When will I get babies?

[Taryn7]

Hi everyone..

8 days ago I bought one male and 2 female mice to breed.. I treat them like royalty, they get 3 different types of food, a hamster wheel to run on - they never get off it! I also just bought them this great habitrail water dispenser shaped like a mushroom.. So they are well looked after :spinner:

My question is - how long will they take to breed?? I read somewhere they can produce every 18 - 28 days.. Do you think they have mated? The females don't look any fatter though. I can't wait for them to have babies - they are sooo cute..

 

[Flagg]

Gestation is about 21 days but it might take them up to 2 months before they actually get started.

 

[claireree]

yes I would agree it could take a couple of months to get them all established first, I have some mice which have been together for about 6 weeks now, she was pregnant when I first got her but with all the stress she ate her first litter, she might be pregnant now as she is getting a little bit fatter but it does take a bit of time and patience Im afraid.

In my other cage I have a 1:3 ratio and they breed regulary I currently have 3 litters in there and have removed the male to give the mums a break will reintroduce him when the babies are a bit older.

Sorry but you will just have to be patient they dont get really fat until the end, once you think she is pregnant leave her alone especially when they are born as there is a risk she may kill them if they feel threatened.

Hope this helps.

 

[Taryn7]

Thanks alot!!

They are not very tame so I dont handle them at all.. I basically check on them once a day, give them fresh food and water and leave them alone. The are quite scared of me so I dont want to stress them out..

Ok - I will stop counting the days and just wait it out :spinner:

 

[Brich]

Breeding Mice

As noted above, mouse gestation period is about 21 days. Females are fertile at about 25 days. Males are fertile at about 42 days. If you want to crank out litters of mice you need to wean them at about 21 days so that the next litter does not get trampled and neglected. Females often go into estrus right after birth, so many will produce a litter every 21 days. It is generally best to replace breeders at 8 to 12 months, but they certainly can go longer.

Several other fine points in no particular order:

2 or 3 females with one male works well as long as the cage is big enough. I would say a minimum of 150-200 square inches.

Too much noise or vibration will distress the mothers and they may neglect pups. Similarly, smell of predators (cats, rats, perhaps snakes) will inhibit breeding and/or nursing.

They should have a consistent light/dark cycle.

There are high-fat chows that improve fertility and nursing (yield of pups).

If the dad gets too fat from eating high-fat chow he may stop breeding.

Soft paper material for the moms to make nests will give healthier pups.

If the humidity is too low (< 50%) you may find ring-tail in which a ring forms around the tail and it can die and fall off.

You can mix and match females, but do not put males together unless they are brothers who have been together continuously since they were weaned. If you do they will fight.

 

[Flagg]

Females fertile at 25 days? I've always heard it was 35, 5 weeks minimum.

 

[Brich]

Breeding mice - correction

Thanks Flagg, I was a bit sloppy.

25 days is a good rule of thumb for a deadline for weaning. It is an age at which you can be confident that they are not pregnant. There is a lot of variability in the age at first estrus depending on strain and nutrition, but it does not seem to be before 28 days. If you are setting up females for routine breeding I would not expect many to be pregnant before 35 days of age.

A really good reference for mouse biology is now available online from the Jackson Laboratories:

http://www.informatics.jax.org/greenbook/