There is a permanent interest to identify and to understand the lactogenic activity of some plant extracts. In the case of barley, pectins and β-glucans (glucose polysaccharides linked with both β-1,3 and β-1,4 backbone bonds) seems to increase the synthesis of prolactin because of their homology with its receptors. Administration of β-glucans i.v. proved to have lactogenic responses in ewes, although the effect of an oral administration and its degradation in the rumen have not been studied yet. Therefore, a short-term investigation was carried out to assess the potential lactogenic effects of a commercial source of barley β-glucans (Glucagel, Zeus Ibérica, Barcelona, ES) supplemented to dairy ewes. Five Lacaune lactating ewes (66.7 ± 2.6 kg BW, 202 ± 22 DIM and 1.58 ± 0.12 kg/d milk yield) fed with alfalfa hay and concentrate, were allocated in metabolic cages and submitted consecutively to 2 dietary treatments differing in their β-glucan content (C, control low in β-glucans; BG, β-glucans supplemented at a rate of 1.62 g/kg metabolic BW) during 10 d (C, d1 to 5; BG, d6 to 10). ¹H Nuclear Magnetic Resonance Spectroscopy (Bruker Avance-III; 600.13 MHz and 298°K) and Multivariate data analyses, including PCA (principal component analysis) and PLS-DA (partial least square–discriminant analysis) were used to generate an integrated vision of changes of metabolic profile in blood plasma, milk and urine samples, obtained at the end of each experimental period. Blood content of β-glucans was analyzed by chromogenic kinetics (Fungitell, Associates of Cape Cod, East Falmouth, MA) as (1,3) β-D-glucan in the laboratory Fontlab2000 (Santa Eulalia de Ronçana, Barcelona, ES). Although β-glucans content in blood did not change (618 ± 43 pg/mL, on average; P = 0.426), metabolomics showed that ewes fed β-glucans for 5 d had higher β-glucose in plasma (P = 0.019), lactose in milk (P = 0.035) and a higher excretion of sucrose in urine (P = 0.004). Further research and examination in long-term studies are needed to establish the lactogenic properties of β-glucans when administrated orally to ruminants.