Small animals are widely used for human disease modelling, developmental and genetic studies.
Mice are the most popular model mammal. Rats and other rodents are also widely used, due to structural advantages they possess over mice. All small mammals require tight temperature control for ideal activity levels. Elevated humidity may also be required, depending on the ambient humidity level. Diurnal light control is required, to prompt circadian rhythms, although most rodents have poor eyesight, and don’t require high illuminance levels. General rearing parameters include:
- Mice – 20-26C, 40-70% RH, low light levels, 12/12 diurnal cycle
- Rats– 20-24C, 40-70% RH, low light levels, 12/12 diurnal cycle
While small animals are reared in temperature-controlled rooms, reach-in chambers provide a secure and highly controlled environment, ideal for critical research on small animals, which may also include other rodents, birds, and fish.
Rodents and other small mammals require 10-15 chamber air exchanges per hour, to limit ammonia buildup within their cages. Chambers built for this purpose must feature special air exchange ports, that can typically be adjusted to increase or decrease the exchange level.
General cleanability is also a concern. Spills of food and bedding material can lead to fungal and mite infestations that can sicken test animals. Automated decontamination or sterilization processes, along with easily removable chamber components, can reduce the effort associated with preventing this issue.
Animal chambers are also used for specialized Zebrafish rearing applications. Recent studies have found that Zebrafish propogate best, with higher hatch rates, fewer mutations, and higher individual weight, when only exposed to specific blue-spectrum light, from 440-50Onm. High efficiency LED lights now make it possible to create lighting systems tuned to this very specific band of wavelengths.