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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.

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    Fungal treatment of lignocellulosic biomass
    Kuijk, S.J.A. van - \ 2016
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): John Cone; Anton Sonnenberg. - Wageningen : Wageningen University - ISBN 9789462576544 - 191
    lignocellulosic wastes - fungi - treatment - ruminant feeding - rumen digestion - wheat straw - wood chips - livestock feeding - nutrition physiology - animal nutrition - lignocellulosehoudend afval - schimmels - behandeling - herkauwersvoeding - pensvertering - tarwestro - houtspaanders - veevoeding - voedingsfysiologie - diervoeding

    Summary PhD thesis Sandra J.A. van Kuijk

    Carbohydrates in plant cell walls are highly fermentable and could be used as a source for ruminant nutrition or biofuel production. The presence of lignin in cell walls hampers the utilization of these carbohydrates and should thus be removed. In this thesis, the possibilities of a fungal treatment of lignocellulosic biomass are investigated.

    A review of the scientific literature focusing on the potential of fungal treatments to increase the utilization of lignocellulosic biomass in ruminants feed ingredients is presented in Chapter 2. A prerequisite to the effective use of high lignocellulose feed ingredients is lignin removal, since lignin is negatively correlated to in vitro rumen degradability. Selective lignin degrading fungi have proven to increase in vitro rumen degradability with Ceriporiopsis subvermispora and Pleurotus eryngii showing the greatest potential. The effectiveness of fungal treatment is not only dependent on the choice of fungal strain, but also on the choice of substrate and culture conditions.

    Based on the literature review, four different edible fungal species, i.e. Ganoderma lucidum, Lentinula edodes, P. eryngii and P. ostreatus were chosen to treat four different substrates, i.e. miscanthus, rice straw, wheat straw and wood chips. The results of these fungal-substrate combinations are described in Chapter 3 and confirm that fungal species, substrate and incubation time are important factors in fungal treatment. The most promising fungus-substrate combinations are L. edodes treatment of wheat straw and L. edodes treatment of wood chips. These two fungus-substrate combinations were used in a more detailed characterization of changes in lignin upon fungal treatment.

    In Chapter 4, a study is described where L. edodes treated wheat straw and wood chips are analyzed by pyrolysis coupled to gas chromatography and mass spectrometry (Py-GC/MS) confirming the selective lignin degradation as determined with the detergent fiber analysis. Structural changes in lignin were observed with preferential degradation of syringyl (S) lignin units over guaiacyl (G) lignin units by L. edodes. Upon fungal delignification, a number of degradation products of lignin were observed. The building blocks in the original lignin consist of phenolic groups with 3 C-atoms in the side chain, while degradation products consist of phenolic groups with 0 to 2 C-atoms in the side chain. The ratio between side chain degradation products and original compounds was increasing in both wheat straw and wood chips upon L. edodes treatment. Besides side chain degradation, L. edodes modified the Cα-atom of the side chain by oxidation. Although correlations were found, a clear relationship between lignin composition and in vitro rumen degradability could not be demonstrated.

    The safety of a fungal treatment of ruminant feed ingredients requires the used fungus to have a Generally Regarded As Safe (GRAS) status. The literature data compiled in Chapter 2 indicates C. subvermispora, which does not have a GRAS status, as one of the most promising fungi for fungal treatment. For this reason this fungus was included in the remaining chapters. This fungus was researched in Chapter 5 with the substrates wheat straw and wood chips and compared to L. edodes. Both fungi selectively degraded lignin and improved in vitro rumen degradability and the amount of sugar released upon enzymatic saccharification. L. edodes continuously grew on wheat straw and wood chips while degrading lignin and hemicellulose at the same time. C. subvermispora colonized the wheat straw within the first week of treatment and starts degrading lignin and hemicellulose thereafter. Growth continued again after 5 weeks, which was accompanied by cellulose degradation. On wood chips, C. subvermispora stopped growing after the first week of treatment, while lignin degradation continued until 4 weeks of treatment. From 5 weeks onwards, no chemical changes were observed in wood chips. One of the explanations for this lack of change is the dense structure of the wood as observed with light microscopy. Both fungi degraded hemicellulose simultaneously with lignin. The loss of carbohydrates during fungal treatment and the long treatment times of up to 8 weeks represent a major disadvantage of fungal treatment of lignocellulosic biomass.

