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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.

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    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

    SUMMARY

    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.

    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.

    What happens in the bag? : development and evaluation of a modified in situ protocol to estimate degradation of nitrogen and starch in the rumen
    Jonge, L.H. de - \ 2015
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Jan Dijkstra; H. van Laar. - Wageningen : Wageningen University - ISBN 9789462574519 - 175
    herkauwers - pensfermentatie - stikstof - zetmeelvertering - pensvertering - protocollen - evaluatie - methodologie - schatting - voedingsfysiologie - ruminants - rumen fermentation - nitrogen - starch digestion - rumen digestion - protocols - evaluation - methodology - estimation - nutrition physiology

    The most widely used method to estimate the rumen degradation of dietary components in feedstuffs is the in situ or in sacco method. This method is based on rumen incubation of substrate (feed) in nylon or dacron bags followed by rinsing and analysis of the residue. Small pores in the bag allow microbes to enter the bag whilst a variable portion of the feed is retained in the bag. The results are used to estimate the ruminal effective degradation (ED) that is used in several protein evaluation systems. The weaknesses of the in situ method are its low precision, the lack of standardization, and its inaccuracy. The accuracy can be divided in a bias with respect to the in situ method itself, and the difference between the in situ and in vivo degradation. The bias of the in situ method itself is related to several assumptions regarding the size and degradation rate of the washable fraction, secondary particle loss, and microbial contamination. The aim of this thesis was to examine possibilities to reduce this bias by modification of the in situ methodology.

    The bias related to the assumptions regarding the washout fraction was successfully reduced by developing and using a modified rinsing method that involves less vigorously shaking conditions and a solvent which mimics the rumen pH and osmolality. This modified rinsing method markedly reduced the soluble (S) fraction of N, especially for legume seeds, and the non-soluble washout (W-S) fraction, especially for starch, compared to the conventional method. Consequently, the estimation of the ED became less dependent on the assumptions regarding the degradation of the S and W-S fraction. In vitro results did not support the assumption of a much faster degradation of the W-S fraction of starch than that of the non-washout fraction of starch. The modified rinsing method also allowed measuring the in situ degradation of products that contain mainly small particles such as wheat yeast concentrates.

    The bias related to the breakdown of particles was also successfully reduced by development and application of a combination of the modified rinsing method and an in vitro method that simulates particulate matter loss during incubation. This in vitro method was based on in situ results obtained with an inert marker (i.e., silica gel) which showed that particulate matter loss during incubation was moderate and limited to particles smaller than approximately 40 μm. Correction for these losses decreased the estimated ED of feed ingredients used. This study also showed that the fractional degradation rate of starch in grains was strongly affected by the process of secondary particulate loss when using the conventional method, and applying the modified rinsing method markedly reduced the error due to secondary particulate loss.

    In comparison to the conventional method, the modified method resulted in an increase of the bias related to microbial contamination of the residues. The ratio between diaminopimelic acid (DAPA), a marker for bacterial protein, and N in the residues was higher when using the modified method than that in the conventional method. The results obtained for the modified method also indicated lysis of bacterial cells during rinsing. This bias led to a lower ED when using the modified method with the impact greatly depending on the degree of lysis of bacterial cells.

    In summary, the modified method increased the non-washout fraction of N and starch of various feed ingredients, which offers the possibility to use it for a larger range of feed ingredients, and reduced the bias related to assumptions on the washout fraction and the breakdown of particles compared to the conventional method. On the other hand, the modified method increased the bias related to microbial contamination and enlarged the difference between the in situ and in vivo degradation.

    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.

