Purification and Molecular Characterization of Fucoidan Isolated from Ascophyllum nodosum Brown Seaweed Grown in Ireland.

The present study investigates the molecular characteristics of fucoidan obtained from the brown Irish seaweed Ascophyllum nodosum, employing hydrothermal-assisted extraction (HAE) followed by a three-step purification protocol. The dried seaweed biomass contained 100.9 mg/g of fucoidan, whereas optimised HAE conditions (solvent, 0.1N HCl; time, 62 min; temperature, 120 °C; and solid to liquid ratio, 1:30 (w/v)) yielded 417.6 mg/g of fucoidan in the crude extract. A three-step purification of the crude extract, involving solvents (ethanol, water, and calcium chloride), molecular weight cut-off filter (MWCO; 10 kDa), and solid-phase extraction (SPE), resulted in 517.1 mg/g, 562.3 mg/g, and 633.2 mg/g of fucoidan (p < 0.05), respectively. In vitro antioxidant activity, as determined by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging and ferric reducing antioxidant power assays, revealed that the crude extract exhibited the highest antioxidant activity compared to the purified fractions, commercial fucoidan, and ascorbic acid standard (p < 0.05). The molecular attributes of biologically active fucoidan-rich MWCO fraction was characterised by quadruple time of flight mass spectrometry and Fourier-transform infrared (FTIR) spectroscopy. The electrospray ionisation mass spectra of purified fucoidan revealed quadruply ([M+4H]4+) and triply ([M+3H]3+) charged fucoidan moieties at m/z 1376 and m/z 1824, respectively, and confirmed the molecular mass 5444 Da (~5.4 kDa) from multiply charged species. The FTIR analysis of both purified fucoidan and commercial fucoidan standard exhibited O-H, C-H, and S=O stretching which are represented by bands at 3400 cm-1, 2920 cm-1, and 1220-1230 cm-1, respectively. In conclusion, the fucoidan recovered from HAE followed by a three-step purification process was highly purified; however, purification reduced the antioxidant activity compared to the crude extract.

The effects of mushroom powder and vitamin D2 -enriched mushroom powder supplementation on the growth performance and health of newly weaned pigs.

A complete randomised block design experiment was conducted to examine the effects of mushroom powder (MP) and vitamin D2 -enriched mushroom powder (MPD2 ) on growth performance, faecal scores, coefficient of apparent total tract digestibility (CATTD) of nutrients and selected microflora in weaned pigs up to day 35 post-weaning. One hundred and ninety-two weaned pigs (7.8kg [SD 1.08kg]) were blocked according to live weight, sex and litter of origin and randomly assigned to the following: (T1) control diet; (T2) control diet +MP; (T3) control diet + MPD2 ; and (T4) control diet +zinc oxide (ZnO) (n = 12 replicates/treatment). Mushroom powders were included at 2 g/kg of feed achieving a ß-glucan content of 200ppm. ZnO was included at 3100 mg/kg feed and halved to 1550 mg/kg after 21 days. Vitamin D content was enhanced in MPD2 using synthetic UVB exposure to obtain a vitamin D2 level of 100 µg/kg of feed. Faecal samples were collected on day 14 for microbial and nutrient digestibility analysis. There was no difference (p > 0.05) in ADG, G:F, faecal scores, microbial populations and CATTD of nutrients in pigs supplemented with MP or MPD2 compared with the control diet. The supplementation of MP and MPD2 caused a reduction (p < 0.05) in feed intake compared with the control and ZnO diet throughout the 35-day experimental period. ZnO supplementation increased ADG and ADFI (p < 0.05) during the first period (D0-21) compared with pigs offered MP and MPD2 . In conclusion, MP and MPD2 supplementation resulted in similar ADG, G:F, faecal scores compared with the control but were not comparable to ZnO, mainly due to a reduction in feed intake.

Effect of Supplementing Seaweed Extracts to Pigs until d35 Post-Weaning on Performance and Aspects of Intestinal Health.

