Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    A generic method to analyse yield gaps in feed-crop livestock systems
    Linden, Aart van der - \ 2017
    Wageningen University. Promotor(en): Imke de Boer; Martin van Ittersum, co-promotor(en): Simon Oosting; Gerrie van de Ven. - Wageningen : Wageningen University - ISBN 9789463430746 - 214
    animal production - fodder crops - livestock feeding - crop production - crop yield - crop ecology - quantitative analysis - beef production - farming systems - dierlijke productie - voedergewassen - veevoeding - gewasproductie - gewasopbrengst - gewasecologie - kwantitatieve analyse - rundvleesproductie - bedrijfssystemen

    Global livestock production is expected to increase in future decades, and expansion of the agricultural area for feed production is not desired. Hence, increasing livestock production per unit agricultural area is essential. The bio-physical scope to increase production of livestock systems with the corresponding feed crop production (feed-crop livestock systems) could not be assessed generically at the start of this research. In crop production, however, crop models based on concepts of production ecology are widely applied to assess the bio-physical scope to increase actual production. The difference between the biophysical scope and actual production is referred to as the yield gap. The objectives of this thesis were 1) to develop a generic framework to assess the scope to increase production in feed crop-livestock systems based on concepts of production ecology, 2) to develop a generic livestock model simulating potential (i.e. maximum theoretical) and feed-limited livestock production, and 3) to apply this framework and model to feed-crop livestock systems, and conduct yield gap analyses.

    Concepts of production ecology for livestock were specified in more detail. Feed efficiency at herd level was a suited benchmark for livestock production only, and production of animal-source food per hectare for feed-crop livestock systems. Application of the framework showed that the yield gap was 79% of the potential beef production of a cow-calf system, and 72% of a cow-calf-fattener system in the Charolais region of France. The model LiGAPS-Beef (Livestock simulator for Generic analysis of Animal Production Systems – Beef cattle) was developed to simulate potential and feed-limited production of beef cattle using input data about animals’ genotype, climate, and feed quality and availability. The model consists of sub-models describing thermoregulation, feed intake and digestion, and energy and protein utilisation. Model evaluation under different agro-ecological conditions indicated live weight gain was estimated fairly well (15.4% deviation from measured values). LiGAPS-Beef was coupled with crop growth models to simulate potential and resource-limited production of twelve grass-based beef production systems in the Charolais region. Resource-limited production combines feed-limited production of cattle and water-limited production of feed crops. Yield gaps were on average 85% of potential live weight production per hectare, and 47% of resource-limited production. Yield gaps were attributed to feed quality and quantity limitation (41% of potential production), water-limitation in feed crops (31%), the combination of sub-optimal selling or slaughter weights, culling rates, calving dates, age at first calving, and stocking densities (9%), and the combination of prolonged calving intervals and calf mortality (2%). Improved grassland management and an earlier start of the grazing season may increase live weight production per hectare. Furthermore, the resource-limited production of bulls was simulated to increase by 6-14% from 1999-2006 up to 2050 due to climate change.

    From the results of this thesis, it can be concluded that 1) a generic framework using concepts of production ecology is available now to assess the bio-physical scope to increase production in feed-crop livestock systems per unit area; 2) the mechanistic model LiGAPS-Beef simulates potential and feed-limited production of beef cattle fairly well; 3) combining LiGAPS-Beef with crop growth models allows to quantify yield gaps in feed-crop livestock systems, and to analyse these yield gaps. The method described in this thesis can be used subsequently to identify options to mitigate yield gaps, and to increase livestock production per unit area, which may contribute to sustainable intensification of agriculture.

