Early Pregnancy Detection of Iraqi Riverine Buffalo (Bubalus bubalis) Using the BioPRYN Enzyme‐Linked Immunosorbent Assay for PSPB and the Progesterone Assay

Abstract

This study was undertaken to detect pregnancy in Iraqi riverine buffalo (Bubalus bubalis) using three different methods (rectal palpation, plasma progesterone concentration and detection of the presence of pregnancy-specific protein B (PSPB) with the BioPRYN(®) enzyme-linked immunosorbent assay (ELISA) test. The aim of the study was to identify the most sensitive, early and accurate method for detecting pregnancy. Twenty-two female riverine buffalo that were 6.0 ± 0.93 years old were used. Four blood samples per buffalo were taken via jugular venipuncture at days 22-24, 32-34, 42-44 and 58-61 post-mating (PM) to measure the progesterone concentration (ng/ml) and to detect the presence of plasma PSPB. The rectal palpation method was employed to evaluate all buffalo on days 42-44 and 58-61 PM. The BioPRYN(®) test differed (p<0.01) from the other tests with earlier accuracy for detecting pregnant and non-pregnant buffalo. Eighty-eight percent of pregnant and 76.9% of non-pregnant buffalo were distinguished early (days 22-24 PM) using BioPRYN(®) and plasma PSPB-ELISA level (2.09 ± 0.12 ng/ml) in relation to 66.7% and 53.9% detected using the progesterone assay at similar days (4.30 ± 0.40 ng/ml). In conclusion, these results described, for the first time, the early and accurate pregnancy detection of water riverine buffalo using BioPRYN(®) technology and provided the plasma levels of PSPB using an ELISA test. These findings will improve the reproductive and productive efficiency of Iraqi riverine buffalo by adapting the recent management and reproductive strategies in Iraq and in the world.

Validation of the BioPRYN enzyme‐linked immunosorbent assay for detection of pregnancy‐specific protein‐B (PSPB) and diagnosis of pregnancy in American bison (Bison bison)

“…Dairy cattle studies using a PSPB ELISA test for pregnancy detection showed a sensitivity of 93.9% and specificity of 95.5% on day 28, while the overall accuracy at days 28, 30 and 35 was 94.7% (Romano & Larson, ). The specificity results in this study are similar to the data from both domestic cattle and Iraqi water buffalo (Abdulkareem et al., ; Romano & Larson, ). The lower sensitivity results in this study when compared to other bovid studies could likely be explained by sampling times relative to breeding dates.…”

“…This correlates with a previous study using PSP‐RIA in wild wood bison, showing an overall accuracy of 95% (Haigh et al., ). A study using this specific PSPB ELISA test (BioPRYN ® ) in captive Iraqi water buffalo showed a sensitivity of 88.88% on days 22–24 post‐mating, which increased to 100% after 32 days post‐mating; the specificity data in this same study were 76.92% at days 22–24 post‐mating, but increased to 92.31% at days 32–34 and subsequently to 100% after day 58 post‐mating (Abdulkareem et al., ). Dairy cattle studies using a PSPB ELISA test for pregnancy detection showed a sensitivity of 93.9% and specificity of 95.5% on day 28, while the overall accuracy at days 28, 30 and 35 was 94.7% (Romano & Larson, ).…”

“…Bison at the first sampling were, on average, 62.9 days bred, with a BioPRYN ® ELISA test sensitivity and specificity of 87.1% and 100%, respectively, similar to the sensitivity and specificity of the test in water buffalo and domestic dairy cows in early (~30 day) gestation (Abdulkareem et al., ; Romano & Larson, ). The bison at second (spring) sampling were, on average, 229.2 days bred with test sensitivity and specificity of 96.3% and 100%, respectively.…”

“…The bison at second (spring) sampling were, on average, 229.2 days bred with test sensitivity and specificity of 96.3% and 100%, respectively. The increasing sensitivity with advancing gestation in the bison is also reflected in studies using BioPRYN ® assay in water buffalo, which showed test sensitivity increase from 88.88% at days 22–24 post‐mating to 100% after day 32 post‐mating (Abdulkareem et al., ).…”

“…Since then, this protein was isolated again using the same method as before and was alternatively named “pregnancy‐associated glycoprotein” (Zoli et al., ). PSPB assays were developed for use in domestic cattle, and these compounds have also been detected and utilized for pregnancy diagnosis in both domestic ungulates, including water buffalo (Abdulkareem et al., , ) and sheep (Ruder, Stellfug, Dahmen, & Sasser, ), as well as in non‐domestic ungulates, including mountain goats (Houston, Robbins, Ruder, & Sasser, ), red deer (Haigh, Cranfield, & Sasser, ), mule deer (Wood et al., ), white‐tailed deer (Wood et al., ), muskoxen (Rowell, Flood, Ruder, & Sasser, ) and moose (Haigh, Dalton, Ruder, & Sasser, ). Pregnancy testing using assays for PSPB has been shown to have great accuracy in diagnosing early pregnancy in cattle with a single blood sample: 93.9% sensitivity on day 28 compared with 46.3% sensitivity of trans‐rectal ultrasound (Howard, Gabor, Passavant, & Sasser, ; Romano & Larson, ).…”