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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    Genetic diversity in the dutch friesian horse
    Ducro, B.J. ; Bovenhuis, H. ; Neuteboom, J.H. ; Hellinga, I. - \ 2006
    dierveredeling - paarden - paardenrassen - paardenfokkerij - stamboom - voorouders - inteelt - populatiegenetica - genetische diversiteit - fries (paardenras) - animal breeding - horses - horse breeds - horse breeding - pedigree - ancestors - inbreeding - population genetics - genetic diversity - frisian (horse breed)
    The pedigree structure of the Dutch Friesian horse breed (n=79,962) was analysed to asses the genetic diversity still present in the population. The effective number of founders explaining the genetic diversity in the reference population (i.e female horses born between 1995 and 2005) was 26, whereas the effective number of ancestors was 16. The rate of inbreeding was 1.5% per equivalent generation which is beyond the critical level of 1%. The analysis indicated that the population has suffered from a bottle-neck shortly after the establishment of the population, and that a substantial loss of allelic diversity has occurred due to drift because of small population size. The increase of average kinship during recent generations has declined and this coincided with a substantial growth of the population. A decline of the rate of inbreeding might be expected, but a proper conservation programme is still needed to further reduce allelic loss from the population
    Variation in rank abundance replicate samples and impact of clustering
    Neuteboom, J.H. ; Struik, P.C. - \ 2005
    NJAS Wageningen Journal of Life Sciences 53 (2005)2. - ISSN 1573-5214 - p. 199 - 221.
    gegevensverwerking - wiskunde - waarschijnlijkheid - statistiek - populatiedynamica - populatie-ecologie - grafieken - data processing - mathematics - probability - statistics - population dynamics - population ecology - graphs - species-area - occupancy - patterns
    Calculating a single-sample rank abundance curve by using the negative-binomial distribution provides a way to investigate the variability within rank abundance replicate samples and yields a measure of the degree of heterogeneity of the sampled community. The calculation of the single-sample rank abundance curve is used in combination with the negative-binomial rank abundance curve-fit model to analyse the principal effect of clustering on the species-individual (S-N) curve and the species-area curve. With the usual plotting of S against log N or log area, assuming that N is proportional to area, S-N curves and species-area curves are the same curves with only a shifted horizontal axis. Clustering results in a lower recorded number of species in a sample and stretches the S-N curve and species-area curve over the horizontal axis to the right. In contrast to what is suggested in the literature, we surmise that the effect of clustering on both curves will gradually fade away with increasing sample size. Since the slopes of the curves are not constant, they cannot be used as species diversity indices or site discriminant. S-N curves and species-area curves cannot be extrapolated.
    A versatile curve-fit model for linear to deeply concave rank abundance curves
    Neuteboom, J.H. ; Struik, P.C. - \ 2005
    NJAS Wageningen Journal of Life Sciences 53 (2005)2. - ISSN 1573-5214 - p. 167 - 197.
    modellen - wiskundige modellen - populatiedynamica - populatie-ecologie - gegevensverwerking - gegevensanalyse - statistiek - grafieken - observatie - models - mathematical models - population dynamics - population ecology - data processing - data analysis - statistics - graphs - observation - species abundance - number - area
    A new, flexible curve-fit model for linear to concave rank abundance curves was conceptualized and validated using observational data. The model links the geometric-series model and log-series model and can also fit deeply concave rank abundance curves. The model is based ¿ in an unconventional way ¿ on the negative- binomial distribution and calculates (like the log-series model) a species-diversity index. The index is defined as the expected number of singleton species (species present with one individual) in an infinitely large sample. The new model could satisfy the need for more flexible curve-fit models with which differences and changes in the shape of the rank abundance curve can be more accurately investigated. The common rank abundance curve-fit models are lacking that flexibility.
