The lopped ear trait is multifactoralÂ*and polygenic - genetic "code" unknown.Â* There's no "lop ear gene" Â* "more is unknown than known" about the inheritance of these types of polygenic traits.

The most info you're going to be able to find is:

 

• A number ofÂ*loci are involved in the expression of the trait.

• There is no dominance or recessivity at each of these loci.

• The loci act in concert in an additive fashion, each adding or detracting a small amount from the phenotype.

• The environment interacts with the genotype to produce the final phenotype.

• As well as this info that I posted previously:There are no consistent stats on breeding lop x erect. Generally, most of the ears will be erect. However, there are cases of lop earsÂ*from breeding erect x erect.Warm steady temperatures and wide crowns help the ears to drop. Sex of the rabbit doesn't appear to be a major factor.