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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    Understanding the gastrointestinal physiology and responses to feeding in air-breathing Anabantiform fishes
    Goodrich, Harriet R. ; Bayley, Mark ; Birgersson, Lina ; Davison, William G. ; Johannsson, Ora E. ; Kim, Anne B. ; My, Phuong Le; Tinh, Tran H. ; Thanh, Phuong N. ; Thanh, Huong Do Thi ; Wood, Chris M. - \ 2020
    Journal of Fish Biology 96 (2020)4. - ISSN 0022-1112 - p. 986 - 1003.
    acid–base regulation - ammonia excretion - feeding - gut - ion regulation - urea excretion

    The Mekong Delta is host to a large number of freshwater species, including a unique group of facultative air-breathing Anabantiforms. Of these, the striped snakehead (Channa striata), the climbing perch (Anabas testudineus), the giant gourami (Osphronemus goramy) and the snakeskin gourami (Trichogaster pectoralis) are major contributors to aquaculture production in Vietnam. The gastrointestinal responses to feeding in these four species are detailed here. Relative intestinal length was lowest in the snakehead, indicating carnivory, and 5.5-fold greater in the snakeskin, indicating herbivory; climbing perch and giant gourami were intermediate, indicating omnivory. N-waste excretion (ammonia-N + urea-N) was greatest in the carnivorous snakehead and least in the herbivorous snakeskin, whereas the opposite trend was observed for net K+ excretion. Similarly, the more carnivorous species had a greater stomach acidity than the more herbivorous species. Measurements of acid–base flux to water indicated that the greatest postprandial alkaline tide occurred in the snakehead and a potential acidic tide in the snakeskin. Additional findings of interest were high levels of both PCO2 (up to 40 mmHg) and HCO3 (up to 33 mM) in the intestinal chyme of all four of these air-breathing species. Using in vitro gut sac preparations of the climbing perch, it was shown that the intestinal net absorption of fluid, Na+ and HCO3 was upregulated by feeding but not net Cl uptake, glucose uptake or K+ secretion. Upregulated net absorption of HCO3 suggests that the high chyme (HCO3 ) does not result from secretion by the intestinal epithelium. The possibility of ventilatory control of PCO2 to regulate postprandial acid–base balance in these air-breathing fish is discussed.

    Entry Points for Reduction of Greenhouse Gas Emissions in Small-Scale Dairy Farms: Looking Beyond Milk Yield Increase
    Vries, Marion de; Zahra, Windi Al ; Wouters, Adriaan P. ; Middelaar, Corina E. van; Oosting, Simon J. ; Tiesnamurti, Bess ; Vellinga, Theun V. - \ 2019
    Frontiers in Sustainable Food Systems 3 (2019). - ISSN 2571-581X
    climate change mitigation - dairy cattle - feeding - greenhouse gases - manure management

    Increasing milk yield per cow is considered a promising climate change mitigation strategy for small-scale dairy farms in developing countries. As it can be difficult to increase cow productivity, mitigation options beyond this production strategy need to be identified. The aim of this study was to identify entry points for mitigation of GHG emissions in small-scale dairy farms in Lembang Sub-district, West Java, Indonesia. Data on herd composition, productivity, feeding, and manure management were collected in a survey of 300 randomly selected dairy farms. Characteristics of farms with the 25% lowest (<3291 kg milk/cow/y), medium 50% (3291–4975 kg milk/cow/y), and 25% highest milk yields (≥4976 kg milk/cow/y) were compared. Life cycle assessment was then performed to estimate the cradle-to-farm gate GHG emission intensity (EI) of farms. The relationship between EI and milk yield per cow for all farms was modeled and farms with an EI below and above their predicted EI were compared (“low” and “high” EI farms). Results showed that milk yield explained 57% of the variance in EI among farms. Farms with medium and high milk yields were more often specialized farms, fed more tofu waste and compound feed, and had higher feed costs than farms with low milk yields (P < 0.05). Farms with high milk yields also applied less manure on farm land than farms with low milk yields (P < 0.05). Low EI farms had fewer cows, and fed less rice straw, more cassava waste, and more compound concentrate feed (particularly the type of concentrates consisting largely of by-products from milling industries) than high EI farms (P < 0.05). In addition, low EI farms discharged more manure, stored less solid manure, used less manure for anaerobic digestion followed by daily spreading, and applied less manure N on farmland than high EI farms (P < 0.05). Some associations were affected by confounding factors. Farm management factors associated with milk yield and the residual variation in EI were considered potential entry points for GHG mitigation. Feeding less rice straw and discharging manure, however, were considered unsuitable mitigation strategies because of expected trade-offs with other environmental issues or negative impacts on food-feed competition.

