First fill and/or Whole cask bottlings

Yes this does happen (shipping casks whole and unbroken). I can't think of which distilleries do this, off the top of my head. Pretty sure this used to be the norm before modern day demands and shipping efficiency came into the picture, though.

Many distilleries use first fill casks of all kinds to varying degrees - either in very small quantities added to "beef up" a whisky's complexity (e.g. in mainstream bottlings), or to be bottled specifically as a single cask or limited batch release (e.g. Glenlivet Nadurra).

I've heard they use a lot of first fill sherry casks at Glenfarclas, as do GlenDronach. Aberlour too, with A'bunadh obviously. A lot of the newer (and non Diageo) distilleries are using first fill casks as a selling point.

The malts that go into first fill casks are usually the more robust ones that can stand up to the cask influence. I daresay Mortlach would be one of those too (even as a Diageo distillery), although we don't see many official bottlings of Mortlach as most of it goes off to the blenders.

@PeatyZealot - Forty Creek of Grimsby , Ontario, Canada uses barrels shipped whole - I believe the term is 'wet barrels'.