Which category includes animals being bred but not yet used for studies?

The category that includes animals being bred but not yet used for studies is Category B. This classification is specifically designed to encompass animals that are bred for research purposes but have not yet been utilized in any experimental procedures.

Category B includes various species of animals that are bred strictly for use in research and may exist in a controlled environment until they reach the age or condition suitable for experimentation. This is crucial for understanding the different stages of animal use in research, as it distinguishes between animals that are currently involved in studies and those that are still in the breeding phase.

Recognizing this classification is important for compliance with the Animal Welfare Act regulations, which mandate proper care and oversight of all animals involved in research settings, regardless of their stage in the research process. This understanding helps ensure humane treatment and adherence to ethical standards in animal research.