Pre- and postnatal development of adipose depots in meat animals with a specific focus on the pig

Pre- and postnatal development of adipose depots in meat animals with a specific focus on the pig. 65. International Congress of Meat Science and Technology (ICoMST

Le sport comme espace de reproduction et de contestation des représentations stéréotypées de la féminité

De plus en plus de filles et de femmes participent à des sports de tradition masculine tels que le hockey, l'haltérophilie ou la boxe. Cette transformation de la réalité sportive a-t-elle un impact sur les normes dominantes de la féminité? L'objectif principal des auteures de cette étude était double : d'une part, vérifier dans quelle mesure les adolescentes et les adolescents québécois adhèrent ou résistent aux normes de féminité véhiculées par l'institution sportive; d'autre part, voir dans quelle mesure leurs dispositions à l'égard de ces normes sont liées à une conception plus ou moins stéréotypée de la féminité. Deux des processus de construction sociale du genre proposés par Harding (1986), soit le symbolisme dichotomique de genre et la structuration selon le genre des sphères d'activités sociales, sont au fondement de cette recherche

Le sport comme espace de reproduction et de contestation des représentations stéréotypées de la féminité

De plus en plus de filles et de femmes participent à des sports de tradition masculine tels que le hockey, l’haltérophilie ou la boxe. Cette transformation de la réalité sportive a-t-elle un impact sur les normes dominantes de la féminité? L’objectif principal des auteures de cette étude était double : d’une part, vérifier dans quelle mesure les adolescentes et les adolescents québécois adhèrent ou résistent aux normes de féminité véhiculées par l’institution sportive; d’autre part, voir dans quelle mesure leurs dispositions à l’égard de ces normes sont liées à une conception plus ou moins stéréotypée de la féminité. Deux des processus de construction sociale du genre proposés par Harding (1986), soit le symbolisme dichotomique de genre et la structuration selon le genre des sphères d’activités sociales, sont au fondement de cette recherche. Une démarche méthodologique qualitative a été privilégiée. Au total, 354 jeunes (180 filles et 174 garçons) de cinquième secondaire de trois milieux socioéconomiques différents ont rédigé une « lettre d’opinion » sur leur conception de la féminité et sur leur perception des filles qui pratiquent des sports socialement perçus comme « masculins ». L’analyse de contenu des lettres d’opinion révèle que la sphère sportive constitue à la fois un espace de reproduction et un espace de contestation de la division sexuelle. Les résultats confirment des rapports inégalitaires entre les sexes : les garçons sont trois fois plus nombreux que les filles à exprimer un jugement négatif au regard de la participation de ces dernières à des sports de tradition masculine. À l’opposé, une forte majorité de filles voient dans ces pratiques un lieu de contestation de l’ordre social de genre. L’analyse des conceptions de la féminité indique, par ailleurs, que l’adhésion aux représentations stéréotypées du sexe est plus prégnante dans l’imaginaire des jeunes que l’assignation sexuée des pratiques sportives, et ce, tant chez les filles que chez les garçons. Enfin, l’examen des interconnexions entre le sexe et le niveau socioéconomique suggère une double domination pour les filles du milieu populaire et une forme de complicité dans la domination chez les garçons et les filles du milieu bien nanti.More and more girls and women currently engage in sports of masculine tradition like hockey, weightlifting and boxing. Does this transformation in the sport reality have an impact on the dominant norms of femininity? The overall objective of this study was two-fold: first, to verify if Québec adolescents adhere to or contest the norms of femininity carried by the sport institution, and second, to evaluate to what extent their opinion with regard to theses norms are linked to a stereotyped conception of femininity. Two of the processes proposed by Harding (1986) with regard to the social construction of gender, « gender symbolism » and « gender structure », are at the foundation of our research. A qualitative methodology was adopted. Three hundred fifty-four teenagers (180 girls and 174 boys) of fifth grade (high school) from three different socioeconomic milieus wrote an « opinion letter » on their conception of femininity and of girls who play so called « male sports ». A content analysis of the opinion letters reveals that the sport arena is altogether a site of reproduction and of contestation of the gender order. Results confirm gender inequality: the boys being three times numerous than the girls to express a negative judgement with regard to girls playing « male sports ». In contrast, a good majority of girls see in this transgression of the gender sport order an opportunity to contest the social gender order. The analysis of the conceptions of femininity shows however that the adhesion to the gender stereotypes is more salient in the teenagers' imagination than the gendered division of sport practices, and this, among the girls as well as among the boys. The examination of the intersection between gender and socioeconomic milieu suggests that girls from undeserved milieu experience a double domination (gender and class) and that there is a kind of complicity between the girls and the boys of the affluent milieu in the exercise of domination

