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Neonates with intrauterine growth restriction (IUGR) are prone to suffer from digestive diseases. Using neonatal pigs with IUGR, we tested the hypothesis that IUGR may induce alterations in the developmental pattern of intestinal barrier and thereby may be responsible for IUGR-associated increased morbidity. Piglets with a birth weight near the mean birth weight (+/-0.5 SD) were identified as normal birth weight (control) and piglets with a mean -2 SD lower birth weight (-30%) were defined as piglets with IUGR. The developmental pattern of intestinal structure, transcriptomic profile, and bacterial colonization was investigated from birth to d 5 postnatal. At birth, intestinal weight and length, ileal and colonic weight per unit of length, and villous sizes were lower (P < 0.05) in piglets with IUGR than in same-age control piglets. These IUGR-induced intestinal alterations further persisted, although they were less marked at d 5. Counts of adherent bacteria to ileal and colonic mucosa were greater (P < 0.05) in 2-d-old piglets with IUGR than in same-age control piglets. Dynamic analyses of the transcriptomic profile of the intestine revealed molecular evidence of IUGR-induced intestinal growth impairment that may result from a change in the cell proliferation-apoptosis balance during the first days of life, while a protective process would occur later on. In addition, changes in the expression of several genes suggest a pivotal role of both glucocorticoids and microbiota in driving IUGR intestinal development during the neonatal period.

Predicting aspects of pork quality becomes increasingly important from both a nutritional and technological point of view. The aim of the present study was to provide quantitative information on the relation between nutrient intake and whole-body fatty acid (FA) deposition. This information is essential to develop mechanistic models predicting the FA content of tissues. A serial slaughter study was carried out in which thirty pigs were slaughtered between 90 and 150 kg. The diet included 15 g/kg soyabean oil and contained 44 g/kg fat. Only 0·31 and 0·40 of the digested n-6 and n-3 FA were deposited, respectively. Approximately one-third of the n-3 supply that was deposited resulted from the conversion of 18 : 3 to other metabolites (i.e. EPA, docosapentaenoic acid and DHA). This proportion was affected by the pig genotype. De novo-synthesised FA represented 0·86 of the total non-essential FA deposition, and its average composition corresponded to 0·017, 0·286, 0·025, 0·217 and 0·454 for 14 : 0, 16 : 0, 16 : 1, 18 : 0 and 18 : 1, respectively. Although the average whole-body FA composition was relatively constant during the finishing period, this was not so for the tissues. In the carcass (without backfat), the content of 18 : 1 increased during the finishing period, whereas that of 16 : 0 and 18 : 0 decreased. Backfat captured a proportionally greater fraction of 18 : 2 than did the carcass or the residual tissues. In contrast, a proportionally greater fraction of the dietary 18 : 3 supply was deposited in the carcass compared to other tissues.

This article is available online at http://www.jlr.org derived from the biosynthetic pathways resulting in the conversion of essential precursors to their respective elongated polyenoic products.The availability of PUFA in mammalian cells greatly depends on the activity of enzymes involved in FA metabolism. In animals and humans, the ⌬ 5-and ⌬ 6-desaturases are the pivotal enzymes introducing de novo unsaturations in the carbon chain of precursors leading to the synthesis of long-chain PUFA (LC-PUFA). These enzymes were cloned 10 years ago from mammals ( 2-5 ). In parallel, Marquardt et al. ( 6 ) described the human genomic structure of the fatty acid desaturase ( FADS ) cluster including the FADS1 and FADS2 genes coding, respectively, for the ⌬ 5-and ⌬ 6-desaturases. A third gene, named FADS3 , was identifi ed, revealing 62% and 70% nucleotide sequence identity with FADS1 and FADS2 , respectively. Further studies showed a signifi cant correlation between FADS3 polymorphism and lipid metabolism markers such as PUFA, high density-or low density-lipoprotein cholesterol, and triglyceride levels ( 7-10 ). The newly discovered gene was thereafter integrated into a serial analysis of gene expression and a DNA microarray succeeding in more physiological data. FADS3 was therefore found to be highly expressed at the implantation site of the embryo in mouse uterus ( 11 ) and downregulated during human neurogenic differentiation ( 12 ). More recently, Park et al. described, in baboon, different alternative transcripts of FADS3 generated by alternative splicing, which suggests the occurrence of multiple FADS3 gene products ( 13 ). This study also showed a different pattern of expression in response to human neuroblastoma SK-N-SH cell differentiation. All data together only concern the FADS3 gene with no description of the functional role of the putative FADS3 protein. PUFAs are key components involved in a variety of physiological functions ( 1 ). Some of them, belonging to the n-6 or n-3 families, have to be fulfi lled from the diet or This work was supported by the Région Bretagne, the Groupe Lipides et Nutrition, Valorex (Combourtillé, France), and Polaris (Pleuven, France).

