Production Decrease

I have a 1.6 group of mice in a 56qt tub. They are fed and watered daily. Cage is cleaned once weekly. I used to pull only 30 babies per month out of this tub. They've had about 5 group litters. Litter #5 is incredibly small. Only 5-6 babies. They are huge/fat babies, but with only 5-6 and no other females looking pregnant, should I possibly consider feeding off the entire group and replace them?

I was thinking of re-doing my mouse colonies anyway since I'm moving all the mice to tubs. The other group, the offspring of the group mentioned above have okay numbers as far as production. Again it is a 1.6 group. Right now I have probably 10 babies in there, after having fed off 7 pinkies. And 2-3 of the females are still pregnant. So their numbers are okay. I'm thinking of thinning down the number of females so the groups are 1.4. This particular group has had 3-4 litters so far. I lost track of how many, but I know its no more than 4.

The only other "group" I have is a pair. I kept two of their daughters in the group so now it is a 1.4. Original pair have had 3 litters. The daughters have not had any yet.

So what do you think? Should I kill off the first group and replace them? I could keep some of the females from their current litter to raise up but I kind of don't want to wait for them to mature enough to breed.

5 litters per doe is a lot. I'd say switch out your does for younger ones.

Also, howdy from Mechanicsville! ;)

Make sure the temperatures didn't drop any, temperature can change the production, especially if it's too hot. Also try and rotate females so they don't get burned out.

Rotate females how? I keep males in 24/7.

I don't think every female in that group has had 5 litters though. I was only pulling 30 babies (sometimes only 20) per group litter (the pile o' babies that they all took care of) every month. That would mean only 5 babies per mouse. And usually just before I'd get the huge pile of babies, only 2-3 females would be ready to give birth by then.

I think I'm going to feed off the 7 mice in that group and start over with new mice. A 1.4 group and see how they do. I'm trying to build up a colony that is large enough to feed 7 baby corns, 3 adult corns, 9 ball pythons, and a red tail boa.

I try to keep written records of how many babies I pull from each mouse colony (although when I'm short on time, I take care of the mice and skip the records, so it isn't a perfect system). Sometimes I'll get a colony that goes through a round of litters with low numbers, then production picks up again. Maybe the moms were just a little overworked from constantly raising babies, and having a small litter gave them a bit of a break?

If I have a colony with low production through 2 rounds of litters, I feed them off and replace with a new colony.

Mice and I have a good average 12 to 16 babies per litters, I either retire after 5 litters or if when the production drops significantly, given the number I get If they produce less than 6 babies they are retired.

Do you recommend leaving the male in and letting the moms have back to back litters? Or would it be better to remove the male and let the females birth and raise the offspring away from him? (Like many do with rats).

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Originally Posted by Jay_Bunny

Do you recommend leaving the male in and letting the moms have back to back litters? Or would it be better to remove the male and let the females birth and raise the offspring away from him? (Like many do with rats).

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I actually do both, I have 1.2 setups where the males rotate between tubs (being moved every 2 weeks) and I have two 1.4 harems where they stay together at all time.

Bottom line you need to find what works for you.

I went through all my mice and pulled the old ones and fed them off. I fed off 6 breeder females and 1 breeder male, a few male weans. I was able to put together a group of 4 females. When they reach breeding size (in about a month) I'm going to purchase a male for them to add some new blood. My other 1.6 group is probably getting old too. I'm going to let them have one more set of babies, and pull females from that group of babies to raise up to replace them, then feed off that group too. I'm going to start keeping strict records of everything.

Thanks everyone.