The objective of this study was to examine the effects of feeding laminarin (LAM) and fucoidan (FUC) enriched seaweed extracts up to d35 post-weaning on measures of animal performance, intestinal microbial and transcriptome profiles. 75 pigs were assigned to one of three groups: (1) basal diet; (2) basal diet + 250 ppm fucoidan; (3) basal diet + 300 ppm laminarin with 7 replicates per treatment group. Measures of performance were collected weekly and animals sacrificed on d35 post-weaning for the sampling of gastrointestinal tissue and digesta. Animal performance was similar between the basal group and the groups supplemented with FUC and LAM (P > 0.05). Pigs fed the basal diet had higher alpha diversity compared to both the LAM and FUC supplemented pigs (P < 0.05). Supplementation with LAM and FUC increased the production of butyric acid compared to basal fed pigs (P < 0.05). At genus level pigs fed the LAM supplemented diet had the greatest abundance of Faecalbacterium, Roseburia and the lowest Campylobacter of the three experimental treatments (P< 0.05). While neither extract had beneficial effects on animal performance, LAM supplementation had a positive influence on intestinal health through alterations in the gastrointestinal microbiome and increased butyrate production.

Seasonal Variation of the Proximate Composition, Mineral Content, Fatty Acid Profiles and Other Phytochemical Constituents of Selected Brown Macroalgae.

The main objective was to determine the chemical, phytochemical, fatty acid and mineral profiles of three commercially relevant brown macroalgae (Laminaria digitata, Laminaria hyperborea and Ascophyllum nodosum) collected each season for two years off the west coast of Ireland. All the chemical, phytochemical, fatty acid and minerals analysed varied significantly depending on the macroalgal species, season and year of collection. Overall, the protein contents of macroalgae were negatively correlated with carbohydrate content. Protein (2-11%) was at its highest during winter and/or spring, decreasing to a minimum during summer and/or autumn. The three macroalgal species analysed in this study had clearly differentiated fatty acid profiles. The concentration of fatty acids was higher in A. nodosum compared with both Laminaria species. The mineral profile of the three macroalgal species was rich in essential metals, particularly Ca, Mg and P, while the levels of I were approximately 9- to 10-fold higher in both Laminaria spp. compared with A. nodosum. The levels of toxic metals (Cd, Hg and Pb) in all the macroalgal species studied were low in the current study; while the levels of total As were high (49-64 mg/kg DW macroalgae) compared with previous reports.

Evaluation of the Antibacterial and Prebiotic Potential of Ascophyllum nodosum and Its Extracts Using Selected Bacterial Members of the Pig Gastrointestinal Microbiota.

Ascophyllum nodosum and its extracts are promising antibacterial and prebiotic dietary supplements for pigs. The objectives of this study were to evaluate the effects of the increasing concentrations of: (1) two whole biomass samples of A. nodosum with different harvest seasons, February (ANWB-F) and November (ANWB-N), in a weaned pig faecal batch fermentation assay, and (2) A. nodosum extracts produced using four different extraction conditions of a hydrothermal-assisted extraction methodology (ANE1-4) and conventional extraction methods with water (ANWE) and ethanol (ANEE) as solvent in individual pure culture growth assays using a panel of beneficial and pathogenic bacterial strains. In the batch fermentation assay, ANWB-F reduced Bifidobacterium spp. counts (p < 0.05) while ANWB-N increased total bacterial counts and reduced Bifidobacterium spp. and Enterobacteriaceae counts (p < 0.05). Of the ANE1-4, produced from ANWB-F, ANWE and ANEE that were evaluated in the pure culture growth assays, the most interesting extracts were the ANE1 that reduced Salmonella Typhimurium, enterotoxigenic Escherichia coli and B. thermophilum counts and the ANE4 that stimulated B. thermophilum growth (p < 0.05). In conclusion, the extraction method and conditions influenced the bioactivities of the A. nodosum extracts with ANE1 and ANE4 exhibiting distinct antibacterial and prebiotic properties in vitro, respectively, that merit further exploration.

Effect of a Laminarin Rich Macroalgal Extract on the Caecal and Colonic Microbiota in the Post-Weaned Pig.

