Which has more of litter size impact? Doe or Buck?

[macksmom98]

Just curious, which parent has a bigger part in litter size? My guess is the buck, because on of ours produced litters of 7, 8, and 4 last year. Same does with a new Buck are at 2, 5, and 5. I feel age could possibly be a factor, our Buck is older and the gals aren't getting younger either, but the oldest is close to 3 now. Not sure on age of the new Buck. Getting an almost 1 yr old tomorrow, gonna try him out too. Thanks in advance for the feedback!

 

[akane]

If you get a good mating then the doe. It will depend how many eggs she releases, implant, and manage to raise to full term. There are so many things that could impact either gender though. Heat sterility in bucks could impact the sperm for months sometimes and give you no or small litters despite good mating. If there are no external factors though and both are healthy the limit would be on the doe. I've had does consistently throw the same number with little variation despite 3 or 4 different bucks once they were in full production and if it was during an ideal part of the year so neither gender was affected by extreme weather. I've also had small litters more often from does who weren't really in the mood but did manage to get bred, first timers, or coming off long breaks even when the buck was throwing large litters on does in more ideal condition.

 

[macksmom98]

One is now missing! I have looked everywhere to no avail....

 

[Dood]

The doe

The buck releases millions of sperm and, barring heat sterility the majority of those will be viable.

The doe on the other hand has an extensive reproductive tract and a significatly higher chance of things going wrong. Excess abdominal fat can reduce the chance of ovum getting to the Fallopian tubes and restrict the movement of sperm through the reproductive tract. Infection and/or scaring of the uterus can prevent fertilized eggs from implanting and/or interfere with nutrient transfer to the fetuses so they might get re-absorbed later in pregnancy

Age does not effect ovulation in rabbits like it does in humans and most animals don't go through a menopause. A reduction in fertility is usually due to the previously mentioned conditions

Bucks also remain fertile well into their golden years, my first buck was a pet for the first 7 years of his life before he became a herd sire, and he was still siring litters of 12 when he was 10 years old and likely would still be productive if his arthritis hadn't started to interfere with his ability to cover the does

 

[Zass]

In this part of Pennsylvania, heat sterility is non existent.

So from my perspective, the doe is the one who manages how many kits you will actually see.
My bucks have pretty much always been able to produce 10+ kits with just one fall off. The reason, as Dood said, is because that one fall off could have fertilized millions so 10 or 12 babies was nothing.

For the first time in years, I'm getting smaller litters. I know the cause. Body fat accumulation from a too relaxed breeding schedule.

I've looked inside pregnant does more than I'd like. They often start with 14 or 15 fertilized embryos, but then some of them stop developing along the way. Factors may include nutrition or physical space. With fat crowding a doe's body cavity, there may only be enough space to develop a few babies. The rest remain small, and are usually aborted when they give birth to the viable kits.

The whole thing is pretty incredible, really.

 

[macksmom98]

We had excellent success last spring, and I am beginning to wonder if there is something going on. It seems litter size I going down and fatalities are up. Maybe last seaso just happend to be phenomenal, and this year is just a down year. I'll keep good records and see if things pick up. We are not loosing whole litters, just having more issues than we were. Thank you for the insight, what was said makes sense.