Improving maternal welfare during gestation has positive outcomes on neonatal survival and modulates offspring immune response in pigs.

Improving the housing of pregnant sows by giving them more space and access to deep straw had positive effects on their welfare, influenced their maternal behavior and improved the survival of their offspring. The present study aimed at determining whether these effects were actually due to environmental enrichment and whether the provision of straw pellets and wood can partly mimic the effects of straw bedding during gestation. Three graded levels of enrichment were used, that were, collective conventional pens on slatted floor (C, n = 26), the same pens with manipulable wood materials and distribution of straw pellets after the meals (CE, n = 30), and larger pens on deep straw litter (E, n = 27). Sows were then housed in identical farrowing crates from 105 days of gestation until weaning. Decreased stereotypies, blood neutrophils, and salivary cortisol, and increased behavioral investigation indicated that health and welfare of sows during gestation were improved in the E environment compared with the C environment. The CE sows responded as C or E sows depending on the trait. Piglet mortality rate in the first 12 h after birth was lower in E and CE litters than in C litters, but enrichment level during gestation had only small effects on lactating sow behavior and milk composition postpartum. On days 2 and 3 of lactation, E sows interrupted less often their nursing sequences than C and CE sows. On day 2, milk from both E and CE sows contained more minerals than that from C sows. In one-day-old piglets, the expression levels of genes encoding toll-like receptors (TLR2, TLR4) and cytokines (interleukin-1, -6 and -10) in whole blood after 20-h culture, were greater in E piglets than in CE or C piglets. In conclusion, housing sows in an enriched environment during gestation improved early neonatal survival, probably via moderate and cumulative positive effects on sow behavior, milk composition, and offspring innate immune response. The gradation in the effects observed in C, CE and E housing environment reinforced the hypothesis of a causal relationship between maternal environmental enrichment, sow welfare and postnatal piglet traits.

ASICS: an R package for a whole analysis workflow of 1D 1H NMR spectra.

MOTIVATION: In metabolomics, the detection of new biomarkers from Nuclear Magnetic Resonance (NMR) spectra is a promising approach. However, this analysis remains difficult due to the lack of a whole workflow that handles spectra pre-processing, automatic identification and quantification of metabolites and statistical analyses, in a reproducible way. RESULTS: We present ASICS, an R package that contains a complete workflow to analyse spectra from NMR experiments. It contains an automatic approach to identify and quantify metabolites in a complex mixture spectrum and uses the results of the quantification in untargeted and targeted statistical analyses. ASICS was shown to improve the precision of quantification in comparison to existing methods on two independent datasets. In addition, ASICS successfully recovered most metabolites that were found important to explain a two level condition describing the samples by a manual and expert analysis based on bucketing. It also found new relevant metabolites involved in metabolic pathways related to risk factors associated with the condition. AVAILABILITY AND IMPLEMENTATION: ASICS is distributed as an R package, available on Bioconductor. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Influence of litter size on insulin sensitivity in multiparous sows.

The objectives were to examine effects of litter size on insulin sensitivity in multiparous sows at the end of pregnancy. Twelve sows were allocated in two treatments after weaning: control (CTR) or ligature of the left oviduct (LIG). At 68 d of the subsequent pregnancy, catheters were implanted in a jugular vein, in a carotid artery, and in the main vein draining one uterine horn. A blood flow probe was fitted around the artery irrigating the same uterine horn. A meal test, a tolerance test, and an euglycemic hyperinsulinemic clamp test were performed at 108 ± 3 d of pregnancy. Serial blood samples were drawn simultaneously from the uterine vein and the carotid artery before and during the tests. The number of fetuses in the studied uterine horn was lower (3.7 vs. 8.0, P < 0.001), and piglets at birth were heavier (1.71 vs. 1.31 kg, P = 0.04) in the LIG sows than in the CTR sows. Treatment did not affect uterine blood flow (UBF), but UBF/fetus in the uterine horn was greater for the LIG treatment (0.67 vs. 0.34 L/min, P = 0.002). During meal test, glycemia, glucose uptake in the uterine horn and glucose uterine uptake/fetus were similar in both groups of sows, while insulin levels were higher in the LIG sows (P = 0.04). The decrease of NEFA concentrations was similar across treatments. Glucose half-life did not differ between treatments (13.4 min as a mean; P = 0.63) during tolerance test, but area under the insulin curve was greater in the LIG sows (P = 0.02). The glucose infusion rate during euglycemic hyperinsulinemic clamps was lower in the LIG sows than in CTR sows (6.1 ± 0.2 vs. 7.8 ± 0.1 mg glucose.kg-1 min-1; P = 0.01). The LIG sows are less sensitive to insulin than the CTR sows without adjustment of maternal glycemia and glucose tolerance. Insulin sensitivity adaptation to litter size in late pregnancy of sows would rather be connected to growth rate than to number of fetuses.