    Sainfoin (Onobrychis viciifolia) : a forgotten crop for dairy cows with future potential
    Huyen, Nguyen Thi - \ 2016
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Wilbert Pellikaan; Martin Verstegen. - Wageningen : Wageningen University - ISBN 9789462577268 - 160
    onobrychis viciifolia - dairy cows - fodder legumes - fodder crops - legume silage - rumen digestion - nutrition physiology - methane production - milk yield - dairy performance - animal nutrition - onobrychis viciifolia - melkkoeien - voederpeulvruchten - voedergewassen - peulvruchtenkuilvoer - pensvertering - voedingsfysiologie - methaanproductie - melkopbrengst - melkresultaten - diervoeding

    Sainfoin (Onobrychis viciifolia): a forgotten crop for dairy cows with future potential


    The world population growth and rising incomes are expected to increase the consumption of animal-derived foods such as meat, eggs and milk. However, livestock production should not only be directed towards increasing productivity but should also incorporate environmental, food safety and animal welfare aspects. Therefore, farm businesses have to respond to the high environment impact of their activities, by using low-input systems including the use of forage legumes. Recent studies have demonstrated that forage legumes with moderate levels of condensed tannins (CT) are beneficial for animal nutrition and animal health. Sainfoin (Onobrychis viciifolia Scop.) is a tanniniferous forage legume containing CT that has potential nutritional and health benefits, i.e. preventing bloating, reducing nematode larval establishment, improving nitrogen (N) utilization and reducing greenhouse gas and N emissions (Chapter 1). However, the use of sainfoin as a fodder crop in dairy cow rations in northwestern Europe is still rather unknown. This thesis investigated the potential of sainfoin in the dairy cow diets and the effect of CT structural properties on rumen fermentation and biohydrogenation (BH).

    Chapter 2 reports a study where the effect of sainfoin silage on nutrient digestibility, animal performance, energy and N utilization and methane (CH4) production in dairy cows was investigated. Six rumen cannulated, lactating dairy cows were randomly assigned to either a control (CON) or sainfoin based (SAIN) diet. The CON diet was a mixture of grass silage, corn silage, concentrate and linseed. In the SAIN diet, 50% of the grass silage DM in the CON diet was exchanged by sainfoin silage. Total daily dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) intake did not differ between the two diets. The apparent digestibility of DM, OM, NDF and acid detergent fiber (ADF) were respectively, 5.7, 4.0, 15.7 and 14.8% lower for the SAIN diet. Methane production per kg DM intake was lowest for the SAIN diet and CH4 production as a percentage of gross energy intakes tended to be lower while milk yield was greater for the SAIN diet. Nitrogen intake, N retention and energy retained in body protein were greater for the SAIN than the CON diet. Nitrogen retention as a percentage of N intake tended to be greater for the SAIN diet. These results showed that inclusion of sainfoin silage at the expense of grass silage in dairy cow rations reduced CH4 per kg DM intake. Although nutrient digestibility was decreased, sainfoin silage improved milk production and redirected metabolism towards body protein accretion at the expense of body fat.

    In Chapter 3, reticular fatty acid (FA) flow and ruminal BH of C18:3n-3 is reported using the reticular sampling technique (Cr-EDTA and Yb-acetate as digesta flow markers) in the lactating cows fed the SAIN and CON diet in Chapter 2. The reticular flows of DM, OM and N were not affected by dietary treatment. However, NDF flow was higher (1.87 vs. 1.40 kg/d) where the cows were fed the SAIN diet. A higher mono-unsaturated FA flow was caused by the higher trans-9-C18:1 and cis-9-C18:1 flow for the SAIN compared to the CON fed cows. The flows of trans-9,trans-12-C18:2 and cis-12,trans-10 C18:2 were higher in the SAIN diet fed cows, but total poly-unsaturated FA flow was not affected by the different diet treatments. The SAIN diet fed cows had a significant lower ruminal BH of cis-9-C18:1 and C18:3n-3, compared to the CON fed cows and tended to a lower ruminal BH in case of cis-9,cis-12-C18:2. These results show that inclusion of sainfoin silage at the expense of grass silage in dairy cow rations reduces ruminal BH of dietary cis-9-C18:1 and C18:3n-3.