Predicting aspects of pork quality becomes increasingly important from both a nutritional and a technological point of view. Little information is, however, available concerning the quantitative relation between nutrient intake and fatty acid (FA) deposition at the whole-animal level. In this study, eight blocks of five littermate barrows were used in a comparative slaughter trial. At 24 kg body weight (BW), one pig from each litter was slaughtered to determine the initial FA composition. The other littermates were assigned to one of four feeding levels (ranging from 70 % to 100 % of intake ad libitum) and were given a diet containing 0·36 g/kg lipid and 0·22 g/kg FA. The temperature for each block was maintained at either 23 or 308C. At 65 kg, the pigs were slaughtered and the body lipid and FA composition was determined. Seventy per cent of the digested n-6 FA and 50 % of the n-3 FA were deposited. The average composition of de novo synthesised FA corresponded to 1·7, 30·3, 2·4, 19·7 and 45·9 % for 14 : 0, 16 : 0, 16 : 1, 18 : 0 and 18 : 1 FA, respectively. At 238C and for feeding ad libitum, 33 % of 16 : 0 FA was deposited, 1·7 % shortened to 14 : 0, 63 % elongated to 18 : 0 and 2·8 % unsaturated to 16 : 1. Twenty-eight per cent of 18 : 0 FA was deposited and 72 % unsaturated to 18 : 1. At 308C, 18 : 0 FA desaturation was reduced by 3·5 %. Feed intake and temperature independently affected the elongation of 16 : 0 FA. A reduction in feed intake increased the elongation rate, whereas the increase in temperature reduced the elongation rate. Lipid deposition: Fatty acid composition: Pig: ModelPredicting aspects of pork quality becomes increasingly important from both a technological and a nutritional point of view. The lipid content and fatty acid (FA) profile in the tissues have an impact on the technological transformation (i.e. a high content of PUFA increases the risk of oxidation) and affect the nutritional and organoleptic quality (e.g. intramuscular lipid content, saturated FA content, and the n-3 : n-6 ratio).Lipid and FA deposition in pigs is strongly affected by factors including genotype, sex, age, live weight, environmental temperature and nutrition (e.g. Wood, 1984;Lebret & Mourot, 1998;Le Dividich et al. 1998). Although numerous studies have studied the relation between nutrition and FA composition of the tissues (e.g. Miller et al. 1990;Madsen et al. 1992; Wiseman & Agunbiade, 1998;Gatlin et al. 2002;Ostrowska et al. 2003), these relations are often limited to a single tissue (typically backfat). Consequently, for predictive purposes, this information can only be exploited using empirical relationships. A more mechanistic representation of the relation between nutrition and FA composition is desirable in order to define nutritional strategies that modulate the FA profile of the tissues. Lizardo et al. (2002) developed a model to predict pork quality based on relatively simple hypotheses concerning the fate of dietary FA, the FA profile of the de novo synthesised FA and the partitioning of lipids a...

Most nutritional pig growth models are based on the deposition of whole body protein (P) and lipid (L) mass. Chemical analysis of the whole animal is the best method to determine body composition. However, this method is expensive, time consuming and the carcass is lost. Alternatively, P and L may be estimated using simple indicators that should be precise and easily accessible. Although empty body weight (EBW) is a good indicator for P (through the strong relation between water and P), L is more difficult to estimate. This study was carried out to evaluate the relationship between simple carcass measurements and L. Measurements included backfat thicknessin vivoand at slaughter in the hot and cold carcass and the weight of carcass, organs and primal cuts. To maximize variations in adiposity a total of 30 females and barrows from two genotypes (Piétrain×(Landrace×Large White) and Large White) were slaughtered at body weights typically used in Europe (i.e. 90 to 150 kg) and ground for chemical analysis. Backfat mass (in combination with EBW) was the best indicator for L (L (kg)=0·0590×EBW (kg)+2·99×backfat mass (kg),R2=0·96). Different backfat thickness measurements were highly correlated and appeared reasonable indicators for total backfat mass. Backfat thickness measured in the hot carcass between 3rd and 4th last lumbar vertebra at 8 cm from the mid line was the second best indicator for L (L=(0·0855+0·0073×backfat thickness)×EBW,R2=0·94). On average, 18% of total body lipids were located in the backfat. Although these equations can be used to obtain a reasonable estimate of whole body lipid mass, a significant genotype effect remained. Differences between genotypes in the partitioning of lipids between different tissues suggest that the quantification of an external lipid depot alone is insufficient to precisely estimate whole-body lipid mass across genotypes.

The R package FAMT (factor analysis for multiple testing) provides a powerful method for large-scale significance testing under dependence. It is especially designed to select differentially expressed genes in microarray data when the correlation structure among gene expressions is strong. Indeed, this method reduces the negative impact of dependence on the multiple testing procedures by modeling the common information shared by all the variables using a factor analysis structure. New test statistics for general linear contrasts are deduced, taking advantage of the common factor structure to reduce correlation and consequently the variance of error rates. Thus, the FAMT method shows improvements with respect to most of the usual methods regarding the non discovery rate and the control of the false discovery rate (FDR). The steps of this procedure, each of them corresponding to R functions, are illustrated in this paper by two microarray data analyses. We first present how to import the gene expression data, the covariates and gene annotations. The second step includes the choice of the optimal number of factors, the factor model fitting, and provides a list of selected genes according to a preset FDR control level. Finally, diagnostic plots are provided to help the user interpret the factors using available external information on either genes or arrays.

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