Thirty does at the late stage of pregnancy were used in this study, aged 3-5 years and housed under the same environmental conditions in the same locality (Cairo-alexandria desert area). All does were given antiparasitic treatment for external and internal parasites. The does were divided into 3 groups, group1 (N=10) used as a control group, group 2 (N=10) supplemented with monensin extract as a premix in a dose of 2.72 mg/head/day for 15 successive days. Group 3 (N=10) were drenched with propylene glycol in a dose of 100 ml/head/day for 15  successive days. The treatment was done at the beginning of 4^th month of pregnancy. Serum samples were analysed from all treated and control groups for blood level of glucose, urea, calcium, triglyceride, total cholesterol, inorganic phosphorous, BHB, NEFA, insulin, liver enzymes and thyroid hormones. Present results revealed that elevation of serum calcium, cholesterol, insulin, glucose, BHB and NEFA in propylene treated group while liver enzymes, total triglycerides and thyroid hormones was decreased followed by monensin treated group in the same manner. The study also illustrated shortened postpartum open days in propylene treated group followed by monensin treated group. while conception rates was significantly increased in propylene drenched group. The study preferred uses of propylene glycol and monensin extract for pregnant does at the late stage of pregnancy for prophylaxis of lamb losses and also for enhancing some fertility parameters.