    The effects of replacing grass silage by sainfoin silage in a TMR on milk production and FA in milk fat of the dairy cows in Chapter 2 is reported in Chapter 4. Milk yield reported in Chapter 4 was highest for the SAIN diet with every kg of OM digested of the SAIN diet resulting, on average, in 0.2 kg more milk production. The SAIN diet fed cows had a higher C18:3n-3 and cis-9,cis-12-C18:2 proportion in milk fat compared to the CON diet fed cows. A higher proportion of total trans-C18:1 was found in the cows fed the SAIN diet. There were no differences in proportion of total saturated and unsaturated FA in milk fat between the two diets. Our results showed that replacing grass silage by sainfoin silage improved milk yield and milk FA profile of dairy cows.

    Effects of the structural properties of CT, i.e. average polymer size (or mean degree of polymerization, mDP); percentage of cis flavan-3-ols (%cis) and percentage of prodelphinidins (%PD) in CT extracts on CH4 production and fermentation characteristics of rumen fluid using an in vitro gas production technique was investigated in Chapter 5. Extracts of CT from eight plants; black currant leaves, goat willow leaves, goat willow twigs, pine bark, red currant leaves, sainfoin plants, weeping willow catkins and white clover flowers were extracted, in order to obtain CT with a wide range in mDP, %PD and %cis. All CT extracts reduced CH4 concentration, decreased the maximum rate of fermentation for CH4 production and rate of substrate degradation. The correlation between CT structure on the one hand and CH4 production and fermentation characteristics on the other hand showed that the %PD within CT had the largest effect on fermentation characteristics, followed by mDP and %cis.

    Chapter 6 reports results of an in vitro study to investigate the effects of the structural properties CT (mDP, %cis and %PD) on rumen fermentation and BH end-products. The total volatile FA (VFA), ammonia concentration and the proportion of branched chain VFA was reduced in all CT extracts, compared to the control. The proportion of cis-9-C18:1; cis-9,cis-12-C18:2; cis-9,cis-12,cis-15-C18:3 were numerically higher in all CT sources, while the proportion of C18:0 and fractional rate of BH of C18:3n-3 were numerically lower in all CT sources, compared to the control. The correlation between CT structural properties on the one hand and fermentation and BH end-products on the other hand showed that the CT with a high %PD and smaller mDP had the largest effect on fermentation end-products. However, mDP was found to be the most important factor affecting rumen BH.

    Chapter 7 provides a general synthesis on the major findings of the studies presented in the preceding chapters. In addition, results are reported of a further in vitro as well as an in situ study in which I investigated the mechanisms of CT action in the rumen, in the post-rumen compartments and digestive tract. In the in situ study, fresh sainfoin (Esparcette) was incubated in the rumen and in the abomasum before digested during passage through the digestive tract. For the in vitro study, sainfoin (Ambra) was incubated with rumen fluid buffer for 1, 2, 4, 8, 12, 24 hours. After incubation in situ and in vitro, the incubated material was analyzed for tannin content by butanol-HCl assay. The results showed that the soluble CT dramatically reduced upon introduction in the digestive tract. Additional analyses showed that CT had bound to the fiber and protein (diet and microbes) fractions in the digestive tract.

    The present work showed that sainfoin silage can be used in dairy cow rations to improve milk production and N utilization and reduce CH4 emissions per kg DM intake. Moreover, sainfoin silage, when replacing part of the grass silage in a TMR of dairy cows, increases ruminal unsaturated FA flow into the reticulum and reduces ruminal BH of dietary cis-9-C18:1 and C18:3n-3. Cows fed sainfoin silage at the expense of grass silage in a TMR increase the proportion of unsaturated FA in milk fat. In terms of condensed tannin structure, mDP and %PD appear to be the most important properties of CT that affect fermentation and BH end-products. Condensed tannins with a mDP ranging from 5 to 10 monomeric units and a %PD > 70.0% seem to have the highest biological activity in the rumen.

