Everyone will have a different approach to keeping a self-sufficient homestead, and it’s unlikely that any two 1-acre farms will follow the same plan or methods or agree completely on how to homestead. Some people like cows; other people are afraid of them. Some people like goats; other people cannot keep them out of the garden. Some people will not slaughter animals and have to sell their surplus stock off to people who will kill them; others will not sell surplus stock off at all because they know that the animals will be killed; and still others will slaughter their own animals to provide their family with healthy meat.
For myself, on a 1-acre farm of good, well-drained land, I would keep a cow and a goat, a few pigs and maybe a dozen hens. The goat would provide me with milk when the cow was dry. I might keep two or more goats, in fact. I would have the dairy cow (a Jersey) to provide the pigs and me with milk. More importantly, I would keep her to provide heaps and heaps of lovely cow manure to increase my soil fertility, for in order to derive any sort of living from that 1 acre without the application of a lot of artificial fertilizer, it would have to be heavily manured.