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Extensive and semi-extensive production based on local swine breeds such as Majorcan Black Pig, Cinta Senese, Gascon, Krškopolje and Turopolje is becoming extremely rare and on the verge of disappearing in Europe. In this context, the main aim of this study was to assess the potential feasibility of marketing strategies to act as guidelines for stakeholders along the supply chain to create and improve added value and match market demands. The sustainability of five production systems was evaluated together with 60 stakeholders representing five local swine breeds, using a World Café (WC) method combined with an Analytical Hierarchical Process (AHP). The results showed that the proposed strategies could differ slightly depending on each system, while the product strategy was a common marketing priority for most of the stakeholders and represented all the systems evaluated. Diversifying production toward quality, innovative products, enhanced standardization, and quality labeling or seals of guarantee, such as the protected geographical indication or the protected designation of origin, would contribute to the sustainability of these chains. Advertising the storytelling of the meat products and emphasizing their healthier properties were also considered as positive strategies. To this effect, promotion should involve improving knowledge of the local systems and raising the profile of the meat products via public relations (networks, web pages, food and gastronomic events, workshops and so on) in the Hotels, Restaurants and Catering (HORECA) sector, stores selling top-quality products and local food shops. Better showcasing of these products and keeping the price in the premium segment would indirectly help the primary sector. By way of conclusion, other more developed local swine systems could be strong competitors, hence it is extremely important to effectively identify and trace all autochthonous swine breed products throughout the production chain. Furthermore, the entire chain must place greater emphasis on grazing (extensive or semi-extensive), the origin of the swine and their meat products. However, of utmost importance is cooperation between farms, firms and institutions.

Genetic and feeding factors were combined to improve various quality attributes of pork. Thirty Duroc (D) and thirty Pietrain NN (P) female crossbreeds received a control (C) or an R diet including extruded faba bean and linseed, from 30 to 115 kg. Growth, feed efficiency and slaughter weight were higher for P vs. D pigs and for R vs. C pigs. D pigs had fatter carcasses than P, whereas feeding did not affect carcass fatness. Compared with P, loin meat from D pigs had lower drip, higher ultimate pH and lipid content, and higher marbling, tenderness and juiciness scores (P 0.05). R feeding did not modify sensory traits but improved pork nutritional value by markedly reducing n-6:n-3 and saturated:n-3 fatty acid ratios (P 0.001). Combining D genotype and R diet is a favorable strategy for sensory, nutritional, technological properties and societal image of pork through relocation of feed resources, but requires a better market valorization to be implemented.

Le porc est la principale viande consommée en France et dans le monde, sous forme d’une multitude de produits frais ou transformés. La grande diversité des produits aux caractéristiques intrinsèques particulières, associée aux attentes qualitatives spécifiques des différents acteurs de la filière, rend très complexe la notion de qualité de la viande porcine. Celle-ci inclut différentes composantes dont l’importance varie selon les acteurs et les produits considérés : valeur commerciale des carcasses ou des pièces de découpe, aptitude à la transformation en produits cuits ou secs, caractéristiques nutritionnelles et sensorielles, impact des conditions d’élevage sur le bien-être des animaux et l’environnement. Le développement d’outils de prédiction de la qualité de la viande et les démarches d’intégration des composantes qualitatives relatives aux produits et aux systèmes de production contribueront à mieux répondre aux attentes diverses des acteurs de la filière et à garantir la durabilité de la production., Pork is the first meat consumed in France and worldwide, either as fresh meat or various processed products. The wide variety of pork products exhibiting particular intrinsic characteristics together with the specific demands of the different actors of pork chains, make the notion of pork quality very complex. This includes many components whose importance depends on the chain actors and products considered: commercial value of carcasses or primary cuts, ability for processing into cooked or cured products, nutritional or sensory properties, impact of rearing conditions on animal welfare or the environment. The development of tools to predict pork quality and of approaches integrating quality components of products and production systems will contribute to fulfill the various demands of the chain actors and ensure the sustainability of pig production.

Cette synthèse présente l’influence des caractéristiques des animaux et de leurs conditions d’élevage sur les qualités des viandes et des chairs des principales espèces animales d’élevage (porc, bovins, ovins, poulets, poissons). Les dimensions intrinsèques (composition des carcasses, qualités sensorielle, nutritionnelle et technologique) et extrinsèques (interactions entre productions animales et environnement, bien-être des animaux, origine des produits, authenticité des pratiques de production…) de la qualité des produits sont considérées. Dans toutes les espèces, le type génétique et la conduite alimentaire sont les principaux déterminants de la composition des carcasses. La nature de l’alimentation des animaux constitue le principal levier pour moduler la qualité nutritionnelle, toutefois le niveau d’enrichissement des viandes et chairs en acides gras, minéraux ou vitamines favorables à la santé humaine varie selon les espèces. Pour une espèce donnée, les caractéristiques des animaux, leurs conditions d’élevage et d’abattage interagissent pour déterminer les propriétés (teneurs en lipides, glycogène, myoglobine…) et le métabolisme péri et post-mortem des muscles, et consécutivement la qualité sensorielle des viandes ou chairs et de leurs produits. A l’inverse, la qualité technologique, composante importante dans les filières porc, poulet et poisson résulte essentiellement du type génétique et des conditions d’abattage des animaux et de transformation des viandes. Dans les différentes filières animales, les qualités extrinsèques des produits font partie intégrante de certaines démarches collectives ou privées et sont garanties aux consommateurs au travers des signes officiels de qualité. Elles visent à améliorer les interactions favorables entre les productions animales et l’environnement et/ou le bien-être des animaux, garantir l’origine des produits et/ou valoriser l’authenticité des méthodes de production et de transformation. Différents exemples sont développés pour illustrer la prise en compte par les acteurs des filières de cette demande croissante des consommateurs et plus largement des citoyens envers leur alimentation., This review describes the influences of the characteristics of animals and their rearing conditions on the quality of meat and flesh in the main livestock species (pig, cattle, sheep, poultry, fish). Both the intrinsic (carcass composition and sensory, nutritional and technological qualities) and extrinsic (interactions between animal production and the environment, animal welfare, origin of products, authenticity of production practices…) dimensions of quality of meat and flesh products are considered. In all animal species, the genotype and feeding practices are the main factors determining carcass composition. Feed composition is the main factor modulating nutritional quality, even though the enrichment level of meat or flesh with fatty acids, minerals or vitamins favorable for human health depends on the species considered. Within species, interactions between the characteristics of animals and their rearing and slaughtering conditions determine the properties (intramuscular fat, glycogen, myoglobin contents…) and peri and postmortem metabolism of muscles and, consequently, the sensory quality of meat or flesh and their products. Conversely, the technological quality of meat, which is important especially for pig, poultry and fish mainly results from the animal genotype and the slaughtering and processing techniques. In all meat animal chains, some productions are differentiated on claims on extrinsic qualities of products and are guaranteed to consumers by official quality schemes. They aim at improving the positive interactions between animal production and environment and/or animal welfare, or guaranteeing products origin or authenticity of production and processing methods. Some examples are described to underline the awareness of meat chain actors about the increasing demand from consumers and more generally citizens towards their diet.