Pre- and postnatal adipose tissue development in farm animals: from stem cells to adipocyte physiology

To view supplementary material for this article, please visit http://dx.doi.org/10.1017/S1751731116000872Both white and brown adipose tissues are recognized to be differently involved in energy metabolism and are also able to secrete a variety of factors called adipokines that are involved in a wide range of physiological and metabolic functions. Brown adipose tissue is predominant around birth, except in pigs. Irrespective of species, white adipose tissue has a large capacity to expand postnatally and is able to adapt to a variety of factors. The aim of this review is to update the cellular and molecular mechanisms associated with pre- and postnatal adipose tissue development with a special focus on pigs and ruminants. In contrast to othertissues, the embryonic origin of adipose cells remains the subject of debate. Adipose cells arise from the recruitment of specific multipotent stem cells/progenitors named adipose tissue-derived stromal cells. Recent studies have highlighted the existence of a variety of those cells being able to differentiate into white, brown or brown-like/beige adipocytes. After commitment to the adipocyte lineage, progenitors undergo large changes in the expression of many genes involved in cell cycle arrest, lipid accumulation and secretory functions. Early nutrition can affect these processes during fetal and perinatal periods and can also influence or pre-determinate later growth of adipose tissue. How these changes may be related to adipose tissue functionalmaturity around birth and can influence newborn survival is discussed. Altogether, a better knowledge of fetal and postnatal adipose tissue development is important for various aspects of animal production, including neonatal survival, postnatal growth efficiency and health

Growth, body composition and hormonal status of growing pigs exhibiting a normal or small weight at birth and exposed to a neonatal diet enriched in proteins

Small birth weight and excess of early protein intake are suspected to enhance later obesity risk. The present study was undertaken to determine the impact of neonatal diets differing in protein content on growth, body composition and hormonal status of 70-d-old pigs born with normal weight (NW) or small weight (SW). At 7d of age, male and female suckled piglets were assigned to the NW (approximately 1·4kg at birth) or SW (approximately 0·99kg at birth) groups. They were fed milk replacers formulated to provide an adequate protein (AP) or a high protein (HP) supply for 3 weeks. From weaning to 70d of age, all animals received ad libitum the same standard diet. Growth rates were higher (P<0·05) in HP piglets than in AP piglets during formula feeding and remained higher (P<0·05) only in HP male pigs thereafter. No difference in feed consumption was detected between groups during the periods examined. Carcass lipid content and the relative weight of perirenal adipose tissue did not differ between the AP and HP pigs. Whereas plasma leptin concentration was higher (P<0·05) in HP pigs than in AP pigs with a marked difference in SW pigs, plasma insulin-like growth factor (IGF)-I concentration and expression of IGF system genes were not affected by the diets. In summary, a HP intake during the suckling period induced an increase in growth rate that persisted only in male pigs during the post-weaning period. This response was not associated with any difference in adiposity parameters in this perio

The protein level of isoenergetic formulae does not modulate postprandial insulin secretion in piglets and has no consequences on later glucose tolerance

Early postnatal nutrition is involved in metabolic programming, an excess of protein being suspected to enhance early growth and the propensity to later develop insulin resistance and type 2 diabetes mellitus. The aim of the present study was to test the hypothesis that excessive protein intake during the suckling period would overstimulate the endocrine pancreas in the short term and alter durably its maturation, contributing to the later disruption of glucose homeostasis. Normal-birth-weight and low-birth-weight piglets were fed isoenergetic formulae providing an adequate-protein (AP, equivalent to sow milk) or a high-protein (HP, +48%) supply between 7 and 28d of age and were fed a standard diet until 70d of age. During the formula-feeding period, the HP formula did not modify postprandial insulin secretion but transiently increased fasting insulin and the homeostasis model assessment-insulin resistance index (HOMA-IR, P<0·05). Fasting insulin and HOMA-IR were restored to AP piglets' values 1month after weaning. The structure of the endocrine pancreas was not affected by the protein content of the formula. The weight at birth had no major effect on the studied parameters. We concluded that a high-protein supply during the suckling period does not interfere with insulin secretion and endocrine pancreas maturation in the short term. It has no consequences either on glucose tolerance 1month after weaning. The present study demonstrated that up-regulation of postprandial insulin secretion is not involved in higher growth observed in piglets fed a HP formul