    Handboek snijmaïs
    Schooten, H.A. van; Philipsen, A.P. ; Groten, J.A.M. - \ 2015
    Wageningen UR Livestock Research (Handboek / Wageningen UR Livestock Research 27) - 199
    voederkwaliteit - maïs - voedergewassen - maïskuilvoer - zea mays - rassen (planten) - rassenlijsten - teeltsystemen - teelt - plantenvoeding - bemesting - rentabiliteit - melkveehouderij - akkerbouw - forage quality - maize - fodder crops - maize silage - zea mays - varieties - descriptive list of varieties - cropping systems - cultivation - plant nutrition - fertilizer application - profitability - dairy farming - arable farming
    Na gras is snijmaïs het belangrijkste gewas voor de melkveehouderij. Dit handboek beschrijft de actuele stand van zaken over teelt, oogst, voeding en economie van snijmaïs.
    Het percentage regionaal eiwit in het Nederlands veevoerrantsoen : update voor 2014
    Cormont, A. ; Krimpen, M.M. van - \ 2015
    Milieudefensie - 14
    voedergewassen - diervoedering - streekgebonden producten - europese unie - eiwitten - nederland - duurzame veehouderij - fodder crops - animal feeding - regional specialty products - european union - proteins - netherlands - sustainable animal husbandry
    Milieudefensie heeft Alterra en Livestock Research, beide onderdeel van Wageningen University and Research centre, eerder gevraagd in meer detail het aandeel regionaal eiwit in het totale veevoergebruik in de Nederlandse veehouderij in beeld te brengen voor de jaren 2011 en 2013. Wij hebben destijds daarbij twee aspecten onderscheiden: het percentage regionaal geproduceerd eiwit in (1) het totale Nederlandse veevoer en (2) in het eiwitrijke veevoer met een ruw eiwitgehalte van meer dan 157 g/kg per grondstof. Voor 2014 hebben we het tweede aspect, het aandeel van regionaal geteeld eiwitrijk veevoer in het Nederlandse veevoerrantsoen, opnieuw onderzocht. Hierbij definiëren we ‘regionaal eiwit’ als die ingrediënten die het veevoerrantsoen van eiwit voorzien en die afkomstig zijn van gewassen die geteeld zijn in geografisch Europa.
    Handboek melkveehouderij 2015/16
    Remmelink, G.J. ; Middelkoop, J.C. van; Ouweltjes, W. ; Wemmenhove, H. - \ 2015
    Wageningen : Wageningen UR Livestock Research (Handboek / Wageningen UR Livestock Research 30) - 386
    melkvee - melkveehouderij - bodemeigenschappen - bemesting - graslandbeheer - voedergrassen - voedergewassen - rundveevoeding - dierveredeling - diergezondheid - melkproductie - landbouwbedrijfsgebouwen - nederland - handboeken - dairy cattle - dairy farming - soil properties - fertilizer application - grassland management - fodder grasses - fodder crops - cattle feeding - animal breeding - animal health - milk production - farm buildings - netherlands - handbooks
    Duurzaam bodembeheer maïs; projectresultaat 2014
    Riemens, M.M. ; Huiting, H.F. ; Deru, J.G.C. ; Schooten, H.A. van; Verloop, J. ; Weide, R.Y. van der - \ 2015
    Wageningen : Wageningen UR (PPO/PRI rapport 632) - 72
    akkerbouw - maïs - bodembeheer - veehouderij - voedergewassen - flevoland - nederland - teeltsystemen - duurzame landbouw - arable farming - maize - soil management - livestock farming - fodder crops - flevoland - netherlands - cropping systems - sustainable agriculture
