3709 research outputs found
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Heat treatment of liquid ultrafiltration concentrate influences the physical and functional properties of milk protein concentrate powders
peer-reviewedLiquid milk protein concentrate (MPC; 18.3 and 16.5%, w/w, total solids and protein, respectively) was heat treated at 80 °C (low-heat), 100 °C (medium-heat) and 120 °C (high-heat) for 30 s, or did not undergo heat treatment (control), prior to spray drying. Viscosity of the liquid MPC increased with increasing heat treatment temperature. Physical properties of MPC powders were influenced by heat treatment, with the size of powder particles generally increasing with increasing temperature. Heat treatment of ultrafiltration concentrate influenced the heat stability of MPC powders, with high-heat treated MPC having highest heat stability at pH 6.9 and 7.0 (140 °C). However, particle size distribution profiles showed a decrease in powder dispersion with increased heat treatment temperature. This study demonstrated that heat treatment of ultrafiltration concentrate at temperatures ≥100 °C can present challenges with solubilising subsequent MPC powders
Sensorial, cultural and volatile properties of milk, dairy powders, yoghurt and butter: A review
peer-reviewedCountries with an established dairy tradition consume milk, milk powder, yoghurt and butter
directly or as an ingredient; however, in countries without this tradition the lack of familiarity and
unknown expectations can be challenging to overcome. Therefore, having a better understanding of
the volatile properties that influence their sensory appeal can aid overcoming these challenges. This
review focusses on traditional and novel sensory methods used to research milk, milk powders,
yoghurt and butter as well as the extraction techniques used in gas chromatography mass spectrometry and gas chromatography olfactometry to identify volatiles in these products that influence sensory perception.Teagas
Use of Probiotic Bacteria and Bacteriocins as an Alternative to Antibiotics in Aquaculture
peer-reviewedIn addition to their use in human medicine, antimicrobials are also used in food animals and aquaculture, and their use can be categorized as therapeutic against bacterial infections. The use of antimicrobials in aquaculture may involve a broad environmental application that affects a wide variety of bacteria, promoting the spread of bacterial resistance genes. Probiotics and bacteriocins, antimicrobial peptides produced by some types of lactic acid bacteria (LAB), have been successfully tested in aquatic animals as alternatives to control bacterial infections. Supplementation might have beneficial impacts on the intestinal microbiota, immune response, development, and/or weight gain, without the issues associated with antibiotic use. Thus, probiotics and bacteriocins represent feasible alternatives to antibiotics. Here, we provide an update with respect to the relevance of aquaculture in the animal protein production sector, as well as the present and future challenges generated by outbreaks and antimicrobial resistance, while highlighting the potential role of probiotics and bacteriocins to address these challenges. In addition, we conducted data analysis using a simple linear regression model to determine whether a linear relationship exists between probiotic dose added to feed and three variables of interest selected, including specific growth rate, feed conversion ratio, and lysozyme activity
Detection of stx2 from Shiga toxin-producing Escherichia coli (STEC) by a surface enhanced Raman spectroscopy (SERS) sensor using recycled silicon chips
peer-reviewedIn this research, a selective, cost-efficient, and highly sensitive Ag nanostructure Surface Enhanced Raman Spectroscopy (SERS) sensor was developed as a methodological approach to rapidly detect a targetss-DNA (stx2) in STEC (Shiga toxin-producing Escherichia coli). The Ag nanostructure-based SERS substrate was functionalized by two types of thiols: thiol-ss-DNA for bonding target ss-DNA and 6-Mercapto-1-hexanol (HS(CH2)6OH) for blocking the Ag nanostructure surface. Methylene Blue (MB) was used as a Raman marker to quantify target ss-DNA, as well as a model molecule to characterize the electrodeposited Ag nanostructure SERS substrate. Ag nanostructure SERS substrates showed good sensitivity and repeatability towards MB detection, with a LOD = 0.3158 μM, and RSD = 12.48% (at 45 different random points for 0.1 μM MB). More importantly, the Ag nanostructure/ss-DNA SERS substrate showed good selectivity towards STEC O157 stx2 target DNA, as well as good linearity and sensitivity towards its detection in a buffer solution. A limit of detection of 0.4900 aM and a wide linear range from 1 aM to 100 pM were demonstrated. The SERS sensors were able to identify target DNA (stx2) in a STEC strain and the study showed proof of principle that SERS substrate has potential as a cost-effective, highly selective, highly sensitive DNA and bacteria sensor without the aid of DNA amplification. With further development and validation, this methodological approach has the potential for point-of-use detection for instance on a farm or in the food industry
Impact of a total mixed ration or pasture/pasture silage-based feeding strategy in the initial stages of lactation of spring-calving dairy cows on milk production, composition and selected milk processability parameters
