Breed cards: Alentejano pig

History and current status of the breed

The Alentejano pig belongs to the Mediterranean group and derives, as the Iberian breed pig, from the primitive Sus scrofa mediterraneus. Alentejano pig belongs to the Iberian type breeds, characterized by low prolificacy and low growth rate (except under “montanheira” regime). It is also quite adipogenic. Its meat and fat are considered as excellent for both fresh meat market and to process high-grade sausage and dry cured products. Alentejano pigs are well adapted to the environment and to the use of natural resources as feed. Already in the first century AD, Roman documents stressed out the importance of acorns from holm oak forests and in the outdoor rearing of these pigs from Lusitanos. Before change and domination of indoors pig production system, Alentejano was the main pig breed in Portugal, representing over 45% of the total national pig population. This breed was predominantly distributed by the regions south of the Tagus river. Due to several factors, this breed declined in numbers and importance, mainly since the second half of the twentieth century, and was on the edge of extinction in the 1980s. Gradually, from the end of 1980s onward, a slight but consistent recovery of this breed and its traditional production system occurred, fostered by grants of several agents for conservational purposes. Nowadays, the Alentejano pig recovered and represent an economic, ecological and social add value to Alentejo region. Census of Alentejano pig breed is presented in Figure 1. By the end of 2017, 6464 breeding sows and 510 boars were registered in the breed herdbook, distributed by 137 herds. Each farm had, on average, 47 sows.

Exterior phenotypic characteristics

The information on the morphology of the Alentejano pig is summarized in Table 1. Alentejano is a medium-sized pig with a light bone structure, black coat colour and scarce black, blonde or reddish thin hair (Figure 2). It has a long, thin head with a pronounced frontonasal angle, and relatively small, thin, forward-facing ears, triangular in shape and slightly tipped out. The body is not too wide and deep; the back is of medium length and width, slightly arched; the shoulders and hams are regularly developed and medium in width; the extremities are short and slim, ending with small feet with uniform black pigmented hooves. Their temperament is considered energetic. Nowadays, the classifications used by the technicians from the breeders’ association vary between placid and friendly to moderately tractable (ANCPA, personal communication), considering the differences found between farms.

Table 1. Summary of morphology information on Alentejano pig breed.

¹Measured from the tip of the nose to the starting point of the tail.
²Entire males at 120 kg live weight.

Geographical location and production system

This breed’s origin and present location is the southwest of the Iberian Peninsula. It is reared under extensive conditions, perfectly adapted to the environment and the use of natural feedstuff resources. It participates into a well-defined agro-sylvo-pastoral system known as “Montado”. As a strategic step of this production system, the intensive fattening of animals occurs in Quercus forests from late October to late February (“montanheira”).

Traditionally, the herds were divided into three categories: breeding sows, growing pigs and fattening pigs. Breeding sows and growing pigs were fed with natural pastures and, when necessary (e.g., during summer) supplemented with cereal grains (barley, oats or corn), legumes (chickling vetch, faba bean or black chickpea), and local agricultural by-products, which conditioned the growth and duration of the production cycle. Pigs fattened with acorns and grass present very high average daily gains. Conversely, nowadays, there is no uniform production system. Breeding season, feeding management, weight and age at slaughter vary among farms, depending on the tradition and the production objectives. However, most production systems usually use two farrowing seasons (spring-summer and fall-winter). Piglets born between April and September go to montanheira the following year. Piglets born between December and March supply the roast piglets’ market, the fresh meat market with pigs weighing on average less than 120 kg, and are used for herd replacement when purebred. In some cases, alike the observed in Spain with the Iberian pig, in this last farrowing season, a terminal cross with Duroc breed is used to obtain crossbred pigs with better growth performances, higher yields and leaner carcasses (ANCPA, personal communication). The extensive and semi-extensive systems are the most common, and the presence of a free-range feeding period is obligatory for production of PDO and PGI products. However, Alentejano pigs are increasingly reared in semi-extensive systems where, to improve and standardize performance and productivity, most sows and growing pigs receive concentrated balanced feeds. Breeding farms are also abandoning the traditional concrete facilities (“malhadas”) and in most cases, farrowing occurs outdoor, in a “camping” environment with huts and/or collective shelters.