    How to get every piglet eating
    Middelkoop, Anouschka ; Choudhury, R. - \ 2017
    creep feeding - feed intake - weaning - feeding - research
    Behavioural adaptation to a short or no dry period with associated management in dairy cows
    Kok, A. ; Hoeij, R.J. van; Tolkamp, B.J. ; Haskell, M.J. ; Knegsel, A.T.M. van; Boer, I.J.M. de; Bokkers, E.A.M. - \ 2017
    Applied Animal Behaviour Science 186 (2017). - ISSN 0168-1591 - p. 7 - 15.
    rest period - lying - feeding - cattle - trasition period - sensor data
    From calving, dairy cows are typically milked for about a year, and subsequently managed to have a non-lactating or ‘dry period’ (DP) before next calving. However, the use of a DP may reduce cow welfare because typical DP management involves the cow changing groups and ration. Also, the DP results in a severe negative energy balance after calving. Shortening or omitting the DP may have beneficial effects on cow welfare through fewer changes in management before calving, and a lower milk yield after calving. Our objective was to assess the effects of no DP and a short DP (30 days) with associated management on feeding, lying, and number of steps of dairy cows in late gestation and early lactation. Feeding behaviour was recorded by computerized feeders for 122 periods (42 with a short DP and 80 with no DP) from week −6 to week 7 relative to calving. Steps and lying behaviour of 81 of these cows (28 with a short DP and 53 with no DP) were recorded with accelerometers in week −4 and in week 4 relative to calving only. Effects of DP treatment and parity on behaviour were analysed with mixed models. Before calving, cows with a short DP were fed a DP ration, and moved to a dry cow group. During this time, cows with a short DP spent more time lying (13.7 vs. 12.6 h per day; P = 0.01) and feeding (240 vs. 209 min per day; P < 0.01), and stepped less (663 vs. 1130 steps per day; P < 0.01) than cows with no DP. After calving, all cows were fed the same lactation ration and were housed in the same herd. Cows with a short DP, however, had a lower feed intake (35.7 vs 39.1 kg per day; P < 0.01), and spent less time lying (10.7 vs. 11.6 h per day; P = 0.03) after calving than cows with no DP. Milk yield was negatively correlated with daily lying time (r: −0.22; P < 0.05), but was not correlated with daily feeding time. Also, less time was spent on both lying and feeding after calving than before calving. These results indicate that lying time was not constrained by feeding time. Lying time was positively correlated with energy balance (r: 0.28; P < 0.01). Compared with a short DP with associated ration and group changes, no DP reduced lying time and increased the number of steps in late gestation, and resulted in a higher feed intake and longer lying time in early lactation.
    Automatic monitoring of cow behaviour to assess the effects of variations in feeding delivery frequency
    Mattachini, Gabriele ; Riva, E. ; Pompe, J.C.A.M. ; Provolo, G. - \ 2015
    - p. 473 - 481.
    Automatic monitoring - cow behaviour - feeding
    Impact of marine debris on Antarctic fur seals Arctocephalus gazella at Cape Shirreff: diet dependent ingestion and entanglement : Preliminary results
    Bravo Rebolledo, Elisa ; Franeker, J.A. van - \ 2015
    Den Helder : IMARES - 7
    seals - plastics - ingestion - animal welfare - microplastics - water pollution - animal health - feeding - zeehonden - kunststoffen - inname - dierenwelzijn - microplastics - waterverontreiniging - diergezondheid - voedering
    For several decades it has been known that plastics in the marine environment can harm marine organisms, most visibly birds, turtles and mammals (Shomura and Yoshida, 1985). These animals can become entangled in this synthetic debris and can ingest macro- and micro-plastics. Recently, increased awareness of plastic fragmentation into small persistent particles (‘plastic soup’) and the potential chemical hazards from ingestion have heightened the concern regarding the chemical impact on the marine food chains and ultimately the consequences for humans as end consumers (UNEP, 2011). UNEP listed plastic debris in the oceans as one of the three main emerging issues of concern for the global environment. Within the framework of the Commission for the Convention of Antarctic Marine Living Resources (CCAMLR) there has been attention to beached litter and seal entanglements, but little systematic work on the ingestion of plastic materials has been done.
    Olfaction: An Overlooked Sensory Modality in Applied Ethology and Animal Welfare
    Nielsen, B.L. ; Jezierski, T. ; Bolhuis, J.E. ; Amo, L. ; Rosell, F. ; Oostindjer, M. ; Christensen, J.W. ; Mckeegan, D. ; Wells, D.L. ; Hepper, P. - \ 2015
    Frontiers in Veterinary Science 2 (2015)69. - ISSN 2297-1769
    odors - chemoreception - behavior - feeding - stress - housing - reproduction - disease
    Microalgae diets for landbased aquaculture of the cockle Cerastoderma edule: impacts of dietary fatty acids on growth
    Reis Batista, I.C. dos - \ 2015
    Wageningen University. Promotor(en): Aad Smaal, co-promotor(en): Johan Kamermans; R.H. Wijffels. - Wageningen : Wageningen University - ISBN 9789462575875 - 132
    schaaldieren - schaal- en schelpdierenteelt - algen - voedering - voersamenstelling - diëten - vetzuren - groei - tanks - plassen - aquacultuur - shellfish - shellfish culture - algae - feeding - feed formulation - diets - fatty acids - growth - tanks - ponds - aquaculture

    Land-based shellfish culture as a part of a multi-trophic aquaculture systems has yet to be implemented in Europe. Recently the pilot project Zeeuwse Tong (The Netherlands) evaluated the feasibility of a system of fish (Dover sole), ragworms, phytoplankton and bivalves. This thesis focused on the dietary fatty acids impact on growth, survival and fatty acid composition of juveniles (shell length >5mm) of the common cockle Cerastoderma edule, for land-based culture.

    Dietary fatty acids were chosen as the main nutritional research subject given the existing literature indicating their importance for reproduction, and growth and survival of larvae, post-larvae, spat and seed of most bivalves. However, since grow-out of juvenile cockles in land-based aquaculture is not common, no information is available on the dietary fatty acid requirements of juveniles. To determine if the presence of specific fatty acids is more important for growth and survival of juvenile cockles than the total amount of dietary fatty acids supplied, least cost linear programming was used to design live microalgae diets. Monocultures of indigenous algae were grown under controlled conditions and sampled to determine their quality in terms of dry weight, organic matter, lipid and fatty acids composition. These differences in biochemical composition of the microalgae were used in a least-cost programming software, and allowed the formulation of three diets with different fatty acid contents, but similar dry weight, organic matter, lipid and total fatty acid content. The formulated diets were then used to determine the importance of dietary fatty acids for growth, survival and fatty acid composition of juvenile cockles (Cerastoderma edule). Juvenile cockles (6.24±0.04 mm) were constantly fed live microalgal diets with similar lipid, organic matter and total fatty acid contents but different individual fatty acid concentrations: high-EPA, no-DHA and low-ARA diets. Growth was positively affected by high-EPA and low-ARA diets, whereas no significant growth was observed for the no-DHA diet. However, high mortality of cockles fed no-DHA diet and the low absorption efficiency and clearance rate of this diet indicate that this diet is unsuitable for juvenile cockles. In balanced diets with EPA and DHA, lower concentrations of ARA did not limit growth. The combination of EPA and DHA in a live microalgae diet was beneficial for the growth and survival of juvenile cockles, but no conclusion on the importance of supplying only EPA could be made. To address this, an additional growth experiment was designed. Growth and fatty acid profiles of juveniles cockles were determined after 28 days of feeding diets:1) with EPA 2) with DHA; 3) with EPA and DHA from a mixture of a diatom with a green algae; 4) with EPA and DHA from a mixture of the two green algae and 5) without long-chain (>C20) fatty acids. Significantly higher growth rate was observed with the treatment rich in EPA, while the lowest growth rates were found in without EPA. These results indicate that EPA is necessary for the short-term growth of cockles. Moreover, the fatty acid profile of the polar lipids confirmed that, like most marine invertebrates, juvenile C. edule are not able to biosynthesize EPA and DHA from 18:3n-3 but are capable of biosynthesizing diene and triene NMI fatty acids. The occurrence of the NMI fatty acids was diet related, thus refuting the possibility of production of NMI as replacement for EPA and DHA.

