Bee propolis extract as a phytogenic feed additive to enhance diet digestibility, rumen microbial biosynthesis, mitigating methane formation and health status of late pregnant ewes

•Red propolis extract (RPE) contains twenty phenolic compounds, all belonging to the flavonoids.•The supplementation of RPE enhances apparent nutrient digestibility, rumen fermentation and microbial protein syntheses.•RPE possess antimethanogenic activity and reduces the cortisol, triiodothyronine and thyroxine of late pregnant ewes.•Propolis represents a promising natural supplement for supporting ewes through the late pregnancy period. Late pregnancy is one of the most critical stressed periods of reproductive lives of ewes that can effectively affect the whole animal subsequent productive life. Propolis is considered as an effective enhancer of rumen fermentation and the whole animal health conditions in growing and dairy cattle; however no study has confirmed these positive effects in late pregnant ewes. The aim of this study was to evaluate the beneficial effects of supplementing red propolis extract (RPE) on apparent digestibility, purine derivatives, methane (CH4) emission and blood metabolites of late pregnant ewes. Eighteen Santa Inês ewes (52.5 ± 2.50 kg body weight) were kept individually in indoor pens. The trail lasted for 44 d of which 14 d were for adaptation and 30 d for data collection. Ewes were allotted into a randomized complete block design (9 blocks × 2 dietary treatments). The treatments were: control diet (CTL); the basal diet without supplementations and propolis diet (RPE); the basal diet supplemented with 3 g RPE/ ewe/ day. The GC/MS analysis of RPE showed 20 different components all belonging to the flavonoids class were detected. Propolis supplementation increased (P = 0.02) organic matter and crud protein digestibility compared to the control. Higher intake of nitrogen (P = 0.03) and body N retention (P = 0.01) were observed with RPE supplementation compared to CTL, also, the retained N expressed as g/g N intake tended to increase (P = 0.063). The administration of RPE increased (P