peer-reviewedThe objective of this experiment was to investigate the effect of feeding strategy on milk production, composition and selected processability parameters in the initial stages of lactation. Twenty Holstein Friesian cows were allocated to one of two dietary treatments (n = 10; 7 multiparous and 3 primiparous) in a randomised complete block design for 21 d from day 10 to day 31 post-calving. Treatment 1 (pasture-based system [PBS]) was a pasture/pasture silage-based diet where cows were offered ad libitum grazed pasture or pasture silage (when weather did not permit grazing) plus 3 kg DM/d or 5 kg DM/d concentrate supplementation, respectively. On average, cows grazed pasture for 7.5 d and were fed pasture silage indoors for 13.5 d. Treatment 2 (TMR) was a total mixed ration (TMR) diet made up of concentrate, plus maize silage, pasture silage, beet pulp, soya bean meal and straw. Multiparous cows were blocked on calving date and balanced for parity and milk yield. Primiparous cows were balanced for live weight. Milk attributes pertinent to composition and functionality (e.g., fatty acids and rennet coagulation time [RCT]) were examined over a 21-d experimental period from day 10 to day 31 post-calving. Cows offered PBS tended to have a lower test day milk yield (PBS = 24.2 kg/cow vs. TMR = 26.8 kg/cow, P = 0.09) and a greater milk urea nitrogen (MUN) content compared to TMR (PBS = 0.030 g/100 g milk vs. TMR = 0.013 g/100 g milk, P < 0.001). Most notably, PBS-derived milks had a greater (P < 0.001) concentration of cis-9 trans-11 conjugated linoleic acid (CLA) compared to TMR. In conclusion, milk produced during early lactation from both feeding strategies was suitable for processing. Feeding a TMR compared with ad libitum pasture/pasture silage had no impact on average milk pH, casein concentration or RCT. Cows fed a pasture/pasture silage-based diet produced milk with a desirable RCT for milk processing, while the higher MUN content from cows offered PBS did not impact the processability of milk. Furthermore, milk from cows offered PBS had greater concentrations of cis-9 trans-11 CLA, which may offer human health benefits
An outline of achievements in selected areas of forest research in Ireland 1960–2021
peer-reviewedIn this paper, we provide an overview of achievements in forest research in Ireland carried out by various agencies over the past 60 yr. Many of the outcomes of the research have ensured that policy and practice are well-founded, and many of the research results form the basis of current forest standards and practice. Forest research has, and will continue to have, a significant role in national policy development and international reporting commitments. The achievement of future goals and targets is increasingly dependent on the maintenance of the goods and services that forests provide; these can be enhanced through the establishment of new forests and by appropriate management of the resource (e.g. The EU Green Deal and EU Forest Strategy). We outline the current state of knowledge which can be used to inform afforestation goals and the importance of tree improvement, forest management and forest protection to improve competitiveness and sustainability. Research into forestry and carbon provides a focus on the opportunities and challenges of climate change to Irish forestry. Future efforts will involve longer-term monitoring of environmental change commensurate with the forest rotation to reduce the uncertainties associated with climate change. Research into forestry economics, attitudinal surveys and behavioural studies may help inform the achievement of future policy goals. Reducing the impacts of biotic attack through efficient surveying, disease monitoring and assessing future risk is likely to be the focus of future research effort
Datafile: Grassland legacy effects on yield of a follow-on crop in rotation strongly influenced by legume proportion and moderately by drought
peer-reviewedDataset contains the dry matter and nitrogen yield responses of a Lolium multiflorum crop (summed across harvests). The L. multiflorum crop was sown on plots comprising grassland communities of one to six species (and one to three functional groups) that were growing for the previous two years.
An experimental summer drought was implemented on half of each plot during the grassland phase but not the crop phase.
Data were collected in Wexford, Republic of Ireland (52.299584, -6.506458) in 2020
Sperm DNA methylation patterns at discrete CpGs and genes involved in embryonic development are related to bull fertility
peer-reviewedBackground
Despite a multifactorial approach being taken for the evaluation of bull semen quality in many animal breeding centres worldwide, reliable prediction of bull fertility is still a challenge. Recently, attention has turned to molecular mechanisms, which could uncover potential biomarkers of fertility. One of these mechanisms is DNA methylation, which together with other epigenetic mechanisms is essential for the fertilising sperm to drive normal embryo development and establish a viable pregnancy. In this study, we hypothesised that bull sperm DNA methylation patterns are related to bull fertility. We therefore investigated DNA methylation patterns from bulls used in artificial insemination with contrasting fertility scores.
