How many litters?

marisa · 09-14-04, 01:54 PM

How many litters do you guys let your female rats have before they are "done" ?

I have three female rats, all have had 3-4 litters each. They have been given a 6 week break in betwee litters 2 & 3 and now have been on a few weeks of break as well (I don't have time to let them just breed and breed or else I would just stock up)

Anyways so how many litters before I should replace my females?

Marisa

mice4you · 09-14-04, 08:37 PM

We usually rotate our breeders at eight months of age. This usually gives us 5-6 litters. Although they will definitely breed past this age, production will start to go down hill. By rotating regularly, you are able to keep production up.

mykee · 09-14-04, 08:40 PM

I let my females breed consistently as long as they remain over 250g. From my astute observations however, I've realized that my females (your's may be different) breed consistently and well for about a year or so then they start to trail off with their litter sizes.

Jayson · 09-14-04, 09:29 PM

Raising the young is what wears the mothers out, Its not rearing the babies. I had three females that i was taking the babies from as soon as they were born, All three of these females produced babies every 21-22 days consistantly for 12 months and the smallest litter was 14. then i let them raise a few litters for about 4 more months before i decided to retire them.
Typically i dont keep track of how many litters i let them have, I just visually monitor their health and watch the litter sizes.
I would say anywhere from 5-12 months of back to back breeding per female.

capsicum · 09-15-04, 12:31 AM

For us it depends on each rat. We have two females that usually have 6 or less babies each litter. Now, normally we'd say "Ok, they aren't producing enough", however both of these females will produce milk even without their own babies. I had one hairless female, whom I thought was sterile, suckle 14 big and healthy babies past 7 weeks! Their own mother didn't nurse them (though she has nursed others), but Gia did wonderful with that, and has gone on to produce 2 healthy litters, and to be a wet nurse for many a pink.

So maybe even if they don't deliver the babies, they may still be worth keeping around.

TK

Edited to say without instead of with

justinO · 09-15-04, 11:19 AM

we just go by litter sizes..... under 10 and they get "retired"

but what capsicum said is SO true, you will have crappy mothers who don't take care of babies well, or litters over a certain size..... I can not explain how valuable wet nurses are!!!

As far as age goes, we've been trying to pay attention, and anyone over a year will get to go. Our main breeder boy though "Spermy", we hope will last a while longer.

Jessy

Jayson · 09-15-04, 07:34 PM

All of my breeders must be the whole package, or they go!!
Big healthy litters and big healthy and good mothers

Linds · 09-16-04, 06:14 PM

I generally go by the same rule as Jessy, and anything under the 10 mark gets culled. Most of my females get killed off before they even get to that point however, because I keep getting other females that are so pretty I want to keep, or would make a good addition to a specific colony (I like to play with genetics). I've had a female producing well for two years before her litter sizes dropped, but I kept her around longer than that because she was my first orange rat and I didn't want to part with her. Luckily I was able to retire her eventually at a friend's place. I have a few females in my colonies now that are producing well at I would guess to be about 1+ years of age. I don't really keep track well. When I use to breed them as pets, I had a 5 year old female that was still producing litters (albeit the weren't huge). I have one male that I have had for years (and aquired as a huge, mature male - so who knows how old he is) , and am going to be replacing him with one of his sons, because he is looking a bit tattered. He still produces large litters however, but his hair is thinning and he is a bit wheezy. I've never seen a rat as large as him, he is simply mammoth. Back on topic though, I believe it is a mix between how they are cared for/fed and what lies in their genes what makes for the active breeding span. They are all different, but you can try to max it all with the best care you can provide. While some of us deem litter sizes below the double digits inadequate, if you don't have too many mouths to fill, it may be ok to keep them breeding in to their later years.

marisa · 09-16-04, 07:23 PM

Thanks guys. I don't have "too" many mouths to feed so I'll give these girls another round or two. But I think I'll hold back a new crop of females from their next litter to replace them. I'd rather be ahead of the game, then rushing to replace when they are already well tired out.

Thanks guys!

Marisa