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

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.