Brown Horse, Black Cow

This is a story I've mused about for sometime. Some years ago my family and I attended church out in the country. Every Sunday we would pass by a spacious pasture with a brown horse and black cow in it. It was evident the two were inseparable as week after week we'd see them grazing together in different parts of the field. One Sunday we were shocked to find them on opposite sides of the pasture. We speculated on the events which led to their rift. Was there a misunderstanding? An argument? Had the neighboring livestock gossiped and driven them apart? My short story will fill in the blanks. ~Mario