Detection of pregnancy in sheep using an ELISA for pregnancy-specific protein B

Abstract

The early detection of pregnancy and the determination of fetal numbers have economic benefits in sheep production because of the seasonal breeding patterns where missing a breeding opportunity means the loss of one productive year. The purpose of this study was to evaluate the efficacy of the B6-HRP ELISA for ovine pregnancy-specific protein B (oPSPB) measurement in the detection of pregnancy and estimation of fetal numbers in different sheep breeds. BioPRYN® ELISA assay kit was used for the detection of pregnancy in the experimental animals. Ninety-three ewes of three breeds (British Milksheep - BM, Lacaune - L and Transylvanian Racka - TR), each from three farms in Hungary, were included in the study. BM and L ewes were artificially inseminated (AI). Thirty-five days after AI, all ewes were examined by transabdominal ultrasound. The TR flock was mated naturally over a six-week period. At the end of the mating period, the ewes were similarly examined by ultrasound. Blood samples were taken from all pregnant ewes twice (35 and 65 days after AI), and serum samples were assayed by the BioPRYN test. It can be concluded that the detection of serum PSPB by ELISA is a much easier, safer, less expensive and highly accurate method for the detection of ovine pregnancy. Although some breed-related differences were detectable at 35 and 65 days post breeding, no differences in oPSPB levels were found in pregnant ewes carrying different numbers of fetuses.

Comparability of Pregnancy Specific Protein-B (PSPB) Concentration in Serum and Urine of Kedah-Kelantan (KK) Cattle

“…The increase in PSPB on days 24 and 42 occurred during fertilization. PSPB production is boosted since embryonic development is supported by the hormone progesterone [4]. However, on day 42, serum PSPB levels decreased from 17.53 ± 1.77 ng/ml to 15.98 ± 2.00 ng/ml on day 164.…”

“…Early pregnancy diagnosis is essential for operational management to control and monitor pregnancy effectively [3,4]. Early detection of pregnancy has been demonstrated using pregnancyspecific protein B (PSPB) produced in binucleated cells called trophoblasts during blastocyst development [5,6,7].…”

Early Pregnancy Markers in the Serum of Ewes Identified via Proteomic and Metabolomic Analyses

“…Numerous clinical and immunologic methods have been developed for sheep pregnancy diagnosis. Previously, methods based on ELISA had been used to assay hormonal, early pregnancy factor (EPF) and pregnancy-associated antigens in order to detect the early pregnancy of ewes [ 35 , 36 , 37 , 38 ]. However, the pregnancy diagnosis of ewes in practice still depends primarily on the identification of animals that do not return to estrus or the use of B-mode ultrasonography; these methods provide a pregnancy status from 35 days of pregnancy onwards.…”

Serum pregnancy–associated glycoprotein profiles during early gestation in Karya and Konya Merino sheep

“…Depending on the breed, plasma PAGs levels have been reported to alter during pregnancy (Milisits-Németh et al, 2018;Redden & Passavant, 2013;Ranilla et al, 1994). In previous research conducted in Türkiye, the early pregnancy serum PAGs levels of ewes of the Konya Merino (Kaplan et al, 2018;Uçar et al, 2018) and Awassi (Akköse et al, 2021) breeds, both of which are commonly raised in the country, have been monitored.…”

“…Using the RIA and enzyme‐linked immunosorbent assay (ELISA) methods, these molecules have been demonstrated to reach detectable levels in the ovine plasma as of the 18th–20th days of pregnancy (Alabart et al., 2010 ; Barbato et al., 2009 ; De Carolis et al., 2020 ; El Amiri et al., 2014 , 2015 , 2014 , 2015). Depending on the breed, plasma PAGs levels have been reported to alter during pregnancy (Milisits‐Németh et al., 2018 ; Redden & Passavant, 2013 ; Ranilla et al., 1994 ). In previous research conducted in Türkiye, the early pregnancy serum PAGs levels of ewes of the Konya Merino (Kaplan et al., 2018 ; Uçar et al., 2018 ) and Awassi (Akköse et al., 2021 ) breeds, both of which are commonly raised in the country, have been monitored.…”