Accuracy of B-mode ultrasonography for diagnosing pregnancy and determination of fetal numbers in different breeds of goats

A total of 150 does of different breeds were used to evaluate the accuracy of transrectal (TRU) and transabdominal ultrasonography (TAU) for pregnancy diagnosis and fetal number estimation and to study the effect of breed and age of goats on the accuracy of ultrasonography. All does were scanned by TRU at days 17–22, 24–29 and 31–36 and by TAU at days 39–44 and 46–51 after breeding.The sensitivity (Se) of TRU for detecting pregnant does increased significantly (81.6% vs. 97.7%; P < 0.0005) from days 17–22 to 24–29. There was a significant (P < 0.05) effect of breed of goats on the specificity (Sp) of TAU for diagnosing non-pregnancy between days 39 and 51. In addition, there was a significant (P < 0.01) effect of breed of goats on the Se and Sp of TRU for determination of does carrying multiples and singles, respectively, between days 24 and 36. The sensitivity of TAU for diagnosing pregnant does tended to be significantly (P = 0.06) higher in young does (1.5–2 yr) than in older does (>2–9 yr) at days 39–44. The accuracy of TRU for determination of does carrying singles was significantly (P < 0.05) higher in young does than that in older ones at days 24–29.In conclusions, TRU could be accurately used for early pregnancy diagnosis and fetal number estimation at days 24–29 and days 31–36, respectively, with accuracy similar to that of TAU at days 39–51. Furthermore, breed and age of does might influence the accuracy of ultrasonography for pregnancy diagnosis and fetal numbers estimation.