Extended weaning time request form
Instructions:
1. Fill out this form completely.
2. Double litters (a dam with a 21 day old litter and a newborn litter) are not permitted due
to humane concerns. Any breeding scheme involving late weaning must include
measures to prevent double litters.
3. If your request is approved, you will be issued special Late Weaning stickers to place on
the cage cards of your breeding stock. When new litters are born, LASC will use the late
weaning day, rather than 21 days, to determine the weaning due date.
4. In general, other options should be tried before resorting to late weaning. If pups are too
small or undeveloped at 21 days to be weaned, this may be an indication of maternal
neglect or insufficient maternal milk supply. Adding a foster mother or co-mother with
an adequate milk supply can result in healthier pups and more litters from the dam.
Principal Investigator:
Protocol #:
Strain of mice:
Briefly describe the phenotype:
Weight of pups at 21 days:
Location of mice:
Weaning age requested: (21-28 days):
# of breeding cages:
Avg. # of litters per month:
Avg. # pups/litter
Reason for requesting late weaning:
Method for preventing double litters (e.g. removal of the male prior to the birth of the first litter):
Note:
1. Double litters are not permissible due to humane concerns. The breeding scheme
outlined above must not permit double litters.
2. Cages with double litters are immediately separated by LASC on an emergency basis
without the usual 24 hour wait for overcrowded cages.
3. Repeated incidents of double litters may result in revocation of the late weaning
agreement.
________________________
Principal Investigator Date
_____________________________
LASC Authorization
Date