How to get large litters in mice/rats

[Auskan]

Just wondering what you do to get larger litters (if there's anything you can do). I have bred mice for years but was always going for fancy colors before, not quantity. Now that I am doing it for feeders, I'm more interested in large litters. I have 2 breeder females. One had 8 for her first litter (hasn't had the second yet) and the other had 5 & then 7. Is there anything I can do to increase their litter sizes? (I currently feed a combination of a home-made mix that contains mostly cereals, with a few sunflower seeds and raisins thrown in, some packaged "mouse/rat forumla food" that isn't that great because its full of stuff that they won't eat, and some dog food for extra protein. I'm also thinking about getting a bag of bird seed to add to their feed bowl. In addition, I occasionally (one a week or so) give them a bit of bread soaked in olive oil, which they love, and they also get the occasional fresh vegies as I have them).

[Auskan]

Hmmm...interesting. Just did a web search to try to find some answers, and found one scientific paper that said that Vitamin D has an impact on litter size. I.e., rats & mice with vitamin D deficiency produced must smaller litters than those that were Vitamin D sufficient. I'll have to look at what I'm feeding and see if there's a way to increase Vitamin D intake, since sitting them in front of a window to bake in the sun doesn't seem like the best strategy (like we've seen the sun lately anyway :) )

[marisa]

Probably your best bet is like you mentioned, make sure your diet is up to par....then possibly start with lab strain mice.

If you cannot get lab mice (I never do) hold back all the females from any mother that produces large litters, over and over again. Keeping holding back the ones that produce the biggest litters and breeding them back to each other. I have done this and normally I always get between 10-25 babies per litter. 25 is rare although 20,21 has happened quite often. That's just what I do.

Marisa

[Auskan]

Well, I got home from work and discovered I needed to correct my original post. I guess I must have checked on the nest when she was still in the middle of delivering, because my latest litter now contains 10 instead of only 7 pups. That seems like a more reasonable number so maybe the diet is ok after all.

[CHRISANDBOIDS14]

The common average is 8-12.

[Pixie]

It sounds like you are doing pretty good so far!

A great diet goes a long way when breeding rodents. My rats get a staple of cheap dog food and rodent mix. To this I supplement with anything I can think of that will give them either: extra fat, protein and/or vitamins and minerals (hard boiled eggs, breakfast cereals, multigrain bread, fruits and vegetables, etc.). Basically, anything that is lying around and about to go bad I recycle for rat food. They eat it before it spoils so everyone's happy!

I give my female breeders cheese on a regular basis, at least once a week. They are always pregnant and/or lactating which must deplete their calcium reserves. The bonus fat is appreciated too!

My females have given me litters of 12+ consistenly over the past year. My champ "Lola" has had the biggest and the most consistent litters. Her smallest was 16, she usually has 18-19 and all of them make it.

Choosing good breeders is the other key. Some females just aren't cut out for breeding on a large scale. Either having small litters or not caring for her young properly, I give those 2-3 litters to get it right. If not, they are replaced.

Pixie

[Jayson]

I use mazuri 6f only and the average litter is 12-14, largest litter ever in my colonies was 21, I have 125 breeding females they only get other foods once in a while, If i have the extra time to prepare it.

Mazuri 6f was spacifically formulated for breeding rats for animal consumption. (claims Mazuri) And it is by far the best food i have ever used.

[annieb_mice]

Originally posted by Jayson
Mazuri 6f was spacifically formulated for breeding rats for animal consumption. (claims Mazuri) And it is by far the best food i have ever used.


*** If you have the money to afford the Mazuri food, I agree! It is one of the best animal feeds available and doesn't contain a lot of crap fillers and chemicals that might transfer over to your snake or whatever.
Take care
Annie B. <:3 )~~

[Linds]

I used low-quality dog food for a long time as a staple for my breeders (rats) with success. When I found out about Mazuri 6F I gave that a shot and was less than impressed with the results I got. After several months of back to back breeding my females eventually became quite worn. They were looking a bit emaciated and started producing somewhat smaller litters. I used Mazuri for a more than fair trial (around 9 months or so). I ended up switching back to dog food and have not since experienced any problems with my females weight or litter sizes (they consistently produce 12-18 per litter).

I do not recall what happened with the mice, but to be fair, I couldn't make a fair comparison anyways because they wer lab mice at the time, and were switched to fancy mice after the colony went nuts. I think mice might do well on it, I don't think they require as high protein and fat levels as rats do.

[Jayson]

Linds If it were the mazuri causing your problems with your rats then i would think that everyone using it would be complaining of the samethings. As i said all my rats have thrived on it for the last 2.5 years

[CHRISANDBOIDS14]

Arent there different types of Mazuri?

[Linds]

Well I'm just sharing my experience and findings during the period I used Mazuri. I'm not saying anything is for scientific fact, that is just what happened in my colonies during the time I experimented with Mazuri. Nothing else had ever been altered. They have always had the same setup, temperatures, substrates, etc. Maybe my definition of a good breeding weight differs. So far dog food has been the best bet for me :)

[Lisa]

I find temperature is important too, not just food.