    In Chapter 6, the incubation of C. subvermispora and L. edodes with wheat straw and wood chips were supplemented with urea to stimulate growth, and manganese and linoleic acid to stimulate lignin degradation via the enzyme manganese peroxidase produced by the fungi. Addition of manganese increased the selectivity of C. subvermispora treatment of wheat straw within the first 4 weeks of treatment. Addition of 150 µg manganese per g substrate improved lignin degradation and in vitro rumen degradability the most. A combination of manganese and linoleic acid did not show synergistic effects.

    In Chapter 7 the particle size of wheat straw and wood chips, and the amount of C. subvermispora or L. edodes at the start of the treatment was varied. The amount of fungus added at the start of the treatment did not have an effect on colonization rate, lignin degradation or in vitro rumen degradability. L. edodes treatment of wheat straw chopped to 2 cm particles resulted in a higher lignin degradation and in vitro rumen degradability compared to L. edodes treatment of wheat straw chopped to a length of 0.5 cm. The particle size of wood chips did not have an effect on C. subvermispora treatment. In C. subvermispora treated wheat straw and L. edodes treated wood chips, a reduced growth was observed, which was unexpected based on results from previous experiments. A toxic compound to fungi (fungicide) was identified.

    This thesis describes the potential of fungal treatment to increase utilization of lignocellulosic biomass. Fungal treatment resulted in an increased in vitro rumen degradability, and thus an increased cellulose accessibility. The same theory applies for biofuel production in which fungal treatment results in an increased accessibility of cellulose for enzymes. The major disadvantages of this low cost, relatively simple and environmentally-friendly biotechnological treatment are the loss of carbohydrates during the relatively long process of fungal incubation. Future studies should focus on optimization of the fungal treatment to enable large scale application.

    Voederbomen in trek
    Eekeren, N.J.M. van; Luske, B.L. ; Vonk, M. ; Anssems, E. - \ 2015
    V-focus 12 (2015)1. - ISSN 1574-1575 - p. 38 - 39.
    melkveehouderij - geitenhouderij - schapenhouderij - melkveevoeding - geitenvoeding - schapenvoeding - bomen als veevoer - herkauwersvoeding - mineralenopname - sporenelementen - dairy farming - goat keeping - sheep farming - dairy cattle nutrition - goat feeding - sheep feeding - fodder trees - ruminant feeding - mineral uptake - trace elements
    Bladeren en twijgen van bomen en struiken hebben potentie in het rantsoen van koeien, geiten en schapen, omdat ze een aanvullende bron zijn van eiwit, mineralen en sporenelementen. Daarnaast bevatten veel bomen secundaire plantenstoffen die een positief effect kunnen hebben op de vertering en de gezondheid van herkauwers. In het Praktijknetwerk Voederbomen en Functioneel Landgebruik (www.voederbomen.nl) is de inpasbaarheid van voederbomen op melkveebedrijven getest.
    Grain filling, starch degradation and feeding value of maize for ruminants
    Ali, M. - \ 2013
    Wageningen University. Promotor(en): Paul Struik; Wouter Hendriks, co-promotor(en): John Cone. - Wageningen : Wageningen UR - ISBN 9789461738196 - 177
    maïs - zea mays - groeifasen, rijp - genotypen - zetmeelvertering - pensvertering - voedingswaarde - herkauwersvoeding - korrels (granen) - maïskuilvoer - kuilvoerbereiding - gewasfysiologie - voedingsfysiologie - maize - zea mays - maturity stage - genotypes - starch digestion - rumen digestion - nutritive value - ruminant feeding - kernels - maize silage - silage making - crop physiology - nutrition physiology