Dietary supplementation with 300 ppm of a laminarin rich macroalgal extract reduces post-weaning intestinal dysfunction in pigs. A comprehensive analysis of the impact of laminarin on the intestinal microbiome during this period is essential to inform on the mode of action of this bioactivity. The objective of this study was to evaluate the effects of supplementing the diet of newly weaned pigs with 300 ppm of a laminarin rich extract, on animal performance, volatile fatty acids, and the intestinal microbiota using 16S rRNA gene sequencing. Pigs fed the laminarin-supplemented diet had higher average daily feed intake, growth rate, and body weight compared to pigs fed the control diet (p < 0.05). Pigs fed the laminarin-supplemented diet had reduced abundance of OTUs assigned to Enterobacteriaceae and increased abundance of OTUs assigned to the genus Prevotella (p < 0.05) compared to pigs fed the control diet. Enterobacteriaceae had negative relationships (p < 0.05) with average daily feed intake (ADFI), average daily gain (ADG), and butyric acid concentrations. In contrast, Prevotellaceae were positively correlated (p < 0.05) with ADFI, ADG, total VFA, acetic, propionic, butyric acids, and negatively correlated with isovaleric acid. Hence supplementation with a laminarin enriched extract potentially improves performance during the post-weaning period by promoting the proliferation of bacterial taxa such as Prevotella that favourably enhance nutrient digestion while reducing the load of potentially pathogenic bacterial taxa including Enterobacteriaceae.

The Effects of the Marine-Derived Polysaccharides Laminarin and Chitosan on Aspects of Colonic Health in Pigs Challenged with Dextran Sodium Sulphate.

This study examined the effects of dietary supplementation with laminarin or chitosan on colonic health in pigs challenged with dextran sodium sulphate (DSS). Weaned pigs were assigned to: (1) a basal diet (n = 22); (2) a basal diet + laminarin (n = 10); and (3) a basal diet + chitosan (n = 10). On d35, the basal group was split, creating four groups: (1) the basal diet (control); (2) the basal diet + DSS; (3) the basal diet + laminarin + DSS; and (4) the basal diet + chitosan + DSS. From d39-42, the pigs were orally challenged with DSS. On d44, colonic tissue/digesta samples were collected. The basal DSS group had reduced growth, higher pathology score and an increased expression of MMP1, IL13 and IL23 compared with the controls (p < 0.05); these parameters were similar between the DSS-challenged groups (p > 0.05). In the basal DSS group, the relative abundance of beneficial taxa including Prevotella and Roseburia were reduced while Escherichia/Shigella were increased, compared with the controls (p < 0.05). The relative abundance of Escherichia/Shigella was reduced and the molar proportions of acetate were increased in the laminarin DSS group compared with the basal DSS group (p < 0.01), suggesting that laminarin has potential to prevent pathogen proliferation and enhance the volatile fatty acid profile in the colon in a porcine model of colitis.

Effects of reducing dietary crude protein concentration and supplementation with laminarin or zinc oxide on the faecal scores and colonic microbiota in newly weaned pigs.

A 2 × 3 factorial design experiment was conducted to examine the effects of reducing dietary crude protein (CP) concentration and/or supplementation with zinc oxide (ZnO) or laminarin on faecal scores (FS) and the large intestinal microbiota post-weaning (PW). One hundred and forty-four pigs were assigned to (T1) 21% standard CP diet (SCP); (T2) SCP + ZnO (SCP ZnO); (T3) SCP + laminarin (SCP LAM); (T4) 18% low CP diet (LCP); (T5) LCP + ZnO (LCP ZnO); and (T6) LCP + laminarin (LCP LAM; n = 8 replicates/treatment). The LCP diet had no effect on FS (p > .05), it increased two measures of alpha diversity, reduced Bacteroidetes and increased Enterobacteriaceae and Helicobacteraceae in the colon relative to the SCP diet (p < .05). ZnO supplementation reduced FS and increased Ruminococcaceae compared with unsupplemented pigs (p < .05). ZnO supplementation increased the genera Frisingicoccus (p < .001), Lachnoclostridium (p < .05) and Peptoclostridium (p < .05) in the colon and reduced total caecal volatile fatty acids (VFA) concentrations compared with the unsupplemented and laminarin-supplemented pigs. Laminarin supplementation reduced FS compared with unsupplemented pigs but had no major effect on the microbiota compared with the unsupplemented pigs. There were CP concentration × additive interactions on both Firmicutes and Proteobacteria. Firmicutes were increased in the LCP ZnO group compared with the LCP group, but there was no difference between the SCP groups. Proteobacteria were reduced in the LCP ZnO group compared with the LCP and LCP LAM groups (p < .05), but there was no difference between the SCP groups. In conclusion, reducing CP did not improve FS; it increased the relative abundance of Enterobacteriaceae; however, it also increased bacterial diversity. Supplementation with ZnO and laminarin improved FS, although all groups had scores within the healthy range. ZnO altered the large intestinal microbiota and VFA concentrations; however, laminarin did not enhance these parameters, suggesting these compounds have differing modes of action.