Integrated Analysis of Proteomic and Transcriptomic Data Highlights Late Fetal Muscle Maturation Process.

In pigs, the perinatal period is the most critical time for survival. Piglet maturation, which occurs at the end of gestation, is an important determinant of early survival. Skeletal muscle plays a key role in adaptation to extra-uterine life, e.g. motor function and thermoregulation. Progeny from two breeds with extreme neonatal mortality rates were analyzed at 90 and 110 days of gestation (dg). The Large White breed is a highly selected breed for lean growth and exhibits a high rate of neonatal mortality, whereas the Meishan breed is fatter and more robust and has a low neonatal mortality. Our aim was to identify molecular signatures underlying late fetal longissimus muscle development. First, integrated analysis was used to explore relationships between co-expression network models built from a proteomic data set (bi-dimensional electrophoresis) and biological phenotypes. Second, correlations with a transcriptomic data set (microarrays) were investigated to combine different layers of expression with a focus on transcriptional regulation. Muscle glycogen content and myosin heavy chain polymorphism were good descriptors of muscle maturity and were used for further data integration analysis. Using 89 identified unique proteins, network inference, correlation with biological phenotypes and functional enrichment revealed that mitochondrial oxidative metabolism was a key determinant of neonatal muscle maturity. Some proteins, including ATP5A1 and CKMT2, were important nodes in the network related to muscle metabolism. Transcriptomic data suggest that overexpression of mitochondrial PCK2 was involved in the greater glycogen content of Meishan fetuses at 110 dg. GPD1, an enzyme involved in the mitochondrial oxidation of cytosolic NADH, was overexpressed in Meishan. Thirty-one proteins exhibited a positive correlation between mRNA and protein levels in both extreme fetal genotypes, suggesting transcriptional regulation. Gene ontology enrichment and Ingenuity analyses identified PPARGC1A and ESR1 as possible transcriptional factors positively involved in late fetal muscle maturation.

Nutrient uptake of the uterus during the last third of pregnancy in sows: Effects of litter size, gestation stage and maternal glycemia.

Effects of litter size, pregnancy stage, and glycemia level on uterine uptake of energetic nutrients were studied on multiparous sows left intact (CTR; n=6) or subjected to unilateral oviduct ligation (LIG; n=6). A jugular vein, a carotid artery, and the main vein draining one uterine horn were catheterized. A blood flow probe was fitted around the artery irrigating that horn. A meal test and two glucose infusion tests (1.15 or 2.30g glucose·(100kg BW)-1min-1) were performed at 79, 93, and 106 d of pregnancy. Number of fetuses in the measured uterine horn was lower (3.7 vs. 8.0, P<0.001) and newborn piglets were heavier (1.71 vs. 1.31kg, P=0.04) in the LIG than in the CTR sows. Treatment did not affect uterine blood flow (UBF), but UBF/fetus was greater for the LIG treatment (0.57 vs. 0.32L/min, P=0.003). Glucose and lactate uterine uptakes were never significantly affected by treatment. During both tests, uterine uptake of glucose/fetus was greater in the LIG sows, which was associated with greater growth rate of their fetuses. Glucose and lactate uterine uptakes per fetus increased with glucose infusion level (P=0.03) and stage of pregnancy (P=0.04). Extraction coefficient of glucose decreased during infusion (P<0.001). Uptakes of NEFA and triglycerides were small and decreased during hyperglycemia. Glucose and lactate uptakes increased with pregnancy stage due to increased uterine blood flow. Altogether, the nutrient uptake per fetus was greater in the sows with few fetuses.

Comparing the intestinal transcriptome of Meishan and Large White piglets during late fetal development reveals genes involved in glucose and lipid metabolism and immunity as valuable clues of intestinal maturity.

