Review. Divergent selection for residual feed intake in the growing pig

To view supplementary material for this article, please visit https:/doi.org/10.1017/S175173111600286XThis 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<0.001) line differences for RFI (−165 g/day in the low RFI (LRFI) line compared with high RFI line) and daily feed intake (−270 g/day). Low responses wereobserved on growth rate (−12.8 g/day, P <0.05) and body composition (+0.9mm backfat thickness, P = 0.57; −2.64% lean meat content, P<0.001) with a marked response on feed conversion ratio (−0.32 kg feed/kg gain, P<0.001). Reduced ultimate pH and increased lightness of the meat ( P<0.001) were observed in LRFI pigs with minor impact on the sensory quality of the meat. These changes in meat quality were associated with changes of the muscular energy metabolism. Reduced maintenance energy requirements (−10% after five generations of selection) and activity (−21% of time standing after six generations of selection) of LRFI pigs greatly contributed to the gain in energy efficiency. However, the impact of selection for RFI on the protein metabolism of the pig remains unclear. Digestibility of energy and nutrients was not affected by selection, neither for pigs fed conventional diets nor for pigs fed high-fibre diets. A significant improvement of digestive efficiency could likely be achieved by selecting pigs on fibre diets. No convincing genetic or blood biomarker has been identified for explaining the differences in RFI, suggesting that pigs have various ways to achieve an efficient use of feed. No deleterious impact of the selection on the sow reproduction performance was observed. The resource allocation theory states that low RFI may reduce the ability to cope with stressors,via the reduction of a buffer compartment dedicated to responses to stress. None of the experiments focussed on the response of pigs to stress or challenges could confirm this theory. Understanding the relationships between RFI and responses to stress and energy demanding processes, as such immunity and lactation, remains a major challenge for a better understanding of the underlying biological mechanisms of the trait and to reconcile the experimental results with the resource allocation theory

Overview of the conservation status of Mediterranean anthozoans

The IUCN Red List of Threatened SpeciesTM – Regional AssessmentThis report presents the conservation status of the anthozoans occurring in the Mediterranean Sea, based on the assessment of 136 species using the IUCN Red List methodology. It identifies those species that are threatened with extinction at the regional level to guide appropriate conservation actions in order to improve their statusVersión del edito

Pork quality differences between lines divergently selected for residual feed intake

Recent studies demonstrated that a selection for residual feed intake (RFI) led to improved feed conversion ratio and carcass lean meat content. However, the understanding of the relationships between RFI and pork quality is still unclear and deserves further study to meet producer, processing industry and consumer demands. Our objective was to evaluate the impact of a divergent selection on RFI on technological and sensory quality of meat. After six generations of selection, growth performance, carcass composition, muscle biochemical and meat quality traits were studied in 117 Large White females and castrated males from two divergent RFI lines fed ad libitum. Despite similar growth rate, the low RFI line (RFI-) pigs were more efficient (p<0.001), exhibited leaner carcasses (p<0.001) and a greater carcass yield (p<0.001) than high RFI line (RFI+) pigs. Selection for low RFI affected meat quality parameters by increasing muscle glycogen content (p<0.001) as well as the extent of pH decline (p<0.001) and drip loss (p<0.001), and decreasing IMF content (p<0.001) in the Longissimus muscle. Visual appearance of fresh meat was also influenced, with lower scores for marbling, homogeneity and intensity of red color of the RFI- pork. However, these differences between RFI lines had no effect on meat tenderness and juiciness. Regarding trade-offs between economical results for producers (lower feeding cost, higher carcass lean content) and environmental issues, the negative impact of selection for low RFI on pork quality could be moderated

Vers une sélection sur la consommation alimentaire résiduelle chez le porc en croissance pour concilier efficacité alimentaire, qualité des viandes et impact environnemental