    Methaanuitstoot spiegel van rantsoen : lager eiwitgehalte in gras door huidig mestbeleid geeft meer methaanuitstoot
    Bannink, A. ; Dijkstra, J. - \ 2012
    Veeteelt 29 (2012)11. - ISSN 0168-7565 - p. 12 - 14.
    melkveehouderij - melkkoeien - pensvertering - methaan - emissie - darmgas - melkveevoeding - graslandbeheer - luchtkwaliteit - dairy farming - dairy cows - rumen digestion - methane - emission - flatus - dairy cattle nutrition - grassland management - air quality
    De uitstoot van methaangas door een koe is een afspiegeling van haar voedselvertering. Wageningen UR onderzoekt het effect van rantsoenaanpassingen. Het levert een aantal concrete handvatten voor het terugdringen van de methaanuitstoot.
    Gezondere koe en varken door genomics
    Veerkamp, R.F. - \ 2011
    Kennis Online 2011 (2011)14 juni. - p. 7 - 7.
    rundveehouderij - dierveredeling - functionele genomica - eigenschappen - pensvertering - efficiëntie - rundveevoeding - cattle husbandry - animal breeding - functional genomics - properties - rumen digestion - efficiency - cattle feeding
    Nederlandse fokbedrijven hebben zo’n twintig procent van de agrarische wereldmarkt voor genetisch materiaal veroverd. Als het genomicsproject Genome Wide Breeding slaagt, dan blijft dat zo en wordt de veehouderij tegelijkertijd wat diervriendelijker, schoner en efficiënter.
    pH pensinhoud interessante variabele
    Klop, A. - \ 2010
    V-focus 7 (2010)6. - ISSN 1574-1575 - p. 18 - 19.
    rundveehouderij - pens - zuurgraad - pensinhoud - pensvertering - rundveevoeding - cattle husbandry - rumen - acidity - rumen contents - rumen digestion - cattle feeding
    De processen in de pens van de koe vormen een complex en dynamisch geheel. De zuurgraad (pH) in de pens is een van de graadmeters die daar wat over zegt. Door continue meting is het verloop van de pH nauwkeurig in beeld te brengen. Met enig rekenwerk kan het grillige verloop uitgedrukt worden in kengetallen, waardoor de gegevens van verschillende koeien beter met elkaar te vergelijken zijn.
    Een vat vol organismen
    Vuuren, A.M. van - \ 2010
    Veeteelt 27 (2010)11. - ISSN 0168-7565 - p. 48 - 49.
    melkveehouderij - melkkoeien - fermentatie - pensvertering - pensfermentatie - voedingsstoornissen - dairy farming - dairy cows - fermentation - rumen digestion - rumen fermentation - nutritional disorders
    Een laag melkvetgehalte, dunne mest, een lage voeropname en klauwproblemen bij melkvee worden te gemakkelijk toegeschreven aan stoornissen in de pens. Ook het advies om dan ‘prik’ bij te voeren is een te eenvoudige voorstelling van zaken bij het ontstaan van fermentatiestoornissen.
    Benutting van biologisch rantsoen slechter?
    Klop, A. ; Bannink, A. - \ 2009
    V-focus 6 (2009)5. - ISSN 1574-1575 - p. 22 - 23.
    melkveehouderij - ruwvoer (forage) - verteerbaarheid - biologische landbouw - pensvertering - zuurgraad - melkveevoeding - voederkwaliteit - dairy farming - forage - digestibility - organic farming - rumen digestion - acidity - dairy cattle nutrition - forage quality
    Een goede vertering van het ruwvoer hangt af van de eigenschappen van het ruwvoer én van het micromilieu in de pens. Een combinatie van beide factoren geeft inzicht in voerbenutting. Vergelijk het met een composteringsproces. Zowel de soort organisch materiaal als het broeiproces in de hoop spelen een grote rol
    Methaan te lijf via voer
    Bannink, A. ; Sebek, L.B.J. ; Dijkstra, J. - \ 2009
    Veeteelt 26 (2009)9. - ISSN 0168-7565 - p. 10 - 12.
    melkveehouderij - dierlijke meststoffen - methaanproductie - emissie - rundveevoeding - voersamenstelling - pensvertering - melkproductie - agrarische bedrijfsvoering - milieubescherming - dairy farming - animal manures - methane production - emission - cattle feeding - feed formulation - rumen digestion - milk production - farm management - environmental protection
    De melkveesector draagt bij aan de uitstoot van broeikasgassen. Hoe kunnen veehouders die emissie terugdringen? Wageningse onderzoekers verwijzen onder meer naar het spoor van het rantsoen. Ook een hogere melkproductie per koe helpt.
    Toevoeging van enkele onderdelen aan een dynamisch pensmodel
    Bannink, A. ; Dijkstra, J. - \ 2009
    Lelystad : Animal Sciences Group, Wageningen UR (Rapport / Animal Sciences Group 219) - 52
    melkveehouderij - melkkoeien - pens - pensfermentatie - pensvertering - vetzuren - modellen - melksamenstelling - dairy farming - dairy cows - rumen - rumen fermentation - rumen digestion - fatty acids - models - milk composition