    Furthermore, in order to develop land-based culture of cockles it is crucial to have a supply of high quality live microalgal diets produced with minimum effort. Therefore, the use of simplified microalgae media, with different nitrogen sources (nitrate or ammonium) and molar N:P ratio, phosphorus, silica, iron, manganese and vitamins were also investigated. Chaetoceros muelleri, a marine diatom that was chosen given its robustness and quality as food for juvenile cockles, reacted positively to all simplified media. At the exponential phase, all cultures had reached similar cellular concentrations and dry weight productions. Cultures grown on ammonium media had a longer cultivation period, 20 days. Considering dry-weight production, culture duration, nutrient efficiency and lipid composition, the simplified media containing ammonium, phosphorus, silica, iron, manganese and vitamins proved to be a viable choice for batch culture of C. muelleri. The choice between these two media depends on the final purpose of the microalgae cultures and whether lipid contents (NH49:1), dry weight biomass (NH425:1) or nitrogen input and output (NH49:1) are more important.

    In this thesis it was demonstrated that mono-algal diets with high EPA, as well as mixed live microalgae diets with high EPA and DHA contents proved to be suitable diets for C. edule juveniles. In addition, a positive relation between growth and the amount fed was found. The growth rates of the cultured cockles in this thesis are in accordance with the rates observed under natural conditions. The use of the simplified microalgae culture medium tested represents a significant decrease in the cost and preparation of the medium, as well as longer production and harvest periods, while maintaining microalgae quality. These results indicate that land-based aquaculture of cockles and microalgae is therefore a promising venture, with potential for expansion.

    Mineralen-, sporenelementen- en vitaminenbehoeften van paarden
    Top, A.M. van den; Blok, M.C. ; Everts, H. - \ 2012
    Lelystad : CVB, Productschap Diervoeder (CVB-documentatierapport nr. 54) - 68
    paarden - diervoeding - voeding - voedering - voedingsstoffen - mineralenvoeding - sporenelementen - vitaminen - horses - animal nutrition - nutrition - feeding - nutrients - mineral nutrition - trace elements - vitamins
    In deze publicatie wordt beschreven hoe de in CVB verband tot stand gekomen voedernormen voor deze voedingsstoffen tot stand zijn gekomen. De publicatie is het resultaat van een deskstudie waarbij allereerst de Duitse DLG normen en de Amerikaanse NRC normen zijn geëvalueerd. Daar waar nodig is gericht gekeken of er nieuwe studies beschikbaar zijn, of is teruggegrepen op de oorspronkelijke publicaties. Voor de macromineralen (calcium, fosfor, magnesium, natrium, kalium, chloor) zijn de voedernormen gebaseerd op de zgn. factoriële methode. Voor sporenelementen en de vitamines bleek deze benadering niet mogelijk. Het rapport bevat een groot aantal tabellen waarin de voedernormen voor de genoemde nutriënten voor alle relevante fysiologische stadia.
    Effects of hatching time and hatching system on broiler chick development
    Ven, L.J.F. van de - \ 2012
    Wageningen University. Promotor(en): Bas Kemp; Peter Groot Koerkamp, co-promotor(en): Henry van den Brand; A.V. van Wagenberg. - S.l. : s.n. - ISBN 9789461734471 - 173
    vleeskuikens - kuikens - kunstmatig bebroeden - broedmachines - postnatale ontwikkeling - broedfactoren - broedinstallaties - dierfysiologie - groei - voedering - pluimveehouderij - broilers - chicks - artificial hatching - brooders - postnatal development - hatching factors - hatcheries - animal physiology - growth - feeding - poultry farming

    Key words: hatching time, hatching system, chick physiology, broiler growth, chick quality.

    Chicks hatch over a time window of 24-36 hours and are only removed from the hatcher when the majority of the chicks have hatched. Especially for the early hatching chicks this leads to delays in the first feed and water access and consequently negative effects on chick development. In an alternative hatching system, named Patio, the hatching and brooding phase are combined, thereby enabling direct posthatch feed and water access. Environmental conditions in Patio differ from those in hatchers, which may further influence chick quality, physiology, and growth. Chicks hatching at different moments may respond differently to these different conditions in both hatching systems. In this thesis, the first aim was to determine effects of hatching in the Patio system on hatchability, chick quality, and growth. The second aim was to determine the physiological status of chicks of different hatching moments, in the hatcher and the Patio system, at hatch, and at chick collection (21.5 d of incubation). Effects of hatching time and moment of first feed and water access on posthatch growth were also included.

    Hatchability of fertile eggs was 1.03% higher in the Patio system compared to the hatcher, which was probably due to different climate conditions during the hatching phase. At hatching, chick physiology was not clearly affected by hatching system, but effects of moment of hatching in the hatch window were clear: longer incubation times led to increased organ weights and decreased yolk weights, suggesting a higher level of maturation in late hatching chicks. At the moment of chick collection, Patio chicks, having immediate feed and water access,showed larger body and organ weights, higher hepatic glycogen reserves, higher plasma glucose and T3 levels, and lower corticosterone levels compared to hatcher chicks which were fasted between hatching and chick collection. Usinga chick qualitative score based on physical traits and the incidence of second grade chicks, chick quality was lower in Patio than in hatcher chicks. However the quality scores used were not predictive for posthatch performance. Patio chicks showed improved posthatch growth compared to hatcher chicks, which was not related to different climate conditions during hatching, but to earlier feed and water access. Apart from higher growth from d0-7 in early and midterm vs late hatching chicks, effects of hatching time on growth were not clear from this thesis.

    In conclusion, despite considerable differences in climate and other environmental factors, effects of hatching system on physiology of broiler chickens at hatch and growth performance up to slaughter age are limited. Perinatal chick physiology is affected by the moment of hatching in the hatch window, and by posthatch conditions in the hatching system, especially early feed and water access.

