Accuracy of pregnancy diagnosis in swine by ultrasonography

Early and accurate diagnosis of nonpregnant sows and gilts has the potential to increase reproductive efficiency and the financial income in pig production by reducing non-productive days per sow per year. The objectives of this study were to compare the efficiency of pregnancy diagnosis between Doppler Echo+ and real time ultrasonography (RTU) and to compare the efficiency by using RTU at different days post-mating (days 17 to 24) under commercial conditions. In the 1st study, using crossbreed sows and gilts (n=107), pregnancy diagnoses were done with Doppler Echo+ and then with RTU. Between 28 and 65 days of gestation, Doppler Echo+ had 85% sensitivity and 32% specificity, and efficiency was 73%. In the 2nd study, sows (n=142) were scanned for pregnancy diagnosis between 17 and 24 d post-mating (PD1) and reconfirmed between 38 and 45 days of gestation (PD2). After 21 days of gestation, RTU had over 90% sensitivity and 45% specificity, and 70% efficiency. Accuracy between PD1-farrowing was 75.5% and between PD1 and PD2 was 80.6%. In the 3rd study, sows were diagnosed pregnant by RTU (n=151) at 17 to 24 days of gestation or A-mode ultrasound (n=172) at 28 to 30 days of gestation. There were no significant differences in conception rate (P > 0.09) and farrowing rate (P > 0.67) between both groups. Hence, there was no improvement in fertility and farrowing rate by using RTU instead of A-mode ultrasound under commercial conditions.