LAUSR

The objective of the current study was to evaluate the accuracy of trans-rectal color Doppler ultrasonography for early diagnosis of pregnancy in Egyptian buffalo based on subjective assessment of luteal blood flow (LBF). After timed artificial insemination (TAI), a total of 112 pluriparous buffalo were subjectively evaluated for LBF and there were score scales or grades (I-IV) determined at different times (Days 6, 14, 17, 21) post-TAI. Another trans-rectal B-mode ultrasonography of the uterus was performed at Day 35 to confirm pregnancy diagnosis based on recognition of the positive signs of pregnancy. Retrospectively, the results of B-mode ultrasonography were compared to that of the subjective evaluations of LBF for determining accuracy values. Furthermore, serum progesterone (P4) concentrations were determined as an indicator of corpora lutea (CL) function. Results indicate 68 of 112 buffalo (60.7%) were diagnosed as pregnant. The accuracy value of the LBF subjective evaluation was significant (80.4%; P <  0.05) at Day 17, and there was the maximum accuracy (96.4%) at Day 21 post-TAI. The percentage of false diagnoses was less at Days 17 and 21 compared with Day 6 and 14 post-TAI. There was a significant matching value between P4 concentrations and scores for LBF on and after Day 17 post-insemination. In conclusion, subjective evaluation of LBF using color Doppler ultrasonography is considered an accurate technique for early detection of pregnancy in Egyptian buffalo especially the non-pregnant animals as early as Day 17, with maximum accuracy at Day 21 post-TAI.