Although many aspects of the husbandry of rodents will be similar between mice and rats, and exploration of the information on mouse husbandry may offer useful insights, there are certainly differences that require attention. The size of rats will require additional caging area, and the water and caloric needs of rats will be higher. Estrous cycle length will affect breeding schemes, and weaning times for juveniles will be different.
An overview of the important aspects of the physical plant is capably described in the Physical Plant chapter of the Guide for the Care and Use of Laboratory Animals. Husbandry topics specific for the rat are also considered in the Animal Husbandry and Production part of The Laboratory Rat. Some aspects of husbandry, such as the social environment, will vary by strain or by experimental conditions, and will need to be explored specifically for those cases. But there are some foundational components that would be required for maintenance of mouse colonies anywhere in the world.
Access to potable, quality water must be provided. Sometimes these are simple water bottles, other times more complex automated systems. This organization will vary by the demands of the local facility.
Bedding and Sanitation
The primary enclosure for rats generally consists of a secure and safe cage, with bedding material. Of course, proper ventilation is required, and a means to feed the animals and clean the cages easily are required. Cages and bedding need to be changed and sanitized regularly. Activity and resting space is necessary. The specific enclosure will vary depending on the experimental needs, and depending on the local facility’s practices. Supplements to the cage environment can be provided. For example, some researchers will use “igloos” to provide benefits to the living situation. These may be plastic or can be cardboard devices placed in the cage for the animals to use. The choice of this may vary depending on whether visual access to the animals is needed.
Food and Diet
Proper nutrition is crucial for the health of the rats. Providers of animal feeds can offer specific details of the components of the rat chow that are suited for the animals. If it is necessary to autoclave or irradiate the food—for immune-compromised animals for example, special considerations for the vitamin content may need to be addressed. It may also be important for the strain or experimental situation to alter the standard diet, for content or certain dietary restrictions. These aspects should be coordinated with the animal care staff of the facility.
Colony Management Tools
Managing the research animals also requires a means to track the individuals correctly, and supervise the breeding program appropriately. Physical aspects of this can include tagging the mice in various ways, such as ear tags or notches, or sometime tattoos. Radio-frequency chips may also be employed in some facilities. Cage bar-coding may also be in use. Record keeping strategies around all of the data is necessary. Most commonly, colony management software tools are used for this. One system particularly suited to the needs of rodent researchers is The Jackson Laboratory Colony Management System (JCMS). This actively supported project provides free software for this purpose, and community support is available as well. A related pedigree tracker is also provided. More details can be found in this publication. Other freely-available software and commercial packages are available and may be right for different purposes of colony management and pedigree tracking and analysis.
Like the community of mouse researchers, the rat research community assembles and provides helpful resources for working with rat models. The Rat Genome Database (RGD) maintains information on Animal Husbandry that includes tagging and identification systems, caging system suppliers, links to food providers, and a number of other colony management software providers.