Carlo Leifert

, Newcastle upon Tyne
Agricultural Plant Science, Horticulture, Plant Fertilization, Animal and Human Nutrition
39.16

Publications

  • Advances in Animal Biosciences - Proceedings of the British Society of Animal Science, Chester, UK; 04/2015
  • The Journal of Agricultural Science 03/2015; 153:708-731. · 2.89 Impact Factor
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    ABSTRACT: Recommendation to reduce fat consumption from ruminant meat does not consider the contribution of nutritionally beneficial fatty acids in lean beef. Here we report effects of production system (organic vs conventional) and finishing season on meat and fat quality of sirloin steaks from retail outlets and simulated fatty add intakes by consumers. There was little difference in meat quality (pH, shear force and colour), but the fat profiles varied considerably between production systems and season. Meat fat from organic and summer finished cattle contained higher concentrations of conjugated linoleic acid, its precursor vaccenic add and individual omega-3 fatty acids and had a lower ratio of omega-6 to omega-3 fatty acids compared with non-organic and winter finished cattle respectively. The fat profile from summer finished organic beef aligns better to recommended dietary guideline including those for long chain omega-3 fatty acids compared with that from winter finished, non-organic steak.
    Meat Science 02/2015; 100:306-318. DOI:10.1016/j.meatsci.2014.10.015 · 2.23 Impact Factor
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    ABSTRACT: The decline of bumblebees in Europe has been linked primarily to agricultural intensification, although climate change also has the potential to disrupt plant–pollinator interactions, partly through an increased frequency of extreme short-term weather events. There have been few attempts to use time-series models to determine meteorological variables affecting forager activity at hourly time periods over several months.Time-series models require large datasets to be reliable. We describe the use of infrared detectors at nest entrances to record forager exits/returns from 36 captive colonies of Bombus terrestris audax on a mixed farm in northern England, recording over a 78-day period.Over 1.73 million individual records of forager activity were obtained. These were aggregated into 1872 hourly blocks and analyzed with autoregressive time-series models that used nine meteorological factors as explanatory variables.Forager activity was positively linked to air temperature and solar elevation, and negatively associated with rainfall, humidity and wind-speed. The effects of increased variability in meteorological conditions are considered in the context of these results. The time-series models that we describe will be useful in future analyses of the large datasets of foraging behaviour that are becoming available through new technologies such as radio-frequency identification and video tracking.
    Agricultural and Forest Entomology 01/2015; DOI:10.1111/afe.12102 · 1.56 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 12/2014; 164:293–300. DOI:10.1016/j.foodchem.2014.05.021 · 3.26 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; 199(1-2). DOI:10.1007/s10681-014-1206-1 · 1.69 Impact Factor
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    ABSTRACT: One approach to decrease the environmental impact of crop production and reduce costs is to optimize agronomic practices and genotypes so that nutrients are used more efficiently. In this study the effects of agronomic practices (rotations, crop protection, fertilization) on yields, nitrogen use efficiency (NUE) and associated parameters were studied in an experiment using two winter wheat genotypes (Cordiale and Scaro) in one season and two potato genotypes (Sarpo Mira and Sante) in two seasons. The wheat showed no varietal differences in yield and NUE; instead the fertilization regime was the main factor affecting yield and NUE with higher values observed when conventional fertilization was used. The exception was for wheat grown after three years grass/clover ley when there was no added yield benefit from conventional fertilization of the organically bred variety (Scaro). This demonstrates the potential for N fixing crops to provide sufficient N to high yielding cereals if grown for long enough prior to planting. The greatest gains in NUE were achieved by combining an N efficient genotype with conventional crop manage- ment in an organic rotation. Fertilization and geno- typic variation were the main factors affecting potato tuber yield and NUE, with the late maturing Sarpo Mira displaying elevated yields and NUE compared with the early maturing Sante. The use of organic fertility sources resulted in lower NUE, but N release from organic sources may increase NUE of future crops. This highlights the need for long-term nutrient balance and modelling studies to assess NUE at the crop rotation scale.
    Euphytica 07/2014; 199(1-2):119. DOI:10.1007/s10681-014-1181-6 · 1.69 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; 112(05):1-18. DOI:10.1017/S0007114514001366 · 3.34 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). DOI:10.1007/s11306-013-0573-2 · 3.97 Impact Factor
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    ABSTRACT: Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious pest of solanaceous plants, especially tomato. Commonly known as the tomato leaf miner or South American tomato pinworm and originating from Central America, it has been a major problem there for tomato production for over 30 years. It appeared in Europe in 2006 in Eastern Spain, progressed rapidly around the Mediterranean basin and then throughout Europe, Africa, and Asia. Other countries are being invaded and it is now considered one of tomato’s most devastating pests worldwide in conventional, low-input and organic systems in both field and protected (greenhouse) situations. Crop damage occurs throughout the tomato growing cycle. Larvae feed on foliage, stems and fruit, and as they burrow deep into plant tissues, become protected from contact pesticides and most predators. They are very difficult to control, even with intensive pesticide applications, and yield losses of up to 100 % have been reported in severe epidemics. Commercial tomato hybrids resistant to T. absoluta would be a major component of control strategies in all production systems. However, despite breeders’ efforts, host plant resistance has not yet been achieved in commercial varieties. In the meantime, control of this devastating pest must rely on integrated control programmes adopting a range of available techniques applicable to both conventional and organic, field and greenhouse production systems but without reliance on resistant varieties. This review considers the challenges of T. absoluta control in tomatoes. It begins with a brief summary of the origin, host range, geographical distribution and biology of the insect and the economic impacts of the damage that it causes. Then, chemical and biological control methods and host plant resistance are considered. Evaluation of current knowledge and understanding of T. absoluta, the efficacy of the existing control measures and identification of deficiencies is key to defining and developing regimes which are effective in organic, low-input and conventional production systems against this devastating pest.
    03/2014; 4(1):43-61. DOI:10.1007/s13165-014-0064-4
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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 02/2014; 9(2):e87597. DOI:10.1371/journal.pone.0087597 · 3.53 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 12/2013; 8(12):e82429. DOI:10.1371/journal.pone.0082429 · 3.53 Impact Factor
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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 11/2013; 51:71-60. DOI:10.1016/j.eja.2013.06.003 · 2.92 Impact Factor
  • 64th Annual Meeting of the European Association of Animal Production, Nantes, France; 08/2013
  • 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
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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. DOI:10.1016/j.foodchem.2013.01.078 · 3.26 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. DOI:10.1016/j.eja.2013.03.004 · 2.92 Impact Factor
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