La viande et la chair de poisson constituent une source essentielle de protéines, de vitamines et de micronutriments pour l’alimentation humaine. Les produits carnés représentent une activité économique importante au niveau mondial ; le niveau et l’évolution de leur consommation varient fortement selon les espèces et les zones géographiques. Le volume des productions doit répondre à l’accroissement de la population mondiale, tout en considérant les composantes environnementales, sociétales et économiques du développement durable. Cet article constitue une introduction générale au numéro spécial « Le muscle et la viande ». Il définit les principales composantes de qualité des carcasses, de la viande ou de la chair communes aux différentes espèces animales. Dans les articles suivants les principales filières (bovin, ovin, porc, poulet, poisson) sont présentées : production, consommation, problèmes de qualité spécifiques et attentes des acteurs, enjeux et questions de recherche prioritaires., Meat and fish flesh are important suppliers of proteins, vitamins and micronutrients in the human diet. Meat and fish products play an important economic role at the world level. The level and evolution of consumption highly differs according to species and geographical areas. Production level needs to fulfill the increasing population worldwide, while considering the environmental, societal and economic components of sustainable development. This manuscript presents a general introduction of the main common quality components of carcasses, meat and fish flesh. In the next papers, each main meat/flesh chain (cattle, sheep, pork, poultry and fish), is described: production, consumption, specific meat quality components and expectations of chain actors, main issues and research topics.

International audience

International audience; The quality of pork products from local breeds in extensive systems depends, among other things, on pig production. In particular, the variability in climatic conditions and feeding resources may influence the properties of tissues at slaughter and the quality of pork and processed products. The present study (part 2) was part of a larger project that assessed the influence of the finishing season and feeding resources on carcass and tissue traits and the quality of meat and dry-cured ham from Gascon pigs in an extensive system. Following the specifications of the Protected Designation of Origin “Noir de Bigorre”, castrated Gascon males were reared on rangelands (grassland and forest areas) and received a supplementary diet from 5 to 6 months of age until slaughter at a minimum of 12 months and ca. 170 kg BW. Three finishing seasons were considered: Winter (n = 18), Spring (n = 22) and Autumn (n = 23). To estimate the specific effects of season on quality traits and avoid bias due to effects of genes known to influence these traits, polymorphisms in the RYR1, PRKAG3, MC4R and LEPR genes were included in the analysis models. Compared to Winter pigs, Spring and Autumn pigs had higher ultimate pH in the semimembranosus and gluteus medius (GM) muscles, lower meat lightness (P < 0.05) and tended to have higher GM intramuscular fat (IMF) content (P < 0.10). They also had higher GM contents of saturated, monounsaturated and polyunsaturated fatty acids (FAs) than Winter pigs (P < 0.05). Spring pigs had the lowest n-6:n-3 polyunsaturated FA ratio and the highest GM α-tocopherol content (P < 0.001), indicating pig grazing. The finishing season did not influence the processing yield of dry-cured hams (24-month process). Within each seasonal group, ten hams selected for genetic variability and IMF content were analyzed by a trained sensory panel. The season did not modify the appearance or odor, but influenced texture and taste. Hams from Winter and Spring pigs had higher tenderness and melting fat scores than hams from Autumn pigs (P < 0.01). Hams from Spring pigs had higher taste intensity and salty taste (P < 0.01) but lower positive tastes (e.g. fruits, forest) than hams from the other groups. Overall, finishing season had moderate effects on ham sensory traits. Furthermore, our results reveal high redness, tenderness, taste and odor intensity, and low rancid flavor of hams from Gascon pigs produced in an extensive system.

International audience; The ‘organic’ label guarantees a production process that avoids the use of synthetic fertilisers, pesticides and hormones and minimises the use of veterinary drugs; however, consumers are demanding guarantees regarding food quality. This article reviews the current state of knowledge on the quality of organic animal products, including the authentication of their organic origin. Quality has been considered as an integrative combination of six core attributes: commercial value, and nutritional, sensory, technological, convenience and safety attributes. The comparison of these attributes between organic and conventional animal products shows high heterogeneity due to variability in farming pratices in both organic and conventional systems. To overcome this, we pinpoint the farming practices underlying the differences observed. This enables light to be shed on the consequences of possible trajectories of organic farming, if specifications are relaxed or tightened up on commitments concerning farming practices that impact product quality. Two recent meta-analyses showed better nutritional attributes in organic milk and meat linked to their higher poly-unsaturated fatty acid (PUFA) content, particularly n-3 PUFAs. Regarding safety, we point to a lack of integrated studies quantifying the balance between positive and negative effects. Organic farming reduces the risk of drug residues and antibiotic resistance, but both outdoor rearing and a frequently longer rearing period increase the animals’ exposition to environmental contaminants and the risk of their bioaccumulation in milk, eggs, meat and fish flesh. We highlight antagonisms between quality attributes for certain animal products (lamb, pork). In general, attributes are more variable for organic products, which can be explained by lower genetic selection (poultry), lower inputs and/or greater variability in farming conditions. However, the literature does not address the implications of this greater variability for the consumers’ acceptability and the necessary adaptation of manufacturing processes. Further research is needed to document the impacts on human nutritional biomarkers and health. Methods used to authenticate organic origin are based on differences in animal diet composition between organic and conventional systems, but their reliability is hampered by the variability in farming practices.

The aim of the study was to ascertain the acceptability of Traditional (T) and Innovative (IT) pork products by European consumers considering also the influence of the sensory properties. The tests were performed in Barcelona, Bologna, Toulouse and Zagreb, with products from autochthonous pig breeds Porc Negre Mallorquí (patties), Cinta Senese (dry-fermented sausages), Gascon-Noir de Bigorre (dry-cured hams) and Turopolje (dry-cured hams), respectively. The methodological approach relied on the expectancy-disconfirmation model and the assimilation theory (blind, expected and informed tests). All consumers had a similar behaviour: higher expectations of T and IT differentiating them significantly from the remaining products, except in Barcelona test, because consumers in this city were not acquainted with the production system. Innovation in T products focusing on healthy and process innovation highlighted the need to provide information about the breed and the production system, but we can conclude that the sensory quality had a significant role on the preferences of consumers. info:eu-repo/semantics/acceptedVersion