Analysis of the basal colonic innate immune response of pigs divergent in feed efficiency and following an ex vivo lipopolysaccharide challenge.

While feed efficiency is influenced by multiple physiological processes, it is not known how efficient and inefficient pigs differ in relation to their basal immune response, and particularly their innate immune response to a microbial challenge. Hence, the objective was to examine the expression of genes encoding innate immune response markers in basal colonic tissue and colonic tissue following an ex vivo lipopolysaccharide (LPS) challenge from pigs divergent in residual feed intake (RFI). Pigs that differed in RFI were selected from two different farms of origin. Colonic tissue was harvested from high RFI (HRFI) and low (LRFI) pigs, and two experimental conditions were explored: the first was basal unchallenged tissue and the second was colonic tissue following an ex vivo LPS challenge. RNA was extracted and tested on a Nanostring panel of 72 genes coding for barrier defense proteins, transmembrane receptors, kinases, transcription regulators, cytokines, and cytokine regulators. In the basal unchallenged tissue, the LRFI pigs had increased expression of AOAH, AP1, and TRAM and the cytokines TNF, IL10, and CXCL8, compared with the HRFI pigs (P < 0.05), with a significant effect of farm of origin on 31 genes (P < 0.05). In the LPS-challenged tissues, the LRFI group had higher expression of TLR1, TLR7, TLR8, GPR43/FFAR2, JAK2, and NFAM1 compared with the HRFI group (P < 0.05). In conclusion, these data suggest that LRFI pigs have an upregulated basal colonic inflammatory state and a heightened response to an LPS challenge compared with the inefficient HRFI pigs. This immune profile potentially enhances their capacity to respond to an infectious challenge.

A comparative analysis of the transcriptome profiles of liver and muscle tissue in pigs divergent for feed efficiency.

BACKGROUND: The improvement of feed efficiency is a key economic goal within the pig production industry. The objective of this study was to examine transcriptomic differences in both the liver and muscle of pigs divergent for feed efficiency, thus improving our understanding of the molecular mechanisms influencing feed efficiency and enabling the identification of candidate biomarkers. Residual feed intake (RFI) was calculated for two populations of pigs from two different farms of origin/genotype. The 6 most efficient (LRFI) and 6 least efficient (HRFI) animals from each population were selected for further analysis of Longissimus Dorsi muscle (n = 22) and liver (n = 23). Transcriptomic data were generated from liver and muscle collected post-slaughter. RESULTS: The transcriptomic data segregated based on the RFI value of the pig rather than genotype/farm of origin. A total of 6463 genes were identified as being differentially expressed (DE) in muscle, while 964 genes were identified as being DE in liver. Genes that were commonly DE between muscle and liver (n = 526) were used for the multi-tissue analysis. These 526 genes were associated with protein targeting to membrane, extracellular matrix organisation and immune function. In the muscle-only analysis, genes associated with RNA processing, protein synthesis and energy metabolism were down regulated in the LRFI animals while in the liver-only analysis, genes associated with cell signalling and lipid homeostasis were up regulated in the LRFI animals. CONCLUSIONS: Differences in the transcriptome segregated on pig RFI value rather than the genotype/farm of origin. Multi-tissue analysis identified that genes associated with GO terms protein targeting to membrane, extracellular matrix organisation and a range of terms relating to immune function were over represented in the differentially expressed genes of both liver and muscle.

The Effect of Increasing Inclusion Levels of a Fucoidan-Rich Extract Derived from Ascophyllum nodosum on Growth Performance and Aspects of Intestinal Health of Pigs Post-Weaning.

