I don't think so. As far as I know new Zealand or Californian have the best meat to bone ratio.
Barren didn't have as much meat on them tbh
Perhaps they need more time to grow
Though it's a long time since we kept a herd, I think I can still offer a bit of useful input for you ( despite me having had a couple of strokes and memory problems ) .
What you have said there, is the reason we kept very detailed records on Excel spread sheets for each cage and subsequent pages for their off spring
.
When we first set up our rabbit farm for meat we used a Russel rabbit style feed made by the ton locally to our well researched specifications.
Our tin can we used as the scoop of known measure held on average of 50 scoops ….118 grams when levelled across the rim. So it was easy to work out the feed conversion rate to a fairly accurate degree using the figure of 120 grams per scoop ( including wastage weights ) for a run of 20 does and two bucks.
At 8 weeks the FCR feed conversion rate to meat was not quite at it's peek but at nine weeks & four days it was starting to cost us money to keep feeding them hence our selling at 8 weeks and one day when ever possible get maximum returns. Keeping them to 10 weeks meant we may as well have purchased 20 sacks of feed but only asked for 15 to be delivered. The FCR to meat produced decays tremendously once th peek is reached .
We ran Carolina's initally as the processor demanded them ….. as usual.
Though to our minds the larger NZ's were better because of their bigger fleshed bodies we got a great overall weight of rabbits with we think a slightly better dress out rate.
We also tried to re cross the NZ& Carolina's in our seven lines of separation to get what we considered better rabbits . But we couldn't get consistent results maybe another five or six years at it would have seen us performing better