    Keywords; Maize (Zea mays L), Genotypes, Grain filling, Growth temperature, Kernels, Gas production, Starch degradation, Oven-drying, Silage, Ensiling temperature, Ensiling duration, Feeding value, Lactating cows

    Maize (Zea mays L.) is a major component in the ration of dairy cows in many parts of the world. The currently increasing economic importance of maize has highlighted the need to determine its nutritional value, and to assess the factors influencing its nutritive value. Genotypic make-up (especially differences in starch and endosperm), growing conditions, maturity stage at harvest, and post handling processes, like oven-drying, can influence nutritive value of maize kernels. Similarly, ensiling temperature and duration can affect feeding value of maize silage. This thesis is divided into three parts; the first aim was to characterize the dry matter (starch) accumulation of maize different genotypes in different environments under controlled (glasshouse) and on different locations (sand and clay) in field conditions. Maize genotypes used were different in starch structure and composition, and in type of endosperm. Starch structure refers to amylose and amylopectin; and composition refers to their proportions, whereas type of endosperm defines levels of vitreousness. The vitreousness is the ratio of vitreous (hard) to floury (soft) endosperm. Six maize genotypes, differing in amylose content and vitreousness, were grown under three contrasting day/night temperature regimes during grain filling and harvested at different maturity stages from two greenhouse experiments. Similar investigations were carried on another set of genotypes grown on sandy and clay soils and with different sowing times under field conditions. Water contents and dry matter (starch) accumulation were significantly influenced by growth temperature, genotype, soil type and sowing time (P<0.0001). The second aim of thesis was to establish a relationship between rumen in vitro starch degradation (feeding value) of maize kernels and different factors, like genotype, growth temperature during grain filling, and maturity stage. Oven-dried kernels of six maize genotypes, from the two greenhouse experiments mentioned before were investigated. Starch content was measured using an enzymatic method and the gas production technique was used to assess starch degradation in rumen fluid of dairy cows. The extent of starch degradation at different incubation times was calculated from measured gas production data (6, 12 and 20 h, respectively) and a published equation. At each maturity stage, whole kernel and starch degradation in rumen fluid depended on the genotype (P<0.0001), growing conditions (P<0.0001), starch content (P<0.0001) and starch amount (P<0.0001) in the kernels. The same but fresh (not oven-dried) maize kernel samples were investigated using gas production technique to determine the impact of oven-drying on rumen in vitro starch degradation of maize kernels. Oven-drying significantly (P<0.0001) influenced the rumen in vitro starch degradation in maize kernels various incubation times, with more starch being degraded in the fresh than in the oven-dried maize kernels, although the differences were small. There was a consistent and highly significant (P<0.009 to 0.0002) interaction between oven-drying and genotype, with the high-amylose genotype showing larger effects of oven-drying than the other genotypes. The third aim of thesis was to investigate effect of ensiling temperature and duration on feeding value of maize silage. Samples of maize whole plants (dry matter 33%) were collected from the medium vitreous endosperm cultivar, grown in different seasons on sandy soils. Maize plants were chopped and ensiled in mini silos at three different temperatures. Samples from the silos were taken after 0 (not ensiled, i.e. control), 4, 8 and 16 weeks of ensiling. The gas production technique was used to evaluate the influence of the ensiling temperature and duration of ensiling on the degradation of the fresh ground silage samples in rumen fluid. The final pH of the silages and the gas production was significantly influenced by ensiling temperature in both seasons (P<0.0001). Gas production and pH decreased with an increase in ensiling duration (P<0.0001). The relationship between pH and gas production was quadratic and depended on the ensiling temperature (P<0.002). It was found that ensiling temperature and ensiling duration determine the rate of change and final pH, and play a significant role in feeding value of maize silage. The finding of thesis can be used to determine the exact feeding value of maize kernels and silage, and also can be used as a tool to revise the current feeding evaluation systems i.e. shift from oven-dried to fresh samples.