Productive performance

Reproductive traits

Despite the availability of commercial artificial insemination doses, in most cases females are naturally mated. At farm level, the ratio of boar:sow varies from 1:5 up to 1:15. The mean age of sows at first parturition ranges from 10.6 to 16.6 months, but the gilts management (especially feeding) in each farm can greatly influence this trait, justifying individual variations from 9 up to 24 months of age, at farm level. Gestation is shorter than in other breeds or genotypes (111 days). Regarding the litter characteristics, sows of Alentejano breed have a number of live born piglets ranging from 6.7 to 9.4, weighing between 1.0 and 1.3 kg at birth. The reported stillbirth rate varies between 1.2 and 11.3%.

Growth performance

The average daily gain in the lactation period ranged from 133 to 191 g/day. The lactation periods considered varied from 35 to 56 days, and in most cases, piglets were supplemented 15–21 days after birth. Average daily gain in the early growing stage (192 g/day) is also considerably lower than those observed in modern breeds, denoting lesser intensity of rearing and/or growth potential. Also, the middle and late growing stages, the fattening stage, and the overall stage are generally characterized by relatively slow growth and high heterogeneity.

Body composition and carcass traits

In Portugal, in most common commercial conditions, Alentejano pigs are slaughtered at weaning for roasted piglet market, at 90–100 kg live weight for the fresh meat market, at 120–140 kg for the production of dry-cured sausages, and at 150–170 kg for the ham industry in Portugal or in Spain. In different studies, the backfat thickness at withers ranged from 45 to 78 mm, while at the level of the last rib it varied from 12 to 63 mm. Similarly, muscularity measured as lean meat content varied from 35.9 to 51.7%, the loin eye area from 15 to 32 cm², whereas the muscle thickness measured above Gluteus medius muscle varied from 36 to 43 mm, which indicates lower muscular development compared to modern breeds. This variation in backfat and muscle thickness is a consequence of the wide range of final live weights of pigs and different feeding regimes applied in the considered studies.

Meat and fat quality

In the studies reporting meat quality in Alentejano pigs, pH measured in Longissimus muscle at 45 min post-mortem ranged from 5.89 to 6.45, while at 24 h post mortem it varied between 5.39 and 5.79. These pH 24 values reported in the carcasses of Alentejano pigs are slightly higher than those from modern breeds, suggesting the existence of lower glycogen stores before slaughter and more oxidative muscle metabolism. These high pH 24 values are also associated with lower drip loss, which corroborates with higher intramuscular fat content (ranging from 3.1 and 7.5%) and darker colour (high Minolta L* value; L* varying from 43 to 51). Studies found higher proportions of SFA and particularly of MUFA, in contrast to lower PUFA content, in comparison to the modern meaty type of pigs. This can be attributed to a higher synthesis of MUFA (which increases with age) and SFA, caused by higher fat deposition, as shown by the results of body composition (backfat thickness at the level of the last rib = 40 mm on average).

Use of the breed and main products

The Alentejano pig is bred for the production of high-quality meat, sausages and dry-cured products. This slow growing-fat local pig breed is mostly reared in extensive finishing conditions, using the different agro-forest resources at their disposal. It must be produced according to the conditions established in the Portuguese legislation. Meat, fat and offal from Alentejano pigs are also used for the production of high-quality products. There are currently five PDO and 23 PGI certified products.

Full text and references are available here: Alentejano Pig.

Rui Charneca, José Martins, Amadeu Freitas, José Neves, José Nunes, Hugo Paixim, Pedro Bento and Nina Batorek-Lukač (February 6th 2019). Alentejano Pig, European Local Pig Breeds - Diversity and Performance. A study of project TREASURE, Marjeta Candek-Potokar and Rosa M. Nieto Linan, IntechOpen, DOI: 10.5772/intechopen.83757. Available from: https://www.intechopen.com/books/european-local-pig-breeds-diversity-and-performance-a-study-of-project-treasure/alentejano-pig