In context it makes more sense, it was from an article about some company promoting a variant of a "smell-o-vision" peripheral, an idea which has popped up a few times over the years but never actually taken off to any degree. And whoever concocted the chemical mix for sheep smell got it wrong if, as they said, the scent of manure is prominent. Sheep poo has scarcely any odour, and being amongst sheep doesn't smell manure-y. Damp wool, lanolin and maybe the scent of ram is more like it!