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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    Effect of dietary energy source on hormone status and protein utilisation in growing pigs
    Lenis, N.P. ; Meulen, J. van der; Weij-Jongbloed, R. van der; Koopmans, S.J. - \ 1999
    In: Protein metabolism and nutrition : Book of abstracts of the VIIIth international symposium on protein metabolism and nutrition, Aberdeen, UK, 1-4 September 1999. - Wageningen : Wageningen Press - p. 8 - 8.
    Effect of the ratio between essential and nonessential amino acids in the diet on utilization of nitrogen and amino acids by growing pigs
    Lenis, N.P. ; Diepen, H.T.M. van; Bikker, P. ; Jongbloed, A.W. ; Meulen, J. van der - \ 1999
    Journal of Animal Science 77 (1999)7. - ISSN 0021-8812 - p. 1777 - 1797.
    In 36 growing pigs (30 to 60 kg), N balance and amino acid (AA) composition of weight gain were measured to evaluate the interactive effect of the ratio between N from essential amino acids (EAA(N)) to nonessential amino acids (NEAA(N)) and total N level (T(N)) in the diet on N retention and utilization of N, EAA(N), NEAA(N), and AA. Nine diets composed from ordinary feedstuffs and supplemented with crystalline AA were used (three EAA(N):NEAA(N) ratios of 38:62, 50:50, and 62:38 at three T(N) levels of 18.8, 22.9, and 30.0 g/kg). Pigs were fed restrictedly, at a level of 2.8 x energy for maintenance. In all diets, EAA (including arginine) supply was according to or slightly above the recommended ratios to lysine. Measurements were done in four blocks of nine pigs each. In a concomitant slaughter experiment, the AA composition of deposited body protein was determined to estimate AA utilization. The effects of T(N) and EAA(N):NEAA(N) and their interaction for N retention and utilization were significant. Nitrogen retention increased with higher T(N) in the diet. Increasing EAA(N):NEAA(N) from 38:62 to 50:50 improved N retention only at the two lower T(N) levels. Increasing EAA(N): NEAA(N) above 50:50 failed to improve N retention significantly at any of the three T(N) levels. Lowering T(N) improved the utilization of total and digested N and of EAA(N) and NEAA(N). The increase in EAA(N): NEAA(N) consistently resulted in a lower utilization of EAA(N), but this was compensated by a higher utilization of NEAA(N). The utilization of T(N) was improved by increasing EAA(N):NEAA(N) from 38:62 to 50:50 at the two lower T(N) levels and was relatively unaffected by EAA(N):NEAA(N) at the highest T(N). However, a lower utilization of N was observed at a ratio of 62:38 at a T(N) level of 22.9 g/kg. The effects were similar for utilization of individual EAA and NEAA. Utilization of alanine, aspartic acid, and glycine was close to or >100% at the highest EAA(N):NEAA(N), which was expected because all of these AA are synthesized in pigs. Also, the utilization of arginine was >100% in most of the treatments, which confirms the semiessential character of this AA for maintenance. We concluded that the required ratio of EAA(N):NEAA(N) for optimal N retention and utilization is approximately 50:50. The EAA(N):NEAA(N) is more important at lower dietary protein levels. This study indicates that EAA(N): NEAA(N) can be increased up to 70:30 without lowering the utilization of N. Thus, deaminated EAA(N) was efficiently utilized for the synthesis of NEAA(N).
    New technologies in low pollution swine diets: Diet manipulation and use of synthetic amino acids, phytase and phase feeding for reduction of nitrogen and phosphorus excretion and ammonia emission
    Lenis, N.P. ; Jongbloed, A.W. - \ 1999
    Asian-Australasian Journal of Animal Sciences 12 (1999)2. - ISSN 1011-2367 - p. 305 - 327.
    In the paper insight is given in the legislation policy to restrain environmental pollution by pig husbandry, focused on The Netherlands (Mineral Accounting System). Besides, nutritional measures are presented to reduce environmental pollution by lowering excretion of N and P, emphasizing (multi) phase feeding, the use of low protein, synthetic amino acids supplemented diets, phytase and its effect on phosphorus and calcium digestibility, its interaction with phytic acid and proteins, and the environmental impact of the use of phytase in pig diets. Also, nutritional means are indicated to reduce ammonia volatilization from pig operations. It is concluded that nutrition management can substantially contribute to reduction of N and P excretion by pigs, mainly by lowering dietary protein levels, (multi) phase feeding and the use of microbial phytase, and that the use of phytase on a large scale in The Netherlands has a tremendous environmental impact. In 20 years the excretion of P in growing-finishing pigs has more than halved. Ammonia emission from manure of pigs can be reduced substantially by lowering dietary protein content, but also by including additional non-starch polysaccharides in the diet. A very promising method to reduce ammonia emission is to manipulate dietary cation-anion difference, e.g. by adding acidifying salts to the diet, which will lower pH of urine substantially. Further research is desirable. This also applies to determining dietary factors influencing the odour release from manure. Finally, some speculation on the future of pig farming from an environmental viewpoint is presented.
