THE EFFECT OF DIETARY FIBRE CONTENT ON SKATOLE AND INDOLE PRODUCTION IN FAECES OF IMMUNOCASTRATED MALE PIGS

The effect of dietary fibre content on intestinal production of indolic compounds was studied in immunocastrated pigs (IC). In addition, entire males (EM) and IC were compared on control diet (with low fibre content). For the study 32 crossbred pigs were assigned, within a litter to 4 treatment groups; 24 pigs were immunocastrated (at the age of 77 and 112 days) and 8 pigs were kept as entire males (EM). IC were split into three groups (IC_H, IC_M and IC_L) fed three diets differing in crude fibre (34, 60 and 80 g/kg dry matter, respectively) and net energy (NE) (10.0, 9.3, 8.5 MJ NE/kg/DM, respectively). EM were fed high NE i.e. low fibre diet. The experiment started when pigs were 84 days old and finished at the age of 172 days, when pigs were sent to slaughter. Skatole and indole concentrations were determined in the samples of intestinal content taken from caecum (CE), ascending (AC) and descending colon (DC). The concentration of indole was the highest in CE and proximal part of the colon, while skatole concentration increased in the distal parts of the large intestine. Concentrations of indolic compounds did not differ between EM and IC that were fed the same diet. Lowering dietary NE by inclusion of high fibre ingredients reduced the production of indole in the intestinal content of IC pigs, whereas the production of skatole was not affected

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

Ecofog - Gagner en compétitivité et réduire les impacts environnementaux de la filière foie gras

On a worldwide scale, France is the leading producer of foie gras. To maintain this leadership, the sector must remain competitive and control its production costs while meeting specific societal and environmental expectations such as preservation of product quality, respect for animal welfare or limited use of natural resources. The aim of the project was to develop innovative production systems that would limit the impacts of feed and its surrounding practices on the competitiveness of the sector and the environment. An experimental approach was associated with a multi-criteria sustainability assessment (farm level), complemented by an analysis of production cost (farm level) and environmental impacts (product level). Two domains were studied: one related to feed, and the other related to ambient conditions during breeding and force-feeding. Several issues have been identified to progress. Reducing the amount of food distributed (-10%) appears as a possible solution to reduce feeding costs during rearing. The use of sorghum is also of interest but its use should be limited to the rearing phase. Lastly, semi-open air system, compared to open-air system, helps to improve IC (Consumption Index) and reduces animal heterogeneity and mortality. This project also provided original results related to the understanding of mechanisms involved in body temperature regulation of ducks on the one hand and on the other hand to LCA results of different innovations. Lastly, it contributed to the creation of two tools: one to drill ventilation ducts and another to calculate production costs. The results were disseminated to the professionals throughout the project in order to make all data available.À l’échelle mondiale, la France est le premier producteur de foie gras. Afin de conserver ce leadership, la filière doit rester compétitive et maîtriser ses coûts de production tout en répondant à des attentes sociétales et environnementales spécifiques telles que la préservation de la qualité des produits, le respect du bien-être animal ou la gestion économe des ressources. Le projet ECOFOG avait pour objectif de développer des systèmes de production innovants, permettant de limiter l’impact de l’alimentation des canards et des pratiques qui l’entourent pour gagner en compétitivité de la filière et diminuer l’impact environnemental de la filière. La démarche expérimentale a été associée à une démarche d’évaluation multicritère de la durabilité à l’échelle de l’atelier, complétée par une analyse des coûts de production à l’échelle de l’atelier et des impacts environnementaux à l’échelle du produit. Deux axes d’étude ont en particulier été développés : l’un autour de l’aliment, et l’autre autour des conditions d’ambiance en élevage et en gavage.Plusieurs pistes ont été identifiées pour progresser. La réduction de la quantité d’aliment distribué (-10%) est une solution possible pour réduire les coûts d'alimentation. L’utilisation de sorgho présente par ailleurs un intérêt environnemental mais son utilisation devrait être limitée à la phase d’élevage. En termes de bâtiments enfin, le système semi plein-air, comparé au système plein-air, contribue à améliorer l’IC (Indice de Consommation) et réduit les écarts de poids entre les animaux et la mortalité. Ce projet a permis d’obtenir des résultats originaux sur les mécanismes impliqués dans la régulation de la température corporelle des canards. Il a aussi permis d’évaluer les impacts environnementaux de la production de foie gras, et d’analyser les conséquences des différents systèmes de production innovants sur les performances, les coûts et la durabilité de la production. Il a enfin contribué à la création de deux outils utiles pour la filière : un outil d’aide au perçage des gaines de ventilation en atelier de gavage et un outil de calcul du coût de production. Ces résultats ont été largement diffusés vers les professionnels afin de rendre l’ensemble de ces données disponibles

