this website has a course that has some intresting information about rabbit nutrion and how it effects does ect... My first email I got from it mentioned why does lose litters.
http://www.naturalrabbitfood.com/free-r ... ni-course/
here an intresting excert from an email I got that might help you
". The reason why this occurs is because fat cells, called
adipocytes, produce a hormone that signals to the brain the amount
of fat storage the rabbit has. The more adipocytes (and fat) a
rabbit has the more of this hormone gets made which then sends a
stronger signal to the brain.
In response to this signal the brain will suppress the appetite of
the Doe...not good!
2. A low appetite during pregnancy prevents the Doe from
getting the calories, protein, and nutrients needed for her growing
kits. This leads to an increase in still-births.
3. A reduced appetite during lactation also limits milk production
and increases the mortality rate of kits.
These scenarios will cause a major loss of body reserves (fat,
protein, minerals, and other nutrients) of the Doe and will
directly reduce her reproductive lifespan."
also I would use purina rabbit chow or maybe mana pro but I have never met a breeder that uses mana pro rabbit chow so I don't know how well it works.