National audienceSelecting to decrease Residual Feed Intake (RFI) represents a relevant way to improve feed efficiency in growing pigs and thus toreduce feeding costs. Nevertheless in a sustainable meat production context, relationships between RFI, meat quality andenvironmental impact deserves further study to meet producer, consumer and citizen demands. After 6 generations of divergentselection conducted at INRA, this work aims at simultaneously evaluating selection impact on growth performances, bodycomposition, muscle characteristics and meat quality, as well as polluting losses (N, P, and K).Data collected on 117 animals made it possible to carry out a variance analysis, a multivariate analysis and a simulation of growth(INRAPorc© software), and an estimation of pollutant nutrient excretion.This study underlines that a low RFI generates muscle metabolism adaptation which globally goes against technological meatquality but only slightly affects sensory quality. Multivariate analysis identifies efficient animals within RFI‐ line with lean carcassesand good technological and sensory meat quality. Associated with environmental benefits of lowering RFI, this evaluation opens away to refine the selection index for RFI in order to find a balance between meat quality and the economic and environmentalpillars of pig production.Sélectionner pour une diminution de la Consommation Alimentaire Résiduelle (CMJR) est un moyen efficace pour améliorer l’efficacité alimentaire des porcs en croissance et ainsi réduire les coûts alimentaires. Néanmoins, dans un contexte de production de viande durable, les relations entre la CMJR, la qualité des viandes et l’impact environnemental méritent d’être précisées afin de répondre aux attentes des éleveurs, des consommateurs et de la société. Après 6 générations de sélection divergente sur la CMJR menée à l’INRA, ce travail vise à évaluer conjointement l’impact de cette sélection sur les performances de croissance, la composition corporelle, les caractéristiques musculaires et les qualités de la viande, ainsi que sur les rejets polluants (N, P, K). Les données collectées pour 117 animaux permettent de réaliser une analyse de variance, une analyse multifactorielle et une simulation des profils de croissance (logiciel INRAPorc©), pour étudier respectivement l’effet lignée (inter, intra) et estimer la part des éléments polluants excrétés. Cette étude met en évidence qu’une diminution de la CMJR engendre des adaptations du métabolisme musculaire qui sont globalement défavorables pour la qualité technologique des viandes, mais qui affectent peu la qualité sensorielle. L’analyse multidimensionnelle identifie au sein de la lignée CMJR‐ des animaux efficaces présentant à la fois des carcasses maigres et une bonne qualité technologique et sensorielle des viandes. Cette évaluation, couplée aux bénéfices environnementaux d’une diminution de la CMJR, suggère la possibilité d’affiner l’indice de sélection sur la CMJR afin de concilier à la fois la qualité des viandes et les dimensions économiques et environnementales de la production porcine

Economic valuation of social demand for key features of the Noir de Bigorre pork production chain

International audienceExtensive farming systems produce for the society goods and services definable as public goods (biodiversity…), or having public good features (landscape attractiveness…). The provision of these public goods may not be guaranteed due to the lack of recognition of their values in markets and policies that ultimately can put in risk the future of these systems. Within TREASURE project, a choice experiment (CE) survey was applied to assess the social demand for relevant attributes of the Noir de Bigorre (NB) French regional pork chain producing Gascon local pig breed in extensive system with public good character. CE is an economic valuation method estimating the social demand for a given attribute or for combinations of them in management scenarios. Five relevant attributes of the NB chain and their current and potential levels in alternative management options were identified from focus groups: probability of existence of the breed in next 25 years, farm size, feedstuff origin, geographical availability of the products and type of selling places. A monetary attribute was included to assess the social demand for the previous attributes. A valuation questionnaire was administered to 418 individuals (365 through web-based survey, 53 face-to-face), half of them located in the South West of France, i.e. the production area of the NB chain. Results of the CE showed that the respondents had a distinctively urban profile, with no agricultural family background. Almost 40% of the respondents did not know or consume products from the NB chain. On average guaranteeing the survival of the breed achieved the highest willingness to pay (112.37 €/household/year). Respondents were willing to pay 42.35€ to maintain equal number of small and medium farms and 21.86€ to have feedstuff produced in the proximity of the farms. Geographical availability and selling places of products contributed to a lesser extent to shape their preferences. Funded by European Union’s H2020 RIA program (grant agreement no. 634476)

