
Having bred small livestock, Rabbits I would agree that fertility matters such as litter size, maternal behaviour, and birthing problems, or lack are definately familial, mostly on the female line.
The breeding of small livestock also proves and disproves some of the much vaunted theories on inbreding. Inbreeding seems to be a tool used much more with this sort of livestock, as the turn around of generatrions is quite fast, so results or mistakes can be seen quite quickly.
With Poultry and Rabbvits, some of the moral dilema in an experimental/close mating is removed, as if it goes wrong you can put them in the pot, lesson learned, and move on.
Inbreeding does not cause any problems, it brings latent onesto the surface. Inbreeding depression (loss of fertility and viability) tends to occur only when a family is very inbred, say 10 generations of close breeding between close relatives.