Physiological status and litter size affect ewes' hematological parameters, which serve as health indicators. These parameters reflect changes in an animal's physiological condition. Therefore, this study examined the hematological profiles of Awassi ewes with single and twin pregnancies during pregnancy and postpartum. A total of 232 sexually mature and healthy ewes (123 with single pregnancies and 109 with twin pregnancies) between the ages of 3 and 4 years were included in the current study. The sheep's blood was collected and hematological tests were conducted immediately on the samples. Results revealed variation in hematological parameters between ewes during pregnancy based on litter size. Twin-pregnant ewes had significantly higher amounts of RBC, PCV %, MCH, and MCHC during pregnancy months as compared to single-pregnant ewes. Compared to single pregnancies, Awassi ewes with twin pregnancies had higher leukocytes, lymphocytes, granulocytes, lymphocytes %, and granulocytes % than those with a singleton. Logistic regression confirmed that litter size contributes to the increase in hematological parameters. In conclusion, Awassi ewes with twin pregnancies exhibited an increase in the counts of leukocytes and erythrocytes constituents. This study provided valuable information about the association of twin-pregnant ewes with hematological parameters that could be used in sheep breeding and reproduction to improve diagnosis, prognosis, and treatment in the field.

One of the most valuable traits in production and breeding is a sheep’s prolificacy which is influenced by several genes, one of which is the osteopontin ( OPN) gene. Thus, this study aimed to determine the effect of genetic variation within the OPN gene on Awassi ewe prolificacy. Genomic DNA was extracted from 123 single-progeny ewes and 109 twin ewes. Polymerase chain reaction (PCR) was used to amplify 4 sequence fragments (289, 275, 338, and 372 bp), representing exons 4, 5, 6, and 7 of the OPN gene. A 372 bp amplicon was identified with 3 different genotypes: TT, TC, and CC. Sequence analysis revealed a novel mutation in TC genotypes p.Q>R234. Statistical analysis revealed that the single nucleotide polymorphism (SNP) p.Q>R234 was associated with prolificacy. Ewes carrying the p.Q>R234 SNP had significantly ( P ⩽ .01) lower litter sizes, twinning rates, and lambing rates, and more days to lambing than those with the TC and TT genotypes. The p.Q>R234 SNP was confirmed to be responsible for lower litter size through logistic regression analysis. From these results, we can conclude that the missense variant p.Q>R234 adversely affects the traits of interest and shows that the p.Q>R234 SNP negatively influences the prolificacy of Awassi sheep. Based on this study, it is evident that ewes in this population carrying the p.Q>R234 SNP have a lower litter size and are less prolific.