Getting started

The short version

• Start with young animals that grew up together in one cage: one male with two or three females.
• Skip "older" adults. They are often worn-out breeders.
• Don't put grown-up strangers together. They can fight badly.
• Get animals from two different breeders. Later you can pair animals that are not related.
• Keep new animals in their own cage, away from your other rodents and your snakes, for about 4 weeks. Watch them for mites and sickness.

What to buy

Young animals raised together. Ask for young groups, one male with two or three females, that grew up in the same cage. Avoid "older" adults. When a feeder breeder offers an old adult, it is usually a retired breeder that has almost stopped having litters.

Don't plan on mixing adults. Putting unfamiliar adults together can cause serious fighting. The research does not agree. One early study found ASF accepted strangers into groups more easily than the other rodents it tested [1]. A lab colony never kept unrelated adults of the same sex together. Most of its fights were inside breeding pairs, and usually the female attacked the male [2]. Hobby breeders warn that once a female has had a litter, adding new adults or putting back removed ones "will almost always cause brutal fights that typically end in death" [3]. Assume the risk is real.

Two unrelated lines. Buy from two different breeders so you can cross the lines later instead of breeding siblings (see Running a colony).

Ask the seller:

• How old are they, and were the groups raised together?
• What do they eat?
• Any mites, skin problems or unexplained losses in the colony?

Quarantine

New animals stay in their own cage, away from your colony and your snakes, for about 4 weeks. The NIH lab colony kept its first animals apart and tested them over 4 weeks [2]. During that time check for mites (scratching, scabs, fur loss around the neck and rump), fight wounds and anything that looks unwell. Keep each seller's animals apart until quarantine is done.

Step by step: bringing new animals home

1. Set up a cage for them away from your colony and your snakes. Our plan is a separate room or rack with its own gloves.
2. Give each breeder's animals their own cage. Keep them apart until quarantine is done.
3. Keep them there for about 4 weeks.
4. Check them for mites: scratching, scabs, and fur loss around the neck and rump.
5. Check them for fight wounds and anything that looks unwell.
6. When the 4 weeks are up and nothing looks wrong, quarantine is done.

Equipment

• Cages or tubs with escape-proof lids (see Housing).
• Water bottles (and spares) or an automatic watering system you've tested.
• Lab block rodent food and a hopper or heavy dish.
• Aspen bedding and paper nesting material.
• A gram scale, cage cards and a marker.
• Gloves: nitrile for daily work, a thick pair for catching biters.
• A thermometer/hygrometer for the room, and a heater on a thermostat for winter.
• For culling: a CO2 cylinder with a regulator and a flowmeter, not dry ice (see Humane euthanasia and freezing).
• A freezer and bags, if you'll freeze feeders.

Sources for this chapter

1. Choate, T. S. (1972), behavioural studies on southern African rodents, Zoologica Africana, PDF
2. Safronetz, D. et al. (2021), establishing a Mastomys natalensis breeding colony, Viruses, PMC8065687
3. ASF Breeding Hub, ASF Care File v1.2 (hobby, 2021)