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L-Carnitine (LC) is known to play key roles in lipid metabolism and antioxidative activity, implicating enhanced cryotolerance of bovine blastocysts. However, sustainability of LC supplementation during culture period on preimplantation development beyond the blastocyst stage has not been investigated so far. Therefore, all embryos were cultured under fatty acid-free conditions, one group with LC (LC embryos) and the control group without LC (control) supplementation. Transfer to recipients was conducted on day 6. Elongation-stage embryos were recovered on day 14; metrics of embryo recollection, developmental rates as regards early elongation-stage as well as mean embryo length did not differ between the groups. Gene expression analyses via NGS revealed 341 genes to be differentially regulated between elongation-stage embryos derived from LC supplementation compared to controls. These played mainly a role in molecular functions and biological processes like oxidoreductase activity, ATP-dependent activity, cellular stress, and respiration. Pathways like oxidative phosphorylation and thermogenesis, extracellular matrix receptor signaling, PI3K-Akt, and focal adhesion were affected by differentially regulated genes. Moreover, all DEGs located on the mitochondria were significantly downregulated in LC embryos, being in line with lower mitochondrial copy number and mtDNA integrity compared to the control group. Finally, we uncovered alterations of the bioenergetic profile on day 7 as a consequence of LC supplementation for the first time, revealing significantly higher oxygen consumption rates, ATP linked respiration and spare capacity for LC embryos. In summary, we uncovered direct effects of LC supplementation during the culture period on the bioenergetic profile along with sustainable effects on mtDNA copy numbers and transcriptome profile of bovine day 14 embryos. [ABSTRACT FROM AUTHOR]

Pig production depends on a health and performance balance. An approach to improve intestinal health is the oregano essential oil (OEO) supplementation within a conventional diet. Intestinal integrity regulating effects, for example gene expression, of some feed ingredients are important key factors for that balance. We hypothesized that OEO affects the expression of genes associated with pigs' intestinal integrity. In four trials, a total of 86 pigs have been used. From weaning, the 'treated' group (n = 42) was additionally fed an oregano flavour additive [1500 mg/kg (7.5% pure OEO)] within the basal diet. The 'control' group (n = 44) was kept under identical environmental conditions, except the OEO. At age of 6 months, pigs were slaughtered with an average weight of 111.1 ± 10.9 kg. In addition to automatically generated 'Fat‐o‐Meter' (AutoFOM) data, carcass quality factors have been measured manually. Valuable cuts of meat, such as ham and belly, were significantly reduced in the OEO group. Effects of OEO on pigs' haematologic parameters were very limited. For transcriptome analysis, the most interesting microarray expression results have been listed in a table (topTable). Selected genes were technically validated by qPCR. As a result, few significant differences in animal development and meat quality have been found between the OEO treated and the control group. Depending on OEO supplementation, we found 93 differently regulated genes in the jejunal tissue (70 up, 23 down) and 60 in the ileal tissue (48 up, 12 down). Just three genes (GRIN3B [glutamate ionotropic receptor NMDA type subunit 3B], TJP1/ZO‐1 [tight junction protein ZO‐1] and one uncharacterized gene) were affected by OEO both in jejunum and ileum. qPCR validation revealed AKT serine/threonine kinase 3 (AKT3), Interferon (IFN) ‐ε, ‐ω, tight junction protein (TJP1)/ZO‐1 (ZO‐1) to be upregulated in the jejunum and C‐C motif chemokine ligand 21 (CCL21) was upregulated in the ileum of pigs that were supplemented with OEO. OEO supplementation had limited effects on pigs' performance traits. However, we were able to demonstrate that OEO alters the expression of genes associated with adaptive immune response in pigs' small intestine. These findings help to explain OEOs' beneficial impact on pigs' intestinal integrity. [ABSTRACT FROM AUTHOR]

Abstract Background Leg weakness issues are a great concern for the pig breeding industry, especially with regard to animal welfare. Traits associated with leg weakness are partly influenced by the genetic background of the animals but the genetic basis of these traits is not yet fully understood. The aim of this study was to identify quantitative trait loci (QTL) affecting leg weakness in pigs. Methods Three hundred and ten F2 pigs from a Duroc × Pietrain resource population were genotyped using 82 genetic markers. Front and rear legs and feet scores were based on the standard scoring system. Osteochondrosis lesions were examined histologically at the head and the condylus medialis of the left femur and humerus. Bone mineral density, bone mineral content and bone mineral area were measured in the whole ulna and radius bones using dual energy X-ray absorptiometry. A line-cross model was applied to determine QTL regions associated with leg weakness using the QTL Express software. Results Eleven QTL affecting leg weakness were identified on eight autosomes. All QTL reached the 5% chromosome-wide significance level. Three QTL were associated with osteochondrosis on the humerus end, two with the fore feet score and two with the rear leg score. QTL on SSC2 and SSC3 influencing bone mineral content and bone mineral density, respectively, reached the 5% genome-wide significance level. Conclusions Our results confirm previous studies and provide information on new QTL associated with leg weakness in pigs. These results contribute towards a better understanding of the genetic background of leg weakness in pigs.

Abstract Background Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, carcass composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for carcass composition and meat quality traits in pig. Methods Five hundred and eighty five F2 pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 carcass composition and meat quality traits was available for all F2 animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program. Results A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for carcass composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance. Conclusions Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and trait-specific relationships of loci within and across chromosomes.