    Nitraat voeren effectief tegen methaanemissie
    Vegte, D.Z. van der; Sebek, L.B. ; Hilhorst, G.J. ; Verloop, K. - \ 2013
    V-focus 10 (2013)4. - ISSN 1574-1575 - p. 30 - 31.
    melkveehouderij - herkauwersvoeding - melkveevoeding - nitraat - voersamenstelling - voedertoevoegingen - methaan - emissiereductie - mineralenboekhouding - dairy farming - ruminant feeding - dairy cattle nutrition - nitrate - feed formulation - feed additives - methane - emission reduction - nutrient accounting system
    Nitraat is niet alleen een waardevolle kunstmest, maar kan ook als voeradditief gebruikt worden om de methaanemissie uit de pens van herkauwers te verminderen. Voor een klimaatneutrale melkveehouderij kan het een belangrijk middel zijn om de doelstelling te verwezenlijken. Daarom heeft Knowledge Transfer Centre De Marke in een pilotexperiment onderzocht of het voeren van nitraat past in het management van het melkveebedrijf en of er risico’s voor de diergezondheid zijn. Ook is onderzocht wat het effect van deze extra stikstofbron is op de N-kringloop van het bedrijf. Als de vermindering van de methaanemissie gepaard gaat met meer verliezen uit de N-kringloop (nitraatuitspoeling, ammoniakemissie en lachgasemissie) dan is het middel misschien erger dan de kwaal.
    En de koe boert voort
    Dijkstra, J. - \ 2011
    WageningenWorld 3 (2011). - ISSN 2210-7908 - p. 34 - 39.
    methaan - emissie - melkproductie - broeikasgassen - rundveehouderij - herkauwersvoeding - methane - emission - milk production - greenhouse gases - cattle husbandry - ruminant feeding
    Tientallen landen werken samen om de bijdrage van de landbouw aan het broeikaseffect te verminderen. Zo is er veel winst te boeken, vooral in de Derde Wereld, door herkauwers regelmatig goed voer voor te zetten. Ook de boer heeft daar baat bij.
    Eiwitwaardering voor herkauwers; het DVE-OEB 2007 systeem
    Tamminga, S. ; Brandsma, G.G. ; Duinkerken, G. van; Vuuren, A.M. van; Blok, M.C. - \ 2007
    Wageningen : Wageningen University (CVB-documentatierapport nr. 52) - 62
    herkauwers - eiwitten - voederwaardering - eiwitverteerbaarheid - eiwitwaarde - eiwitbalans - pensvertering - herkauwersvoeding - diervoeding - ruminants - proteins - feed evaluation - protein digestibility - protein value - protein balance - rumen digestion - ruminant feeding - animal nutrition
    Protein evaluation for ruminants : the DVE/OEB 2007-system
    Tamminga, S. ; Brandsma, G.G. ; Duinkerken, G. van; Vuuren, A.M. van; Blok, M.C. - \ 2007
    Wageningen : Wageningen University (CVB-documentation report no. 53) - 58
    herkauwers - eiwitten - voederwaardering - eiwitverteerbaarheid - eiwitbalans - eiwitwaarde - pensvertering - herkauwersvoeding - diervoeding - ruminants - proteins - feed evaluation - protein digestibility - protein balance - protein value - rumen digestion - ruminant feeding - animal nutrition
    Background of the copper and zinc requirement for dairy cattle, growing-finishing pigs and broilers
    Jongbloed, A.W. ; Kemme, P.A. ; Top, A.M. van den - \ 2004
    Wageningen : Animal Sciences Group (Report / Animal Sciences Group 04-000635) - 57
    veevoeding - spijsvertering - voedingswaarde - chemische samenstelling - voedingsstoffenbehoeften - varkensvoeding - herkauwersvoeding - koper - zink - livestock feeding - digestion - nutritive value - chemical composition - nutrient requirements - pig feeding - ruminant feeding - copper - zinc
    Re-evaluation of the current authorized levels of Cu and Zn in animal rations has been initiated by the European Union (EU). The physiological requirements should be the basis for the future maximum authorized dietary levels for minerals in the EU, resulting in lowering of these maximum levels. Based on an earlier study, the basis of the recommendations for Cu and Zn of dairy cattle, growing pigs, and broilers as used by different countries seemed to be questionable. These recommendations are based on research at relatively low animal production levels as compared with the current Dutch situation. Therefore, a survey of the scientific literature underlying the recommendations of ARC, NRC, DLG, COMV, and INRA was carried out, together with other reports on dietary Cu or Zn requirements of the animal categories mentioned
    The potential of improving napier grass under smallholder farmers' conditions in Kenya
    Kariuki, J.N. - \ 1998
    Agricultural University. Promotor(en): S. Tamminga; C.K. Gachuiri; G.K. Gitau. - Naivasha : Kariuki - ISBN 9789054859642 - 197
    melkvee - pennisetum purpureum - melkveehouderij - gemengde landbouw - herkauwersvoeding - voedingsstoffenverbetering - voedingswaarde - voedersupplementen - voeropname - verteerbaarheid - groeitempo - vaarzen - kenya - dairy cattle - pennisetum purpureum - dairy farming - mixed farming - ruminant feeding - nutrient improvement - nutritive value - feed supplements - feed intake - digestibility - growth rate - heifers - kenya