    Hoe kunnen veetelers met minder input meer resultaten halen bij snijmaïsteelt? Dat is de centrale vraag van het project “Duurzaam bodembeheer maïs” (BO-31.03-001-003). Veel melkveehouderijbedrijven telen snijmaïs, een gemakkelijk te telen ruwvoergewas met een goede productie van constante hoge kwaliteit. Als zetmeelbron met een ruime energie/eiwitverhouding past het goed in het runderdieet, naast gras en graskuil. De maïsteelt kan echter nadelige effecten hebben voor de bodem door gewasbeschermingsmiddelen en het uit- en afspoelen van nutriënten. Wageningen UR en het Louis Bolk Instituut onderzoeken in opdracht van het ministerie van EZ duurzame en praktisch haalbare verbeteringen en vernieuwingen. Teeltsystemen die zorgen voor een gezonde bodem worden daarbij gezien als sleutel tot duurzame teelt. Op drie locaties worden diverse teeltsystemen vergeleken in meerjarige proeven uitgevoerd op zand- en kleigrond. Daarbij wordt onder andere gekeken naar opbrengst, onkruiddruk, bodemstructuur, aanwezigheid van regenwormen, indringingsweerstand, waterinfiltratie, stikstofdynamiek en economische aspecten. Deze kennis wordt vervolgens doorgegeven aan de praktijk middels o.a. de beslisboom snijmaïs, een instrument om praktische kennis naar veetelers en erfbezoekers te brengen.
    Aandachtspunten voor een betere ruwvoerteelt
    Verloop, J. ; Oenema, J. - \ 2015
    V-focus 12 (2015)3. - ISSN 1574-1575 - p. 38 - 39.
    melkveehouderij - voedergewassen - gewasteelt - ruwvoer (forage) - graskuilvoer - maïskuilvoer - bemesting - dairy farming - fodder crops - crop management - forage - grass silage - maize silage - fertilizer application
    Koeien & Kansen-deelnemers besteden in ‘Productieslag’ extra aandacht aan de teelt van gras en mais om een maximale productie te realiseren met de beschikbare meststoffen. Op elk bedrijf zoeken veehouders, samen met hun adviseurs en onderzoekers, naar punten waar verbeteringen mogelijk zijn.
    Fulfilling 100% organic poultry diets: concentrates : ICOPP Technical Note 1
    Crawley, K. ; Krimpen, M.M. van - \ 2015
    ICOPP Consortium
    pluimveehouderij - pluimveevoeding - biologische landbouw - eiwitbronnen - aminozuren - voedergewassen - poultry farming - poultry feeding - organic farming - protein sources - amino acids - fodder crops
    This guide analyses the potential of locally produced and novel protein sources as viable, alternative feed sources for the organic poultry industry.
    Ruimtelijke optimalisatie van voederstromen in de Peel : nieuwe landgebruiksvormen en clustering ten behoeve van regionale productie van veevoer
    Walsum, P.E.V. van; Galama, P.J. ; Roelsma, J. ; Cormont, A. ; Hack-ten Broeke, M.J.D. - \ 2014
    Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2615) - 49
    melkveehouderij - milieueffect - krachtvoeding - rundveevoeding - voedergewassen - duurzaamheid (sustainability) - ruimtelijke verdeling - nutriëntenuitspoeling - duurzaam bodemgebruik - regionaal landbouwbeleid - veevoederindustrie - de peel - dairy farming - environmental impact - force feeding - cattle feeding - fodder crops - sustainability - spatial distribution - nutrient leaching - sustainable land use - regional agricultural policy - feed industry - de peel
    In een eerdere studie werd verkend in hoeverre het economische en milieutechnisch haalbaar zou zijn om in regio De Peel krachtvoervervangers regionaal te verbouwen. In de in dit rapport beschreven studie stelden we ons de vraag of ruimtelijke optimalisatie wel tot milieuwinst zou kunnen leiden en vervolgens hoe regionale voercentra kunnen bijdragen en op welke locatie deze zouden moeten liggen.
    Mengteelten graan met erwten of veldbonen
    Beeckman, A. ; Govaerts, W. - \ 2014
    Biokennis bericht Dierlijke sectoren (2014)1. - 4 p.
    gemengde teelt - graansoorten - erwten - tuinbonen - voedergewassen - eiwitleverende planten - peulvruchten - biologische landbouw - rassenkeuze (gewassen) - mixed cropping - cereals - peas - faba beans - fodder crops - protein plants - grain legumes - organic farming - choice of varieties