    Het pensmodel van Dijkstra et al. (1992) werd op 3 onderdelen aangepast: een weergave werd toegevoegd voor 1. de invloed van het voeropnamepatroon en van de verkleining en passage van deeltjes op pensfermentatie bij melkkoeien; 2. de invloed van langketen vetzuren op het verloop van de pensfermentatie en omgekeerd, en 3. de vertering in de darm, de absorptie van afzonderlijke typen nutriënten uit het maagdarmkanaal, de benutting van deze nutriënten voor melkproductie en de potentiële melkproductie op deze nutriënten gegeven de melksamenstelling. De toegevoegde onderdelen en het volledige model werden geëvalueerd door een vergelijking tussen modelsimulaties en in de literatuur gerapporteerde effecten en inzichten in het functioneren van de pens. Daarnaast werden modelvoorspellingen vergeleken met gerapporteerde resultaten op enkele praktijkbedrijven
    Energiearm voeren, minder problemen bij energiearm droogstandrantsoen
    Bloemert, J. - \ 2008
    Veeteelt 25 (2008)3. - ISSN 0168-7565 - p. 44 - 45.
    melkveehouderij - melkkoeien - gustperiode - rundveevoeding - voer - energetische waarde - pensvertering - melkziekte - agrarische bedrijfsvoering - dierziektepreventie - vergelijkend onderzoek - dairy farming - dairy cows - dry period - cattle feeding - feeds - energy value - rumen digestion - parturient paresis - farm management - animal disease prevention - comparative research
    Op de Waiboerhoeve heeft Agrifirm onderzoek gedaan naar de relatie tussen het energieniveau in droogstandsrantsoenen en de mate waarin stofwisselingsproblemen na afkalven voorkomen
    Praktijk van het pensmodel
    Bannink, A. ; Dijkstra, J. - \ 2008
    Veeteelt 2008 (2008)2. - ISSN 0168-7565 - p. 12 - 15.
    melkveehouderij - melkkoeien - melkproductie - pens - pensvertering - simulatiemodellen - rundveevoeding - methaanproductie - diergezondheid - dairy farming - dairy cows - milk production - rumen - rumen digestion - simulation models - cattle feeding - methane production - animal health
    Goed voeren van een melkkoe om zonder problemen de beoogde melkproductie te halen komt voor een groot deel neer op het managen van de penswerking. Hoe die pens werkt, wordt steeds duidelijker. Onderzoekers van Wageningen UR vernieuwden het ASG-pensmodel, wat zorgt voor verbeterde rantsoenadviezen
    Verteerbaarheid (ileaal en faecaal) van biologisch geteelde eiwitrijke voedergrondstoffen bij varkens = Digestibility (ileal and faecal) of organically-grown protein-rich raw materials in pigs
    Jongbloed, A.W. ; Diepen, J.T.M. van - \ 2007
    Lelystad : Animal Sciences Group (Rapport / Animal Sciences Group : Divisie Veehouderij 51) - 19
    dierhouderij - varkenshouderij - varkens - voer - diervoedering - fecessamenstelling - chymus - pensvertering - verteerbaarheid - voedingswaarde - ruwe grondstoffen - biologische landbouw - voedersystemen - animal husbandry - pig farming - pigs - feeds - animal feeding - faeces composition - digesta - rumen digestion - digestibility - nutritive value - raw materials - organic farming - feeding systems
    In this research the ileal digestibility of nitrogen and amino acids and the faecal digestibility of organic matter, nitrogen, fat, non-starch polysaccharides, energy and phosphorus of protein-rich organicallygrown feed raw materials were evaluated in pigs. The products were rapeseed meal expeller, soybean meal expeller, sunflower seed expeller, sesame seed expeller and lupins. In some feedstuffs, chemical composition and digestibilities deviated somewhat from tabulated values.
    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
    Beperkingen van de pens : versneld opvoeren krachtvoergift leidt niet tot pensverzuring : special Koe en voer
    Bannink, A. - \ 2006
    Veeteelt 23 (2006)18. - ISSN 0168-7565 - p. 46 - 47.
    melkveehouderij - rundveevoeding - voeropname - pens - pensinhoud - pensontwikkeling - pensvertering - pensepitheel - agrarische bedrijfsvoering - krachtvoeding - lactatiestadium - dairy farming - cattle feeding - force feeding - lactation stage - feed intake - rumen - rumen contents - rumen development - rumen digestion - rumen epithelium - farm management
    ASG onderzocht hoe de penswand van melkkoeien zich ontwikkelt bij het opvoeren van de krachtvoergift na het afkalven. 2 voerstrategieën werden vergeleken: een langzame strategie, waarbij de krachtvoergift in de eerste 20 dagen na afkalven werd verhoogd tot maximale waarde (14 kg krachtvoer droge stof per dag), en een snelle strategie, waarbij dit in 10 dagen gebeurde
    Volkoren krachtvoer, fijn of grof? Grof geplet graan verlaagt de voeropname
    Klop, A. ; Riel, J.W. van - \ 2005
    V-focus 2 (2005)6. - ISSN 1574-1575 - p. 26 - 26.
