A comprative study on pregnancy diagnosing using transrectal ultrasonography, progesterone level and early conception factor assay in dairy cows [electronic resource].

Includes references.

This study aimed to compare using of the early pregnancy factor (ECF), the progesterone (P4) level and the trasnsrectal ultrasonography (US) tests in determination of early pregnancy diagnosis in dairy cattle. Thirty two Holstein cows aged 4-8 years were involved in this study. Blood samples were collected from each cow on days 7 and 14 for detecting ECF and on days 21 and 24 after breeding for P4 determination. Pregnancy was diagnosed by ECF test, assaying P4 in serum and US technique. The three methods of were evaluated based on the result of the rectal palpation on day 50 after breeding. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of each test were calculated. Results indicated that using ECF test on day 7 after breeding revealed that 2 cows of the 14 pregnant cows diagnosed pregnant by rectal palpation were non-pregnant and later on day 14 after breeding was able to identify all the 14 pregnant cows. Thus the sensitivity of the test was 85.7% on day 7, reached 100% on day 14 post breeding. The incidence of the false-negative results was 14.3% and zero% on days 7 and 14 post breeding, respectively. Using the ECF test on days 7 and 14 after breeding determined 4 and 3 cows of the 18 non-pregnant cows diagnosed by rectal palpation were pregnant, respectively. The specificity of the test was 77.6% on day 7, increased to 83.3% on day 14 after breeding. The incidence of the false-positive results decreased from 22.2% on day 7 to 16.7% on day 14 post insemination. Using progesterone test on days 21 or 24 after breeding was successfully able in detecting all the pregnant cows. The sensitivity of the P4 test was 100% in identifying the pregnant animals, In contrast, the P4 assay failed in detecting the non-pregnant cows with the same sensitiVity. The P4 test specificity was lower on day 21 (55.6%) than that on day 24 (66.7%) post breeding. the incidence of the false-positive results was very high ( 44.4% and 33.3% on days 21 and 24 after breeding, respectively). The transrectal US was very effective method in detecting all the non-pregnant cows. While it determined one cow of the 14 cows diagnosed pregnant by palpation was non-pregnant. It could be concluded that using ECF test on day 14 after breeding seems to be more effective than that on day 7 after breeding in diagnosing pregnancy in cattle with accuracy 81.3-90.6% and could be conducted as a valuable method in culling and rebreeding of non-pregnant cows early after A.I. besides being as a valuable tool for controlling breeding program.

Summary in Arabic.

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