Reproduction and breeding

This chapter presents an overview of the rat’s normative reproductive biology and breeding and factors that influence breeding performance. From puberty to parturition, the biology subsection encompasses relevant data and practices on sex determination and estrous cycle through lactation and weaning. The chapter further details common factors observed in the research environment that have been documented to have an impact on breeding performance, such as light, noise, vibration, caging, diet, and handling. Finally, the most commonly used breeding schemes are described with their respective advantages and disadvantages, such as stable-pair continuous mating. Important reproductive characteristics of common stocks and strains are provided for reference, as well as genetic maintenance of inbred and outbred rats. Record keeping and management are also included to emphasize the importance of records in maintaining a healthy rat breeding colony.