National audience; Carcass adiposity of pigs slaughtered in France has decreased by 45% on average between 1977 and 2016. The production of increasingly lean animals has been initiated in the 1950-1960’s by setting up commercial grading scales for carcasses and differentiated payment according to their lean content, to the detriment of fatty tissues. This evolution led to a standardization of production, leading to difficulties in meeting the quality demand of certain market segments. However, a renewed interest for fat has occurred recently within the French pork industry. Indeed, fatty tissues have many advantages, both for ability for processing into cured products and delicatessen, as for sensory and nutritional qualities of products. This review provides an update on pig genetics’ improvement in France in relation to adiposity and product quality. After a reminder of the characteristics of fat tissues and their importance for the quality of meat and pork products, the factors influencing adiposity and the traits related to fat quantity taken into account in breeding programs are presented. An inventory of the genetic variability of fatness that remains within French pig populations (selected and local breeds) is drawn up. This will allow defining future selection strategies, to better meet the various expectations of pork industry and consumers; L’adiposité des carcasses des porcs abattus en France s’est réduite en moyenne de 45 % entre 1977 et 2016. La production d’animaux de plus en plus maigres a été initiée dans les années 1950-1960 avec la mise en place des grilles de classement commercial des carcasses et de paiement différencié en fonction de leur teneur en tissus maigres, au détriment des tissus gras. Cette évolution a conduit à une standardisation de la production, entraînant des difficultés pour répondre à la demande qualitative de certains segments de marché. Toutefois, le gras connaît actuellement un regain d’intérêt au sein de la filière porcine française. Les tissus gras présentent en effet de nombreux atouts, tant pour l’aptitude à la transformation en produits de charcuterie et salaison que pour les qualités sensorielles et nutritionnelles des produits. Cette synthèse fait le point sur les évolutions de l’amélioration génétique du porc en France en lien avec l’adiposité et la qualité des produits. Après un rappel des caractéristiques des tissus gras et leur intérêt pour les qualités des viandes et produits du porc, les facteurs de variation de l’adiposité et les caractères de quantité de gras pris en compte dans les programmes d’amélioration génétique sont présentés. Un état des lieux de la variabilité génétique de l’adiposité qui demeure au sein des populations porcines françaises (races sélectionnées et races locales) est dressé. Ce bilan permettra de définir les futures stratégies de sélection, afin de mieux répondre aux diverses attentes des industriels et des consommateurs.

Postnatal heat stress (HS) effects on pig physiology and performance are widely studied but prenatal HS studies, albeit increasing, are still limited. The objective of this study was to evaluate the chronic prenatal HS effects in growing pigs raised in postnatal thermoneutral (TN) or in HS environment. For prenatal environment (PE), mixed-parity pregnant sows were exposed to either TN (PTN; cyclic 18 to 24 °C; n = 12) or HS (PHS; cyclic 28 to 34 °C; n = 12) conditions from day 9 to 109 of gestation. Two female offspring per sow were selected at 10 wk of age and allotted to one of two postnatal growing environments (GE): GTN (cyclic 18 to 24 °C; n = 24) and GHS (cyclic 28 to 34 °C; n = 24). From 75 to 140 d of age, GTN pigs remained in GTN conditions, while GHS pigs were in GTN conditions from 75 to 81 d of age and in GHS conditions from 82 to 140 d of age. Regardless of PE, postnatal HS increased rectal and skin temperatures (+0.30 and +1.61 °C on average, respectively; P < 0.01) and decreased ADFI (−332 g/d; P < 0.01), resulting in lower ADG and final BW (−127 g/d and −7.9 kg, respectively; P < 0.01). The GHS pigs exhibited thicker backfat (P < 0.01), lower carcass loin percentage (P < 0.01), increased plasma creatinine levels (P < 0.01), and decreased plasma glucose, nonesterified fatty acids, T3, and T4 levels (P < 0.05). Prenatal HS increased feed intake in an age-dependent manner (+10 g·kg BW–0.60·d−1 for PHS pigs in the last 2 wk of the trial; P = 0.02) but did not influence BW gain (P > 0.10). Prenatal HS decreased the plasma levels of superoxide dismutase on day 3 of GHS (trend at P = 0.08) and of T4 on day 49 (P < 0.01) but did not affect T3 on day 3 nor 49 (P > 0.10). Prenatal HS increased rectal and skin temperatures and decreased temperature gradient between rectal and skin temperatures in GTN pigs (+0.10, +0.33 and −0.22 °C, respectively; P < 0.05) but not in GHS pigs (P > 0.10). There were also PE × GE interactions found with lower BW (P = 0.06) and higher backfat (P < 0.01) and perirenal adiposity (P < 0.05) for GHS–PHS pigs than the other groups. Overall, increased body temperature and altered thyroid functions and physiological stress responses suggest decreased heat tolerance and dissipation ability of pigs submitted to a whole-gestation chronic prenatal HS. Postnatal HS decreased growth performance, increased carcass adiposity, and affected metabolic traits and thyroid functions especially in pigs previously submitted to prenatal HS.

Autochthonous pig breeds provide products of differentiated quality, among which quality control is difficult to perform and insufficient for current market requirements. The present research evaluates the predictive ability of near-infrared (NIR) spectroscopy, combined with chemometric methods as a rapid and affordable tool to assure traceability and quality control. Thus, NIR technology was assessed for intact and minced muscle Longissimus thoracis et lumborum samples collected from 12 European autochthonous pig breeds for the quantification of lipid content and fatty acid composition. Different tests were performed using different numbers of samples for calibration and validation. The best predictive ability was found using minced presentation and set with 80% of the samples for the calibration and the remaining 20% for the external validation test for the following traits: lipid content and saturated and polyunsaturated fatty acids, which attained both the highest determination coefficients (0.89, 0.61, and 0.65, respectively) and the lowest root mean square errors in external validation (0.62, 1.82, and 1.36, respectively). Lower predictive ability was observed for intact muscles. These results could contribute to improve the management of autochthonous breeds and to ensure quality of their products by traditional meat industry chains., This research was funded by the European Union’s Horizon 2020 research and innovation program, grant number 634476, for the project with acronym TREASURE. The content of this article reflects only the authors’ view and the European Union Agency is not responsible for any use that may be made of the information it contains. Junta of Extremadura and the European Social Fund for the pre-doctoral grant (PD16057) and the GR18098.

To view supplementary material for this article, please visit https:/doi.org/10.1017/S175173111600286X; This review summarizes the results from the INRA (Institut National de la Recherche Agronomique) divergent selection experiment on residual feed intake (RFI) in growing Large White pigs during nine generations of selection. It discusses the remaining challenges and perspectives for the improvement of feed efficiency in growing pigs. The impacts on growing pigs raised under standard conditions and in alternative situations such as heat stress, inflammatory challenges or lactation have been studied. After nine generations of selection, the divergent selection for RFI led to highly significant ( P

Biological processes underlie all livestock traits, including post-mortem meat quality traits. Biomarkers are molecular components of the biological processes showing differential expression associated with the phenotype of the trait. The phenotypes of the meat quality traits are determined by the animal's genotype interacting with the environment affecting the expression of the genome. The omics technologies enable measuring the expression of the genome at all levels: transcriptome, proteome, and metabolome. Associations between the phenotype of the traits and expressions measured with the omics techniques are a first step in developing biomarkers. Biomarkers enable the monitoring, diagnosis, and prediction of changes in meat quality related to external (environmental, e.g. feed and animal management conditions) stimuli and interactions with the genotype. In this paper we review the development of biomarkers for meat quality of pigs in diverse pig breeds, environments, and pork production chains.

