On that trip to London two weeks ago I passed a lot of big modern barns, especially dairy barns. The agricultural landscape of southern Ontario changes dramatically when you get 30 miles south of the valley, to flatter, and much more open, with better soil for farming. The contrast is apparent in these pictures.
This is a large, quite new dairy barn. It has full open sides and lots of rooftop ventilation. It also has 'drive-through' feeding and cleaning. The large doors in the end enable the farmer to drive straight through with his tractor, to drop off feed to the cattle, and to clean up manure.
This is a different style of expansion, with the old barn retained, but new extensions added. Still lots of open-window sides, and lots of ventilation, but without the same arrangement for drive-through cleaning and feeding. The silo usually marks it as a dairy barn.
And on this farm they are still building an entirely new big barn.
These on the other hand, are chicken barns. You can usually recognize them because they are two floors in height.
A LOT of large black ventilation fans on the ends of these barns!
And these last two are hog barns, long and low, with the open-window sides, and ventilation, but no large silos, just the smaller feeder silos.
These two hog barns are at the far distant back of the same farm. This reflects Ontario's 'minimum-distance' separation rules, whereby new hog barns must be 1000 feet from existing residences. The rules are a little more complex than that, but they result in many hog barns being sited a long distance from the roads. It's because of the odour.