Abstract ' A mobile expert system for disease diagnosis of
dairy cow was developed for dairy cow farmers and animal
husbandmen in Thailand. The application can be used both
online and offline modes. Our mobile expert system application
was uploaded in Google play store; the user can download
application for free. The mobile expert system was designed to
be easy and convenient for usage. In this research, we
proposed a method of disease diagnosis which consisted of
disease screening step and disease diagnosis step. We
established the novel model of knowledge representation for
inference using gender, age range and significant weight of
symptom for disease screening and established the model of
uncertain knowledge representation for inference using the
significant weight of symptom and the certainty factor of
symptom occurred for disease diagnosis. From accuracy
measurement results of the disease diagnosis by our expert
system which was compared with the veterinarian, it was
found that our expert system provided the accuracy of 93.56
%. And the evaluation result of system user satisfaction with
Likert-scale by dairy cow farmers and animal husbandmen
were 4.80 and 4.65 respectively.