Climatic environment is one of the main limiting factors of production efficiency in the swine industry especially in tropical countries. The aim of aim of this study was to evaluate the effects of heat exposure during most of gestation on the growth performance and carcass composition of the offspring. A total of 24 mixed parity sows pregnant sows were housed at thermoneutrality (PTN, 18-24 °C, n=12) or in HS conditions (PHS, 28-34 °C, n=12) from the 7th to the 106th day of gestation. At 70 d of age, 48 females from the 24 litters were selected, moved to two climatic chambers and exposed to TN (18-24 °C) or HS (28-34 °C) conditions. Prenatal HS did not impair growth performance. Postnatal HS reduced by 15 and 11% the average daily feed intake and BW gain, respectively. Changes in lean and fat tissue accretion were observed only when pigs were exposed to both the prenatal and postnatal HS.

This review is aimed at providing an overview of recent advances made in the field of meat quality prediction, particularly in Europe. The different methods used in research labs or by the production sectors for the development of equations and tools based on different types of biological (genomic or phenotypic) or physical (spectroscopy) markers are discussed. Through the various examples, it appears that although biological markers have been identified, quality parameters go through a complex determinism process. This makes the development of generic molecular tests even more difficult. However, in recent years, progress in the development of predictive tools has benefited from technological breakthroughs in genomics, proteomics, and metabolomics. Concerning spectroscopy, the most significant progress was achieved using near-infrared spectroscopy (NIRS) to predict the composition and nutritional value of meats. However, predicting the functional properties of meats using this method—mainly, the sensorial quality—is more difficult. Finally, the example of the MSA (Meat Standards Australia) phenotypic model, which predicts the eating quality of beef based on a combination of upstream and downstream data, is described. Its benefit for the beef industry has been extensively demonstrated in Australia, and its generic performance has already been proven in several countries.

Dietary extra hydroxyl-methionine supply: associated changes in muscle biological processes in finishing pigs

The effects of dietary methionine (Met) supplies above growth requirements on tissue biology and pork quality were studied. At 70 kg, 45 crossbred pigs were fed a control (CONT) diet adequate in Met (0.22% Met) up to 105 kg. For the last 14 days before slaughter, pigs were fed with the CONT diet or with diets where the Met level was increased to Met3 (0.66% Met) or Met5 (1.10% Met). Growth performance and carcass composition did not change with the treatment. Pigs fed the Met5 treatment displayed lower TBARS and higher glutathione levels (P ≤ .05), along with higher ultimate pH (P

Dry-fermented pork sausages, from Cinta Senese local breed, were manufactured replacing sodium nitrite (NIT) with two mixtures of natural antioxidants consisting of: i) grape seed extract and olive pomace hydroxytyrosol (GSE); ii) chestnut extract and olive pomace hydroxytyrosol (CHE). The effects on physical-chemical, aromatic and sensory traits, as well as the microbiological safety, were tested. Nitrite replacement lowered the pH in GSE and CHE samples and resulted in several differences in physical traits between CHE and NIT samples. Listeria monocytogenes, Salmonella and Clostridium botulinum were not found in any samples. GSE and CHE mixtures showed a slightly lower antioxidant activity. Volatile profile showed a similar aromatic profile among the three treatments with differences mainly to abundance of the single compounds, indicating that replacement of nitrite by natural antioxidants did not affect the overall aroma profile, as outlined by olfactometry results. In addition, the replacement did not affect the overall acceptability, except for color-related traits, underscored in GSE and CHE products., The research was carried out with funds from the European Union's Horizon 2020 research and innovation program under grant agreement No 634476 (acronym TREASURE). Authors also acknowledge the financial support of AGL2015–64673-R (MINEICO, Spain) and FEDER funds.

Both breed and production systems are responsible for production efficiency and quality traits of pork. Effects of breed and production system within breed on growth, body fatness, and adipose tissues traits were assessed in the pure Basque (B, nonselected, local French) and conventional Large White (LW) breeds, reared either in a conventional (C, slatted floor), alternative (A, indoor straw bedding and outdoor area), or extensive (E, free range) system. A total of 100 castrated males were produced in 2 replicates, each involving 50 pigs distributed in 5 treatments based on breed and production system (i.e., BC, BA, BE, LWC, and LWA [10 pigs/group and per replicate]). From 35 kg BW to slaughter at around 145 kg BW, the BC, BA, LWC, and LWA pigs received the same growing and finishing diets, whereas the BE pigs had free access to the natural resources of the E pen and received a standard growing-finishing diet at restricted allowance according to the farming practices of the B pork chain. The B pigs had lower (P < 0.001) ADG and G:F than the LW pigs and were much older (P < 0.001) at slaughter. The LWA pigs had similar ADG but lower (P = 0.03) G:F than the LWC. Within the B breed, the BA had higher (P = 0.04) and the BE lower (P < 0.001) ADG compared with BC pigs. The B pigs had a higher (P < 0.001) carcass dressing an exhibited around 2-fold higher (P < 0.001) back fat proportion, perirenal fat weight and LM lipid content than the LW pigs. Compared with C, the A system decreased (P = 0.04) carcass dressing within LW but did not influence carcass traits within B pigs. The E system decreased (P ≤ 0.05) carcass dressing, back fat proportion, and LM lipid content in BE compared with BC pigs. The B pigs exhibited larger (P < 0.001) adipocytes in both subcutaneous adipose tissue (SCAT) and LM than the LW pigs. Malic enzyme activity was higher in SCAT of B than LW pigs despite their greater fatness, and was higher (P ≤ 0.01) in BA but lower (P < 0.001) in BE than in BC pigs. The B pigs had higher (P < 0.001) MUFA but lower (P ≤ 0.006) SFA and PUFA fatty acid percentages in SCAT than the LW pigs. Compared with C, the A system had scarce influence on FA composition within each breed, whereas the E system led to lower (P = 0.015) SFA and greater (P < 0.001) PUFA in SCAT of the B pigs. Altogether, the E production system can counteract the genetic potential of B pigs for growth rate but also body fatness.