    Effect van exploratievoedering en hokbezetting op het welzijn van vleesvarkens = Effect of exploration feeding and space on welfare of growing finishing pigs
    Vermeer, H.M. ; Dirx-Kuijken, N.C.P.M.M. ; Wisman, J.H. ; Bikker, A.M. - \ 2012
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 546) - 18
    dierenwelzijn - varkenshouderij - varkens - vleesproductie - staartbijten - varkensvoeding - voedering - dosering - veebezetting - diergedrag - diergezondheid - animal welfare - pig farming - pigs - meat production - tail biting - pig feeding - feeding - dosage - stocking rate - animal behaviour - animal health
    To improve welfare of growing-finishing pigs the effect of exploration feeding and space allowance were tested and resulted in less skin.
    Kansen op de mestmarkt door mestscheiding en voeraanpassingen
    Hoop, D.W. de; Lakner, D. ; Cooten, W.C. van; Hoop, J.G. de; Bikker, A.M. ; Prins, H. ; Gebrezgabher, S.A. ; Meuwissen, M.P.M. - \ 2011
    Den Haag : LEI, onderdeel van Wageningen UR (Rapport / LEI : Onderzoeksveld Sector en ondernemerschap ) - ISBN 9789086154760 - 54
    dierlijke meststoffen - mestverwerking - scheiding - innovaties - markten - voedering - normen - aanpassing - animal manures - manure treatment - separation - innovations - markets - feeding - standards - adjustment
    Deze studie is gericht op de kansen voor verlichting van de toekomstige mestmarkt door mestscheiding en voeraanpassingen. Dit wordt geplaatst in de context van de toekomstige aanscherping van de normen voor het gebruik van mest. Een plan van aanpak geeft aanbevelingen om deze kansen te benutten.
    Verduurzaming van de zuivelketen via het krachtvoerspoor
    Beldman, A.C.G. ; Doorneweert, R.B. ; Dolman, M.A. ; Bergevoet, R.H.M. - \ 2010
    Den Haag : LEI Wageningen UR (Rapport / LEI : Onderzoeksveld Sector & ondernemerschap ) - ISBN 9789086154074 - 97
    diervoeding - diervoedering - voedering - energie - duurzame energie - animal nutrition - animal feeding - feeding - energy - sustainable energy
    Onderzoek naar de vraag in welke mate (de productie van) krachtvoer kan bijdragen aan verduurzaming verbetering van de efficïentie van energie. Er zijn mogelijkheden: ze zijn echter nogal complex en overstijgen het belang van de individuele agrariër of voerproducent
    Steeds meer inzicht in de celwand. Oogsttijdstip, groeiomstandigheden en ras bepalen celwandverteerbaarheid maïs
    Cone, J.W. - \ 2009
    Veeteelt 26 (2009)3. - ISSN 0168-7565 - p. 12 - 14.
    melkveehouderij - zea mays - plantenveredeling - voedering - celwanden - verteerbaarheid - dairy farming - zea mays - plant breeding - feeding - cell walls - digestibility
    Na jaren van veredeling op het kolfaandeel in de maisplant krijgt nu ook de celwandverteerbaarheid van de restplant meer aandacht. Waarom is de ene celwand wel verteerbaar en de andere niet? Onderzoek door ASG en Wageningen UR moet nieuwe inzichten geven voor verdere veredeling
    Het dieet van de Steenloper Arenaria interpres: een literatuuroverzicht
    Cremer, J.S.M. ; Smit, C.J. - \ 2009
    Texel : IMARES (Rapport / IMARES Wageningen UR C141/09) - 28
    arenaria (vogels) - scolopacidae - voedering - diëten - voedingsgedrag - nederland - voedingsecologie - waddenzee - westerschelde - arenaria (birds) - scolopacidae - feeding - diets - feeding behaviour - netherlands - feeding ecology - wadden sea - western scheldt
    Voeding biologische melkschapen : praktijkevaluatie voedernormen
    Verkaik, J.C. ; Hindle, V.A. ; Middelkoop, J.A. van; Riel, J.W. van; Sebek, L.B.J. - \ 2009
    Lelystad : Animal Sciences Group, Wageningen UR (Rapport / Animal Sciences Group 208) - 38
    schapenhouderij - biologische landbouw - melkveebedrijven - voedering - eiwitbehoefte - melkproductie - evaluatie - schapen - dynamisch modelleren - sheep farming - organic farming - dairy farms - feeding - protein requirement - milk production - evaluation - sheep - dynamic modeling
    On-farm assessment indicates that present feeding standards for dairy sheep lead to overestimation in protein requirement. The proposed lowering of the (protein) standards can be justified on both nutritional and economical grounds. The proposed lowering in feed protein allowance will lead to efficient protein use without reducing milk yield. An overestimation of 0.5 kg milk results in 15 to 25% over feeding. Improvements in roughage quality are essential to compliance with organic feed standards restricting concentrate inclusion to 40% of the ration. Economic optimalization of dairy sheep nutrition is possible using Dynamic Linear Modelling (DLM)
    Duurzaamheid diervoeding: feed vs food or fuel
    Gosselink, J.M.J. - \ 2008
    veevoeder - veevoeding - voer - diervoeding - voedering - bio-energie - biobased economy - voedsel versus brandstof - duurzaamheid (sustainability) - fodder - livestock feeding - feeds - animal nutrition - feeding - bioenergy - biobased economy - food vs fuel - sustainability
    Biomassaproductie ten behoeve van diervoeding (Feed) komt ook in het spanningsveld van de biobased economy terecht. Feed concurreert om biomassa met andere doelen, m.n. voedsel (Food) en bio-energie (Fuel). De concurrentie speelt zich af op basis van biomassa als grondstof alsook het landgebruik. Deze concurrentie zal voorlopig blijven bestaan ondanks dat er nog veel winst is te behalen om in de wereld de biomassaproductie te verhogen
    Eiwitnotering vers gras onderzocht; DVE lager en PEB hoger
    Klop, A. ; Brandsma, G.G. - \ 2008
    V-focus 5 (2008)2. - ISSN 1574-1575 - p. 14 - 15.
    rundveehouderij - weiden - begrazing - voedering - grassen - eiwitwaarde - voedingswaarde - waardesystemen - cattle husbandry - pastures - grazing - feeding - grasses - protein value - nutritive value - value systems
    In dit artikel meer over de eiwitwaarde van vers gras, die in het DVE/OEB-2007 systeem een andere waardering krijgt
    Dynamisch melken en voeren levert geld op
    Ouweltjes, W. ; Andre, G. ; Zom, R.L.G. ; Bleumer, E.J.B. - \ 2008
    V-focus 5 (2008)april (2). - ISSN 1574-1575 - p. 22 - 23, 25.
    melkveehouderij - melken - voedering - krachtvoeding - automatisering - melkstandinrichtingen - robots - lineaire modellen - dynamische modellen - bedrijfsresultaten in de landbouw - dairy farming - milking - feeding - force feeding - automation - milking parlours - robots - linear models - dynamic models - farm results
    Op het High-techbedrijf van de Waiboerhoeve is in 2006 een prototype voor een dynamisch lineair adviessysteem voor melken en voeren ontwikkeld en getoetst. De resultaten geven aan dat met deze benadering een aanzienlijk beter saldo behaald kan worden dan met traditionele adviezen
    AMS groep maakt keuze voor toekomst: weiden of opstallen? [Koe & Wij]
    Animal Sciences Group (ASG), - \ 2007
    melkveehouderij - melkkoeien - weiden - begrazing - voedering - agrarische bedrijfsvoering - melkveebedrijven - dairy farming - dairy cows - pastures - grazing - feeding - farm management - dairy farms
    De laatste bijeenkomst van de praktijkgroep AMS stond onder andere in het teken van de afweging weiden of opstallen. In tweetallen werd gespard over de motieven voor weidegang, de toekomst van het bedrijf en de afweging voor opstallen of weidegang in de nabije toekomst. Op basis van de aspecten economie, arbeid, maatschappelijke en persoonlijke waarden hebben de AMS deelnemers hun (voorlopige) keuze gemaakt en het zogenoemde afwegingspaspoort ingevuld
    Economie van summerfeeding en beweiding vergeleken [Koe & Wij]
    Animal Sciences Group (ASG), - \ 2007
    melkveehouderij - melkkoeien - weiden - begrazing - zomerstalvoedering - economische analyse - agrarische bedrijfsvoering - voedering - melkveebedrijven - dairy farming - dairy cows - pastures - grazing - zero grazing - economic analysis - farm management - feeding - dairy farms
    Tijdens de bijeenkomst van de groep Grote koppel op 12 juni 2007 zijn de vergelijkende cijfers besproken van klanten van Accon-AVM. Bedrijfsadviseur Lubbert van Dellen gaf toelichting op de verschillen tussen weiders en opstallers
    Registratie robotbezoek en voeding [Koe & Wij]
    Harbers, J. ; Groeneveld, L. ; Nistelrooy, J. van - \ 2007
    melkveehouderij - melkkoeien - voedering - opname (intake) - weiden - begrazing - robots - melkproductie - dairy farming - dairy cows - feeding - intake - pastures - grazing - robots - milk production
    Melkveehouders Johan Harbers, Leen Groeneveld en Jan van Nistelrooy uit de AMS groep hebben het voortouw genomen bij de analyse van de voedingsregistraties. Hoewel de drie heren, maar ook de rest van de groep het moeilijk vonden om harde conclusies te verbinden aan de analyseresultaten, is er toch een aantal trends waargenomen
    Weide / opstal-ervaringen zomer 2007 groep AMS [Koe & Wij]
    Animal Sciences Group (ASG), - \ 2007
    melkveehouderij - melkkoeien - weiden - begrazing - stallen - voedering - melkproductie - melkveebedrijven - dairy farming - dairy cows - pastures - grazing - stalls - feeding - milk production - dairy farms
    De ervaringen van een aantal melkveehouders worden in deze publicatie besproken. Wat viel tegen en wat viel mee in de afgelopen zomer (2007) m.b.t. het beweiden van de koeien? Het waren zeer wisselende ervaringen: sommige veehouders waren tevreden, terwijl anderen veel problemen hebben ondervonden. Blauwtong was hierbij vooral in het zuiden van Nederland een van de problemen. Vooral het wisselende weer had een storende invloed op de beweiding. Positief was het hoge grasaanbod
