Publications

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    ABSTRACT: This paper considers meat and fat quality in retail sirloin steak.•It considers the impact of organic vs. conventional and summer vs. winter purchase.•Fatty acid profiles were influenced by both production system and season.•Summer and organic finishing resulted in higher levels of beneficial fatty acids.•Avoiding subcutaneous fat consumption will drastically reduce CLA intake.
    Meat Science 02/2015; 100:306-318. · 2.75 Impact Factor
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    ABSTRACT: IntroductionIn Europe, the challenge of meeting future food demands while ensuring the sustainability of agricultural systems is increasingly an issue on the public agenda. We have to accept the need of increased efficiency, sustainability and resilience of our agricultural production, while at the same time meeting the emerging challenges such as “feeding the world,” “food or fuel,” “biodiversity,” and “climate change.” EUCARPIA, the European association for research in plant breeding, organized a Section meeting on Organic & Low-input Agriculture in Germany from September 24–26, 2013 at the Georg August University of Göttingen on Breeding for Nutrient Efficiency. This conference focused on the development of new crop breeding strategies to improve nutrient use efficiency as one strategy to address the above mentioned challenges. Next to various contributions on basic concepts and methodologies to improve nutrient efficiency, updates on many ongoing breeding programs and research acti
    Euphytica 08/2014; · 1.64 Impact Factor
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    ABSTRACT: Demand for organic foods is partially driven by consumers' perceptions that they are more nutritious. However, scientific opinion is divided on whether there are significant nutritional differences between organic and non-organic foods, and two recent reviews have concluded that there are no differences. In the present study, we carried out meta-analyses based on 343 peer-reviewed publications that indicate statistically significant and meaningful differences in composition between organic and non-organic crops/crop-based foods. Most importantly, the concentrations of a range of antioxidants such as polyphenolics were found to be substantially higher in organic crops/crop-based foods, with those of phenolic acids, flavanones, stilbenes, flavones, flavonols and anthocyanins being an estimated 19 (95 % CI 5, 33) %, 69 (95 % CI 13, 125) %, 28 (95 % CI 12, 44) %, 26 (95 % CI 3, 48) %, 50 (95 % CI 28, 72) % and 51 (95 % CI 17, 86) % higher, respectively. Many of these compounds have previously been linked to a reduced risk of chronic diseases, including CVD and neurodegenerative diseases and certain cancers, in dietary intervention and epidemiological studies. Additionally, the frequency of occurrence of pesticide residues was found to be four times higher in conventional crops, which also contained significantly higher concentrations of the toxic metal Cd. Significant differences were also detected for some other (e.g. minerals and vitamins) compounds. There is evidence that higher antioxidant concentrations and lower Cd concentrations are linked to specific agronomic practices (e.g. non-use of mineral N and P fertilisers, respectively) prescribed in organic farming systems. In conclusion, organic crops, on average, have higher concentrations of antioxidants, lower concentrations of Cd and a lower incidence of pesticide residues than the non-organic comparators across regions and production seasons.
    British Journal Of Nutrition 06/2014; · 3.30 Impact Factor
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    ABSTRACT: Potato (Solanum tuberosum L.) cv. Santé was grown over 2 years under both conventional and organic fertiliser and crop protection regimes. The tuber metabolome was analysed using mass-spectrometry (MS) based approaches, principally liquid chromatography (LC)–MS and gas chromatography (GC)–MS. Data were analysed using Principal Components Analysis (PCA) and Analysis of Variance (ANOVA) to assess any differences between production practices. GC–MS analysis of non-polar metabolites did not detect any statistically significant differences, but GC–MS analysis of polar compounds identified 83 metabolites showing significant differences in the metabolome between the fertiliser treatments. Of the 62 metabolites that were less abundant in tuber samples from organic compared with conventionally fertilised crops, consistent year on year differences were dominated by free amino acids. The effect on free amino acids is associated with the lower nitrogen (N) content of the organically grown potatoes in this instance (50 % lower than for conventional production). LC–MS provided indications that levels of certain glycoalkaloids may be lower under the organic fertiliser regime in one growing season. Differences associated with the crop protection measures used were much less consistent, and relatively small, compared with the fertiliser effects found.