    In silico sampling reveals the effect of clustering and shows that the log-normal rank abundance curve is an artefact
    Neuteboom, J.H. ; Struik, P.C. - \ 2005
    NJAS Wageningen Journal of Life Sciences 53 (2005)2. - ISSN 1573-5214 - p. 223 - 245.
    gegevensverwerking - computers - gegevensanalyse - statistiek - grafieken - populatiedynamica - populatie-ecologie - data processing - computers - data analysis - statistics - graphs - population dynamics - population ecology - species-area - canonical distribution - diversity - patterns - commonness - rarity
    The impact of clustering on rank abundance, species-individual (S-N)and species-area curves was investigated using a computer programme for in silico sampling. In a rank abundance curve the abundances of species are plotted on log-scale against species sequence. In an S-N curve the number of species (S) is plotted against the log of the total number of individuals (N) in the sample, in a species-area curve S is plotted against log-area. The results from in silico sampling confirm the general shape of S-N and speciesarea curves for communities with clustering, i.e., a curve that starts with a smaller slope but that later is temporarily steeper than the curve expected for Poisson-distributed species. Extrapolation of S-N and species-area curves could therefore be misleading. The output furthermore shows that sigmoid rank abundance curves (curves of the type of a log-normal or broken stick) can be an artefact of the standard procedure of first sorting the species in sequence of abundance in combination with clustering in the low abundant and rare species. This makes the usual explanation given to the log-normal rank abundance curve dubious. An extension of the negative-binomial rank abundance curve-fit model is discussed to make it suitable for also fitting sigmoid rank abundance curves.
    Sward methods
    Lantinga, E.A. ; Neuteboom, J.H. ; Meijs, J.A.C. - \ 2004
    In: Herbage intake handbook, second edition / Penning, P.D., Reading : The British Grassland Society - ISBN 9780905944319 - p. 23 - 52.
    Analysis of the temperature effect on the components of plant digestibility in two populations of perennial ryegrass
    Groot, J.C.J. ; Lantinga, E.A. ; Neuteboom, J.H. ; Deinum, B. - \ 2003
    Journal of the Science of Food and Agriculture 83 (2003)4. - ISSN 0022-5142 - p. 320 - 329.
    leaf extension - anatomy - growth - leaves - stem
    For the development of mechanistic models of herbage digestibility, quantitative insight into the effects of age, temperature and cultivar on digestibility characteristics of individual plant parts is needed. Towards that goal, glasshouse experiments were conducted at day/night temperatures of 13/8, 18/13 and 23/18degreesC with vegetative and reproductive crops of two populations of perennial ryegrass (Lolium perenne L) selected for differences in leaf blade digestibility. Cell wall content (CWC) and true cell wall and organic matter digestibility (CWD and OMD) of vegetative and reproductive tillers were related to dimensions, mass, CWC and digestibility of separate plant parts. Compared with the vegetative tillers, the reproductive tillers had higher rates of leaf appearance, organic matter growth and CWD decline. Strikingly, for both tiller types, no direct effect of temperature on whole tiller CWD was observed, since temperature effects could be eliminated completely by relating CWD to development stage (DVS) expressed as number of leaves appearing on the main tiller. Temperature effects on CWD were restricted to its influence on tiller development rate only. The decline of CWD of individual plant parts with DVS in the reproductive tillers could be described with a negative exponential curve, which reached an asymptote that was higher for leaf blades (755 g kg(-1)) than for leaf sheaths (491 g kg(-1)) and stem internodes (230 g kg(-1)). However, all plant parts in both tiller types had the same fractional CWD decline rate of 0.395 per leaf appearance interval, independent of plant part insertion level, population or temperature. Differences between temperature treatments in OMD were caused by the higher CWC of plant parts at higher temperature, due to a stronger decline of the specific organic matter mass than of the specific cell wall mass of plant parts at increasing temperature. Differences in whole tiller OMD between populations were observed only for vegetative tillers and were also caused by differences in CWC. It is concluded that temperature increase accelerated both the tiller development rate and the rate of decline of CWD during aging to the same extent, whereas plant parts responded similarly in the fractional CWD decline pattern as a function of DVS. These trends offer unique possibilities for modelling grass digestibility under contrasting temperature regimes. (C) 2003 Society of Chemical Industry.