Les muscles squelettiques sont composés de fibres musculaires, de tissus conjonctif et adipeux. Dans cet article, nous décrivons les caractéristiques de ces différents constituants musculaires et leurs relations avec les composantes technologiques et sensorielles de la qualité de la viande chez les principales espèces terrestres d’intérêt agronomique et les poissons. Ainsi, le type contractile et métabolique, la taille et le nombre des fibres musculaires, la teneur, la composition et la distribution du tissu conjonctif au sein du muscle, la teneur et la composition en lipides du tissu adipeux intramusculaire contribuent à déterminer l’aspect, la couleur, la tendreté, la jutosité et la flaveur des viandes ou chairs de poisson. Toutefois, la relative indépendance des caractéristiques biochimiques ou structurales des fibres musculaires, du tissu conjonctif et des lipides intramusculaires suggère qu’il est possible de moduler les propriétés de ces différents constituants de manière indépendante et complémentaire par des facteurs liés à l’animal ou à sa conduite d’élevage. Il apparaît donc possible de pouvoir concilier les impératifs quantitatifs et qualitatifs de la production de viande., Skeletal muscle is composed of several tissues, such as muscle fibers, connective and adipose tissues. This review describes the features of these various muscle components and their relationships with the technological and sensory properties of meat from different livestock species. Thus, the contractile and metabolic types, the size and the number of muscle fibers, the content, composition and distribution of the connective tissue in the muscles, as well as the content and lipid composition of intramuscular fat all contribute to meat appearance, color, tenderness, juiciness, and flavor. However, the biochemical and structural characteristics of muscle fibers, intramuscular connective tissue and intramuscular fat seem to be rather independent. This suggests that the properties of these various muscle components can be modulated independently by genetics or environmental factors in order to achieve both production efficiency and quality of meat.

On sait depuis longtemps que lorsque les animaux sont stressés pendant la période de l’abattage, le risque de produire des viandes avec des défauts de qualité, notamment les viandes exsudatives et à coupe sombre, augmente. Des études récentes basées sur des approches comportementales, physiologiques et/ou génomiques montrent que des niveaux de stress modérés au cours de l’abattage peuvent également influencer les qualités technologiques et/ou sensorielles des viandes de porc, de bovin, d’ovin, de volaille et des chairs de poisson, expliquant jusqu’à 70% de la variabilité des composantes de qualité entre les animaux. La réactivité au stress d’abattage varie selon les individus et peut être partiellement prédite à partir de leurs réactions lors de tests de réactivité réalisés pendant l’élevage. La réactivité au stress d’un animal dépend en partie de ses expériences antérieures et de son patrimoine génétique. En plus des questions relatives au bien-être animal à l’abattage, il est nécessaire aujourd’hui de mieux comprendre les mécanismes sous-jacents aux effets négatifs du stress sur les qualités des viandes. L’espèce doit être prise en considération, car les causes de stress à l’abattage et les critères de qualité de viandes optimaux varient selon l’espèce. Les mécanismes biologiques impliqués dans les effets du stress sur la viande et la chair varient également en fonction de l’espèce., It has long been known that stress during the slaughter period may result in the production of meat with major quality defects, particularly exudative and dark-cutting meat. Recent studies using behavioural, physiological and/or genomic approaches found that less extreme stress levels during slaughter may also influence technological and/or sensory qualites of meat from pigs, cattle, sheep, poultry and fish flesh, sometimes explaining over 70% of inter-animal variability in quality. Stress reactivity at slaughter varies between individuals and may be predicted from their reactions to stressful challenges during the rearing period. The stress reactivity of an animal depends partly on its earlier experiences and genetic background. In addition to slaughter-related animal welfare questions, today’s challenge is to increase our understanding of the physiological and molecular mechanisms underlying the effects of stress on meat quality. The different species should be taken into account, as the causes of stress at slaughter and criteria for optimal meat quality are species-specific. In addition, the biological mechanisms underlying the effect of stress on meat and flesh quality partly differ between species.

Cold environment represents an external stress modulating animal growth and energy use. At muscle level, adaptation to cold conditions potentially involves energy homeostasis regulation gauged by the adenosine monophosphate (AMP)-activated protein kinase (AMPK). Our study aimed at evaluating the bare effects of short- and long-term cold exposure on growth performance, carcass traits, and metabolic characteristics of the oxidative semispinalis (SS) muscle and glycolytic LM and to evaluate the reversibility of short-term effects, with a special emphasis on AMPK activity. A total of 84 pigs fed ad libitum and individually housed were submitted after weaning to either Cold (from 23 ± 1 to 15 ± 3°C) or thermoneutral (T; from 28 ± 1 to 23 ± 1°C) temperature up to 24.7 ± 1.6 kg BW (25 BW). Twelve Cold and 12 T piglets were then slaughtered the same day. Eighteen remaining Cold piglets were reared at 12 ± 2°C (CC) whereas 18 Cold and 24 T piglets were reared at 23 ± 4°C (CT and TT, respectively) and slaughtered at 114.3 ± 5.9 kg (115 BW). The LM and SS samples were analyzed to determine glycolytic potential (GP), activities of lactate dehydrogenase (LDH), citrate synthase (CS), and β-hydroxy-acyl-CoA dehydrogenase (HAD) and to quantify AMPK phosphorylation Threonine 172 phosphorylated form of AMPK α1+α2 isoforms (pAMPK) / total AMPK α1+α2 isoforms (AMPK). Despite a greater ADFI (P < 0.001), Cold piglets exhibited less ADG (P < 0.001) and body fatness (P < 0.03) attesting an acute adaptation to a short-term cold exposure. A long-term cold adaptation evaluated on 115 BW pigs increased ADFI (P < 0.001) but did not influence ADG and carcass lean meat content. Cold environment influenced the dynamic of muscle metabolism in a muscle type dependent manner corresponding to an earlier and acute adaptation in SS from 8 kg onward and a belated adaptation in LM from 25 BW to 115 BW. Cold exposure was associated with a progressive increase of muscle oxidative capacity, first in the SS with greater HAD (P = 0.002) and CS activities (P = 0.03) at 25 BW and then both in SS and LM at 115 BW (P < 0.001). Conversely, in LM of CC pigs, increased GP (P < 0.001) and LDH activity (P = 0.03) were observed in addition to increased CS and HAD activities, highlighting the ability of LM to increase both its glycolytic and oxidative metabolism and to diversify its energy substrates. Pigs from CC group exhibited also less pAMPK/AMPK (P < 0.01) specifically in red SS muscle, denoting a reduced metabolic stress of this muscle after a long-term cold adaptation.