    Knelpunten en oplossingen Praktijkgroep Kleine Huiskavel [Koe & Wij]
    Animal Sciences Group (ASG), - \ 2007
    melkveehouderij - melkkoeien - weiden - begrazing - melkproductie - voedering - bijvoeding - agrarische bedrijfsvoering - melkveebedrijven - verkaveling - dairy farming - dairy cows - pastures - grazing - milk production - feeding - supplementary feeding - farm management - dairy farms - land parcelling
    Twee weideseizoenen heeft het project Koe & Wij inmiddels achter de rug. Hoe is het de deelnemers in de vier praktijkgroepen de afgelopen twee jaren vergaan? Hebben ze gezamenlijk oplossingen gevonden voor de benoemde knelpunten in hun praktijkgroep? Hebben ze die oplossingen ook al in de dagelijkse praktijk toegepast? Allemaal vragen waar per groep antwoord op wordt gegeven in een serie van vier publicaties. In dit eerste deel aandacht voor de praktijkgroep Kleine Huiskavel
    Knelpunten en oplossingen Praktijkgroep Hoge Productie (Koe & Wij)
    Animal Sciences Group (ASG), - \ 2007
    melkveehouderij - melkkoeien - weiden - begrazing - melkproductie - voedering - weer - melkveebedrijven - dairy farming - dairy cows - pastures - grazing - milk production - feeding - weather - dairy farms
    Het project Koe & Wij heeft inmiddels twee weideseizoenen achter de rug. Hoe is het de deelnemers in de vier praktijkgroepen de afgelopen twee jaren vergaan? Hebben ze gezamenlijk oplossingen gevonden voor de benoemde knelpunten in hun praktijkgroep? Hebben ze die oplossingen ook al in de dagelijkse praktijk toegepast? Allemaal vragen waar per groep antwoord op wordt gegeven in een serie van vier publicaties. In dit derde deel aandacht voor de praktijkgroep Hoge Productie
    Knelpunten en oplossingen Praktijkgroep Grote Koppel
    Durksz, D.L. - \ 2007
    Lelystad : Animal Sciences Group - 3
    melkveehouderij - melkveebedrijven - melkkoeien - weiden - begrazing - graslandbeheer - voedering - agrarische bedrijfsvoering - dairy farming - dairy farms - dairy cows - pastures - grazing - grassland management - feeding - farm management
    Het project Koe & Wij heeft inmiddels twee weideseizoenen achter de rug. Hoe is het de deelnemers in de vier praktijkgroepen de afgelopen twee jaren vergaan? Hebben ze gezamenlijk oplossingen gevonden voor de benoemde knelpunten in hun praktijkgroep? Hebben ze die oplossingen ook al in de dagelijkse praktijk toegepast? Allemaal vragen waar per groep antwoord op wordt gegeven in een serie van vier publicaties. In dit vierde en laatse deel aandacht voor de praktijkgroep Grote Koppel
    Voeropname en eettijd goed te sturen : onderzoek naar vermindering verenpikken bij jonge leghennen
    Krimpen, M.M. van - \ 2007
    De Pluimveehouderij 37 (2007)2. - ISSN 0166-8250 - p. 10 - 11.
    pluimveehouderij - passagetijd - voedering - verenpikken - legresultaten - onderzoek - poultry farming - transit time - feeding - feather pecking - laying performance - research
    Onderzoek naar het terugbrengen van verenpikken bij jonge hennen kijkt of een langere voedertijd een oplossing is, zonder dit ten koste te laten gaan van de legprestaties. Verslag van een onderzoek in de eerste acht weken van de legperiode, uitgevoerd door de WUR
    De voedselsituatie voor gruttokuikens bij agrarisch mozaïekbeheer
    Kleijn, D. ; Dimmers, W.J. ; Kats, R.J.M. van; Melman, T.C.P. ; Schekkerman, H. - \ 2007
    Wageningen : Alterra (Alterra-rapport 1487) - 50
    limosa limosa - voedering - natuurbescherming - agrarische bedrijfsvoering - graslandbeheer - overleving - ruimtelijke variatie - nederland - voedingsecologie - weidevogels - agrarisch natuurbeheer - limosa limosa - feeding - nature conservation - farm management - grassland management - survival - spatial variation - netherlands - feeding ecology - grassland birds - agri-environment schemes
    Mozaiekbeheer blijkt niet te leiden tot de gewenste verhoging van overleving bij grutto's. In dit rapport is onderzocht wat de vegetatiesamenstelling van de graslanden is en wat het aanbod aan ongewervelden voor weidevogels in die percelen is. Het blijkt dat kruidenrijke, schrale percelen een goede vegetatiestructuur gedurende de gehele kuikenperiode hebben; terwijl de ongewervelden in mei hoger is dan in juni
    Tibiale dyschondroplasie bij kalkoenen: Vijfde proef: geen effect langzame begingroei.
    Veldkamp, T. ; Voorst, S. van - \ 2007
    De Pluimveehouderij 33 (2007)48. - ISSN 0166-8250 - p. 16 - 17.
    pluimvee - kalkoenen - dierziekten - bewegingsstoornissen - dyschondroplasie - voedering - voedingsrantsoenen - onderzoeksprojecten - poultry - turkeys - animal diseases - movement disorders - dyschondroplasia - feeding - feed rations - research projects
    Vier onderzoeksinstituten in Schotland, Duitsland, Zwitserland en Nederland doen in EU-verband onderzoek naar bewegingsstoornissen bij kalkoenen. Nederland richt zich in zes proeven op de effecten van fokkerij en management op de ontwikkeling van tibiale dyschondroplasie (TD). In de vijfde proef is gekeken naar het effect van voersturing (sturing van het lichaamsgewicht). In dit artikel de bevindingen
    Weinig eiwit nodig in rantsoen met graan
    Klop, A. ; Plomp, M. - \ 2007
    Ekoland 27 (2007)1. - ISSN 0926-9142 - p. 22 - 23.
    melkveehouderij - voedering - voedingsrantsoenen - diergezondheid - graansoorten - tarwe - maïs - melkproductie - vetten - eiwitten - voeropname - melksamenstelling - biologische landbouw - dairy farming - feeding - feed rations - animal health - cereals - wheat - maize - milk production - fats - proteins - feed intake - milk composition - organic farming
    Informatie uit onderzoek naar langetermijneffecten van gemalen tarwe als krachtvoervervanger. Veel voer van eigen bedrijf of eigen regio is een streven van veel biologische melkveehouders. Daarbij kunnen granen als krachtvoervervanger een belangrijke rol spelen. Bij goede opbrengsten kan zelf graan telen financieel aantrekkelijk zijn. Maar hoeveel graan kun je voeren zonder problemen met diergezondheid en eiwitvoorziening? Praktijkcentrum Aver Heino zocht naar de grenzen
    Optimaal en efficient voeren van mosselbroed in een nursery
    Hiele, T.M. van der - \ 2007
    Yerseke : IMARES (Intern rapport / Wageningen, Institute for Marine Resources & Ecosystem Studies (IMARES) nr. 07.009) - 51
    mytilus edulis - mosselteelt - voedering - viskwekerijen - mytilus edulis - mussel culture - feeding - fish farms
    Stage verslag van een student van de hogeschool Zeeland, opleiding aquatische Ecotechnologie. Bij dit onderzoek is gekeken naar optimaal en efficient voeren van mosselbroed in een nursery. Geconcludeerd wordt dat de beste manier om mosselbroed in een nursery te voeren is door de algen toe te dienen in concentraties die gelijk zijn aan de pseudofaecesdrempel. Voeren in concentraties boven de pseudofaecesdrempel is verspilling van kostbaar gekweekte algen en draagt niet bij tot een snellere groei. Dit rapport laat zien dat Chaetoceros spp. een betere groei geeft dan Skeletonema costatum. Experimenten met andere algensoorten en combinaties van algen? soorten moeten uitwijzen welke soort of mix de beste groei geeft.
    Onderzoek naar een optimaal algendieet voor kunstmatig gekweekte mossellarven (Mytilus edulis)
    Marteijn, E.H. - \ 2007
    Yerseke : IMARES (Rapport / Wageningen, Institute for Marine Resources & Ecosystem Studies (IMARES) nr. 07.008) - 73
    mytilus edulis - mossels - mosselteelt - algen - voedering - mytilus edulis - mussels - mussel culture - algae - feeding
    Om tekorten aan mosselzaad aan te vullen hebben mosselvissers zaad geïmporteerd uit Ierland en zijn er mosselzaadinvanginstallaties uitgehangen. Een andere oplossing om het tekort aan te vullen is het kunstmatig kweken van mosselen. Het voedselaanbod bestaat uit fytoplankton, namelijk flagellaten en diatomeeën. Het doel van een hatchery is een hoge groeisnelheid met een hoog overlevingspercentage zien te bereiken
    Graan voeren aan melkvee : effecten op voeropname, productie en diergezondheid
    Klop, A. ; Plomp, M. - \ 2006
    Wageningen : Wageningen UR, Animal Sciences Group - 7
    melkveehouderij - biologische landbouw - melkkoeien - voedering - graan - graaneiwit - eiwitgehalte - tarwe - dairy farming - organic farming - dairy cows - feeding - grain - cereal protein - protein content - wheat
    In de praktijk willen biologische melkveehouders wel graan verbouwen en voeren als er maar geen extra (duur) eiwit uit krachtvoer tegenover hoeft te staan. Uit onderzoek blijkt dat dit niet nodig is. In dit rapport verslaglegging van voederproeven uitgevoerd op praktijkcentrum Aver Heino waarin de mogelijkheden zijn onderzocht van graan voeren in combinatie met een beperkte eiwitvoorziening.
    Dynamics of livestock development in Gujarat, India: experiences of an Indian NGO
    Patil, B.R. - \ 2006
    Wageningen University. Promotor(en): Herman van Keulen, co-promotor(en): Henk Udo; J.B. Schiere. - [S.l.] : S.n. - ISBN 9789085045304 - 158
    veehouderij - india - melkveehouderij - gemengde landbouw - landbouwkundig onderzoek - landbouwontwikkeling - experimenteel veldonderzoek - kruisingsfokkerij - voedering - diervoedering - modellen - bedrijfssystemenonderzoek - livestock farming - india - dairy farming - mixed farming - agricultural research - agricultural development - field experimentation - crossbreeding - feeding - animal feeding - models - farming systems research
    Keywords:    Agricultural R&D, field experimentation, crossbreeding, dairy, feeding technologies, mixed farming, farming systems research, modelling.