    Door de stijgende krachtvoederprijzen – voornamelijk bij de eiwitrijke componenten – stijgt de interesse in eiwitteelten van eigen bodem. De teelt van peulvruchten zoals lupinen, erwten en veldbonen in monocultuur blijft echter een risicovolle onderneming. De voorbije jaren werd zowel in Vlaanderen als in Nederland ruime ervaring opgedaan met mengteelten. Hieronder een aantal praktische wenken gebaseerd op de ervaring en proefresultaten van voorbije jaren.
    Handboek snijmaïs
    Schooten, H.A. van; Philipsen, A.P. ; Groten, J.A.M. - \ 2014
    Lelystad : Wageningen UR Livestock Research (Handboek / Wageningen UR Livestock Research 27) - 198
    maïs - handboeken - grondbewerking - bemesting - rassenkeuze (gewassen) - zaaien - onkruidbestrijding - plantenplagen - gewasopbrengst - diervoeding - agrarische economie - melkveehouderij - voedergewassen - akkerbouw - teelthandleidingen - maïskuilvoer - zea mays - maize - handbooks - tillage - fertilizer application - choice of varieties - sowing - weed control - plant pests - crop yield - animal nutrition - agricultural economics - dairy farming - fodder crops - arable farming - cultivation manuals - maize silage - zea mays
    Na gras is snijmaïs het belangrijkste gewas voor de melkveehouderij. Een optimale teelt en benutting van dit gewas zijn daarmee van belang voor het rendement van de sector. Een actueel en compleet overzicht van de nieuwste informatie kan daar een belangrijke bijdrage aan leveren. De nieuwe informatie en ontwikkelingen over teelt en gebruik van maïs komen vaak nogal versnipperd en soms beperkt bij de melkveehouders. Dit heeft tot gevolg dat het lastig is voor de gebruiker om de juiste informatie te vinden. Dit handboek beschrijft de actuele stand van zaken over teelt, oogst, voeding en economie van snijmaïs. Jaarlijks wordt het handboek geactualiseerd met de nieuwste informatie.
    Nieuwe maisrassen voor hogere opbrengst
    Groten, J.A.M. - \ 2014
    Boerderij 100 (2014)12. - ISSN 0006-5617 - p. R32 - R34.
    maïs - rassen (planten) - rassenlijsten - opbrengsten - rassenproeven - voedergewassen - rundveehouderij - maize - varieties - descriptive list of varieties - yields - variety trials - fodder crops - cattle husbandry
    CSAR en DLV Plant publiceren rassenlijsten met nieuwe maisrassen. Uit beide lijsten blijkt dat kwekers de nadruk leggen op hoge opbrengsten.
    Minder onkruiddruk van ongebruikte percelen
    Dalfsen, Pieter van - \ 2014
    biomass production - fibre plants - fuel crops - fodder crops - economic viability - weed control - biobased economy
    Praktijknetwerk: soja van eigen bodem
    Timmer, R.D. - \ 2014
    akkerbouw - veldgewassen - sojabonen - peulvruchten - teeltsystemen - voedergewassen - voederpeulvruchten - arable farming - field crops - soyabeans - grain legumes - cropping systems - fodder crops - fodder legumes
    De Europese consument is niet happig op genetisch gemodificeerde soja, of sojabonen uit voormalige regenwouden. Maar een groeiende groep pioniers laat zien dat de teelt van soja ook in Nederland mogelijk is. ‘Behalve naar nóg meer pioniers, zijn we nu vooral op zoek naar nieuwe rassen die meer opbrengen en eerder afrijpen’, zegt ing. Ruud Timmer, onderzoeker bij Wageningen UR in Lelystad.
    Soja van eigen bodem is kansrijk
    Timmer, Ruud ; Sikkema, Albert - \ 2014
    arable farming - soyabeans - varieties - temperate crops - variety trials - soil types - fodder crops - netherlands
    Genetics and bioenergy potential of forage maize: deconstructing the cell wall
    Torres, A.F. - \ 2014
    Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Luisa Trindade; Oene Dolstra. - Wageningen : Wageningen University - ISBN 9789462570375 - 202
    zea mays - maïs - voedergewassen - plantengenetica - bio-energie - celwanden - bioethanol - bioconversie - industriële grondstoffen - brandstofgewassen - zea mays - maize - fodder crops - plant genetics - bioenergy - cell walls - bioethanol - bioconversion - feedstocks - fuel crops

