JF Macedo Pinto in the 1878 Compendium of Veterinary wrote:
(...)     "1st Bizare Typo or Celtic - this typo breeds descended from wild boar common and belong exclusively to Europe. Distinguished by the following characteristics: thick head of short, flat forehead, long snout, large mouth, and long drooping ears to just below the eye line, body Varudo, convex and arched on the back, chest diameter vertical well above the horizontal which gives way to boring, long legs, stiff silks of varying color and black most of the individuals. The many races of this typo, which are all over Europe, especially in central and northern d `ella, are distinguished from each other by their degree of corpulência.Os our pigs bred Commum the northern provinces also enter n 'This typo; are slow and late development, only complete their growth in edad de two yeares, and even then are difficult fattening. They give good meat, but are very bony and atocinham little. (...)

(...)    "In Trás-os-Montes, Minho, Beiras Estremadura and north of the Tagus dominates this typo; distinguished by their variety and color corpulence greater or lesser number of bristles. They are pigs that measure 1.50 meters of the neck to tail and almost 1 meter in height, giving in cevo 200 to 250 kilograms. Most of our country are black, the all white and very body that the learned Veterinary SB Lee (1) says it has seen in Monsão Valladares and are called here gallegos because they come from Galicia. Black or white or even spotted, there are very cerdosos and others who call themselves mollarinhos for having few bristles, pelle a smooth soft, and it is these who are considered more Cavadias. Ordinarily all our bizaro are slow growth (the pig done spent from two to five years to create it), fattening and expensive to produce more lean meat than fat, and accumulate more in this flare than in thick blankets bacon. Most bizaro debiqueiros are in food, especially during ceva, and his complexion is not the most robust and healthy. "(...)

Virgil Taborda in 1932 wrote:

(...)" The type that in Trás-os-Montes is the bulk of the species is Bisaro, slow growing, difficult fattening and richer in meat fat ....." "The potato and where chestnut groves abound form the staple diet during the fattening. In many places also the pigs walk in the fields Vezeira ,....... advantage of the lande Oaks (...)"

Póvoa January 1944 newsletter in livestock, wrote:
"The whole state inselecto reveals that race is. Movements generally slow and somewhat graceless. Very prolific; litters sometimes twenty piglets and more. The quality of the meat is lean little atoucinhada. The fat is low and intermingled, its taste varies with the food. "

In 1967 Ramiro Ferrão and J. Ahmed Mira say:
"North of the Tagus, it explores a type of pig meat, which is affiliated ethnic group called the Celtic stem species, which is commonly known in the industrial areas south of the 'pig land" (...).

(...) But our pig that lives in the regions north of the Tejo has special vocation for the production of meat, however, is unfortunately accompanied by equally suited for the production of bone and skin, which greatly devalues. (. ..)

Features

Pigs bred Bisaro, originating in the Celtic stem, are large animals, reaching over a meter tall and 1.5 meters from the neck to base of tail, black coat, white or mottled, thick skin and with long bristles , thick and abundant.

The head is long and thick, with long ears, wide and outstanding, compared underdeveloped and big mouth. The neck is long and muscular regularly. The trunk is long, with back arched, chest high, flat and shallow, wide side down and little, narrow sloping croup and little muscular, stomach tucked.

The limbs are long, bony and not very muscular, with a regular aplomb. The thighs are a good length and thickness deficient because they are very muscular and the feet are well developed. The tail is thick and medium insertion. These animals are very docile temperament, slow and graceful movements somewhat. They have high prolificacy.

The carcass of the pig Bisaro has a greater proportion of muscle to fat, getting a little meat atoucinhada but very streaky, whose flavor is enhanced with the power that these animals are subjected to a rich and varied.

Staff

Once the Bisaro suffered a drastic reduction in its personnel, but their ability to adapt the system of traditional agriculture, their docility, the litter size, ease in piglets and the organoleptic quality of flesh, are essential characteristics for the maintenance of this breed.
Currently, according to the ANCSUB, the breeding herd is about 1286 females and 200 males, spread over 93 farms, located in a region of Tras-os-Montes and Minho, and is the majority of farms in the district of Bragança.

Source: National Association of Pig Breeders Breed Bisaro