the barn. It was just that their bodies instinctively seek out the nutrients packed into kelp.
My suggestion would be to give the pigs between 4 to 8 cloves a day depending on their size, as a preventative measure, and higher amounts should they get sick. If you live in an area where the disease is, your options is to kill them, or experiment with giving them garlic to attempt to prevent, or cure the infected animals. It is totally safe, I know because I use garlic for my own healing and my gut feeling is that you will have no trouble in feeding it to them.