Gascon Pig Lenoir

The present chapter aims to present history and current status of Gascon pig breed, one of the local pig breeds investigated in the project TREASURE. This French autochthonous breed of pigs, which almost disappeared, now enjoys a new boom. The quality of its product is recognized by the consumers and by official quality labels (Protected Designation of Origin). Exterior phenotypic characteristics of the breed, geographical location, production system and main products are described. Reproductive performance data available in the literature and estimated from the LIGERAL database (herdbook) are presented. Literature data on production traits are also summarized for growth (early, middle, late and overall growth), feed intake, body composition and carcass traits. Meat quality traits (pH, colour, intramuscular fat content and composition) and fat tissue characteristics (fatty acid profile) are also described. Studies on Gascon pig breed are scarce and variability between studies, especially regarding productive traits, can be explained by differences in production systems, feeding regimes and feed composition according to studies. Nevertheless, the current review gives updated insights into the reproduction, production and quality traits of this local pig breed.


History and the current status of the breed (census)
The Gascon is a rare breed of domestic pig which has survived at the foot of the Pyrénées mountains in the southwest of France. This pig breed was already present in this region from ancient times: traces from the Gallo-Roman period were found. Like many other local breeds, its production declined during the second part of the twentieth century up to only 34 sows and 2 boars registered in 1981. However, a group of farmers, pork butchers and processors, with the help of technical advisors, gathered together with the objective of reviving the Gascon breed and its highquality products. A breed conservation programme was developed with the help of IFIP and local agricultural chamber. Census of Gascon pig breed and its evolution over the last 20 years are presented in Figure 1. Presently there are 64 registered farms of Gascon pigs with 1423 breeding sows and 177 breeding males in the latest available status (year 2017).
Farms are either related to the Association des Eleveurs de Porcs Gascons des Hautes Pyrénées (AEPGHP), adhering to the Consortium du Noir de Bigorre (CNB), or the Association Nationale de Sauvegarde du Porc Gascon (ANSPG) or unrelated to any breeder group. AEPGHP represents 77% of the sows recorded in the LIGERAL herdbook.
In 2002, the CNB initiated process for further registration of their products as Protected Designation of Origin (PDO) quality label. With the Gascon breed, the CNB has progressively developed based on the production of local, high-quality pork products and vigorous efforts to communicate on their local pig production system as well as the high eating quality of their products. In 2015 the "Noir de Bigorre" fresh loin and "Noir de Bigorre" dry-cured hams, produced from Gascon pigs, obtained the French AOC (Appellation d'Origine Contrôlée) label, which is the national step towards registrations as PDO at European level. Both products obtained PDO registration in September 2017.

Exterior phenotypic characteristics
The Gascon pig breed morphology information is summarised in Table 1. The Gascon is a resistant, slow-growing breed able to live outdoors all year round. As described in the breed standard, animals have a cylindrical shape with thin and tough limbs. They have black skin and are black wire-haired with thicker hair along the dorsal stripe finishing in a swirl on the rump beside a cowlick on the top of the  back. Gascon pigs face is characteristically pointed "like a mole" with narrow ears close to the base, slightly tilted over the eyes with length equal to half the length of the head (Figures 2 and 3).

Geographical location and production system
Gascon pigs produced in the local production system (Noir de Bigorre pork chain) are raised outdoor in extensive conditions at least during a 6-month finishing period. They consume large quantities of grass and fruits (acorns, chestnuts) depending on the season.
The CNB breeding area and pig production system are defined in the AOC specifications [1]. The ANSPG area is wider but predominantly located in the southwest of France, the cradle of the breed.
To benefit from AOC/PDO Noir de Bigorre registration, pure Gascon pigs must be born, reared and slaughtered in the specified geographical area. Pigs (either castrated males or females before any lactation) are generally born and kept indoors on straw with possible outdoor access, up to a maximum of 6 months of age. They are then placed until slaughter on natural or cultivated grassland (max. 20 pigs/ha) providing various grass species or leguminous plants, with possible access to a forest plot (e.g. acorns and chestnut). Plot lands must be approved by the authorities responsible for quality sign management and control. In addition to natural feeding resources, pigs are fed with complementary food based on a minimum of 70%  cereals (wheat, oat, barley, rye and triticale) produced on the geographical area, with potential protein resources (faba beans, peas, rapeseed or sunflower meal), minerals and vitamins. Maize, sorghum and sunflower are not allowed. The farmers themselves often produce complementary food.
Pigs are slaughtered at a minimum of 12 and maximum of 24 months of age. Specifications for carcasses are a minimum of 100 kg of hot carcass weight, minimum 25 mm of fat depth over the gluteus medius muscle (ZP point) and 45 mm of muscle depth (ZP muscle). Whole traceability is guaranteed for pigs and carcasses. Minimum green ham weight of 10 kg and ripening duration of 20 months are required for AOC/PDO Noir de Bigorre hams ( Figure 4).

