Like everything with Bovy, sorting is pretty easy.  If you don't ask Bovy to sort, the answers will be sorted by either barn name or ID, depending on whether you have barn names turned on. 
Lets say you want to find your oldest heifers, and when they're due.
You can ask or type something like 
  Show the age and due dates for heifers, sorted down by age 
You'll get something like this :

So the oldest heifers are at the top of this list, which is what you asked for - "down by age".

You can sort by anything.  For a cows due list, you could ask or type :
Which cows are due in the next two weeks, sort by due date ?
And you'll see the cows due soonest at the top. 

So it's really easy to sort the answers if you want.  And Bovy is pretty good at understanding sorts - you can say "by", or "sort by", or "sorted by", or "downby", yada yada - all that works. 

And of course you can sort by anything - dates, eartags, milk, scc, anything.