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Cette revue a pour objectif de faire un point sur les avancées récentes obtenues dans le domaine de la prédiction de la qualité des viandes. Elle aborde différentes démarches menées au sein des principales filières de production pour développer des équations puis des outils prédictifs basés sur différents types de marqueurs biologiques (génomiques ou phénotypiques) ou physiques (spectroscopiques). Au travers des différents exemples présentés, il apparaît que l’identification de marqueurs biologiques se confronte au déterminisme complexe des paramètres de qualité qui rend encore difficile la mise au point de tests moléculaires génériques utilisables sur le terrain. Toutefois, les avancées ont été notables ces dernières années bénéficiant des récents développements technologiques en génomique, protéomique et métabolomique. Les premières équations de prédiction de la qualité sensorielle et du potentiel technologique des viandes laissent entrevoir des possibilités d’applications dans les années à venir. Concernant la spectroscopie, les principaux résultats ont été obtenus dans le domaine de la Spectroscopie Proche Infrarouge (SPIR) avec des développements aboutis pour prédire la composition et la valeur nutritionnelle des viandes. La prédiction du potentiel technologique des viandes à l’aide de cette méthode et surtout de la qualité sensorielle est en revanche plus difficile. Enfin, l’exemple du modèle phénotypique MSA (« Meat Standards Australia ») de prévision de la qualité sensorielle de la viande bovine basée sur une combinaison de données d’amont et d’aval et dont la plus-value pour la filière a été démontrée en Australie, présente une généricité qui a déjà été éprouvée dans plusieurs pays., This review was aimed at providing an overview of recent advancements obtained in the field of meat quality prediction. The different methods used in the production sectors for the development of equations and the tools used based on different types of biological markers (genomic or phenotypic) or physical (spectroscopy) are discussed. Through the different examples that are presented, it appears that the identification of biological markers is confronted with the complex determinism of quality parameters. This makes the development of generic molecular tests to be used on the field even more difficult. However, in recent years, progress has been made, benefitting from genomics, proteomics and metabolomics technological developments. The first equations that predict the sensorial quality and the technological potential of meat hint to possible applications in the near future. Concerning spectroscopy, the main results were obtained using Near Infrared Spectroscopy (NIR) with developments obtained for the prediction of the composition and nutritional value of meats. The prediction of the technological potential of meats using this method and mainly the sensorial quality is, however, more difficult. Finally, the example of the MSA (« Meat Standards Australia ») phenotypic model which predicts the sensorial quality of bovine meat based on a combination of upstream and downstream data and whose added-value for the sector has been identified in Australia, presents a genericness that has already been proven in several countries.

Residual feed intake (RFI) is defined as the difference between the observed feed intake and that expected based on requirements for maintenance and production. A divergent selection was conducted during 4 generations in Large White male pigs to produce low and high RFI lines. The present study aims at determining the influence of this selection on biochemical and histological traits of skeletal muscle, and relating these changes to correlated effects on growth, carcass composition, and meat quality traits. At 8 d preslaughter, biopsies from the LM were taken in the fed state on 14 females from each RFI line fed ad libitum. Animals were slaughtered at 107.8 ± 8.0 kg of BW without any previous fasting. Samples of LM, semimembranosus (SM), biceps femoris (BFM), and rhomboideus muscles were taken at both 30 min and 24 h postmortem. Myofiber typing was only assessed in LM. Low RFI pigs ("efficient") had leaner carcasses with greater muscle content (P 0.10) between lines was found for citrate synthase and lactate dehydrogenase activities, mitochondrial activity, and expression of genes coding for uncoupling proteins 2 and 3. Differences between RFI pigs in plasma leptin, cortisol, and thyroid hormone concentrations are presented and discussed. In conclusion, selection for low RFI influenced muscle properties in a way favoring muscle mass, but likely impairing meat quality.

A restriction/realimentation feeding strategy was applied to pigs to increase the age at market weight and final ADG, modify protein and lipid deposition rates at carcass and muscle levels, and thereby improve eating quality of the pork. A total of 126 Duroc x (Large White x Landrace) pigs (females and castrated males) were used. At the average BW of 30 kg, within litter and sex, pairs of littermates (blocked by BW) were randomly assigned to ad libitum (AL) feeding during growing (30 to 70 kg of BW) and finishing (70 to 110 kg of BW) periods (AL, n = 56), or restricted feeding at 65% of the ADFI of the AL pigs, on a BW basis, during the growing period and AL feeding during finishing (compensatory growth, CG; n = 56). In each feeding regimen, 15 pigs were slaughtered at 70 kg of BW, and 41 pigs were slaughtered at 110 kg of BW. Additionally, 14 pigs were slaughtered at 30 kg of BW to calculate tissue deposition rates. The CG pigs showed decreased ADG (-35%, P = 0.001) during growing but increased ADG (+13%, P = 0.001) during finishing (i.e., compensatory growth) due to greater (P = 0.001) ADFI and G:F. Hence, CG pigs were 19 d older at 110 kg of BW than AL pigs. The CG pigs were leaner at 70 kg of BW than AL (e.g., 11.7 vs. 13.5 mm of average backfat thickness for CG and AL pigs, respectively, P = 0.023), whereas the differences were reduced at 110 kg of BW (20.6 vs. 21.0 mm of average backfat thickness for CG and AL pigs, respectively, P = 0.536). At 70 kg of BW, intramuscular fat (IMF) content of LM did not differ between CG and AL pigs (1.25 vs. 1.49%, respectively, P = 0.118), whereas CG pigs had less IMF in LM at 110 kg of BW (2.19 vs. 2.53% for CG and AL pigs, respectively, P = 0.034). Feeding regimen influenced the composition of weight gain. From 30 to 70 kg of BW, feed restriction reduced (P = 0.001) lean and adipose tissue deposition at the carcass level and protein and lipid deposition at the muscle level. From 70 to 110 kg of BW, the CG feeding strategy increased (P = 0.016) deposition of adipose but not of lean tissue at the carcass level. However, lipid and protein deposition at the muscle level were not affected. Thus, realimentation promoted deposition of subcutaneous fat over IMF. Feeding regimen hardly affected technological meat quality at 110 kg of BW. The CG feeding strategy decreased (P = 0.014) the meat juiciness score in relation to the decreased IMF but did not influence other sensory traits. Elevated IMF content and improved pork quality might be achieved by modifying the onset or duration of the restriction and realimentation periods.

Muscle lipid concentration is known to influence pork eating quality. This study aimed at evaluating the effect of a restriction–re-alimentation feeding strategy on intramuscular fat deposition in pigs. A total of 70 Duroc × (Large White × Landrace) pigs (castrated males and females) were used. Ten pigs were first slaughtered at 30 kg live weight (LW) to determine initial body and muscle composition. From 30 to 80 kg LW (growing period), pigs were either fed ad libitum (AL) or restricted to 70% of the ad libitum intake of AL pigs (RA). From 80 to 110 kg LW (finishing period), both AL and RA pigs were fed ad libitum. In each group, pigs were slaughtered at 80 kg (n = 10) and at 110 kg (n = 20) LW. During the growing period, the growth rate of RA pigs was reduced by 30% (P < 0.001) compared with AL pigs. During the finishing period, RA pigs had a 7% (P = 0.09) higher growth rate than AL pigs due to compensatory feed intake (+14%). Plasma insulin-like growth factor-1 concentration was lower in RA pigs at 80 kg LW, but markedly increased after re-alimentation up to the level observed in AL pigs (P < 0.001). At 80 kg, the leaner carcasses of RA pigs resulted from a more pronounced reduction in fat than in lean tissue deposition rates. Re-alimentation of RA pigs increased fat tissue deposition (+160% for females, P < 0.01) but not lean deposition in the carcass, leading to limited differences in carcass composition between RA and AL pigs at 110 kg LW. Regarding tissue deposition rates, the response to feeding strategy differs between muscles. In the m. biceps femoris (BF), restriction affected lipid (−50%, P < 0.001) and protein (−25%, P < 0.001) deposition, whereas re-alimentation increased lipid (+62%, P < 0.05) but not protein deposition rates. At market weight, the extent of the difference in BF lipid concentration between RA and AL pigs was strongly reduced, but still significant. By contrast, in the m. longissimus, restriction decreased protein but not lipid deposition, whereas neither of them was modified during re-alimentation. Therefore, an increased muscle lipid concentration at 110 kg LW could not be reached in RA pigs. Modifications of onset and/or duration of restriction and re-alimentation periods should be tested to optimise effects on muscle lipid deposition and thereby achieve improved pork quality.

