World Dairy Expo is a five-day event showcasing dairy cattle and the newest technologies available to the dairy industry. The show is held annually at the Alliant Energy Center in Madison, Wisconsin, United States. Considered the largest and most important dairy cattle show in North America, it has been held in the first week of October since 1967. One of the unusual aspects of the World Dairy Expo is its themes. Since the late 1980s, the show has had a theme, when the showing is decorated with two backdrops that correspond to that year's theme. Themes have ranged from the simple to the extravagant, like the "Excitement is Building" theme which had a huge construction-like backdrop.

Source: Wikipedia