Reptile & Amphibian Forums

Hi Wade.
I have a problem that I hope you can help me with.
I also have a colony of Swiss Webster mice. I purchased mine from Harlan around March, 2003. The problem is my colony averages maybe 8 per litter. Some do produce large litters but the colony average is about 8. I'm thinking the cause may be environmental conditions such as temperature, etc. Can you tell me about your mouse room - things like temperature, light cycle, what you use for heating and cooling, days between pan changes, etc.
I have made some changes in my room conditions in the past month and a half.......hoping to get production up.

During the summer I kept room at 65 - 72 deg using an a/c unit. This winter the temp would often dip to 60 deg at night but I now have a heater in the room to keep temps up a bit.

The light cycle was 15 on/ 9 off with a nightlight. It is now 12/12 and the nightlight is gone.

I also made several other minor changes.

Thanks,

Brian

Brian,

My Swiss Websters are all set up in colonies of 1.5. I have them all on automatic water and feed them 50% lab blocks and 50% my own grain mix I described in a post below. They are all in rack type systems.

The mouse room is a two car garage. It's insulated and air conditioned in the summer, our winters here are very mild so I don't need heat. I try to keep the temperature between 70 and 75* year around. I have a light that is on a timer to give me about 12 hours of light and I leave it at that year around.

I have enough tubs that I can replace their tubs with a new one every Saturday, then I dump the old one and wash it with hot soap and water. (Which is what I am about to do this morning).

I have quite a few snakes and they are eating mice and rats of all different sizes so at any given time I need mice and rats of all sizes. As I go through the colonies, if one colony seems to have too many fuzzies, I pull half of them. If two females both have a litter of 15 at the same time, I know it's going to get too crowded when those get bigger so I pull half of them. I think you can loose lots of babies just because they are too crowded.

When the mice get to weanling size, I kill as many weanlings as I need, set aside as many as I want to grow to adults, and sell the rest to pet stores. I am selling about 600 weanlings to the pet shops per week. I also sell about 300 frozen pinkies a week.

I keep good records of the colonies. I record everything I take out of a colony and then average it every 4 weeks. I call it a mouse unit weather it's a pinky or weanling. Each colony is expected to produce and average of 10 mouse units per week. Most are producing 15-20 per week. If their production drops to 10 or below, I pull the male. Three weeks later, I know that none of the females are pregnant and I pull them as jumbos.

When I need to increase the number of colonies I'm keeping, I look at the records and pull future breeders only from the colonies that are producing well. I think this is the most important part. Over the years, I have doubled my production with the same number of colonies. I think it is because I have selected only good mothers that produce good milk and good fathers that are fertile and attentive to the girls.

Hope that helps.
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Wade's Weptiles & Wodents

certainly sounds like a good method. Every since my great producing male had to be put down, I went through about three other males, including one of his sons, before i could find one that did the job right.