Sélectionner sur l'adiposité pour améliorer la qualité

Sélectionner sur l'adiposité pour améliorer la qualit

The cortisol response to ACTH in pigs, heritability and influence of corticosteroid-binding globulin

In the search for biological basis of robustness, this study aimed (i) at the determination of the heritability of the cortisol response to ACTH in juvenile pigs, using restricted maximum likelihood methodology applied to a multiple trait animal model, and (ii) at the study of the relationships between basal and stimulated cortisol levels with corticosteroid-binding globulin (CBG), IGF-I and haptoglobin, all important players in glucose metabolism and production traits. At 6 weeks of age, 298 intact male and female piglets from 30 litters (30 dams and 30 boars) were injected with 250 µg ACTH(1–24) (Synacthen). Blood was taken before ACTH injection to measure basal levels of cortisol, glucose, CBG, IGF-I and haptoglobin, and 60 min later to measure stimulated cortisol levels and glucose. Cortisol increased 2.8-fold after ACTH injection, with a high correlation between basal and stimulated levels (phenotypic correlation, rp=0.539; genetic correlation, rg=0.938). Post-ACTH cortisol levels were highly heritable (h2=0.684) and could therefore be used for genetic selection of animals with a more reactive hypothalamic–pituitary–adrenocortical axis. CBG binding capacity correlated with cortisol levels measured in basal conditions in males only. No correlation was found between CBG binding capacity and post-ACTH cortisol levels. Basal IGF-I concentration was positively correlated with BW at birth and weaning, and showed a high correlation with CBG binding capacity with a strong sexual dimorphism, the correlation being much higher in males than in females. Basal haptoglobin concentrations were negatively correlated with CBG binding capacity and IGF-I concentrations. Complex relationships were also found between circulating glucose levels and these different variables that have been shown to be related to glucose resistance in humans. These data are therefore valuable for the genetic selection of animals to explore the consequences on production and robustness traits, but also point at pigs as a relevant model to explore the underlying mechanisms of the metabolic syndrome including the contribution of genetic factors

A transcriptome multi-tissue analysis identifies biological pathways and genes associated with variations in feed efficiency of growing pigs

International audienceBackground - Animal's efficiency in converting feed into lean gain is a critical issue for the profitability of meat industries. This study aimed to describe shared and specific molecular responses in different tissues of pigs divergently selected over eight generations for residual feed intake (RFI). Results - Pigs from the low RFI line had an improved gain-to-feed ratio during the test period and displayed higher leanness but similar adiposity when compared with pigs from the high RFI line at 132 days of age. Transcriptomics data were generated from longissimus muscle, liver and two adipose tissues using a porcine microarray and analyzed for the line effect (n = 24 pigs per line). The most apparent effect of the line was seen in muscle, whereas subcutaneous adipose tissue was the less affected tissue. Molecular data were analyzed by bioinformatics and subjected to multidimensional statistics to identify common biological processes across tissues and key genes participating to differences in the genetics of feed efficiency. Immune response, response to oxidative stress and protein metabolism were the main biological pathways shared by the four tissues that distinguished pigs from the low or high RFI lines. Many immune genes were under-expressed in the four tissues of the most efficient pigs. The main genes contributing to difference between pigs from the low vs high RFI lines were CD40, CTSC and NTN1. Different genes associated with energy use were modulated in a tissue-specific manner between the two lines. The gene expression program related to glycogen utilization was specifically up-regulated in muscle of pigs from the low RFI line (more efficient). Genes involved in fatty acid oxidation were down-regulated in muscle but were promoted in adipose tissues of the same pigs when compared with pigs from the high RFI line (less efficient). This underlined opposite line-associated strategies for energy use in skeletal muscle and adipose tissue. Genes related to cholesterol synthesis and efflux in liver and perirenal fat were also differentially regulated in pigs from the low vs high RFI lines. Conclusions - Non-productive functions such as immunity, defense against pathogens and oxidative stress contribute likely to inter-individual variations in feed efficiency