    Smallholder mixed crop livestock systems continue to be a dominant agricultural production system in many developing countries, includingIndia. Dairy farming is part and parcel of many such systems, and it is often seen as an important livelihood option to increase household income and to therefore contribute to poverty alleviation in rural areas. As a result, substantial efforts in agricultural R&D have been directed towards design of new technologies for smallholder dairy farming. Variable success in technology transfer has clearly shown that adoption is context-specific, related to the physical and socio-economic environment, access of farmers to resources, access to information and personal attitudes. A series of concepts and methods were developed to incorporate these considerations, and to replace narrow technology-driven approaches by broader ones such as Farming Systems Research (FSR).

    This thesis describes and analyses experiences of BAIF, an Indian NGO, with the use of FSR methodology in livestock development programmes inGujarat,India. The objectives were to identify criteria and methodologies for selection of appropriate livestock technologies for farm level, and to identify differences in the methods of selection of appropriate technology. Section 1 describes the variation in livestock production systems inIndiain general and in Gujarat-state. Livestock comprises defined and undefined breeds of cattle and buffalo. Total livestock population increased annually by over 1% in the last four decades, with buffalo and goat populations increasing faster than cattle. This section also gives background to the BAIF organization and to FSR methodologies. Section 2 more specifically describes theGujaratresearch area with agro-ecological zone-wise information on animal breeds, herd composition, feed resources, crops, and trends in seasonal availability of feed as derived from transects, Participatory Rural Appraisals, and mapping. Constraint analysis and modelling indicated limited genetic potential of the local breeds and shortage of feed resources, both quantitatively and qualitatively, as major constraints for livestock development. Crossbreeding for breed improvement and use of (improved) local feed resources were identified as suitable technologies to alleviate these constraints.