    Metabolomics 04/2014; 10(2). · 4.43 Impact Factor
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    ABSTRACT: Many studies show concentrations of nutritionally desirable fatty acids in bovine milk are lower when cows have no access to grazing, leading to seasonal fluctuations in milk quality if cows are housed for part of the year. This study investigated the potential to improve the fatty acid profiles of bovine milk by oilseed supplementation (rolled linseed and rapeseed) during a period of indoor feeding in both organic and conventional production systems. Both linseed and rapeseed increased the concentrations of total monounsaturated fatty acids, vaccenic acid, oleic acid and rumenic acid in milk, but decreased the concentration of the total and certain individual saturated fatty acids. Linseed resulted in greater changes than rapeseed, and also significantly increased the concentrations of α-linolenic acid, total polyunsaturated fatty acids and total omega-3 fatty acids. The response to oilseed supplementation, with respect to increasing concentrations of vaccenic acid and omega-3 fatty acids, appeared more efficient for organic compared with conventional diets.
    Food Chemistry 01/2014; 164:293–300. · 3.33 Impact Factor
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    ABSTRACT: 'Omics analysis (transcriptomics, proteomics) quantifies changes in gene/protein expression, providing a snapshot of changes in biochemical pathways over time. Although tools such as modelling that are needed to investigate the relationships between genes/proteins already exist, they are rarely utilised. We consider the potential for using Structural Equation Modelling to investigate protein-protein interactions in a proposed Rubisco protein degradation pathway using previously published data from 2D electrophoresis and mass spectrometry proteome analysis. These informed the development of a prior model that hypothesised a pathway of Rubisco Large Subunit and Small Subunit degradation, producing both primary and secondary degradation products. While some of the putative pathways were confirmed by the modelling approach, the model also demonstrated features that had not been originally hypothesised. We used Bayesian analysis based on Markov Chain Monte Carlo simulation to generate output statistics suggesting that the model had replicated the variation in the observed data due to protein-protein interactions. This study represents an early step in the development of approaches that seek to enable the full utilisation of information regarding the dynamics of biochemical pathways contained within proteomics data. As these approaches gain attention, they will guide the design and conduct of experiments that enable 'Omics modelling to become a common place practice within molecular biology.
    PLoS ONE 01/2014; 9(2):e87597. · 3.53 Impact Factor
  • 64th Annual Meeting of the European Association of Animal Production, Nantes, France; 08/2013
  • 64th Annual Meeting of the European Association for Animal Production; 08/2013
  • 64th Annual Meeting of the European Association of Animal Production, Nantes, France; 08/2013
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    ABSTRACT: This study investigates the quality of retail milk labelled as Jersey & Guernsey (JG) when compared with milk without breed specifications (NS) and repeatability of differences over seasons and years. 16 different brands of milk (4 Jersey & Guernsey, 12 non specified breed) were sampled over 2years on 4 occasions. JG milk was associated with both favourable traits for human health, such as the higher total protein, total casein, α-casein, β-casein, κ-casein and α-tocopherol contents, and unfavourable traits, such as the higher concentrations of saturated fat, C12:0, C14:0 and lower concentrations of monounsaturated fatty acids. In summer, JG milk had a higher omega-3:omega-6 ratio than had NS milk. Also, the relative increase in omega-3 fatty acids and α-tocopherol, from winter to summer, was greater in JG milk. The latter characteristic could be of use in breeding schemes and farming systems producing niche dairy products. Seasonality had a more marked impact on the fatty acid composition of JG milk than had NS milk, while the opposite was found for protein composition. Potential implication for the findings in human health, producers, industry and consumers are considered.
    Food Chemistry 08/2013; 139(1-4):540-8. · 3.33 Impact Factor
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    ABSTRACT: The effects of organic versus conventional crop management practices (fertilisation, crop protection) and preceding crop on potato tuber yield (total, marketable, tuber size grade distribution) and quality (proportion of diseased, green and damaged tubers, tuber macro-nutrient concentrations) parameters were investigated over six years (2004–2009) as part of a long-term factorial field trial in North East England. Inter-year variability (the effects of weather and preceding crop) was observed to have a profound effect on yields and quality parameters, and this variability was greater in organic fertility systems. Total and marketable yields were significantly reduced by the use of both organic crop protection and fertility management. However, the yield gap between organic and conventional fertilisation regimes was greater and more variable than that between crop protection practices. This appears to be attributable mainly to lower and less predictable nitrogen supply in organically fertilised crops. Increased incidence of late blight in organic crop protection systems only occurred when conventional fertilisation was applied. In organically fertilised crops yield was significantly higher following grass/red clover leys than winter wheat, but there was no pre-crop effect in conventionally fertilised crops. The results highlight that nitrogen supply from organic fertilisers rather than inefficient pest and disease control may be the major limiting factor for yields in organic potato production systems.