Systèmes de production basés sur des races locales de porcs et demande sociétale pour la fourniture de biens publics : le cas de la filière Noir de Bigorre

Les races locales de porcs sont fréquemment élevées dans des systèmes de production extensifs adaptés à l’environnement local et aux ressources disponibles. Ces systèmes sont généralement moins efficaces que les systèmes conventionnels mais produisent des biens publics et services pour la société (biodiversité, qualité de l’air, attractivité du paysage). La fourniture de biens publics peut ne pas être garantie par manque de reconnaissance de leur valeur économique, ou de politiques pouvant fragiliser l’avenir de ces systèmes. Des méthodes d’évaluation économique permettent de mesurer les avantages non marchands fournis par ces systèmes, par une estimation de la demande sociale envers leurs principales caractéristiques. Dans le projet européen TREASURE, une enquête d’expérimentation de choix a été réalisée pour évaluer la demande sociétale pour des caractéristiques spécifiques de la filière régionale française Noir de Bigorre (NdB), basée sur l’élevage en système extensif de porcs de race Gascon. Un questionnaire d’évaluation a été distribué, permettant l’obtention des réponses de 418 personnes, pour moitié localisées dans la région de production de la filière NdB. Les résultats montrent que 40% des répondants ne connaissent ou ne consomment pas les produits issus de cette filière. En moyenne, le consentement à payer le plus élevé est attribué pour garantir la pérennité de la race (112,37 €/foyer/an). Les répondants consentiraient à payer 42,35 € pour maintenir un nombre équivalent d’élevages de taille petite ou moyenne, et 21,86 € pour que les aliments des animaux soient produits à proximité des élevages. La disponibilité géographique et le type de points de vente des produits contribuent de façon moindre à construire leurs préférences. Ces résultats montrent qu’une demande sociale existe pour soutenir la pérennité de la race et un système de production extensif en lien avec des ressources locales.Local pig breeds are frequently raised in extensive farming systems adapted to the local environment and the resources it produces. These farming systems tend to be less efficient than their intensive counterparts, but in exchange produce goods and services for society (biodiversity, clean air, landscape attractiveness, etc.). The supply of these public goods may not be guaranteed due to a lack of recognition of their market values, and policies that ultimately can put the future of these systems at risk. Economic valuation methods can measure the non-market benefits provided by these systems as an estimate of the social demand for their key features. Within the European Union TREASURE project, a choice experiment (CE) survey was applied to assess the social demand for relevant attributes of the Noir de Bigorre (NB) French regional pork chain, based on the local Gascon pig breed in an extensive system with the character of a public good. A valuation questionnaire was administered to 418 individuals, half of them located in the production area of NB chain. Results show that almost 40% of the respondents did not know or consume products from the NB chain. On average, guaranteeing the survival of the breed achieved the highest willingness to pay (112.37 €/household/year). Respondents are willing to pay 42.35 € to maintain an equal number of small and medium farms and 21.86 € to have feedstuff produced near the farms. Geographical availability and selling places of products contribute to a lesser extent to shape their preferences. Results show that social demand does exist to support survival of the breed and its extensive production system linked to local resources

A qualitative and participative approach to analyse different strategies of valorization of Noir de Bigorre pork chain

