Doe consistently births litters with 1/2 deformed kits

[pattersp]

Hi there,
I’m new to rabbit breeding, so I’m hoping someone with more experience can help me.

I purchased a “proven” New Zealand white doe in January. I was told she was about a year old. We have had 3 litters with her so far, from two different bucks.
In each litter, she birthed 8-9 kits. Without exception, she births 4 that are healthy (but quite large, probably 1.5x normal size), and the rest are normal-sized but stillborn and look sort of...gelatinous? It’s hard for me to find the right word, they look sorta blob-like. I unfortunately don’t have a picture.
I’m pretty sure going to cull her because I know this isn’t normal, but does anyone know if this issue has a name or a cure?
It’s such a shame because once she gives birth she is an incredibly dedicated mother and her babies grow super fast. If there’s some sort of supplement that I’m supposed to be giving her, I’d love to know.

thanks in advance!

 

[Preitler]

If it's always half of the litter, my thought is that maybe there is something wrong with one of her uterus horns. That's just a shot in the dark never heard of something like that.

You are sure that they were not just uncleaned, still covered in that membrane?

Anyway, such things can happen, even worse stuff, I would give her a third try before culling, unless you don't want to keep her anyway.

 

[Mutt-Dad]

Is it possible that she is being impregnated twice, and that the smaller kits are from the second pregnancy? I've heard rabbits have two sets of ovaries and they can become pregnant with two litters at one time, if a buck is allowed to mate with them mid way through the gestation period.

 

[Deer Heart]

Is it possible that she is being impregnated twice, and that the smaller kits are from the second pregnancy? I've heard rabbits have two sets of ovaries and they can become pregnant with two litters at one time, if a buck is allowed to mate with them mid way through the gestation period.

That's just an old wives tale with no basis in reality. Idk why that myth has become so popular and I don't blame you for repeating it either, it's in way too many books but super super easy to disprove (I frequently re expose does to bucks a week or two after initial breeding to confirm pregnancies over palpations. My pregnant girls growl at bucks on sight).

OP: I had a doe that did the same thing. In her case she was a REW E Angora and it was always her REW babies that were stillborn (about 50% of every breeding). I bred her to several unrelated bucks (that carried REW) because I wanted REW kits. I ultimately decided after about 5 breedings that she had to have some sort of REW-linked kill gene so culled her and all of her offspring from my program. Sorry it's not the sort of answer I'm sure you want to hear.

Alternatively, maybe environmental? I had my biggest breeding issues with NZW. They would frequently abort entire litters if anything spooked them. I couldn't breed mine around New Years or 4th of July and I caused all of them to abort once when I moved their cages into a better layout. Could be something stressing her out at the tail end of her pregnancies?

 

[Zee-Man]

There are many teratogens that can cause what you are experiencing. Lead is the most common one, but there are many others. Herbicides and pesticides are often teratogenic. Heavy metals are also able to cause birth defects.

If your home was built prior to 1986 (USA) lead may be is the plumbing solder. If your hutch is painted with paint manufactured prior to 1978 it highly likely that there is lead exposure. There are test swabs that you can purchase from Home Depot to test for the presence of lead. It might also be advisable to have your water tested in general.

 

[Preitler]

Is it possible that she is being impregnated twice, and that the smaller kits are from the second pregnancy? I've heard rabbits have two sets of ovaries and they can become pregnant with two litters at one time, if a buck is allowed to mate with them mid way through the gestation period.

No, not really. They don't switch from one uterus horn to the other with a ball valve. Pregnancy is 95% hormones that tell the body what to do next, stage after stage, not about a vacant spot in an uterus.

I keep my buck with the girls for 3 weeks, it's a good time for all of them, no problem at all.

I think this double pregnancy thing is mostly a myth, resulting from kits in different development stages - which can be easily explained by problems with the uterus or placenta, bad connection or whatever.
I had once a litter of 16 discernable kits (and quite some gooey mess) all stillborn and at any development stage, and that doe even was with the buck just once. Her next litter was perfectly ok.

As far as I know it can very well be that you get kits from 2 bucks if you breed her with both in a short time, also it is said that multiple fall offs more likely produce bigger litters. Sounds reasonable to me, since they are induced ovulators - I totally could understand that more eggs get released at each mating before pregnancy hormones have a chance to kick in.