The knowledge of the molecular organization of living organisms evolved considerably during the last years. The methodologies associated also progressed with the development of the high-throughput sequencing (SNP array, RNAseq, etc.) and of genomic tools allowing the simultaneous analysis of hundreds or thousands of genes, proteins or metabolites. In farm animals, some proteins, mRNAs or metabolites whose abundance has been associated with meat quality traits have been detected in pig, cattle, chicken. They constitute biomarkers for the assessment and prediction of qualities of interest in each species, with potential biomarkers across species. The ongoing development of rapid methods will allow their use for decision-making and management tools in slaughterhouses, to better allocate carcasses or cuts to the appropriate markets. Besides, their application on living animals will help to improve genetic selection and to adapt a breeding system to fulfill expected quality level. The ultimate goal is to propose effective molecular tools for the management of product quality in meat production chains.

A total of 120 crossbred [synthetic line x (Large White x Landrace)] pigs (castrated males and females) were used to evaluate the influence of rearing conditions for growing-finishing pigs on growth performance, carcass, stress reactions at slaughter, and meat eating quality. At approximately 35 kg of live weight (LW), littermates were allocated to either a conventional (fully slatted floor, 0.65 m2/pig, considered as control, CON) or an alternative (sawdust bedding with free access to an outdoor area, 2.4 m2/pig, OUT) system, until slaughter at approximately 110 kg of LW. Pigs had free access to standard growing and finishing diets. The trials were conducted in spring, summer, and winter, with each season involving 2 pens of 10 pigs in each system. Compared with the CON, the OUT pigs exhibited a greater growth rate (+10%, P 0.10) influence the behavioral activities of pigs during lairage at the slaughterhouse, or the urinary levels of catecholamines and cortisol, and plasma levels of ACTH, cortisol, lactate, creatine kinase, and FFA immediately after slaughter. The OUT pigs had similar (P > 0.10) pH values 30 min postmortem (pH1) in the LM, biceps femoris (BF), and semimembranosus (SM) muscles, similar ultimate pH (pHu) in LM, but lower pHu in SM (- 0.07 unit, P 0.07). Intramuscular fat content was greater in the LM (+17%, P = 0.001), BF (+14%, P = 0.004), and SM (+17%, P = 0.003) of the OUT pigs. Outdoor rearing during summer and winter improved meat juiciness, whereas odor, flavor, and tenderness were unaffected (P > 0.10). Influence of rearing conditions on all the other traits studied did not depend on the season.

Intramuscular fat content is generally associated with improved sensory quality and better acceptability of fresh pork. However, conclusive evidence is still lacking for the biological mechanisms underlying i.m. fat content variability in pigs. The current study aimed to determine whether variations in i.m. fat content of longissimus muscle are related to i.m. adipocyte cellularity, lipid metabolism, or contractile properties of the whole muscle. To this end, crossbred (Large White x Duroc) pigs exhibiting either a high (2.82 +/- 0.38%, HF) or a low (1.15 +/- 0.14%, LF) lipid content in LM biopsies at 70 kg of BW were further studied at 107 +/- 7 kg of BW. Animals grew at the same rate, but HF pigs at slaughter presented fatter carcasses than LF pigs (P = 0.04). The differences in i.m. fat content between the 2 groups were mostly explained by variation in i.m. adipocyte number (+127% in HF compared with LF groups, P = 0.005). Less difference (+13% in HF compared with LF groups, P = 0.057) was noted in adipocyte diameter, and no significant variation was detected in whole-muscle lipogenic enzyme activities (acetyl-CoA carboxylase, P = 0.9; malic enzyme, P = 0.35; glucose-6-phosphate dehydrogenase, P = 0.75), mRNA levels of sterol-regulatory element binding protein-1 (P = 0.6), or diacylglycerol acyltransferase 1 (P = 0.6). Adipocyte fatty acid binding protein (FABP)-4 protein content in whole LM was 2-fold greater in HF pigs than in LF pigs (P = 0.05), and positive correlation coefficients were found between the FABP-4 protein level and adipocyte number (R2 = 0.47, P = 0.02) and lipid content (R2 = 0.58, P = 0.004). Conversely, there was no difference between groups relative to FABP-3 mRNA (P = 0.46) or protein (P = 0.56) levels, oxidative enzymatic activities (citrate synthase, P = 0.9; beta-hydroxyacyl-CoA dehydrogenase, P = 0.7), mitochondrial (P = 0.5) and peroxisomal (P = 0.12) oxidation rates of oleate, mRNA levels of genes involved in fatty acid oxidation (carnitine-palmitoyl-transferase 1, P = 0.98; peroxisome proliferator-activated receptor delta, P = 0.73) or energy expenditure (uncoupling protein 2, P = 0.92; uncoupling protein 3, P = 0.84), or myosin heavy-chain mRNA proportions (P > 0.49). The current study suggests that FABP-4 protein content may be a valuable marker of lipid accretion in LM and that i.m. fat content and myofiber type composition can be manipulated independently.

The objective of this study was to determine the relationships between birth-weight-associated modifications in histological or chemical muscle characteristics and meat quality traits in pigs. At 68 d of age, Pietrain x (Large White x Landrace) female littermates were allocated into 2 groups on the basis of low birth weight (LW = 1.05 +/- 0.04 kg; n = 15) or high birth weight (HW = 1.89 +/- 0.02 kg; n = 15). Pigs were reared in individual pens with free access to a standard diet up to slaughter at approximately 112 kg of BW. During the growing-finishing period, LW and HW pigs had a similar daily feed consumption, whereas G:F was lower (P = 0.009) for LW pigs than for HW littermates. At final BW, LW pigs were 12 d older (P < 0.001) than HW littermates. Estimated lean meat content, relative proportions of loin and ham in the carcass, and weights of LM and semitendinosus muscle (SM) were decreased (P < 0.05) in LW pigs compared with HW pigs. Conversely, the LW pigs exhibited a fatter carcass, greater activity levels of fatty acid synthase and malic enzyme in backfat (n = 15 per group), and enlarged subcutaneous adipocytes (n = 8 per group) compared with the HW pigs. Similarly, lipid content was increased by 25% (P = 0.009), and mean adipocyte diameter was 12% greater (P = 0.008) in the SM from LW pigs compared with that from HW pigs, whereas lipid content did not vary in the LM of either group. Mean myofiber cross-sectional areas were 14% greater in the LM (P = 0.045) and the SM (P = 0.062) of LW pigs than of HW pigs. Conversely, the total number of myofibers was less (P = 0.003) in the SM of LW vs. HW pigs. There were no differences between groups for glycolytic potential at slaughter and rate and extent of postmortem pH decline in both muscles, as well as for LM drip losses. A trained sensory test panel judged the roast loin meat to be less tender (P = 0.002) in LW pigs relative to HW pigs. Scores for juiciness, flavor, flouriness, and fibrousness of meat did not differ between groups. Overall, negative but somewhat low correlation coefficients were found between LM tenderness score and ultimate pH (r = -0.36; P = 0.06) and between LM tenderness and mean cross-sectional area of myofibers (r = -0.34; P = 0.07). This study demonstrates a lower tenderness of meat from pigs that had a LW, partly as a result of their enlarged myofibers at market weight.

