G'day Cletus and welcome to the forum.
I've found with mine (30 sheep on 5 acres) the tasty stuff disappears first then the rest disappears in a descending order of tastiness.
We've divided our place up into 5 paddocks with one large and four smaller areas.
We try and rotate them through to keep the grass at a reasonable height, focused on not letting it get too short.
It takes a lot longer for the grass to bounce back if it's coming back from stubble, that's the plan, though it doesn't always work out that way.
If they're ignoring particular varieties you might need to try and remove them and replace with something more palatable as an ongoing project.
TBH with mine I've found the only thing they don't eat is Scotch thistle.
I think with your stock numbers and area available they are able to pick and choose what they are eating as it is growing back in time for them to revisit.
Joined: Dec 2010 Location: Melbourne Username: battered sav
« Last Edit: March 05, 2017, 10:25:56 AM by Battered Sav »
Hobby farmer, factory worker, thrillseeker.