IACUC
IACUC / ULAR Breeding Cage Policy
Overview
The purpose of this policy is to prevent overcrowding in breeding cages. For reference, the legal animal density limits are 12 10-gram, 7 20-gram, 6 24-gram, or 5 25-gram mice per 12x6.5 inch cage. This policy applies to weaning animals when the animal density standards are not met through culling or other means. The weaning age is to be set at an age appropriate for animals’ thriving after weaning. For this policy, the standard weaning age will be the age stated in an approved IACUC protocol (or amendment) or 21 days (the usual standard for commonly used strains of laboratory mice). Exceptions to the space limitations can be granted by the IACUC on a per case basis when scientifically justified.
- Mouse pups are to be weaned at the standard weaning age by the PI or lab group.
- If pups are still present at 3 days of age past the standard weaning age, University Laboratory Animal Resources (ULAR) staff will wean them and the Principal Investigator (PI) will be charged a technical service charge. (Please Note: ULAR will no longer be placing reminders on cages or emailing/calling the PI regarding the weaning of animals.)
- Fluorescent green breeding cards will be available in the room binder in all rooms where breeding is occurring.
- When pups are observed, breeding cards will be placed behind the parent cage card so that “BREEDING CAGE” is clearly visible with the date of birth noted for the new pups.
- Breeding cards should be placed by ULAR staff (husbandry and animal health technicians), as well as the PI when new pups are first observed/born to ensure appropriate ages at weaning.
- Using the calendar in the room binder, the ‘projected date of weaning’, as well as the ‘wean by’ date on the breeding card will be completed by the PI or ULAR staff on the day pups are observed.
Instructions for PI
- If your IACUC approved standard weaning age is greater than 21 days, please check the box on the breeding card and note the approved weaning age.
- Mice should be separated by sex and placed into new, charged, cages at a maximum number of 5 mice/cage by 24 days of age or by the approved weaning date on protocol.
- Please note new cage locations and place initials on breeding cage card.
- Any new cages used need to be added to the census sheet and in the comments “W + ‘the number of mice weaned’.”
Instructions for ULAR Staff
- Weaning mice (day 25 on or beyond approved weaning date noted on card):
- Mice will be separated by sex and placed into new, charged, cages at a maximum number of 5 mice/cage.
- The location of the new cages will be noted on the breeding card.
- All the information from the front of the parent cage card will be copied over to the new cage card in addition to the DOB, sex of mice, and number of mice in cage.
- The new cages will be added to the census sheet at the time they are weaned and in the comments section W + the number of mice weaned
- If husbandry staff weans the mice, note technical time on the census sheet as well.
Breeding cage cards
- After all litters noted on the card are weaned (up to 3 litters/card)
- The bottom third will be torn off and placed in the designated area for Animal Observation Reports (to be collected by the animal health technicians)
- If pups are weaned by husbandry, tech time should be written on the census sheet at the time of weaning and it will be charged by the facility supervisor at the end of the month
- If pups are weaned by a Medicine-Surgery technician, time will be charged through surgery
- The top two thirds of the breeding card will be left behind the parent cage card
- The card can be used by the PI to note the location of new cages and to keep track of progeny for the month OR
- The card can be thrown away by the PI once all mice have been weaned.
- The bottom third will be torn off and placed in the designated area for Animal Observation Reports (to be collected by the animal health technicians)
