Improving piglet survival is a key objective for breeders. Piglets that have not yet fully developed are more likely to die prematurely. Here, focus was to better characterize maturity at birth. Very immature piglets exhibit a distinctive head morphology with a reminiscent of a dolphin's, with prominent eyes. This study proposed integrating phenotyping data with blood sampling to develop a predictive metabolic signature of piglet maturity at birth. Following analysis of the head morphology, the study categorized 278 newborns (99 Landrace, 87 Large White, 92 LR×LW) according to their maturity level. Furthermore, a metabolomic analysis was also performed by 1H-NMR on blood samples (serum) collected on piglets in the hours following birth. The raw spectra were analyzed using the R package ASICS. The following statistics were based on 55 metabolites with non-zero variance. A subset of 14 metabolites was selected to develop a predictive model based on random Forests and GLM methods. The two models accurately predict 100\% of the severe immaturity status in both the training and test samples. Some piglets that are morphologically classified as mature may be metabolically immature. The 14-metabolite signature can qualify the maturity with a qualitative score as mature or not, and two quantitative scores, a mean predicted value and a stability of the prediction, which allow the confidence of the prediction to be assessed. The predictive model was applied to an independent dataset of blood collected on different farms and from piglets of different genetic origins. This allowed the relevance of the model to be evaluated, taking into account other phenotypes related to the status of birth piglets, such as birth weight, and body mass index. Genetic selection for survival at birth and growth is primarily based on the measurement of birth weight. As these traits are correlated, it is important to unravel these correlations to understand the underlying molecular mechanisms. The identification of a molecular signature could facilitate future experiments aimed at deciphering the genetic architecture of complex traits, such as maturity. Therefore, we have developed a minimally invasive blood sample that allows for low-cost, user-friendly metabolic analysis of serum. While maturity is typically defined at the biometric level, we propose a novel approach to define this complex trait at the metabolic level.
Yersinia enterocolitica strains of biotype 4 (BT4) are the most prevalent in human cases in France, followed by biotype 2 (BT2). We evaluated four BT4 porcine (P) isolates and four BT2 bovine (B) isolates for their ability to survive at 4 °C in culture broth and on meat, exhibit motility at 4 °C and 12 °C, adhere to stainless steel at 12 °C, resist five biocides, and infect human intestinal Caco-2 cells. The objective was to determine whether animal isolates that genetically cluster with human (H) isolates (P+H+, B+H+) differ phenotypically from non-clustering isolates (P+H-, B+H-), based on core genome multi-locus sequence typing (cgMLST) using allelic distance thresholds of ≤5 for BT4 and ≤3 for BT2 isolates. No significant difference was observed for BT4 between P+H+ and P+H- isolates, nor for BT2 between B+H+ and B+H- isolates, for any test, except for motility. Porcine isolates clustering with human isolates (H+) exhibited a significantly reduced motility compared with non-clustering isolates (H-) (p-value < 0.05). In contrast, bovine isolates clustering with human isolates (H+) showed a significantly higher motility than non-clustering isolates (H-). Motility plays a role in the early stages of biofilm formation but is not directly involved in virulence, as Y. enterocolitica becomes non-motile at 37 °C. Animal isolates that did not cluster with human isolates displayed traits enabling their transmission along the food chain, suggesting potential low-level human exposure, asymptomatic carriage, or links to unreported infections.
AniGun®, a portable X-ray Fluorescence (XRF) device (Animine, France), has been calibrated for rapid, cost-effective mineral analysis of forages, enabling precise mineral supplementation in ruminant diets. This study aimed to assess the feasibility of using portable XRF for calibrating and analyzing the mineral composition of swine feces. This portable XRF offers a potentially cheaper and simpler alternative to the widely accepted inductively coupled plasma optical emission spectroscopy (ICP-OES) method for mineral analysis, requiring minimal sample preparation. A pooled set of fecal samples from a previous trial, in which 70 fattening pigs were fed varying levels of copper (Cu) and zinc (Zn), was used. These samples were lyophilized and analyzed for selected minerals (Cu, Zn, manganese (Mn), calcium (Ca), potassium (K), sulfur (S), and phosphorus (P)) using ICP-OES. A pooled set of fecal samples from a previous trial, in which 70 fattening pigs were fed varying levels of copper (Cu) and zinc (Zn), was used. These samples were lyophilized and analyzed for selected minerals (Cu, Zn, manganese (Mn), calcium (Ca), potassium (K), sulfur (S), and phosphorus (P)) using ICP-OES. Thirteen fecal samples representing the highest, lowest, and median values for each mineral were selected to build a multi-elemental calibration, covering the ranges: 30-210 mg/kg for Cu; 144-849 mg/kg for Zn; 305-523 mg/kg for Mn; 9.2-16.9 g/kg for Ca; 3.1-7.8 g/kg for K; 1.1-1.9 g/kg for S; and 4.6-8.8 g/kg for P. Using these data, linearity, limits of detection, and quantification were established for each element. To validate the calibration, accuracy and precision of the XRF measurements were evaluated using random samples from the same pool. Agreement between portable XRF and ICP-OES was assessed through mean percentage bias and mean percentage recovery, with results indicating mean percentage recoveries of 97.4% for Cu, 93.9% for Zn, 96.5% for Mn, 99.2% for Ca, 95.8% for K, 94% for S, and 95.6% for P, with an approximate mean percentage bias of 4%. In summary, the portable XRF demonstrated promising accuracy for mineral quantification in swine feces, offering a rapid and economical approach to mineral analysis in fecal samples. This device has potential applications in digestibility, bioavailability, and performance studies. Further research is warranted to build additional calibrations and expand the application of this portable XRF technology to other biological tissues, such as bones and liver, as well as to complete feed and feed ingredients.
Rearing entire male pigs is of great interest in organic farming to improve animal welfare conditions (castration no longer required). But this raises questions about breeding practices, the expected rate of odorant (boar-tainted) males, and the use of carcasses from non-castrated males (NCM). There is a risk of boar-tainted pork in case of high androstenone and skatole concentrations. Results from an observatory set up on six farms have shown that it would be possible to contain the risk of boar-tainted males’ carcasses to a few percent. This work also provided recommendations for breeders. Experiments carried out at the Porganic experimental farm confirmed the positive effect of dietary fibers on the decrease in pork (backfat) skatole content and highlighted the favorable effects of the feeding strategy on other pork quality properties. Finally, sensory tests on various pork products have confirmed the benefits of diluting pork at risk for boar taint with pork from female pigs to use the meat from NCM in organic farming.