    European Journal of Agronomy 08/2013; 49:83-92. · 2.80 Impact Factor
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    ABSTRACT: Meta-analyses are methods to combine outcomes from different studies in order to investigate consistent effects of relatively small magnitude, which are difficult to distinguish from random variation within a single study. Several published meta-analyses addressed whether organic and conventional production methods affect the composition of plant foods differently. The meta-analyses were carried out using different options for the methodology, and resulted in different conclusions. The types of designs of field trials and farm comparisons widely used in horticultural and agronomic research differ substantially from the clinical trials and epidemiological studies that most meta-analysis methodologies were developed for. Due to this it is proposed to carry out a systematic review and meta-analysis aiming to develop a consolidated methodology. If successful, this methodology can then be used to determine effects of different production systems on plant food composition as well as other comparable factors with small but systematic effects across studies.
    Journal of Agricultural and Food Chemistry 05/2013; · 3.11 Impact Factor
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    ABSTRACT: Very little is known about the effects of an organic or conventional diet on animal physiology and health. Here we report the effect of contrasting crop protection (with or without chemosynthetic pesticides) and fertilization (manure or mineral fertilizers) regimes on feed composition and growth and physiological parameters of rats. The use of manure instead of mineral fertilizers in feed production resulted in lower concentrations of protein (18.8 vs. 20.6 %) and cadmium (3.33 vs. 4.92 µg/100g) but higher concentrations of polyphenols (1.46 vs. 0.89 g/100g) in feeds and higher body protein (22.0 vs. 21.5 %), body ash (3.59 vs. 3.51 %), white blood cell count (10.86 vs. 8.19 ×10(3)/mm(3)), plasma glucose (7.23 vs. 6.22 mmol/L), leptin (3.56 vs. 2.78 ng/mL), insulin-like growth factor 1 (1.87 vs. 1.28 µg/mL), corticosterone (247 vs. 209 ng/mL) and spontaneous lymphocyte proliferation (11.14 vs. 5.03 ×10(3) cpm) but lower plasma testosterone (1.07 vs. 1.97 ng/mL) and mitogen stimulated proliferation of lymphocytes (182 vs. 278 ×10(3) cpm) in rats. There were no main effects of crop protection, but a range of significant interactions between fertilization and crop protection occurred.
    Journal of Agricultural and Food Chemistry 01/2013; 61:1017-1029. · 3.11 Impact Factor
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    ABSTRACT: There is increasing concern about the sustainability and environmental impacts of mineral fertilizer use in agriculture. Increased recycling of nutrients via the use of animal and green manures and fertilizers made from domestic organic waste may reduce reliance on mineral fertilizers. However, the relative availability of nutrients (especially nitrogen) is lower in organic compared to mineral fertilizers, which can result in significantly lower yields in nutrient demanding crops such as potato. It is therefore important to gain a better understanding of the factors affecting nutrient use efficiency (yield per unit fertilizer input) from organic fertilizers. Here we show that (a) previous crop management (organic vs. conventional fertilization and crop protection regimes), (b) organic fertilizer type and rate (composted cattle manure vs. composted chicken manure pellets) and (c) watering regimes (optimized and restricted) significantly affected leaf chlorophyll content, potato tuber N-concentration, proteome and yield. Protein inference by gel matching indicated several functional groups significantly affected by previous crop management and organic fertilizer type and rate, including stress/defense response, glycolysis and protein destination and storage. These results indicate genomic pathways controlling crop responses (nutrient use efficiency and yield) according to contrasting types and rates of organic fertilizers that can be linked to the respective encoding genes.
