A breeding trial under controlled farm conditions was carried out to estimate serum estrogen and progesterone spectrum over the entire gestation length in Kari ewes belonging to three subtypes. Kari is an exceptional breed within ovine species that gestates in variable length of period (85-154 days). Ewes were bred through hand mating, using rams from respective subtype based on the history of pregnancy duration (A:<110, B:111-130 and C:131-150 days). Upon lambing, the gestation length (GL) of ewes within each subtype was found at variance. Blood-serum sampling was carried out weekly, commencing after mating and continued until lambing. Samples collected from open ewes were discarded upon pregnancy confirmation examined through ultrasonography. The serum was analyzed for progesterone and estrogen profiles. The maximum progesterone concentration (24.2 ng/ml) observed in group C, during the 19^th week of its gestation. Advancement in gestation boosted the peripheral blood progesterone concentration but in an undulating pattern. Serum progesterone at the start of pregnancy was at lower (2.1 ng/ml), reached at its peak (24.2 ng/ml) towards the end of gestation and dropped to (12.2 ng/ml) right after lambing. Maximum estrogen level (43.86 ng/ml) was observed on in group C, followed by B. Group A had the lower estrogen level with a minimal undulation throughout the gestation length. Estrogen was found fluctuating across the entire gestation period in ewes irrespective of their gestation length, which surged up towards the pregnancy termination.

Key words: Estrogen, Gestation, Hormone, Kari, Progesterone, Sheep