Determination of pregnancy protein levels to distinguish between singleton and twin pregnancies in Awassi sheep

Abstract

Determining the fetal number to avoid pregnant sheep management, feeding, and delivery issues is of vital importance. This study aimed to determine the levels of pregnancy-associated glycoprotein (PAG) and pregnancy-specific protein B (PSPB), which are pregnancy proteins, to accurately predict singleton and twin pregnancies in Awassi sheep. A total of 40 Awassi sheep were used for the study. According to the number of offspring, pregnant ewes were separated into two groups. The study's first group (Group 1) included singleton pregnant ewe (n=20), while the second group (Group 2) included twin pregnant ewe (n=20). Blood samples were collected from the ewes of both study groups at 30th, 45th, 60th, 75th and 90th day of gestation, which were used for PAG and PSBP evaluation along with ultrasonographic examination. Independent samples t-test and repeated measurements ANOVA were used to analyze the data. The correlations between the measures were calculated using Pearson correlation coefficients. Accordingly, a statistically significant difference was observed between single and twin pregnant sheep for all PAG and PSBP measurements at days 30-45-60-75 and 90 (p<0.05). In singleton and twin pregnant ewes, there was a statistically significant difference in PAG and PSBP measurements (p<0.05). In singleton pregnant ewes, a significant positive correlation was found between PAG30 and PSPB30 values (p<0.05), while a significant negative correlation was found between paired measures of PAG45-PSPB90, PAG60-PSPB90, and PAG75-PSPB90 (p<0.05). In conclusion, significant differences in pregnancy protein levels were found in singleton and twin pregnant ewes. It was deduced that knowledge of this difference might give sheep breeders an idea about management factors.

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

“…Although the serum PAGs profiles of the ewes having not been assessed for singleton and multiple pregnancies constitute a limitation for the present study, the reason for such a classification having not been made was to mimic the probable results expected to be achieved with the use of the bovine PAG‐ELISA test on the field for pregnancy diagnosis. Previous studies have reported that serum PAGs and PSPB levels determined with the RIA and sheep ELISA methods were higher in multiple pregnant ewes, compared to singleton pregnant ewes (Akkuş & Yaprakcı, 2022 ; El Amiri et al., 2014 , 2015 ; Ranilla et al., 1997 ). However, the differences observed in the serum PAGs levels of singleton and multiple pregnant ewes measured with bovine PAG‐ELISA pregnancy tests do not change the results of pregnancy diagnosis (Akköse et al., 2021 ; Alkan et al., 2020 ).…”

“…the Konya Merino(Uçar et al, 2018), Awassi(Akköse et al, 2021;Akkuş & Yaprakcı, 2022), Awassi X Merino crossbreed(Karen et al, 2003), German Blackheaded Mutton (GBM), Rhoen X GBM X Dorper crossbreed(Ledezma-Torres et al, 2006), Sarda X Lacaune crossbreed(De Carolis et al, 2020) and Corriedale and Ile de France X Texel crossbreed(Rovani et al, 2016), the serum PAG1 levels of the Polypay X Dorset crossbreed(Roberts et al, 2017) and the serum PSPB levels of the Awassi(Akkuş & Yaprakcı, 2022) and Yankasa(Adeyeye et al, 2021) with minor differences. The steady increase in the level of PAGs as pregnancy advances appears to be associated with increased PAGs production in the binucleate cells of the placenta.…”