My broken buck is sold but I have people interested in him, so I want to breed him before he leaves. My only available does are his nieces a steel and an agouti.
Grandma was broken ("Rex" but didn't have the rex coat)
Grandpa was REW (NZW)
Uncle and his brother are broken
Mom (uncle's sister) is self black
Nieces are
gold tipped steel (last litter with a NZ sooty fawn/tort was all self black)
Agouti (last litter with a REW NZ was REW, agouti, and steel)
All of those are considered dominant. So do I have any chance of broken with either niece?
Thanks for the help.
Broken <
En> is dominant on the En locus, so a rabbit with that allele will always be broken colored (unless it's a REW or BEW). There are only two known options on this locus: broken <
En> and solid <
en>. A solid colored rabbit cannot carry broken (again, unless it's a REW or BEW).
The usual way to breed brokens is to breed a broken-colored rabbit, like your buck, with a solid doe, like either of the nieces.
Statistically you should see 50% solid and 50% broken kits in a litter from either doe.
You don't say what color your buck is, but if he's from a self black dam he at least carries self <
a> if he's not self himself.
The steel doe who produced self blacks would be an agouti carrying self <
Aa> and since she has a steel phenotype she is <
E(S)_>. (That's on the E locus, which is different from the En locs.) So from the information given, you could suspect she is <
AaB_C_D_E(S)_>. (Being solid colored, you know she's <
enen>.) Depending on what color your buck is you might see steel, agouti varieties and/or self in both solid and broken.
The agouti doe (is she chestnut?) is <
A_>, and full-color carrying REW <
Cc> since she produced REWs. From the information given, if she is chestnut, you could predict she is <
A_B_CcD_E_>. (Again, since she is solid colored, you know she's <
enen>.) What you get from her with your buck really depends on what she and he are both carrying in those second places, which can only be observed by looking at them and at their litters. You will probably see at least some agouti kits; you may possibly get REWs if the buck happens to carry a copy of <
c>.
Knowing the rabbits' grandparents, uncles and siblings doesn't actually tell you much about a rabbit, since it may have inherited similar features or it may not. Sometimes knowing the parents' colors is informative, particularly if they are recessive colors.
A side note: many breeders avoid breeding two broken colored rabbits (or a broken with an REW or BEW known to be broken) together, since about 25% of the litter will get a double dose of the broken allele <
EnEn>. This produces what's called a charlie, which is a very cute rabbit with very little color and a sad tendency to develop a disease called megacolon. Since the disease can show up early or as late as several years of age, many breeders don't want to take the chance.
