Source | F1 hybrid breeders obtained from The Jackson Laboratory, Bar Harbor Maine USA |
Shipping age |
4-6 wks |
Ship to | Test facilities: UM, TJL, UT |
Breeding scheme | One pair per cage (CByB6F1/J x C3D2F1/J); see protocol |
Cages | TJL: Thoren portable PIV rack duplex boxes (model Maxi-miser #11); 12.125 x 4.6 x 6.4" high, floor space approx 55 sq in. UM: Ventilated cages from Allentown, Inc. (7 3/4" W x 12"D x 6 1/2" H) providing 75 sq inches of floor area. Cage: PC75JHT; Wire lids: WBL7115SMD; MI tops: MBT7115RH. UT: non-ventilated cages with the same floor area as UM. |
Enrichment | One nestlet |
Bedding | Bed O' Cobs (Andersons, Maumee OH USA) |
Feed |
Purina 5008 (PMI Nutritional International, Bentwood MO USA), provided ad libitum |
Water |
Acidified tap water (pH 2.5), provided
ad
libitum |
Light-dark cycle | 12h:12h (on at 0600h) |
Temperature | TJL: 23 +/- 2°C. UM: 20-23°C. UT: 23-24°C. |
Humidity | Protocol allows for 30-70% (in winter sometimes less than 30%) |
Note |
Males are left in with females through breeding, birth and weaning processes |
Note |
First litters are discarded |
Note |
Only litters of 7 pups and greater are used in a study, except at UT |
Note | Litters are weaned at 19-21 days of age into same sex cages (3 males per cage, or 4 females per cage). |
Cages | Ventilated cages from Allentown, Inc. (7 3/4" W x 12"D x 6 1/2" H) providing 75 sq inches of floor area. Cage: PC75JHT; Wire lids: WBL7115SMD; MI tops: MBT7115RH |
Enrichment |
One nestlet |
Feed |
Purina 5LG6 (PMI Nutritional International, Bentwood MO USA, provided ad libitum. Control and treatment diets are prepared by TestDiet, Inc. (Richmond IN USA). |
Bedding | Bed O' Cobs (Andersons, Maumee OH USA) |
Water |
Acidified water, provided
ad
libitum |
Light-dark cycle | 12h:12h (on at 0600h) |
Temperature | UM: 20-23°C. UT: 23-24°C. |
Humidity | Protocol allows for 30-70% (in winter sometimes less than 30%) |
Note |
Weanlings from different breeding cages but with the same DOB (+/- 1 day) are combined to make a full cage (pups must have different coat colors, and this information recorded on the cage card). There are 3 males or 4 females per cage. |
Note |
At 42 days +/- 2 days, electronic ID chips (TJL: pre-2015 Trovan microtransponders ID 10-100A, post 2015 Trovan microtransponders ID 100B(1,4) RFID. UM and UT: AVID Friend Chips AVID-2018) are implanted subcutaneously in mice anesthetized with isoflurane by inhalation; wounds are sealed with surgical glue. |
Note |
A tail biopsy may be performed at the time of ID implantation. |
Note | A chip function test is performed 1 wk (UT) or 30-45 days (UM) following implantation; if chips fails for 2 or more mice per cage, the procedure must be repeated for those mice. |
Note |
Ventilated cages and wire feeders are changed every 14 days and water is changed every 7 days. Tops (UM, UT: low MI tops; TJL: wire covers and Nitex tops) are changed every 6 months. At UM, after the 24-month body weights are completed for a cohort, all singly housed mice are moved to a separate rack (cages get fresh water every 14 days and cages/wires changed every 28 days). |
Health monitoring | Each colony is evaluated four times per year at each test site for infectious agents by serological assessment of sentinel animals. |
Care and Use | All procedures are approved by each test site's Institutional Animal Care and Use Committee and follow the guidelines set forth by the NIH (Guide for the Care and Use of Laboratory Animals). |