Complex sentence: Recovering breeds are those that have exceeded the numbers needed for the watch category but that the ALBC still wishes to monitor, while the breeds in the study category lack genetic or historical documentation but are still considered to be of genetic interest.
Split into simpler sentences: Recovering breeds are those that have exceeded the numbers needed for the watch category but that the ALBC still wishes to monitor. Breeds in the study category lack genetic or historical documentation but are still considered to be of genetic interest.