Yes and no... to both your question and assumption!
Yes, there will always be a market for a line of feed efficient rabbits, as this was proven quite recently by a line of Satins which were developed for this purpose. Unfortunately, there are problems, as many simply "assumed" that *all* Satins were more feed efficient, rather than just that one specific line (my own Satins were eating me out of house and home!). Secondly, just as with pasteurella-free rabbits, KEEPING them that way after purchase is the real trick! This involves using the same feed, same feeding schedule, and not breeding with other lines known not proven to be as feed efficient. As always, haphazard breeding destroys a lot of good work and good intentions. Of course, this would have no real bearing on your own claims, but rather, on the expertise of your customers.
The reason why more people are not concentrating on this aspect has to do with individual priorities, wherein most will concentrate mainly on improving growth rates, instead. Culling for too many priorities at the same time can literally wipe out an entire herd, wherein feed efficiency might be culled due to poor weight gain or some other priority. I'm sure you get the idea. Combined with the 6-6-6 curse of the rabbit meat industry, they just never get around to working on feed efficiency before getting out of rabbits. Improving one's herd in all aspects is a life-long on-going project that never ends.
I hope this answers your questions.
Pat Lamar
President
Professional Rabbit Meat Association
http://www.prma.org/