This study examines the effects of increasing dietary inclusion levels of fucoidan, from a 44% fucoidan extract on the growth performance and intestinal health of pigs post-weaning (PW). Seventy-two newly weaned pigs (8.4 kg (SD 1.06)) were assigned to: (T1) basal diet (BD); (T2) BD + 125 ppm fucoidan; (T3) BD + 250 ppm fucoidan (8 pens/treatment). The appropriate quantity of a 44% fucoidan extract was included to achieve these inclusion levels. Faecal scores were recorded daily. On d15 PW, samples were collected from the intestinal tract from 1 pig/pen from the BD and BD + 250 ppm fucoidan groups. Pigs supplemented with 250 ppm fucoidan had improved faecal scores and increased concentrations of total volatile fatty acids and propionate in the colon (p < 0.05). The fucoidan-rich extract reduced the expression of CLDN5 (duodenum), SCL5A1/SGLT1 and SI (jejunum) and TJP1, FABP2, and SLC5A1 (ileum) (p < 0.05). The extract reduced the relative abundance of Prevotella and Lachnospiraceae (p < 0.05) and increased the abundance of Helicobacter (p < 0.01) in the caecum. However, no negative impact on growth performance or small intestinal morphology was observed. Thus, the inclusion of 250 ppm fucoidan improves faecal consistency without affecting growth performance and therefore warrants further investigation as a supplement for the prevention of PW diarrhoea under more challenging commercial conditions.

Enhancing the Extraction of Polysaccharides and Antioxidants from Macroalgae Using Sequential Hydrothermal-Assisted Extraction Followed by Ultrasound and Thermal Technologies.

Fucose sulphated polysaccharides (FSPs) and glucans have recently attracted the attention of the scientific community due to their wide range of biological activities. Both polysaccharides should ideally be selectively extracted using innovative technologies with high extraction efficiency. This study aims to: (1) Optimise the extraction variables used in hydrothermal-assisted extraction (HAE) to obtain high yields of FSPs, total glucans, and antioxidants from Laminaria hyperborea; (2) to apply these optimised protocols to other brown macroalgae; and (3) to explore the application of ultrasound and thermal technologies to increase the recovery of polysaccharides from the residual biomass. Box-Behnken design (three-factor, four-levels) was employed to optimise the HAE variables, and principal component analysis was used to evaluate the recovery of polysaccharides from the residual biomass. The optimal HAE conditions were 120 °C, 80.9 min, and 12.02 mL/g macroalgae from L. hyperborea. The best sequential application of ultrasound and thermal treatment achieved an additional 2971.7 ± 61.9 mg fucose/100 g dried macroalgal residue (dmr) from Ascophyllum nodosum and 908.0 ± 51.4 mg total glucans/100 g dmr from L. hyperborea macroalgal residues.

The variation in hectolitre weight of wheat grain fed with or without enzyme supplementation influences nutrient digestibility and subsequently affects performance in pigs.

A 2 × 2 factorial experiment was conducted to investigate the effect of feeding a wheat-based diet of two different hectolitre weights (66 vs. 74 kg/hl), achieved through different agronomical conditions, with or without the supplementation of a ß-glucanase and ß-xylanase enzyme mix on young pigs. The parameter categories which were assessed included growth performance, coefficient of apparent total tract digestibility (CATTD), faecal consistency, faecal microbial populations and faecal volatile fatty acid (VFA) concentrations. Sixty-four pigs (11.6 kg SD 0.97) were assigned to one of four dietary treatments: (T1) low hectolitre weight wheat diet, (T2) low hectolitre weight wheat diet containing 0.1 g/kg ß-glucanase and ß-xylanase enzyme supplement, (T3) high hectolitre weight wheat diet and (T4) high hectolitre weight wheat diet containing 0.1 g/kg ß-glucanase and ß-xylanase enzyme supplement. The inclusion of wheat was 500 g/kg in the diet. The low hectolitre weight grain had a higher level of zearalenone, aflatoxin and ochratoxin contamination compared to the high hectolitre weight grain. The high hectolitre weight wheat had a higher gross energy (GE), crude protein (CP) and lysine contents compared to the low hectolitre weight wheat. Pigs offered the low hectolitre weight diet had a lower average daily gain (ADG) (p < 0.001), a lower gain to feed (G:F) ratio (p < 0.001) and a higher faecal score (more diarrhoea) (p < 0.001) compared to pigs offered the high hectolitre weight. The low hectolitre weight diet had a reduced CATTD (p < 0.05) of nitrogen (N) and gross energy (GE) compared with pigs offered the high hectolitre weight diet. In conclusion, the higher level of mycotoxins and lower content of GE, CP and lysine in the low-quality wheat reduced ADG and the CATTD of nutrients in pigs offered this diet. The inclusion of a ß-glucanase and ß-xylanase enzyme mix had no effect on growth performance or nutrient digestibility.