BACKGROUND: Maturity of intestinal functions is critical for neonatal health and survival, but comprehensive description of mechanisms underlying intestinal maturation that occur during late gestation still remain poorly characterized. The aim of this study was to investigate biological processes specifically involved in intestinal maturation by comparing fetal jejunal transcriptomes of two representative porcine breeds (Large White, LW; Meishan, MS) with contrasting neonatal vitality and maturity, at two key time points during late gestation (gestational days 90 and 110). MS and LW sows inseminated with mixed semen (from breed LW and MS) gave birth to both purebred and crossbred fetuses. We hypothesized that part of the differences in neonatal maturity between the two breeds results from distinct developmental profiles of the fetal intestine during late gestation. Reciprocal crossed fetuses were used to analyze the effect of parental genome. Transcriptomic data and 23 phenotypic variables known to be associated with maturity trait were integrated using multivariate analysis with expectation of identifying relevant genes-phenotypic variable relationships involved in intestinal maturation. RESULTS: A moderate maternal genotype effect, but no paternal genotype effect, was observed on offspring intestinal maturation. Four hundred and four differentially expressed probes, corresponding to 274 differentially expressed genes (DEGs), more specifically involved in the maturation process were further studied. In day 110-MS fetuses, Ingenuity® functional enrichment analysis revealed that 46% of DEGs were involved in glucose and lipid metabolism, cell proliferation, vasculogenesis and hormone synthesis compared to day 90-MS fetuses. Expression of genes involved in immune pathways including phagocytosis, inflammation and defense processes was changed in day 110-LW compared to day 90-LW fetuses (corresponding to 13% of DEGs). The transcriptional regulator PPARGC1A was predicted to be an important regulator of differentially expressed genes in MS. Fetal blood fructose level, intestinal lactase activity and villous height were the best predicted phenotypic variables with probes mostly involved in lipid metabolism, carbohydrate metabolism and cellular movement biological pathways. CONCLUSIONS: Collectively, our findings indicate that the neonatal maturity of pig intestine may rely on functional development of glucose and lipid metabolisms, immune phagocyte differentiation and inflammatory pathways. This process may partially be governed by PPARGC1A.

Spontaneous intra-uterine growth restriction modulates the endocrine status and the developmental expression of genes in porcine fetal and neonatal adipose tissue.

Low birth weight is correlated with low adiposity at birth, a phenotype that influences neonatal survival and later adiposity. A better understanding of events affecting the fetal adipose tissue development and its functionality around birth is thus needed. This study was undertaken to examine the impact of spontaneous intra-uterine growth restriction (IUGR) on circulating concentrations of hormones and nutrients together with the developmental expression patterns of various genes in subcutaneous adipose tissue of pig fetus during the last third of pregnancy and just after birth. At 71 and 112 days post-conception and 2 days postnatal, pairs of same-sex piglets were chosen within litters to have either a medium (MBW) or a low (LBW) weight (n=6 pairs at each stage). The results indicate that IUGR counteracts the temporal fall of DLK1 gene expression in developing adipose tissue across gestation. It also attenuates the time-dependent increase in expression levels of many genes promoting adipocyte differentiation (PPARG, CEBPA) and lipogenesis (LPL, SREBF1, FASN, FABP4). Opposite responses to IUGR were observed for the IGF system, so that IGF1 mRNA levels were lower (P<0.001) but IGF2 mRNA levels were greater in adipose tissue of LBW piglets compared with MBW piglets. The plasma insulin concentration and the mRNA levels of insulin receptor (INSR) and insulin-responsive glucose transporter (GLUT4) in adipose tissue were also greater in LBW piglets at day 2 postnatal. The data indicate that IUGR delays the normal ontogeny of adipose tissue across gestation and affects the insulin and IGF axes around birth.

Materno-foetal exchanges and utilisation of nutrients by the foetus: comparison between species.

Several general features of nutrient uptake and utilisation by foetuses are similar among mammalian species. Nevertheless, there are also differences linked mainly to differences in placental permeability. Glucose and lactate are the main energetic substrates of the foetus. In normal conditions, the oxidation of carbohydrates accounts for about 75, 60 and 50% of oxygen uptake in the foetal pig, foal and lamb, respectively, and acetate accounts for about 10% in ruminants. Acidic amino acids are synthesised by the foetus, whereas neutral and basic amino acids are transported from the placenta. As shown by the high urea level in foetal blood, amino acids are partly involved in the oxidative metabolism of foetuses; their contribution is higher in ruminants than in humans, horses and pigs. Fatty acids cross the haemochorial placenta of rodents, rabbits and primates, and are incorporated into the foetal lipids, whereas their uptake by ruminant, pig and horse foetuses is very low.