The objective of this study was to provide some information on the influence of outdoor rearing on pasture (O) compared with indoor (I) on carcass and meat quality of cull sows. Twelve sows (6 per group) originating from the same breeding unit were slaughtered 11 days after their last weaning. O sows had heavier and fatter carcasses, however lipid content in Longissimus (L) and Triceps brachii (TB) muscles was not affected. Grazing of O sows led to a high increase in the n - 3 fatty acid content, particularly the C18:3 linolenic acid in the backfat and L muscle, thus improving the meat nutritional quality. Vitamin E content appeared (P = 0.13) to be increased in the backfat of O sows, but not in the muscles. Lipid oxidation in meat during storage was similar between groups. Histological and metabolic observations showed that outdoor rearing increased the glycolytic capacity of the L muscle, and the oxidative capacity of the TB. Outdoor rearing did not influence meat pH1 and pHu, but decreased colour (a* and b* values) of the TB, and increased the processing yield of loin into cured bacon. Outdoor rearing decreased the red colour intensity and homogeneity, but improved tenderness of cured loins.

Muscle fat stores at slaughter partly determine the dietetic and sensory quality traits of pork meat. Nutritional strategies during the growing-finishing period are able to modify intramuscular fat content; however, the underlying mechanisms remain largely unknown. The objective of this study was to determine some of the cellular, biochemical, and molecular bases of muscle fat content variation in response to feeding regimen in pigs. Crossbred pigs of 30 kg BW were allocated to three feeding groups: free access ([C], n = 10) to a standard diet (3.25 kcal of DE/kg, 9.5 g of lysine/ kg), standard diet at 75% of the spontaneous voluntary intake ([FR], n = 10), or both low protein and energy intakes ([PR], n = 10) in order to get the same growth rate as the FR pigs and the same body composition as the C pigs. At slaughter (110 kg BW), FR and PR pigs were 30 d older than C pigs (P < 0.001). In agreement with the protocol, carcass adiposity was similar in PR and reduced (P < 0.01) in FR pigs compared with C animals. Lipid content in longissimus lumborum muscle was reduced by 25% in FR pigs and increased by 40% in PR pigs compared to C pigs (P < 0.001). Commensurate variations in the diameter of muscle adipocytes were observed between the three feeding groups (P < 0.001). The muscle activities of malic enzyme and glucose-6-phosphate dehydrogenase, generating reduced nicotinamide adenine dinucleotide phosphate for fatty acid synthesis, were depressed (P < 0.05) in both FR and PR groups, compared to the C group. The expression level of the sterol regulatory element binding protein that was chosen as the putative candidate at the molecular level was not modified by the feeding regimen. No variations in the oxidative enzyme markers were denoted, whereas lactate dehydrogenase activity was reduced by 13% (P < 0.05) in PR group compared to other groups. In conclusion, moderate long-term feed restriction results in decreased lipogenic capacity of muscle adipocytes and intramuscular fat content. In contrast, the reduction of both protein and energy intakes more likely results in an imbalance between multiple aspects of muscle energy metabolism, in favor of intramuscular fat accretion.

Meat quality (MQ) results from complex phenomenon and despite improved knowledge on MQ development, its variability remains high. The identification of biomarkers and the further development of rapid tests would thus be helpful to evaluate MQ in pork industries. Using transcriptomics, the present study aimed at identifying biomarkers of eight pork quality traits: ultimate pH, drip loss, lightness, redness, hue angle, intramuscular fat, shear force and tenderness, based on an experimental design inducing a high variability in MQ. Associations between microarray gene expression and pork traits (n=50 pigs) highlighted numerous potential biomarkers of MQ. Using quantitative RT-PCR, 113 transcript–trait correlations including 40 of these genes were confirmed (P b 0.05, |r|≤ 0.73), out of which 60 were validated (P b 0.05, |r|≤ 0.68) on complementary experimental data (n=50). Multiple regression models including 3 to 5 genes explained up to 59% of MQ trait variability. Moreover, functional analysis of correlated-trait genes provided information on the biological phenomena underlying MQ.

Session : Bases biologiques de la qualité et génétique/génomique; It has long been known th at stress during the slaughter period may result in the production of meat with major quality defects, particularly PSE and DFD meat. Recent studies using behavioural, physiological and/or genomic approaches fou nd that Jess extreme stress levels during slaughter may a iso influence technological and/or sensory quality of meat of pigs, cattle, sheep, and fowl and of fish flesh, sometimes explaining over 70% of inter-animal variability. Stress reactivity at slaughter varies between animais and may be predicted from reactions to stressful challenges during the rearing period. The stress reactivity of an animal depends partly on its earlier experiences and genetic background. In addition to slaughter-related animal welfare questions, today's challenge is to increase our understanding of the physiological and molecular mechanisms underlying the effects of stress on meat quality. The different species should be taken into account, as the causes of stress at slaughter and criteria for optimal meat quality are species-specific. In addition, the mechanisms underlying the effect of stress on meat and flesh quality differ at !east part! y between species.

The molecular mechanisms underlying the genetic control of fat development in humans and livestock species still require characterization. To gain insights on gene expression patterns associated with genetic propensity for adiposity, we compared subcutaneous adipose tissue (SCAT) transcriptomics profiles from two contrasted pig breeds for body fatness. Samples were obtained from Large White (LW; lean phenotype) and Basque pigs (B; low growth and high fat content) at 35 kg ( n = 5 per breed) or 145 kg body weight ( n = 10 per breed). Using a custom adipose tissue microarray, we found 271 genes to be differentially expressed between the two breeds at both stages, out of which 123 were highly expressed in LW pigs and 148 genes were highly expressed in B pigs. Functional enrichment analysis based on gene ontology (GO) terms highlighted gene groups corresponding to the mitochondrial energy metabolism in LW pigs, whereas immune response was found significantly enriched in B pigs. Genes associated with lipid metabolism, such as ELOVL6, a gene involved in fatty acid elongation, had a lower expression in B compared with LW pigs. Furthermore, despite enlarged adipocyte diameters and higher plasma leptin concentration, B pigs displayed reduced lipogenic enzyme activities compared with LW pigs at 145 kg. Altogether, our results suggest that the development of adiposity was associated with a progressive worsening of the metabolic status, leading to a low-grade inflammatory state, and may thus be of significant interest for both livestock production and human health.