    Ex-post performance monitoring of some BAIF crossbreeding programmes show that crossbred cattle fitted well in the smallholder mixed farming systems of both tribal and non-tribal farmers in all three selected agro-ecological zones (Section 3). Milk production of crossbreds was substantially higher, as was livestock gross margin and household income. Although quality of the roughages is a major limiting factor, farmers owning crossbreds tried to adjust to the needs of the cows by feeding concentrates. There was no difference in workload and labour division between households with and without crossbreds. Crossbreeding thus proved a techno-economically and socially viable livelihood option for both mixed and landless farming systems inGujarat.

    Various modelling approaches were used in Section 4 to explore,ex ante,the suitability of feeding technologies such as urea supplementation, use of local and commercial concentrates, urea-treated straw with concentrates, and leuceana tree leaves for crop-livestock systems inGujarat,India. Major conclusions were that (i) concentrate feeding is beneficial to farmers with market access and crossbred cows, (ii) crossbreeding interventions are more remunerative for landless and tribal farmers than for non-tribal farmers; feeding interventions are more effective for crossbreds than for local cows, (iii) maximum farm income is achieved at medium milk yields per animal; higher milk yields require use of better feeds, which renders the straws of the grains useless for feeding; at farm level, the (economically) optimum cropping pattern would then shift from grain crops to cotton.This section continues with a narrative on BAIF's experiences with field testing of technologies at animal, at herd, at farm and watershed level, including a shift to crop research when dictated by local needs.Over a period of roughly 30 years, three phases in on-field testing can be distinguished, i.e., starting with a period of predominantly top-down approaches, moving to a phase with emphasis on participatory identification and testing of technologies, and then into a phase with work at community and watershed level. A few cases are discussed for each phase, illustrating the processes, methods and types of technologies involved, and drawing lessons on field experimentation for livestock and rural development in general. The studies brought out, among others, that adoption of technologies is facilitated when these use local (feed) resources, that are readily available, requires only small changes in farm practices, are relatively simple to implement, and yield tangible results in the short term.