    Advanced analysis of dry-weight-rank data to discriminate direct and indirect interactions between white clover and grasses in a multi-species pasture under a range of management strategies
    Schulte, R.P.O. ; Neuteboom, J.H. - \ 2002
    Grass and Forage Science 57 (2002). - ISSN 0142-5242 - p. 113 - 123.
    Infestations of pastures by species, such as creeping bentgrass (Agrostis stolonifera), may compromise the white clover (Trifolium repens) content in perennial ryegrass (Lolium perenne) mixtures. However, the interactions between white clover and species other than perennial ryegrass are not well understood. Strategies to prevent creeping bentgrass infestations require an understanding of its interactions with white clover, as the exclusion of white clover from infested pastures could be the result of either direct interaction or niche-differentiation in response to management. A methodology is presented which enables the segregation of the effects of direct interaction and niche-differentiation, based on existing dry-weight-rank measurements of a number of experimental pastures, subjected to a range of management strategies. Only between the two management extremities, i.e. permanent cutting of silage and lax grazing for long periods, did niche-differentiation occur between white clover and creeping bentgrass. The white clover content was enhanced under the cutting regime, whereas lax grazing for long periods stimulated the content of creeping bentgrass. White clover was actively excluded from creeping-bentgrass-dominated patches by direct interaction, whereas it showed a high compatibility with perennial ryegrass. This direct interaction presents challenges to the prevention of creeping bentgrass by management, as creeping bentgrass and white clover showed nearly identical requirements in terms of environmental conditions and grassland management.
    Composition and digestibility during ageing of consecutive leaves on the main stem of Italian ryegrass plants, growing undisturbed or regrowing after cutting
    Groot, J.C.J. ; Neuteboom, J.H. ; Deinum, B. - \ 1999
    Journal of the Science of Food and Agriculture 79 (1999). - ISSN 0022-5142 - p. 1691 - 1697.
    Growth of individual leaves of spring wheat (Triticum aestivum L.) as influenced by temperature and light intensity
    Bos, H.J. ; Neuteboom, J.H. - \ 1998
    Annals of Botany 81 (1998). - ISSN 0305-7364 - p. 141 - 149.
    Morphological analysis of leaf and tiller number dynamics of wheat (Triticum aestivum L.): responses to temperature and light intensity
    Bos, H.J. ; Neuteboom, J.H. - \ 1998
    Annals of Botany 81 (1998). - ISSN 0305-7364 - p. 131 - 139.
    Evaluation of the dry weight rank method for botanical analysis of grassland by means of simulation.
    Neuteboom, J.H. ; Lantinga, E.A. ; Struik, P.C. - \ 1998
    Netherlands Journal of Agricultural Science 46 (1998). - ISSN 0028-2928 - p. 285 - 304.
    With the Dry Weight Rank (DWR) method of 't Mannetje and Haydock [see Journal of British Grassland Society (1963) 18, 268-275] for botanical analysis in pastures, the dry weight proportions of species are estimated from their first, second and third ranks in dry weight in single quadrats. The yield correction of Haydock and Shaw [see Australian Journal of Experimental Agriculture and Animal Husbandry (1975) 15, 663-670] is used additionally to solve the problem of the respective under- and overestimates of the dry weight proportions of high and low yielding species when these grow in patches. In this paper the DWR method is evaluated by means of computer simulation. Main element of the simulation model is a computer sampling program with which a fictitious vegetation can be sampled with a circular quadrat. The output shows that the DWR method works well using relatively small sampling quadrats with, on average, only a few plants per quadrat, irrespective of the horizontal vegetation structure. In vegetations where species grow patchwise, satisfactory results are also obtained using large quadrats with much more plants (i.e. tens) per quadrat. The reason is that in these cases also minor species can compete successfully for first, second and third ranks. However, it appeared that only a certain degree of patchiness is necessary, and with the usually applied quadrat sizes up to 25 dmsuperscript 2, probably in most vegetations this condition is fulfilled. Care should be taken in applying the DWR method for estimating species composition in recently sown grasslands where species usually occur more or less at random. In those cases, in principle a very small sampling quadrat (smaller than 1 dmsuperscript 2) could be used. However, this has practical limitations since the quadrat size should not be too small for realistic yield estimations, needed for the Haydock & Shaw yield correction. The simulations revealed that one condition (i.e., that the sampling quadrat should be at least as large that it usually contains three or more species) is not necessary because of the almost always perfect functioning of the correction for missing ranks. Generally speaking, a sampling quadrat should be chosen not larger than is strictly necessary from the viewpoint of horizontal vegetation structure and from the viewpoint of realistic yield estimations. Multipliers calculated from simulation data could satisfactorily mimic the original multipliers of DWR given by 't Mannetje & Haydock. It is postulated that the DWR method is well suited for studying vegetation changes in old, floristically diverse grasslands with dominant species often in moderate dry weight proportions and species usually growing in patches.