Organisations for breeding, monitoring and conservation
All animals, boars, sows and piglets, are individually identified and recorded in the LIGERAL herdbook. An accreditation committee, composed of an expert and the technician in charge of following-up the farms, validates each potential breeder considering the breed standard, the teats number (minimum of 12 functioning teats) and the inbreeding coefficient. Only pure-bred reproduction is performed using 100% natural mating. Usually, farms self-renew their sows and buy boars. Replacement breeding policy is based on relationship coefficients estimated by IFIP and on the number of live animals per family (sows) or line (boars). One farm belonging to the AEPGHP is dedicated to boars rearing from 2 to 3 months of age (25-30 boars a year). Number of breeders per family or line, reproductive performances and inbreeding are reviewed at least once a year. More complete analyses of the genetic variability based on probabilities of gene origin studies are performed occasionally [2]. AEPGHP and ANSPG adopt common decisions related to the management of the breed in a single pilot committee. There are common people in the accreditation committee and there are exchanges of animals occasionally. Besides, Gascon semen doses are preserved in the French National Cryobank which contains semen collected specifically in the 1990s and the beginning of the 2000s. This heritage material is only dedicated to breed preservation ( Table 2).

Reproductive traits
Basic data obtained on reproductive traits in this review are presented in Table 3. Averages are calculated from data registered in the LIGERAL database. For the last available 5-year period (2012-2016), the age of sows at first parturition is 17 months [11]. On average, sows of Gascon pig breed have 1.7 litters per year with 8.1 piglets born alive. The death rate of piglets until weaning in the considered recent 5-year period is correct and averages 9.8% [11]. Published data are also synthetized in Table 3. Without selection on reproductive performances, litter size (born alive and weaned piglets) tended to degrade between 1997 and 2003. Then a slight improvement was observed until 2007 [8]. Most recent data obtained within TREASURE project confirm that litter size seems now stable [10]. Duration of the lactation is prolonged in comparison with modern intensive systems to 38 days, which is also reflected in the prolonged farrowing interval, 214 days on average. Thus, it can be concluded that Gascon pig breed has moderate fertility compared to the most prevalent breeds.

Growth performance
Basic data on growth performance obtained in this review are presented in Tables 4 and 5. Due to big differences between studies with regard to the live weight range covered, we defined the stages for growth performance as lactation (regardless of how long it was), growing stage (from weaning to approximately 30 kg live body weight) and early, middle and late fattening stages  No. = number, mth = month, d = days. 1 Litters per sow per year calculated as the average number of litters per sow having at least one litter in the year. 2 Least squares means with a GLM model including breed (5 local breeds), parity season as a fixed effect, breed*parity interaction, the age of the sow and birth year as a covariate. 3 Five-year average value from herdbook data (LIGERLA database between 2012 and 2016).  No. = number; ADG = average daily gain in g; Ad lib = ad libitum feeding regime; Semi = semi-ad libitum feeding regime. 1 ADG in a period of fattening is reported for early, middle and late fattening stages estimated between approximately 30 and 60 kg, 60 and 100 kg and above 100 kg live body weight, respectively. Sometimes the source provided only the overall growth rate for the whole studied period (in that case defined as overall). estimated between approximately 30 and 60 kg, 60 and 100 kg and above 100 kg live body weight, respectively. Sometimes the source provided only the overall growth rate for the whole fattening stage (defined as overall). It should also be noted that a big part of the collected studies simulated practical conditions of the production systems used and that only a smaller part of the studies aimed at evaluating the breed potential for growth. In the considered studies, data for performance in the stage of lactation and growing stage are missing. The early, middle, late and overall fattening stage is characterised by slower growth than "modern" selected pigs and big heterogeneity for each of these growing stages as well as for the overall growing-finishing stage (342-537 g/day), related to the fact that this review comprises studies where different systems and feeding levels were considered. In the context of the evaluation of growth performance, it is also of interest to observe the extreme values, because it can be assumed that the maximum figures exhibit the growth potentials of Gascon pigs in ad libitum conditions of feeding (≈537 g/day in overall fattening stage).
In considered studies, the information on feed intake and feed nutritional value were rather scarce (max n = 9 studies), which limits the evaluation of growth potential. Moreover, in some studies, values correspond to the daily feed distributed but not the actual feed intake due to waste of feed by the animals around the feeder. Average estimated daily feed intake increased from 2.5 kg/day [15] in the middle growing stage to max of 3.6 kg/day [16,17] in the overall fattening stage, above values being probably overestimated and corresponding to daily feed distributed, whereas feed "intake" in overall fattening stage averaged 3.0 g/day (n = 9 studies).  No. = number, ADFI = average daily feed intake in kg/day, Semi = semi-ad libitum feeding regime, ME = metabolisable energy, CP = crude protein. 1 ADFI in period of fattening is reported for early, middle and late fattening stages estimated between approximately 30 and 60 kg, 60 and 100 kg and above 100 kg live body weight, respectively. Sometimes the source provided only the overall daily feed intake for the whole studied period (in that case defined as overall). 2 Values in studies from refs. [16,17] that are rather high correspond to average daily feed supply but not actual daily feed intake. Table 5.
Summary of collected literature data on average daily feed intake (in kg/day) in Gascon pig breed.