    Agronomy. 01/2013;
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    ABSTRACT: The performance of winter wheat was evaluated under organic (ORG) and conventional (CON) management systems in the Nafferton Factorial Systems Comparison (NFSC) long-term field trial. The present study separates out the crop protection and fertility management components of organic and conventional production systems using two levels each of crop protection (CP) and fertility management (FM). The experimental design provided the four combinations of crop protection and fertility (CON-CP CON-FM, CON-CP ORG-FM, ORG-CP CON-FM and ORG-CP ORG-FM) to evaluate their effects on yield, quality (protein content and hectolitre weight) and disease levels during the period 2004–2008. The conventional management system (CON-CP CON-FM) out-yielded the organic management system (ORG-CP ORG-FM) in all years by an average of 3.1 t ha−1, i.e. 7.9 t ha−1 vs. 4.8 t ha−1. Fertility management was the key factor identified limiting both yield and grain protein content in the ORG management system. The CON-FM produced on average a 3% higher protein content than ORG-FM in all years (12.5% vs. 9.7%). However the ORG-CP system produced higher protein levels than CON-CP although it was only in 2008 that this was statistically significant. In contrast to protein content it was ORG-FM which produced a higher hectolitre weight than the CON-FM system (71.6 kg hl−1 vs. 71.0 kg hl−1). The clear and significant differences in yield and protein content between the ORG-FM and CON-FM systems suggest a limited supply of available N in the organic fertility management system which is also supported by the significant interaction effect of the preceding crop on protein content. The pRDA showed that although fertilisation had the greatest effect on yield, quality and disease there was also a considerable effect of crop protection and the environment.
    European Journal of Agronomy 01/2013; 51:71-60. · 2.80 Impact Factor
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    ABSTRACT: Over the last century, intakes of omega-6 (ω-6) fatty acids in Western diets have dramatically increased, while omega-3 (ω-3) intakes have fallen. Resulting ω-6/ω-3 intake ratios have risen to nutritionally undesirable levels, generally 10 to 15, compared to a possible optimal ratio near 2.3. We report results of the first large-scale, nationwide study of fatty acids in U.S. organic and conventional milk. Averaged over 12 months, organic milk contained 25% less ω-6 fatty acids and 62% more ω-3 fatty acids than conventional milk, yielding a 2.5-fold higher ω-6/ω-3 ratio in conventional compared to organic milk (5.77 vs. 2.28). All individual ω-3 fatty acid concentrations were higher in organic milk-α-linolenic acid (by 60%), eicosapentaenoic acid (32%), and docosapentaenoic acid (19%)-as was the concentration of conjugated linoleic acid (18%). We report mostly moderate regional and seasonal variability in milk fatty acid profiles. Hypothetical diets of adult women were modeled to assess milk fatty-acid-driven differences in overall dietary ω-6/ω-3 ratios. Diets varied according to three choices: high instead of moderate dairy consumption; organic vs. conventional dairy products; and reduced vs. typical consumption of ω-6 fatty acids. The three choices together would decrease the ω-6/ω-3 ratio among adult women by ∼80% of the total decrease needed to reach a target ratio of 2.3, with relative impact "switch to low ω-6 foods" > "switch to organic dairy products" ≈ "increase consumption of conventional dairy products." Based on recommended servings of dairy products and seafoods, dairy products supply far more α-linolenic acid than seafoods, about one-third as much eicosapentaenoic acid, and slightly more docosapentaenoic acid, but negligible docosahexaenoic acid. We conclude that consumers have viable options to reduce average ω-6/ω-3 intake ratios, thereby reducing or eliminating probable risk factors for a wide range of developmental and chronic health problems.
    PLoS ONE 01/2013; 8(12):e82429. · 3.53 Impact Factor
  • M.D. Eyre, M.L. Luff, C. Leifert
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    ABSTRACT: Ground beetles were sampled in nine crops and four field boundary types on a split conventional/organic farm in northern England in the five years 2005–2009. Multivariate analyses indicated that a combination of crop type, management and boundary type influenced ground beetle species and group activity. Short vegetation boundaries with bare ground had similar activity, mainly of small species, to that in organic arable crops, contrasting with activity in conventional arable and more densely vegetated boundaries. Large, medium-sized, herbivorous and Collembola feeding species all had considerable activity in oilseed rape and activity was generally greatest in conventional arable crops but least in conventional grass. Disturbance and productivity estimations provided basic insights into ground beetle activity. Most small and medium-sized species were found in areas with low productivity but high and low disturbance, respectively. Large and Collembola feeding species were most active in highly productive areas with medium and low disturbance whilst most herbivorous species preferred medium values of both drivers. In crops, species richness was greatest in organic beans and conventional oilseed rape and lowest in conventional grass. There were more species in short vegetation boundaries than in more densely vegetated field edges. There may be potential for the use of productivity and disturbance estimations in the provision of ecosystem services, especially in assessing the conditions required to optimise ground beetle activity for pest control.
    Agriculture Ecosystems & Environment 01/2013; 165:60–67. · 3.20 Impact Factor
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    Proceedings of The Nutrition Society 01/2013; 72(OCE2). · 3.67 Impact Factor

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