Extraction and Yield Optimisation of Fucose, Glucans and Associated Antioxidant Activities from Laminaria digitata by Applying Response Surface Methodology to High Intensity Ultrasound-Assisted Extraction.

The objectives of this study were to employ response surface methodology (RSM) to investigate and optimize the effect of ultrasound-assisted extraction (UAE) variables, temperature, time and amplitude on the yields of polysaccharides (fucose and total glucans) and antioxidant activities (ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity (DPPH)) from Laminariadigitata, and to explore the suitability of applying the optimum UAE conditions for L.digitata to other brown macroalgae (L.hyperborea and Ascophyllumnodosum). The RSM with three-factor, four-level Box-Behnken Design (BBD) was used to study and optimize the extraction variables. A second order polynomial model fitted well to the experimental data with R² values of 0.79, 0.66, 0.64, 0.73 for fucose, total glucans, FRAP and DPPH, respectively. The UAE parameters studied had a significant influence on the levels of fucose, FRAP and DPPH. The optimised UAE conditions (temperature = 76 °C, time = 10 min and amplitude = 100%) achieved yields of fucose (1060.7 ± 70.6 mg/100 g dried seaweed (ds)), total glucans (968.6 ± 13.3 mg/100 g ds), FRAP (8.7 ± 0.5 µM trolox/mg freeze-dried extract (fde)) and DPPH (11.0 ± 0.2%) in L.digitata. Polysaccharide rich extracts were also attained from L.hyperborea and A. nodosum with variable results when utilizing the optimum UAE conditions for L.digitata.

Assessment of RNA Stability in Postmortem Tissue from New-Born Lambs.

The recovery of high quality RNA from postmortem tissue is crucial to gene expression analyses. The acquisition of postmortem tissue has inherent time delays and, hence, understanding the temporal variation in the stability of total RNA is imperative. This experiment aimed: ( 1 ) to qualitatively and quantitatively assess the integrity of total RNA derived from a range of new-born ovine tissues (liver, spleen, thyroid, skeletal muscle, ileum, and perirenal adipose tissue) which were stored at ambient temperature until extraction at 0, 3, 6, and 9 h postmortem; and ( 2 ) to analyze the stability of the reference gene(s) and expression of specific target genes in these tissues. Postmortem sampling time resulted in variable reductions in the relative integrity number (RIN) values across the tissues, ranging from 0.9 to 1.8% in liver, spleen, skeletal muscle, and ileum to 5.7-11.1% in the thyroid and perirenal adipose tissues, respectively (P < 0.05). In conclusion, tissues with small reductions in RIN value can exhibit disproportionately large differences in the normalization factor used to calculate the target gene expression. Hence, changes in transcript abundance due to RNA degradation are not always sufficiently buffered through normalization with reference genes. The normalization factor should be presented alongside the RIN value in postmortem tissue studies.

The application of transcriptomic data in the authentication of beef derived from contrasting production systems.