    melkveehouderij - melkkoeien - biologische landbouw - rundveevoeding - voer - graansoorten - pensvertering - graangewassen - agrarische bedrijfsvoering - tarwe - gerst - dairy farming - dairy cows - organic farming - cattle feeding - feeds - cereals - rumen digestion - grain crops - farm management - wheat - barley
    Graan verbouwen als krachtvoer voor melkvee biedt perspectief voor bedrijven met een ruime ruwvoervoorraad. Om ervaring hiermee op te doen is op Aver Heino een proef gedaan met 3 groepen melkkoeien, die elk een verschillend rantsoen gevoederd kregen: geplette tarwe, gemalen tarwe en ingekuilde gerst.
    Alternatives for forage evaluation in ruminants
    Gosselink, J.M.J. - \ 2004
    Wageningen University. Promotor(en): Seerp Tamminga, co-promotor(en): J.P. Dulphy; J.W. Crone. - [S.I.] : S.n. - ISBN 9789058089724
    herkauwers - ruwvoer (forage) - voederwaardering - verteerbaarheid - pensvertering - experimenten - technieken - in vitro - diervoeding - diervoedering - voedingsfysiologie - in vivo experimenten - alternatieve methoden - ruminants - forage - feed evaluation - digestibility - rumen digestion - experiments - techniques - in vitro - animal nutrition - animal feeding - nutrition physiology - in vivo experimentation - alternative methods
    The objective of this thesis was to validate and to compare in situ and in vitro techniques with in vivo data. These techniques were also evaluated for future and practical use in feed evaluation for ruminants. The techniques were compared using the digestion data of 98 forages and the energy values: in vivo total tract organic matter digestibility (OMD) and rumen fermentable organic matter (FOM), and the protein values: microbial nitrogen synthesised in the rumen (MNS) and rumen escape N (REN). The in situ nylon bag technique, the pepsin-cellulase technique, the gas production technique (GPT) and the Tilley and Terry technique showed good potency to predict OMD and the in situ technique and GPT gave most accurate FOM predictions. MNS was evaluated using in vivo data from the literature and showed a significant relationship with the content of crude protein in forages. The method of conservation of forages had an extra effect on MNS. REN was determined using in situ and different in vitro techniques, but only ADIN (fibre attached N) had a good relationship with in vivo
    Estimating rumen degradability of forages from semi-natural grasslands, using nylon bag and gas production techniques
    Bruinenberg, M.H. ; Gelder, A.H. van; Gonzalez Perez, P. ; Hindle, V.A. ; Cone, J.W. - \ 2004
    Netherlands Journal of Agricultural Science 51 (2004)4. - ISSN 0028-2928 - p. 351 - 368.
    pensvertering - ruwvoer (forage) - grassen - graslanden - kuilvoer - rumen digestion - forage - grasses - grasslands - silage - dairy-cows - degradation - digestibility - fermentation - digestion - ryegrass - nitrogen - maturity - kinetics - protein
    To determine the ruminal digestion of forages from extensively managed semi-natural grasslands, degradation characteristics and kinetics of silages of three different forages in the rumen of lactating dairy cows were estimated in vitro using the gas production technique (GPT), and in situ using the nylon bag technique. Silages originated from intensively managed grassland (IMG), extensively managed species-poor grassland (SPP) and extensively managed species-rich grassland (SPR). Some individual species originating from extensively managed species-poor and species-rich grasslands were used to estimate their degradability with GPT in order to compare the differences among the species occurring on these two types of grassland. All samples were also analysed for in vitro organic matter digestibility. In situ degradability was estimated by nylon bag incubation in the rumen of three dairy cows at two different periods. Rate of organic matter degradation was highest for IMG (4.93 and 4.54% h-1), intermediate for SPR (3.50 and 4.11% h-1) and lowest for SPP (2.62 and 2.72% h-1). The rates of degradation for protein and neutral detergent fibre were highest for IMG. The undegradable fraction was the same for SPP and SPR. Highest cell wall fermentation was observed for IMG and lowest for SPP, but SPP and SPR did not differ statistically in this respect. Cell wall degradability of the individual species from the species-poor and species-rich grasslands were highest for Lolium perenne and Dactylis glomerata and lowest for Lathyrus pratensis and Anthriscus sylvestris. It is concluded that SPR has the highest potential to become a component of the dairy cow ration.
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