Early pregnancy diagnosis in the sow by saliva progesterone measurement using a bovine milk progesterone qualitative test EIA kit. 
We attempted to measure the qualitative saliva progesterone concentration in the sow using a commercial bovine milk progesterone qualitative test EIA kit (qualitative kit), which can measure the progesterone concentration in approximately 10 min, and investigated the possibility of applying this method of progesterone concentration measurement to early pregnancy diagnosis in the sow.  The accuracy of pregnancy diagnosis at 17-24 days after last mating for 138 sows was 91.3% (105/115) for positive cases and 100% (6/6) for negative cases.  The overall pregnancy diagnosis accuracy, including 17 indeterminable cases, was 80.4% (111/138).  A comparison of the diagnoses based on progesterone concentrations measured by the qualitative kit and the saliva progesterone concentrations of identical samples measured by the quantitative kit showed close agreement: 6 cases diagnosed as negative pregnancy by the qualitative kit all had a progesterone concentration of less than 5 ng/ml, while 111 out of 115 cases diagnosed as positive pregnancy by the qualitative kit all showed a progesterone concentration over 5 ng/ml.  Thus, the results of this study show that qualitative measurement of the saliva progesterone concentration in the sow using a bovine milk progesterone qualitative test EIA kit is a practical method for early pregnancy diagnosis.