The Noir de Bigorre (NDB) French regional pork chain produces fresh pork and dry cured ham (under Protected Designation Origin PDO label) from Gascon purebred pigs. Within TREASURE project, a focus group was carried out with stakeholders of the NDB chain to better know andcollect their perception of the way its products are valued. The objectives of this participative approach were to conduct a Strength, Weakness, Opportunity and Threat (SWOT) analysis of theNDB chain and products, as well as to assess the feasibility of potential marketing strategies forcreating added value and matching market demands. A World Café (WC) was conducted with 11 representative stakeholders of the supply chain (farmers, processors, retailers, consumer,governance…). Participants were allocated to four tables. The first WC session was focused on the SWOT analysis and the second session on a 4P (price, products, place, promotion) approach. Then main ideas of the discussion on 4P were selected after voting to conduct an Analytical Hierarchical Process (AHP). Lot of strengths and opportunities have been highlighted. PDO label and high sensorial quality of the products enhance attractiveness and values of the NDB chain. NDB chain characteristics (farming system, naturalness, history, heritage and culture) meet social expectations of consumers. Improvements points have been underlined through weakness and threat regarding sanitary risks and data management. AHP method allows the classified relative importance of each item/strategy within and between the 4P topics. We observed a strong proximity between the strategies preferred by stakeholders. Potential evolutions of the carcass payment system for farmers and the information provided on loin and ham were mentioned. The development of the coverage of local stores in PDO area was a potential strategy suggested to improve local visibility of the products. Promotion of the NDB products is mainly linked to its story. To support products from the animal to tasting is important and needed. This participative approach gives elements to guide the reflections of the NDB chain actors with a constructive and optimistic view to the future

Évaluation économique de la demande sociale pour des caractéristiques clés de la filière Noir de Bigorre

Évaluation économique de la demande sociale pour des caractéristiques clés de la filière Noir de Bigorre. Journée de restitution des résultats du projet TREASUR

Sélection pour la consommation alimentaire moyenne journalière résiduelle chez le porc : impacts sur les caractères et défis pour la filière

Improving feed efficiency remains a challenge for pork production. The usual measure in herds is feed conversion ratio that quantifies the economic efficiency of feed use for animal growth. Residual Feed Intake (RFI) has been proposed as an alternative measure, independent of production traits, in the 1960's. This paper reviews the research in two divergent lines selected for RFI at INRA, the low RFI line with pigs eating less than predicted from the production and maintenance requirements, i.e. more efficient, and the high RFI line eating more than predicted for its less efficient requirements,. These studies show that selection for RFI in growing pigs is possible with a limited impact on production and sow reproduction. However, technological meat quality is unfavourably affected by selection and a control of the impacts of selection for feed efficiency on this trait is necessary, as well as for nutritional requirements of most efficient pigs. Finally, the pig's ability to respond to stressors or various breeding conditions was not affected by selection, unlike that hypothesized by the resources allocation theory applied to livestock species. The challenges for pig production to continue improving feed efficiency in a changing context for livestock production are discussed.L’amélioration de l’efficacité alimentaire est un enjeu majeur pour la compétitivité de la filière porcine. Elle est classiquement mesurée en élevage par l’indice de consommation, indicateur économique de l’efficacité d’utilisation des aliments pour la croissance. Un critère alternatif indépendant des performances des animaux, la Consommation Moyenne Journalière Résiduelle (CMJR), a été proposé dans les années 1960. Cet article synthétise les résultats obtenus à partir de la sélection divergente de deux lignées à l’INRA, une lignée à CMJR faible, animaux consommant moins que prédit pour leurs besoins de production et d’entretien, et donc plus efficaces, et une lignée à CMJR élevée, animaux consommant plus que prédit pour leurs besoins, moins efficaces. Ces recherches montrent qu’il est possible de sélectionner pour la CMJR chez le porc en croissance avec un impact limité sur les caractères de production et de reproduction femelle, permettant ainsi de diminuer les quantités d’aliments utilisées en élevage. La dégradation des paramètres de qualité technologique de la viande en réponse à l’amélioration génétique de l’efficacité alimentaire est un point de vigilance dans les stratégies de sélection, de même que la composition nutritionnelle de la ration alimentaire. Finalement, la capacité de réponse à des stress ou à des changements de conditions d’élevage ne semble pas affectée par la sélection, contrairement à ce qui est suggéré dans la littérature en réponse à la sélection pour une CMJR réduite. Les défis qui résultent de ces résultats pour poursuivre l’amélioration de ce caractère en production tout en répondant à l’évolution des contraintes de l’élevage sont discutés