Results
The DNA methylation patterns were obtained by reduced representative bisulphite sequencing from 10 high-fertility bulls and 10 low-fertility bulls, having average fertility scores of − 6.6 and + 6.5%, respectively (mean of the population was zero). Hierarchical clustering analysis did not distinguish bulls based on fertility but did highlight individual differences. Despite this, using stringent criteria (DNA methylation difference ≥ 35% and a q-value < 0.001), we identified 661 differently methylated cytosines (DMCs). DMCs were preferentially located in intergenic regions, introns, gene downstream regions, repetitive elements, open sea, shores and shelves of CpG islands. We also identified 10 differently methylated regions, covered by 7 unique genes (SFRP1, STXBP4, BCR, PSMG4, ARSG, ATP11A, RXRA), which are involved in spermatogenesis and early embryonic development.
Conclusion
This study demonstrated that at specific CpG sites, sperm DNA methylation status is related to bull fertility, and identified seven differently methylated genes in sperm of subfertile bulls that may lead to altered gene expression and potentially influence embryo development
Antimicrobial resistance in Escherichia coli isolated from on-farm and conventional hatching broiler farms in Ireland
peer-reviewedBackground
On-farm hatching (OH) systems are becoming more common in broiler production. Hatching conditions differ from conventional farms as OH chicks avoid exposure to handling, transport, post-hatch water and feed deprivation. In contrast, chicks in conventional hatching conditions (CH) are exposed to standard hatchery procedures and transported post hatching. The objectives of this pilot study were to investigate the prevalence and frequency of Escherichia coli resistant to antimicrobials, including presumptive ESBL/AmpC-producing E. coli, isolated from environmental and faecal samples from OH versus CH hatching systems, and to investigate the presence of ESBL/AmpC-producing encoding genes.
Results
Environmental samples were collected from one flock in 10 poultry farms (5 OH farms, 5 CH farms) on day 0 post disinfection of the facilities to assess hygiene standards. On D10 and D21 post egg/chick arrival onto the farm, samples of faeces, boot swabs and water drinker lines were collected.
E. coli were isolated on MacConkey agar (MC) and MacConkey supplemented with cefotaxime (MC+). Few E. coli were detected on D0. However, on D10 and D21 E. coli isolates were recovered from faeces and boot swabs. Water samples had minimal contamination. In this study, 100% of cefotaxime resistant E. coli isolates (n=33) detected on selective media and 44% of E. coli isolates (84/192) detected on nonselective media were multidrug resistant (MDR). The antimicrobial resistance (AMR) genotype for the 15 ESBL/AmpC producing isolates was determined using multiplex PCR. Six of these were selected for Sanger sequencing of which two were positive for blaCMY-2, two for blaTEM-1 and two were positive for both genes.
Conclusions
There was no difference in E. coli isolation rates or prevalence of AMR found between the OH versus CH systems, suggesting that the OH system may not be an additional risk of resistant E. coli dissemination to broilers compared to the CH systems. The frequency of β-lactam resistant E. coli in boot swab and faeces samples across both OH (24/33 (73%)) and CH (9/33 (27%)) systems may indicate that hatcheries could be a reservoir and major contributor to the transmission of AMR bacteria to flocks after entry to the rearing farms
Multiclonal human origin and global expansion of an endemic bacterial pathogen of livestock
peer-reviewedMost new pathogens of humans and animals arise via switching events from distinct host species. However, our understanding of the evolutionary and ecological drivers of successful host adaptation, expansion, and dissemination are limited. Staphylococcus aureus is a major bacterial pathogen of humans and a leading cause of mastitis in dairy cows worldwide. Here we trace the evolutionary history of bovine S. aureus using a global dataset of 10,254 S. aureus genomes including 1,896 bovine isolates from 32 countries in 6 continents. We identified 7 major contemporary endemic clones of S. aureus causing bovine mastitis around the world and traced them back to 4 independent host-jump events from humans that occurred up to 2,500 y ago. Individual clones emerged and underwent clonal expansion from the mid-19th to late 20th century coinciding with the commercialization and industrialization of dairy farming, and older lineages have become globally distributed via established cattle trade links. Importantly, we identified lineage-dependent differences in the frequency of host transmission events between humans and cows in both directions revealing high risk clones threatening veterinary and human health. Finally, pangenome network analysis revealed that some bovine S. aureus lineages contained distinct sets of bovine-associated genes, consistent with multiple trajectories to host adaptation via gene acquisition. Taken together, we have dissected the evolutionary history of a major endemic pathogen of livestock providing a comprehensive temporal, geographic, and gene-level perspective of its remarkable success.Wellcome Trus