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)

Abstract

This study assessed the accuracy of the commercial BioPRYN ELISA for the detection of pregnancy-specific protein-B (PSPB) using a single blood sample to determine pregnancy status in American bison (Bison bison). A total of 49 bison cows were used in the study, and sampled at two time-points during the gestation period, fall and spring, correlating with early- to mid-term gestation (average 62.9 days post-mating) and mid- to late-term gestation (average 229.2 days post-mating), respectively. Sensitivity of the test during early- to mid-term gestation sampling period (fall) was 87.1%, while specificity was 100%; sensitivity of the test during late-term gestation sampling period (spring) was 96.3%, while specificity remained at 100%. In total, the test showed a total sensitivity of 91.4%, specificity of 100% and total accuracy of 93.8%, similar to domestic cattle. Use of the single-sample BioPRYN ELISA in American Bison for pregnancy diagnosis is economical and practical, minimizing animal handling time, frequency and subsequent stress while providing accurate results for pregnancy diagnosis at 62 days post-mating. This method should be considered over more traditional pregnancy diagnosis methods for use in managed bison herds.

American Bison (Bison bison) reproductive endocrinology: serum Pregnancy Associated Glycoproteins (PAG), Progesterone, Estrone and Estrone-Sulfate in non pregnant animals and during gestation

“…In 2 and 3TP, PAG concentrations were dramatically below those observed at peak in dairy cows [32] , but were similar to those observed in Water Buffaloes [30] . Total PAG concentrations observed in our study during the 2 last trimesters of American Bison pregnancies were above those observed with the specific PSPB assay in mid and late gestation [6] , conversely to the observations in 1TP. In the present cohort of American Bison, like in Water Buffaloes [30] , no PAG peak was observed during the 2 last trimesters of pregnancy.…”

“…In the present report, a transient peak could have been missed, due to the limited data available in 1TP. An assay for a specific glycoprotein of the PAG family, the PSPB [13] , has been validated in American Bison [6] and showed higher concentration (1.42 ± 1.29ng/mL) in early pregnancy (0-45 d) than our total PAG assay. Despite our caprine PAG RIA kit showed the best detection of the American Bison PAG epitopes, the different sensitivities of the assays could explain those diverging results.…”

“…Despite our caprine PAG RIA kit showed the best detection of the American Bison PAG epitopes, the different sensitivities of the assays could explain those diverging results. Moreover, high PSPB concentration variability was observed during this period [6] and information about PSPB evolution in time and levels in nonpregnant animals were not reported [6] . More data about the PAG evolution in early American Bison pregnancy are required to use our PAG RIA and to explain the differences with the semiquantitative BIO-PRYN ELISA for PSPB [6] .…”

“…They exhibit 5-6 cycles [2] during the ovulatory season in autumn [4] , whereas an anestrus is observed during the other periods of the year [4] . In a natural environment, American Bison calving season is spring (May to July) after around 275 d of gestation [ 5 , 6 ], although weather or grazing areas and nutrition could modulate this duration [6] . The endocrinology of American Bison and bovine gestations seems to share common features, such as Pregnancy Associated Glycoproteins (PAG) [ 6 , 7 ] and estrogens [ 5 , 8 ] production.…”

“…These assays are suitable in serum, but their evolution of concentrations during pregnancy is still unknown. Semiquantitative BIO-PRYN ELISA for Pregnancy-Specific Protein-B (PSPB) [12] , one of the glycoproteins of the PAG family [13] , has recently been described for pregnancy diagnosis in American Bison, but the evolution of PSPB concentration was not precisely reported during pregnancy [6] .…”