    Composition and digestibility during ageing of Italian ryegrass leaves of consecutive insertion levels.
    Groot, J.C.J. ; Neuteboom, J.H. - \ 1997
    Journal of the Science of Food and Agriculture 75 (1997). - ISSN 0022-5142 - p. 227 - 236.
    Leaf dispersion in grass/clover mixtures.
    Nassiri, M. ; Elgersma, A. ; Lantinga, E.A. ; Neuteboom, J.H. - \ 1996
    In: Legumes in sustainable farming systems, D. Younie (ed.). Poster 30th Occasional Symp. British Grassland Society - p. 181 - 182.
    Elements for modelling in vitro digestibility of grass on the basis of morphological and physiological plant characteristics.
    Groot, J.C.J. ; Neuteboom, J.H. ; Lantinga, E.A. ; Deinum, B. - \ 1996
    In: Abstract Utilization of local feed resources by dairy cattle, A.F. Groen, J. van Bruchem (eds.). EAAP Publ. No. 84. Wageningen Pers - p. 137 - 138.
    Simulation of the dry weight rank method.
    Neuteboom, J.H. - \ 1996
    In: Grassland science in perspective / Elgersma, A., - p. 1 - 12.
    Relation between berry weight, number of seeds per berry and 100-seed weight in potato inflorescences.
    Almekinders, C.J.M. ; Neuteboom, J.H. ; Struik, P.C. - \ 1995
    Scientia Horticulturae 61 (1995). - ISSN 0304-4238 - p. 177 - 184.
    Digestibility of cell walls of ageing grass leaves as estimated from in vitro and gas production techniques.
    Groot, J.C.J. ; Deinum, B. ; Lantinga, E.A. ; Neuteboom, J.H. - \ 1994
    In: Grassland and society / 't Mannetje, L., Frame, J., Wageningen : Wageningen Pers - p. 152 - 156.
    Cattle weight changes and botanical composition of an unfertilized sward under continuous grazing.
    Neuteboom, J.H. ; Mannetje, L. 't; Lantinga, E.A. ; Wind, K. - \ 1994
    In: Proc. 15th Gen. Meeting Eur. Grassland Fed.: Grassland and society, L. 't Mannetje, J. Frame (eds.). Wageningen Pers - p. 320 - 323.
    Cattle weight changes and botanical composition of an unfertlized grass sward under continuous grazing.
    Neuteboom, J.H. ; Mannetje, L. 't; Lantinga, E.A. ; Wind, K. - \ 1994
    In: Grassland and society / 't Mannetje, L., Frame, J., Wageningen : Wageningen Pers - p. 320 - 323.
    Sward characteristics of a diploid and a tetraploid cultivar of perennial ryegrass as measured by different sampling techniques.
    Neuteboom, J.H. ; Lantinga, E.A. ; Schlepers, H. ; Mannetje, L. 't - \ 1993
    In: Proc. 17th Int. Grassland Congr. Palmerston North, New Zealand - p. 362 - 363.
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