    De mestmarkt in 2002
    Hoogervorst, N.J.P. ; Egmond, P.M. van; Knol, O.M. ; Daatselaar, C.H.G. ; Wien, J.J.F. ; Dijk, W. van; Lenis, N.P. ; Spoelstra, S. ; Brinkmann, A.J.F. ; Hoek, K.W. van der; Tol, S. - \ 1999
    [Bilthoven] : Rijksinstituut voor Volksgezondheid en Milieu (RIVM) - 50
    mest - nederland - manures - netherlands
    In augustus 1999 is het RIVM verzocht om samen met LEI, ID-DLO en PAV een 'Second Opinion' te geven over het rapport 'Op zoek naar evenwicht 2', dat het Bureau Van de Bunt in april 1999 publiceerde. Het verzoek werd gedaan omdat a) de overheid zich wilde beraden op alternativen voor de Wet Herstructurering Varkenshouderij, die door gerechtelijke uitspraken tijdelijk buiten werking was geraakt en b) er sinds het verschijnen van de studie van Van de Bunt nieuwe relevante informatie beschikbaar was gekomen. In dit rapport zijn de effecten berekend van uitvoering van het vastgestelde mestbeleid, inclusief de korting op varkensrechten. Onder die omstandigheden worden de verliesnormen in 2002 naar verwachting overschreden met 11 mln kg fosfaat uit dierlijke mest en met circa 80 mln kg stikstof uit dierlijke mest en kunstmest. Zonder korting op vakensrechten kan dit oplopen tot 14 mln kg fosfaat. Het werkelijke fosfaat-overschot is 15-20 mln kg groter dan het wettelijke overschot omdat het gebruik van fosfaat-kunstmest niet wordt meegeteld en omdat boeren voor bouwland mogen rekenen met forfaitaire waarden voor gewasafvoer in plaats van met lagere werkelijke waarden
    Feed manufacturing in the Mediterranean region. Recent advances in research and technology
    Jongbloed, A.W. ; Lenis, N.P. ; Brufau, J. ; Tacon, A. - \ 1999
    In: Proceedings of the II conference of feed manufacturers of the Mediterranean, Reus, Spain, 25-27 March, 1998. - Cahiers options Mediterranneennes 37, 1999 - p. 229 - 239.
    Pollution issues in pig operations and the influence of nutrition, housing and manure handling
    Klooster, C.E. van 't; Peet-Schwering, C.M.C. van der; Aarnink, A.J.A. ; Lenis, N.P. - \ 1998
    In: Progress in Pig Science / Wiseman, J., Nottingham : Nottingham University Press - ISBN 9781897676264 - p. 507 - 518.
    Het effect van de energiebron in het voer op de eiwitbenutting en de hormonale status van groeiende varkens van verschillende genetische aanleg en sexe
    Lenis, N.P. ; Weij-Jongbloed, R. van der; Meulen, J. van der - \ 1998
    Lelystad : Instituut voor Dierhouderij en Diergezondheid (Rapport ID-DLO 98.033) - 45 p.
    Dose-response relationship of dietary benzoic acid on animal performance and health, and meat quality in growing pigs
    Lenis, N.P. ; Jongbloed, A.W. ; Diepen, J.Th.M. van; Weij-Jongbloed, R. van der; Bolder, N.M. ; Dijksterhuis, G.B. ; Hulsegge, B. ; Niewold, T.A. ; Stockhofe, N. ; Stoopman, M.L. - \ 1998
    Lelystad : Institute for Animal Science and Health (Report ID-DLO 98.076) - 53 p.
    New technologies in low pollution swine diets: Diet manipulation and use of synthetic amino acids, phytase and phase feeding for reduction of nitrogen and phosphorus excretion and ammonia emission
    Lenis, N.P. ; Jongbloed, A.W. - \ 1998
    In: Proceedings pre-conference symposia of the 8th world conference on animal production. - Seoul, Korea,: Seoul National University, June 28 - July 4, 1998. - p. 218-244
    Environmental problems by livestock and nutritional solutions for diminishing excretion of nitrogen, phosphorus and heavy metals, in particular in pigs
    Lenis, N.P. - \ 1998
    In: Paper seminars Taiwan and Japan, 1998, 41 p
    In vitro studies on the effect of gamma-polyglutamic acid (PGA) on the solubility of calcium and phosphate
    Jonge, L.H. de; Wissink, A. ; Lenis, N.P. - \ 1998
    Unknown Publisher - 12 p.
    Nutrition as a tool to reduce the impact on the environment
    Jongbloed, A.W. ; Lenis, N.P. - \ 1998
    In: Second conference show of mixed feed manufacturers in the Mediterranean, 25-27 March 1998
    Environmental concerns about animal manure
    Jongbloed, A.W. ; Lenis, N.P. - \ 1998
    Journal of Animal Science 76 (1998)10. - ISSN 0021-8812 - p. 2641 - 2648.