    Dairy farming is the main livestock enterprise in the mixed crop/livestock farming system in the high rainfall areas of Kenya. These areas are characterised by a high human population density and very small farms. As a consequence, napier grass ( Pennisetum purpureum ) has been widely adopted because of its relatively high dry matter yield and suitability as a cut fodder. The conventional methods of improving napier grass quality through fertilization or use of concentrates to supplement napier grass diets is limited because most farmers cannot afford these inputs. This has led to poor animal performance mostly attributed to the low protein content in napier grass.

    The most vulnerable group are heifers which receive far less attention compared to calves and cows. This is reflected by low weight gain (less than 0.25 kg day -1) and poor reproductive and life-time performance. Fortunately, several protein-rich forages (PRF) which have the potential to improve the quality of napier grass-based diets have been identified. These include Desmodium spp., Calliandra calothyrsus, Leucaena leucocephala, Ipomoea batatas, Medicago sativa, Musa sapienta, Trifolium semipilosum and Canna edulis .

    The benefits of using PRF include improved rumen function, increased energy and protein intake, improved feed efficiency, increased availability of minerals and vitamins, and generally enhanced animal performance. Appropriate and adequate information on the nutritive value of napier grass at different stages of growth and the PRF would facilitate ration formulation, allow more reliable prediction of subsequent animal performance and assist in the planning of suitable feeding strategies for the resource poor dairy farmers. Therefore, the overall objective of the study was to evaluate the nutritive value of napier grass and determine the potential for improvement in animal performance using PRF. Results from this thesis indicated that intake and utilization can be improved by manipulating the cutting regime of napier grass and varying the levels of PRF supplements.

    Indeed, PRF had a profound effect on fermentation and subsequently improved the intake of organic matter fermented in the rumen by up to 50%. Protein supplementation strategies for low crude protein tropical grasses should first target at optimising microbial protein production and then consider supplements containing a combination of ruminally degradable and bypass protein for high animal performance. Inadequately fed heifers grow poorly and show poor reproductive performance. The positive growth response obtained from the supplemented heifers were attributed to additional rumen degradable protein and/or bypass protein from PRF that overcame protein deficiency in napier grass.

    It was concluded that PRF could play an important role in the improvement of the utilization of napier grass and the subsequent animal performance. The data provided in this study, on the nutritive value of these forages will, consequently, facilitate making appropriate choices for diet formulation at the farm level.

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