After losing my colony of 400 breeder mice to a virus I decided to build the colony up (after disinfecting room and equipment from top to bottom) using Swiss Webster because I read many posts saying that they produce large litters. I started with 51 females purchased from HARLAN and held them to 8 weeks of age before starting the breeding. I knew the first litters would be small - they averaged about 8 per litter. My problem and concern is the second litters only averaged about 6 per litter. Has anyone had similar problems with Swiss Websters? Do they normally take a few litters to reach max litter size? If so, that would not be good because their useful breeding life is usually less than a year.



I feed them Harlan 18% protein diet - the room is well ventilated - the room temp is kept between 62-68 degrees - lights on timer 15 hours on and 9 hours off



Thanks.

Tomsey

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• Swiss Webster low production.....Has anyone had this problem?? - tomsey, Fri May 30 10:47:53 2003
• RE: Swiss Webster low production.....Has anyone had this problem?? - thecaiman, Fri May 30 11:28:22 2003
• Swissies = Low Producers - Sasheena, Sat May 31 11:50:56 2003
• Might just be the time of year. - rodmalm, Sat May 31 14:31:27 2003
• Immunity - DeMak, Sat May 31 19:21:28 2003