    Despite gaining prominence in scientific spheres and political agendas worldwide, the production of biofuels from plant biomass is yet to achieve an economic stronghold in the renewable-energy sector. Plant lignocellulose has evolved to resist chemical and enzymatic deconstruction, and its conversion into liquid fuels requires energetically stringent processes that currently render the industry economically and environmentally unviable.

    To address this challenge, experts have envisioned the development of advanced bioenergy crops which require lower energetic and chemical inputs for their effective fractionation. At its core, this approach requires an in-depth understanding of the composition, synthesis and breeding amenability of the plant cell wall; the principal constituent of total plant dry biomass and the most recalcitrant fraction of the crop at physiological maturity to deconstruction. To this end, the primary aim of this thesis was to dissect and elucidate the biochemical and genetic factors controlling cell wall characteristics relevant to the development of bioenergy grasses with improved processing quality for cellulosic based fuel production. A focus on maize was warranted as it currently represents the de facto model system for bioenergy crop research; offering an unrivalled platform to underpin the complex genetic architecture of cell wall biosynthesis, develop advanced bioenergy-crop breeding strategies and translate cell wall research into innovations and commercial products.

    This thesis exposed that the biomass-to-fuel conversion of crops is a highly complex trait dependent on both, the balance and synergy between multiple cell wall components, and the inherent effectiveness of the conversion technology. Concerning the production of cellulosic ethanol via the combined operations of dilute-acid pretreatment and enzymatic saccharification, our results revealed that the chemical mechanisms affecting biomass conversion efficiency depend on pretreatment severity. Whereas at harsh pretreatments biomass conversion efficiency was primarily influenced by the inherent efficacy of thermochemical cell wall deconstruction, at milder pretreatments, maximum fermentable glucose release was observed for maize genotypes exhibiting systematic cell wall changes leading to higher ruminal cell wall digestibility. These results confirmed that the selection and use of cellulosic feedstocks that best match the processing conditions used in the industry can aid in reaching industrial goals aimed at improving the commercial and environmental performance of cellulosic fuels.

    In turn, the exhaustive characterization of a forage maize doubled haploid (DH) population demonstrated the vast degree of genetic diversity in maize cell wall composition and bioconversion potential amenable to breeding. Principally, these findings suggest that natural diversity in the biochemical composition of the maize cell wall and its physical properties is primarily ascribed to variation in the balance, monomeric make-up, and extent of cross-linking of non-cellulosic cell wall polymers (i.e. lignin and hemicellulose). Indeed, correlation analyses confirmed that the extent of enzymatic depolymerization of maize biomass was strongly and negatively associated to the concentration of cell wall phenolics, but positively impacted by the degree of glucuronoarabinoxylan (GAX) glycosylation and extent of hemicellulose-to-hemicellulose cross-linking. Our results also showed that natural variation in cell wall content and composition is quantitatively inherited and putatively ascribed to the segregation of multiple genetic loci with minor additive effects. In our population, genotypic diversity for cell wall composition and quality was found to be controlled by 52 quantitative trait loci (QTLs). From eight QTLs regulating bioconversion properties, five were previously unidentified and warrant further investigation.

    Despite the apparent complexity of cell wall genetics, however, the high heritability and environmentally stability of cell wall compositional and degradability properties guarantee high selection efficacy during the development of superior DH/inbred material, and predispose that multi-environment testing will only be necessary at advanced stages of bioenergy-maize breeding programs. Moreover, because genetic variation for complex cell wall characteristics appears to be predominantly additive, preliminary selection at the inbred level will expectedly lead to successful hybrid selection; thereby minimizing the need for recurrent test-crossing procedures and evaluations. In this regard, maize cell wall bioconversion efficiency constitutes an excellent selection criterion for immediate application in modern maize breeding programs.

