They are very vigorous animals, with a great adaptation to the environment. Its name derives from Viana do Bolo, capital of its region of origin, O Bolo.
The orographic conditions of this mountainous area of the province of Ourense made difficult the agricultural machining and allowed the systems of traditional exploitations, in need of animals of triple aptitude: work, meat and milk; so this race enjoyed in other times the largest census of the Galician moraines.
Its head is small, with elongated and narrow face in the nose, where it presents dark mucous and whitish border. Characteristic are the abundant hair formations on the forehead called “fringes” and also in the auditory pavilions, the so-called earrings.
The average weight is 560 kg for females and 850 kg for males and the average height at the withers is 132 cm for females and 138 cm for males.
The trunk is broad, with horizontal dorsolumbar line or slightly inclined towards the rump. Brown coat with darker expressions in the bulls and lighter or blondes in the calves.
To the qualities of all rustic breeds, perfectly adapted to the mountainous environment and climatic particularities, we must add its good maternal qualities, mainly milk production, which translates into a high growth rate in calves and guarantees a better classification of the channels.
The exploitation system follows traditional breaks, with the mixed formula of housing during the adverse weather phase, and grazing on meadows, pastures and areas of forest and scrub at the end of spring, summer and part of autumn. Only cattle used in agricultural operations and rearing calves during their preparation for the market receive supplements of concentrates.