Effect of meal frequency on nutrient utilization and energy metabolism in growing and finishing pigs

Variations in feeding frequency may lead to difference in utilization of dietary nutrients. The effects of feeding frequency have been tested in growing pigs and finishing pigs using respiratory quotient and postprandial kinetics of plasma metabolites. A reduced feeding frequency resulted in an increased lipogenesis and proteolysis shortly after the meal both in growing and finishing pigs. Nevertheless, growing and finishing pigs exhibit different metabolic pathways when feeding frequency is reduced

A minimally invasive catheterization of external jugular vein in piglets using ultrasound guidance

There is a growing interest for minimally invasive surgical procedures to improve experimental animal welfare and reduce biases induced by surgery through drug administration or animal behaviour changes. The aim of the study was to develop a simple and reproducible procedure for external jugular vein catheterization in piglets lighter than 10 kg body weight (BW) using ultrasound guidance

Les besoins nutritionnels du veau de boucherie : acquis bibliographiques et données expérimentales

National audienc

Les besoins protéiques et énergétiques du veau de boucherie : détermination et facteurs de variation

National audienceLittle knowledge on the nutritional requirements of veal calves has been acquired since the recommendations of Toullec (1988). Most of the studies used for these recommendations were conducted between the nineteen-sixties and nineteen-eighties, and requirements were expressed as apparently digested proteins and metabolisable energy related to calf body weight, feed intake and body weight gain. Studies conducted later have confirmed these recommendations. However, some points have to be modulated. The efficiency of retention of digested protein cannot be considered as a constant parameter (especially for heavy calves) but rather as a decreasing function of the calf's age or body weight. Separate estimation of both protein and energy requirements would allow the establishment of a synthetic criterion such as the ratio between apparently digested proteins and metabolisable energy. This criterion is rarely used, especially for animals heavier than 150 kg. Moreover, genotypes have evolved (and are still evolving) and new production techniques such as roughage feeding and group-housing are still being developed. These aspects suggest that the updating of the scientific information on nutrient requirements and utilisation in veal calves is necessary in order to propose new recommendations.Les connaissances sur les besoins nutritionnels des veaux de boucherie ont peu évolué depuis la parution des références formulées par Toullec (1988). Ces dernières ont été élaborées à partir de travaux antérieurs et définissent les besoins en protéines digestibles apparentes et en énergie métabolisable selon le poids du veau, son niveau d’ingestion et le gain de poids souhaité. Des travaux effectués au cours de la dernière décennie ont permis de confirmer en partie les équations de prédiction de Toullec (1988) mais quelques aspects ont été nuancés, notamment dans l’estimation de l’efficacité de rétention des protéines alimentaires, qui ne peut plus être considérée comme constante dès lors que l’on s’intéresse à des animaux d’un poids vif élevé mais plutôt comme une fonction décroissante de l’âge (ou du poids vif). Finalement, l’expression indépendante des besoins protéiques et énergétiques nécessiterait d’être complétée par un critère synthétique : le rapport entre les concentrations en protéines digestibles apparentes et en énergie métabolisable. Ces aspects ne sont que faiblement documentés, surtout lorsque les animaux sont lourds : il existe en effet très peu de références concernant les besoins ou les réponses de croissance des veaux de plus de 150 kg ; de surcroît, les génotypes ont évolué et de nouvelles techniques d’élevage se sont développées (apport d’aliment solide, élevage en groupe), qui montrent la nécessité de remise à jour de ces références