    Ultimately, the convergence of classical selection schemes with inexpensive genotyping, advanced biometric models, high-throughput cell wall phenotyping and doubled haploid (DH) production technologies can accelerate development and commercial release of maize cultivars for bioenergy applications. To play a determinant role in the development and realization of sustainable and cost-effective cellulosic fuel processing technologies, however, novel dual-purpose maize cultivars (i.e. delivering both, grain for feed or food and fiber materials for bioconversion) will have to surpass the performance in lignocellulose processing quality and biomass yields of the best elite germplasm. These prospects seem realistic as the parallel advance of grain yield and stover productivity and quality characteristics is a feasible undertaking. Conceptually, the advance of superior bioenergy cultivars (surpassing the performance of modern elite material) would allow us to make the currently available biomass-to-fuel conversion systems more cost-effective and sustainable, and may also have favorable consequences for the ideal size and geographical distribution of biofuel refineries.

    Maisteelt kent grote en kleine zorgen
    Have, H. ten; Kroonen-Backbier, B.M.A. - \ 2014
    V-focus 11 (2014)2. - ISSN 1574-1575 - p. 34 - 35.
    melkveehouderij - zea mays - voedergewassen - bemesting - mestbeleid - groenbemesters - ondergewassen - nitraten - uitspoelen - herbiciden - dairy farming - zea mays - fodder crops - fertilizer application - manure policy - green manures - catch crops - nitrates - leaching - herbicides
    De maisteelt in Nederland kent grote en kleine zorgen. Dat zei Brigitte Kroonen van Praktijkonderzoek Plant & Omgeving (PPO) van Wageningen UR op de themadag ‘Van Beslisboom Snijmais naar een Ruwvoerplatform’ in Hengelo, Gelderland. Eén van de grote zorgen is de mestwetgeving: bemesting van mais op zand- en lössgrond in Zuid(oost)-Nederland wordt lastig.
    Hoving, Idse - \ 2013
    precision agriculture - arable farming - humidity gauges - sensors - roots - crop growth stage - pf-curve - overhead irrigation - irrigation - costs - fodder crops - cost benefit analysis
    Handboek snijmaïs
    Schooten, H.A. van; Philipsen, A.P. ; Groten, J.A.M. - \ 2013
    Lelystad : Wageningen UR Livestock Research (Handboek / Wageningen UR Livestock Research 27) - 196
    melkveehouderij - zea mays - maïs - maïskuilvoer - teelthandleidingen - voedergewassen - akkerbouw - handboeken - onkruidbestrijding - plantenziekten - plantenplagen - gewasbescherming - dairy farming - zea mays - maize - maize silage - cultivation manuals - fodder crops - arable farming - handbooks - weed control - plant diseases - plant pests - plant protection
    Na gras is snijmaïs het belangrijkste gewas voor de melkveehouderij. Dit handboek beschrijft de actuele stand van zaken over teelt, oogst, voeding en economie van snijmaïs.
    Groene veredeling : lupineveredeling voor kalkrijke bodems: onderzoek naar perspectiefvolle lijnen
    Scholten, O.E. ; Lammerts Van Bueren, E. - \ 2013
    lupinus - lupinen - plantenveredeling - biologische plantenveredeling - kalkrijke gronden - eiwitleverende planten - voedergewassen - akkerbouw - lupinus - lupins - plant breeding - organic plant breeding - calcareous soils - protein plants - fodder crops - arable farming
    Brochure met onderzoeksinformatie. Het doel van dit project is een evaluatie van lijnen van witte lupine op hun geschiktheid voor teelt op kalkrijke kleigrond om te beoordelen of er perspectief is voor verdere veredeling voor zowel gangbare als biologische teelt.
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