BACKGROUND: Differences between cattle production systems can influence the nutritional and sensory characteristics of beef, in particular its fatty acid (FA) composition. As beef products derived from pasture-based systems can demand a higher premium from consumers, there is a need to understand the biological characteristics of pasture produced meat and subsequently to develop methods of authentication for these products. Here, we describe an approach to authentication that focuses on differences in the transcriptomic profile of muscle from animals finished in different systems of production of practical relevance to the Irish beef industry. The objectives of this study were to identify a panel of differentially expressed (DE) genes/networks in the muscle of cattle raised outdoors on pasture compared to animals raised indoors on a concentrate based diet and to subsequently identify an optimum panel which can classify the meat based on a production system. RESULTS: A comparison of the muscle transcriptome of outdoor/pasture-fed and Indoor/concentrate-fed cattle resulted in the identification of 26 DE genes. Functional analysis of these genes identified two significant networks (1: Energy Production, Lipid Metabolism, Small Molecule Biochemistry; and 2: Lipid Metabolism, Molecular Transport, Small Molecule Biochemistry), both of which are involved in FA metabolism. The expression of selected up-regulated genes in the outdoor/pasture-fed animals correlated positively with the total n-3 FA content of the muscle. The pathway and network analysis of the DE genes indicate that peroxisome proliferator-activated receptor (PPAR) and FYN/AMPK could be implicit in the regulation of these alterations to the lipid profile. In terms of authentication, the expression profile of three DE genes (ALAD, EIF4EBP1 and NPNT) could almost completely separate the samples based on production system (95 % authentication for animals on pasture-based and 100 % for animals on concentrate- based diet) in this context. CONCLUSIONS: The majority of DE genes between muscle of the outdoor/pasture-fed and concentrate-fed cattle were related to lipid metabolism and in particular ß-oxidation. In this experiment the combined expression profiles of ALAD, EIF4EBP1 and NPNT were optimal in classifying the muscle transcriptome based on production system. Given the overall lack of comparable studies and variable concordance with those that do exist, the use of transcriptomic data in authenticating production systems requires more exploration across a range of contexts and breeds.

Lactoferrin affects the adherence and invasion of Streptococcus dysgalactiae ssp. dysgalactiae in mammary epithelial cells.

Streptococcus dysgalactiae ssp. dysgalactiae is an important causative agent of bovine mastitis worldwide. Lactoferrin is an innate immune protein that is associated with many functions including immunomodulatory, antiproliferative, and antimicrobial properties. This study aimed to investigate the interactions between lactoferrin and a clinical bovine mastitis isolate, Strep. dysgalactiae ssp. dysgalactiae DPC5345. Initially a deliberate in vivo bovine intramammary challenge was performed with Strep. dysgalactiae DPC5345. Results demonstrated a significant difference in lactoferrin mRNA levels in milk cells between the control and infused quarters 7h postinfusion. Milk lactoferrin levels in the Strep. dysgalactiae DPC5345 infused quarters were significantly increased compared with control quarters at 48h postinfusion. In vitro studies demonstrated that lactoferrin had a bacteriostatic effect on the growth of Strep. dysgalactiae DPC5345 and significantly decreased the ability of the bacteria to internalize into HC-11 mammary epithelial cells. Confocal microscopy images of HC-11 cells exposed to Strep. dysgalactiae and lactoferrin further supported this effect by demonstrating reduced invasion of bacteria to HC-11 cells. The combined data suggest that a bovine immune response to Strep. dysgalactiae infection includes a significant increase in lactoferrin expression in vivo, and based on in vitro data, lactoferrin limits mammary cell invasion of this pathogen by binding to the bacteria and preventing its adherence.

Breed differences in humoral and cellular responses of lambs to experimental infection with the gastrointestinal nematode Teladorsagia circumcincta.

While Texel lambs have increased resistance to infection with the gastrointestinal nematode Teladorsagia circumcincta compared to Suffolk lambs, the underlying resistance mechanisms are still unknown. The aim of this study was to compare parasitological, humoral and cellular responses of Texel and Suffolk lambs over time following a single experimental infection with T. circumcincta. Gastrointestinal nematode free (but not naïve) lambs received a single oral dose of 3 × 104 infective T. circumcincta larvae. The variables examined included worm burden, mucosal and serum IgA, abomasal mast cells and eosinophils, haematological parameters and plasma pepsinogen. Texel lambs had significantly lower worm burden on day 14 and lower plasma pepsinogen concentration from day 14 onwards than Suffolks and their response in mucosal IgA to infection occurred earlier. The results from the study suggest that an earlier local IgA response in the Texel contributes to the resistant characteristics of the breed, while the increased level of plasma pepsinogen in the Suffolk lambs implies greater abomasal tissue damage arising from the nematode infection.

Improvements in growth performance, bone mineral status and nutrient digestibility in pigs following the dietary inclusion of phytase are accompanied by modifications in intestinal nutrient transporter gene expression.

