6903
Nonreturn rates can be used to derive more elementary biological measures for reproductive efficiency , such as conception rate and calving rate , which separately might be more reliable than nonreturn rate itself to evaluate the fertility of a bull or the performance of an AI technician .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities:  
Answer:
 None