    The structure of swine production has changed dramatically in the last four decades. Raw materials for swine feeds are often grown in regions other than where swine production takes place. Swine manure is mostly spread in the neighborhood of the facilities, which may lead to soil accumulation of minerals such as P, Cu, and Zn. Moreover, soil nitrate may leach and result in enhanced nitrate levels in ground and surface water. Large swine units generate odors, ammonia, and dust that can exceed tolerable levels. Negative effects of swine production on the environment have already led to new legislation that limits the use of animal manure or the expansion or localization of pig operations in some countries. The consequences of intensive swine production on the environment and possible solutions by means of nutrition are outlined. Also, discussed are experiences from the Dutch situation, forthcoming legislation, and environmental constraints on pig production in the future. Our approach centers more on the system level.
    Requirement for apparent ileal digestible isoleucine of young pigs
    Lenis, N.P. ; Diepen, J.T.M. van - \ 1997
    Journal of Animal Science 75 (1997)suppl. 1. - ISSN 0021-8812 - p. 185 - 185.
    Impact of nutrition on reduction of environmental pollution by pigs: An overview of recent research
    Jongbloed, A.W. ; Lenis, N.P. ; Mroz, Z. - \ 1997
    Veterinary Quarterly 19 (1997). - ISSN 0165-2176 - p. 130 - 134.
    Environmental concerns of animal manure
    Jongbloed, A.W. ; Lenis, N.P. - \ 1997
    Journal of Animal Science 75 (1997)suppl. 1. - ISSN 0021-8812 - p. 139 - 139.
    Lowering ammonia volatilization from pig excreta by manipulating dietary acid-base difference
    Mroz, Z. ; Jongbloed, A.W. ; Canh, T.T. ; Lenis, N.P. - \ 1996
    In: Proceedings of the 8th Animal Science Congress of AAAP, Tokyo, 13-18 October 1996, Volume 2 - p. 762 - 763.
    Effect of dietary neutral detergent fiber on ileal digestibility and portal flux of nitrogen and amino acids and on the nitrogen utilization in growing pigs
    Lenis, N.P. ; Bikker, P. ; Meulen, J. van der; Diepen, J.Th.M. van; Bakker, J.G.M. ; Jongbloed, A.W. - \ 1996
    Journal of Animal Science 74 (1996)11. - ISSN 0021-8812 - p. 2687 - 2699.
    Two experiments were conducted to determine the effects of dietary NDF on apparent ileal and fecal digestibility and portal flux of nitrogen (N) and amino acids, and on N retention in growing pigs. In four equal portions (at 0600, 1200, 1800, and 2400) barrows on Treatment B received a basal diet, based on casein, cornstarch, and dextrose, at a feeding level of 2.6 times energy for maintenance. Barrows on Treatment B+NDF received an additional amount of 15% (wt/wt) of purified wheat bran NDF (pNDF). In Exp. 1, four ileally cannulated barrows (40 to 75 kg) were used in a crossover arrangement comprising two treatments and three periods. The addition of pNDF decreased ileal N digestibility from 94.1 to 88.9% (P < .001), whereas ileal digestibility of most amino acids was 2 to 5.5 percentage units lower (P < .001). Utilization of ileally digested N increased from 64 to 72% with the addition of pNDF, presumably because of the contribution of pNDF to the energy supply. In Exp. 2, three barrows (30 to 54 kg) fitted with catheters in the portal vein and the mesenteric vein and artery were used in a crossover arrangement comprising two treatments and five periods. Portal absorption of nutrients was derived by multiplying the porto-arterial plasma concentration differences by portal vein plasma flow. The pNDF did not significantly affect the absorption of ileally digested amino acids and the portal flux of ammonia and urea. The results showed that addition of NDF reduced amino acid digestibility, but not the portal flux of digested amino acids, and NDF energy presumably improved utilization of ileally digested amino acids.
    Fysiologische voedingsstrategie: een uitdaging voor een efficiënte stikstofbenutting in de intensieve veehouderij.
    Blok, M.C. ; Brenninkmeijer, C. ; Jansman, A.J.M. ; Lenis, N. ; Schreurs, V.V.A.M. - \ 1996
    's-Gravenhage : Produktschap voor Veevoeder - 71
    voer - intensieve landbouw - voedingswaarde - eiwitten - feeds - intensive farming - nutritive value - proteins
    De N- en aminozuurbenutting bij groeiende varkens gevoerd met rantsoenen varierend in het aandeel essentiele en niet-essentiele aminozuren = Nitrogen and amino acid utilization in growing pigs fat on diets with different ratios of essential to non-essential amino acids
    Diepen, J.T.M. van; Lenis, N.P. ; Klok, G. - \ 1995
    Lelystad : ID-DLO (Rapport / ID-DLO, vestiging Runderweg no. 284) - 39
    verteerbaarheid - voer - varkens - eiwitten - digestibility - feeds - pigs - proteins
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