Phytase (PHY) improves growth performance, nutrient digestibility and bone structure in pigs; however, little is known about its effects on intestinal nutrient transporter gene expression. In the present study, a 44 d experiment was carried out using forty-eight pigs (11·76 (sem 0·75) kg) assigned to one of three dietary treatment groups to measure growth performance, coefficient of apparent ileal digestibility (CAID), coefficient of apparent total tract nutrient digestibility (CATTD) and intestinal nutrient transporter gene expression. Dietary treatments during the experimental period were as follows: (1) a high-P (HP) diet containing 3·4 g/kg available P and 7·0 g/kg Ca; (2) a low-P (LP) diet containing 1·9 g/kg available P and 5·9 g/kg Ca; (3) a PHY diet containing LP diet ingredients+1000 phytase units (FTU)/kg of PHY. The PHY diet increased the average daily gain (P< 0·05) and final body weight (P< 0·01) and decreased the feed conversion ratio (P< 0·05) compared with the LP diet. Pigs fed the PHY diet had a higher CAID of gross energy compared with those fed the HP and LP diets (P< 0·001). Pigs fed the PHY diet had increased CAID of P (P< 0·01) and CATTD of Ca and P (P< 0·001) compared with those fed the LP diet. The PHY diet increased the gene expression of the peptide transporter 1 (PEPT1/SLC15A1) (P< 0·05) in the ileum compared with the LP diet. The LP diet decreased the gene expression of the sodium-glucose-linked transporter 1 (SGLT1/SLC5A1) and GLUT2/SLC2A2 (P< 0·05) and increased the expression of membrane Ca channel (TRPV6) and calbindin compared with the HP diet (P< 0·001). In conclusion, feeding a diet supplemented with PHY improves growth performance and nutrient digestibility as well as increases the gene expression of the peptide transporter PEPT1.

Effect of creep feeding pelleted starter diet, liquid milk replacer and a liquid mixture of starter diet and milk replacer to suckling pigs on their growth and medication usage.

The aim of this study was to assess the effect of creep-feeding solid starter diet, liquid milk replacer, and a liquid mixture of starter diet and milk replacer to suckling pigs on their growth and medication usage up to target slaughter weight (approximately 120 kg). Ninety-one sows and their litters were randomly assigned to one of four post-farrowing treatments at day 107 of gestation; (1) no creep feed provided to weaning at day 28 of age (CONTROL; n = 20), (2) dry pelleted starter diet provided as creep feed from day 10 of age to weaning (DPS; n = 25), (3) liquid milk replacer provided as creep feed from day 3 of age to weaning (LMR; n = 23), and (4) liquid milk replacer provided from days 3 to 6 of age followed by a mixture of liquid milk replacer with an increasing proportion of liquid starter diet to weaning provided as creep feed (LMR + S; n = 23). Pig weight and dry matter disappearance (DMd) were recorded during lactation and postweaning until pigs reached target slaughter weight (approximately 120 kg). At target slaughter weight, carcass weight and quality were recorded. Medication (antibiotic and anti-inflammatory) usage per pig on a litter basis, and number of injections and clinical cases of disease per litter were recorded from birth to slaughter. At day 5 postweaning, a subset of pigs (n = 40) were sacrificed and intestinal samples were collected for histological analysis. Piglets supplemented with DPS had higher DMd of creep feed than those supplemented with LMR or LMR + S (P < 0.001). Providing LMR + S to suckling piglets reduced the coefficient of variation (CV) for within-litter piglet weaning weight (P < 0.01) compared to DPS and LMR, but the CV of LMR + S was similar to that of CONTROL. Providing DPS or LMR to suckling piglets increased piglet weaning weight compared to CONTROL (P < 0.001) but pig weight was not significantly different from CONTROL at time points thereafter. Gain to feed ratio from weaning to day 6 postweaning was less for LMR pigs compared to all other treatments (P < 0.001). Providing DPS or LMR + S to suckling piglets tended to increase postweaning ileal villus height (P = 0.07). Diarrhea incidence, as well as the number of clinical cases of disease and injections per litter and volume of antibiotic and anti-inflammatory administered per pig pre- and postweaning, were not affected by treatment (P > 0.05). In conclusion, supplementing suckling pigs with liquid milk replacer or dry pelleted starter diet improved growth at weaning, but the benefit did not persist to slaughter.