Body composition and carcass traits
Basic data obtained in this review with some of the most commonly encountered carcass traits that could be compared are presented in Table 6. In considered studies, pigs of Gascon breed were slaughtered between 183 and 442 days of age (n = 11 studies) and between 98 and 181 kg live weight (n = 16 studies) and had a dressing yield around 80% (n = 8 studies). The backfat thickness measured at the level of the gluteus medius muscle (official site for fat depth measurement in the Noir de Bigorre AOC specification) was high (over 46 mm, n = 8 studies) but variable (reported average value calculated within studies between 38 and 49 mm). Backfat thickness was over 38 mm at the level of the last rib (n = 6 studies) and 42 mm (n = 6 studies) at the level of the first rib (neck). In the studies undertaken within TREASURE project [16,17], muscle thickness measured at ZP point (minimum depth from the vertebral channel to the cranial end of the gluteus medius) was 69 mm on average. Muscularity assessed as lean meat content was between 35 and 40% in the only two available studies [14,15]. Overall, values of fat and muscle depths indicate lower muscular development and greater carcass fatness compared to modern breeds, which can be explained by the absence of selection against fatness and on carcass muscle content in the Gascon breed.  [3] 17 M muscle thickness measured according to ZP method (from the vertebral canal to the cranial edge of the gluteus medius muscle (mm)). 2 S backfat thickness measured according to ZP method (above the gluteus medius muscle (mm)). 3 Measured at the level of the first rib (first thoracic vertebra). 4 Measured at the level of the last rib or reported as the average of measurements taken along the carcass. Table 6.
Summary of collected literature data on body composition and carcass traits in Gascon pig breed.  especially regarding backfat thickness are also a consequence of the wide range of final live weight of pigs and different feeding regimes and production practices applied in the considered studies.

Meat and fat quality
Basic data obtained in this review with some of the most commonly encountered meat and fat quality traits measured in the longissimus muscle that could be compared are presented in Table 7. In the studies reporting meat quality of Gascon pigs, pH measured in the longissimus muscle at 45 min and 24 hours post-mortem varied between 6.34 and 6.76 (n = 9 studies) and 5.55 and 5.92 (n = 14 studies), respectively. These are satisfactory values that indicate lack of major quality defects such as PSE or acid meat. The intramuscular fat content ranged between 2.0 and 3.3% (n = 9 studies). Colour measured in CIE L*, a* and b* colour space denotes a visually red colour and moderate lightness of the meat, which are satisfactory regarding appearance of the meat. In the only available study, SFA, MUFA and PUFA contents of intramuscular fat in the longissimus muscle were 38.1, 52.2 and 9.7%, respectively. Fatty acid composition of backfat lipids (n = 9 studies) shows high proportion of MUFA (average values between 47.6 and 54.2%) and SFA (average values between 39 and 46%) and low proportion of PUFA (less than 8% in 6 out of the 9 available studies) as compared to fatty acid profiles of backfat generally found in modern pig breeds [19]. The high proportion of MUFA and low proportion of PUFA of backfat lipids from Gascon pigs can be explained by their high genetic potential for lipid deposition together with their high energy intake during finishing period, leading to high oleic acid production from lipogenesis, the PUFA resulting only from exogenous supplies in pigs [20].

Use of breed and main products
The French autochthonous pig breed Gascon is valorised in high-quality fresh pork and pork products, mainly by the CNB but also by independent producers. The local production system associated to the know-how of producers that lead to typicity of pork and pork products has now been recognised at French and European levels through recent obtaining of AOC and PDO official quality labels for Noir de Bigorre fresh pork and dry-cured hams. Indeed, the characteristics of the Gascon pigs that exhibit a low growth potential (low growth rate) and a high carcass fatness, associated with the extensive production system with access to local feeding resources, allow for the development of the intrinsic qualities of muscle and fat tissues that lead to high eating qualities of the products [19,21]. Mainly, the meat of Gascon pigs exhibits a dark red colour with low lightness, low rate and moderate amplitude of post-mortem pH decline, low drip loss and adequate IMF content, as well as white and firm backfat with high monounsaturated fatty and low polyunsaturated fatty acid proportions. These properties are favourable for the pleasant appearance and high tenderness and juiciness of the fresh meat, as well as for the processing of dry-cured products with long ripening duration leading to high tenderness and development of specific flavours.
Dry-cured ham is the main and most "valued" product from Gascon pigs. Other main products are listed in Table 8. To still improve the intrinsic qualities (tenderness, flavours) of these hams, processors now intend to increase the hams' ripening duration, from minimum of 20 months required in PDO specifications to 24 months. The production of longer ripening hams is also considered with products aged 36 months to allow further development of specific and very high eating properties and thereby propose a wider range of high-quality "gourmet" products to consumers ( Figure 5).  Table 8.
Main products from Gascon pig breed.