    Section 5 analyses the dynamics in methods and approaches of BAIF's work on livestock development, as it grew from Gandhian roots into a large development organization. It emphasises the dynamics in approaches between top-down, objectivist and reductionist approaches on one hand and bottom-up, constructivist, holistic and self-organized approaches on the other hand. These experiences are set against similar developments on the (inter)national scene and in industrialized countries, along with factors that influence the changes, suggesting that agricultural R&D behaves as a complex adaptive system with its own dynamics and associated paradigm shifts. It also discusses a number of cross-cutting issues such as the notion of real versus perceived problems, hierarchy and grid, phases in development and aspects of holism versus reductionism, also reflected in notions of goal and process orientation.Concluding, the thesis considers development as a continuous process, of which the goals change over time-and-space. This reflects a paradigm issue, and if development is indeed a dynamic process it implies that choice of methodology and technology) should go along with changes occurring in that process. Some guidelines regarding the usefulness of approaches and technologies are given. But agricultural R&D is ultimately considered to be a complex adaptive system, also inGujarat, and development organizations such as BAIF have to, therefore, show dynamic behaviour.
    Dairy cow performance on silage from semi-natural grassland
    Bruinenberg, M.H. ; Geerts, R.H.E.M. ; Struik, P.C. ; Valk, H. - \ 2006
    NJAS Wageningen Journal of Life Sciences 54 (2006)1. - ISSN 1573-5214 - p. 95 - 110.
    melkvee - melkkoeien - diervoedering - veevoeding - voedering - begrazingsexperimenten - voedingswaarde - voedergewassen - melkproductie - herkauwers - dairy cattle - dairy cows - animal feeding - livestock feeding - feeding - grazing experiments - nutritive value - fodder crops - milk production - ruminants - perennial ryegrass - white clover - digestibility - dandelion - chickweed - spurrey - ribwort - systems - sheep - dock
    The effects of including forage from semi-natural grassland in the diet of dairy cows were studied in a feeding trial with cows in mid-lactation. Diets were compared in which part of the silage from intensively managed grassland was replaced with 0% (100IM), 20% (20SPP), 40% (40SPP) or 60% (60SPP) silage from species-poor semi-natural grassland or with 60% silage from species-rich semi-natural grassland (60SPR). On a dry matter basis, the total mixed ration (TMR) contained 63% grass silage, 18% maize silage and 19% concentrates. Concentrates were either low or high in protein to prevent protein surpluses or shortages. High producing cows were offered additional concentrates in concentrate boxes. The additional concentrates had the same composition as the concentrates in the TMR. With the 60SPP diet voluntary daily intake decreased by 1.4 kg DM cow¿¹ day¿¹. Uncorrected milk production was the same for all diets, but milk fat yield was lower with the 60SPP diet and milk protein yield lower with the 60SPR diet than with the other diets. No statistically significant differences in fat and protein corrected milk production were observed between the 100IM and the 20SPP diet. The fat and protein corrected milk production with the other diets was significantly lower than with 100IM. All cows gained body weight, but there were no statistically significant differences between diets. In conclusion, if used in low quantities (<40%), silage from semi-natural grassland can be included in the diet of lactating dairy cows without reducing production. This conclusion is based on the presented results and cannot be generalized.
    Cadmium in bodem en gras in het natuurgebied in en nabij de Malpiebeemden; onderzoek naar de kwaliteit van veevoer in relatie tot gezondheidsrisico's voor grazers
    Römkens, P.F.A.M. ; Rietra, R.P.J.J. ; Sival, F.P. - \ 2006
    Wageningen : Alterra (Alterra-rapport 1299) - 36
    cadmium - zink - begrazing - graasplanten - graslanden - rundvee - voedering - natuurbescherming - risicoschatting - nederland - noord-brabant - ecotoxicologie - cadmium - zinc - grazing - browse plants - grasslands - cattle - feeding - nature conservation - risk assessment - netherlands - noord-brabant - ecotoxicology
    In het Dommeldal nabij en in de Malpiebeemden komen sterk verhoogde gehalten aan cadmium, zink en in mindere mate lood in de bodem voor. Dit komt door zowel aanvoer via het riviersysteem (verontreinigd sediment) als via kwel uit de omliggende hoger gelegen delen. Het gebied is door Natuurmonumenten aangewezen als gebied voor grote grazers. Door de hoge gehalten in de bodem is het niet duidelijk of de kwaliteit van het gras wel voldoet aan wettelijke normen voor veevoer. Onderzoek aan bodem en gras toont aan dat de cadmiumgehalten in de bodem extreem hoog zijn. Waarden tot meer dan 100 mg kg-1 in de bodem zijn geen uitzondering. De aangetroffen waarden behoren daarmee, voor zover bekend, tot de hoogste in heel Nederland. Mede als gevolg van de extreem hoge gehalten in de bodem liggen in veel gevallen ook de cadmiumgehalten van het gras boven de daarvoor geldende norm van 1.1 mg Cd kg-1 ds. Risico's voor de gezondheid van dieren zijn daarmee niet uit te sluiten. De berekende blootstelling van runderen toont aan dat de acceptabele dagelijkse blootstelling in ruime mate overschreden wordt. Daarmee is ook de kans op effecten op de diergezondheid aanwezig. Gezien de hoge gehalten in de bodem, het gras en de daaruit volgende onacceptabele blootstelling moet begrazing en verkoop van het maaisel voor veevoer afgeraden worden. De gehalten in de bodem (en het gras) in de hoger gelegen delen naast het rivierdal komen overeen met eerder gerapporteerde waarden in de Kempen. De bodem- en graskwaliteit is in deze gebieden met beheersmaatregelen (bekalken) te reguleren zodat er geen risico's voor de diergezondheid bestaan.
    Een vergelijking van zes voeders voor paling
    Schram, E. - \ 2004
    IJmuiden : RIVO (RIVO rapport C048/04) - 13
    palingteelt - palingen - voedering - dactylogyrus - behandeling - medische behandeling - eel culture - eels - feeding - dactylogyrus - treatment - medical treatment
    Zes palingvoeders zijn in triplo getest in een volledig gewarde blokkenproef. Op dag 1 van het experiment zijn 18 tanks bezet met elk 100 palingen. Het gemiddelde gewicht van alle palingen in de proef bedroeg 68,4g. Dit leidde tot een gemiddelde initiële bezettingsdichtheid van 41,5kg/m3. De gemiddelde watertemperatuur gedurende het experiment bedroeg 23,5°C. De palingen werden dagelijks tweemaal met de hand gevoerd. Tijdens de tweede voedering werden de palingen tot volledige verzadiging gevoerd. Gedurende het experiment zijn de palingen op dag 9 en 27 met 7‰ NaCl en op de dagen 28, 32 en 38 met 150mg/l formaline behandeld ter bestrijding van (pseudo)dactylogyrus. Op dag 1 en op dag 41 van het experiment is voor elke tank het aantal palingen en de totale biomassa vastgesteld. Op basis hiervan en de geadministreerde dagelijkse voeropname is per voeder het gemiddelde voerniveau en de gemiddelde SGR en FCR berekend. De gemiddelde voerniveaus voor de verschillende voeders lagen tussen de 1,05 en 1,10%BW/d en verschilden onderling niet significant. De gemiddelde voederconversies voor de verschillende voerders lagen tussen de 1,33 en 1,41 en verschilden onderling niet significant. De gemiddelde specifieke groeisnelheden voor de verschillende voeders lagen tussen de 0,75 en 0,85%BW/d. De specifieke groeisnelheden gemeten voor voer 2 en 5 zijn significant lager dan de specifieke groeisnelheden gemeten voor voer 1, 3, 4 en 6. Bij de statische analyse van de gemeten specifieke groeisnelheid zijn twee afwijkende waarnemingen buitenbeschouwing gelaten. De besmetting met (pseudo)dactylogyrus en de behandelingen van de palingen hiertegen zijn hoogstwaarschijnlijk de oorzaak van realtief lage voeropname en groei.
    Na het seksen mesten? : onderzoek met haantjes van legrassen
    Middelkoop, J.H. van; Harn, J. van; Wiers, W.J. - \ 2003
    De Pluimveehouderij 33 (2003)6. - ISSN 0166-8250 - p. 10 - 11.
    kuikenproductie - geslachtsbepaling - hanen - afmesten - voedering - marketing - mestresultaten - voederconversie - vleesopbrengst - productiekosten - chick production - sex determination - cocks - finishing - feeding - marketing - fattening performance - feed conversion - meat yield - production costs
    Bij het mesten van haantjes van legrassen is er niet alleen het probleem van het vinden van een afzetmarkt die dit economisch haalbaar maakt, maar er is ook het probleem van de pikkerij.
    Voersystemen voor drachtige zeugen in groepshuisvesting
    Hoofs, A.I.J. ; Mheen, H. van der - \ 2003
    Praktijkkompas. Varkens 17 (2003)4. - ISSN 1570-8578 - p. 22 - 25.
    varkenshouderij - zeugen - varkensvoeding - zeugenvoeding - brijvoedering - droogvoedering - voertroggen - voedering - effecten - voedersystemen - groepshuisvesting - pig farming - sows - pig feeding - sow feeding - wet feeding - dry feeding - feed troughs - feeding - effects - feeding systems - group housing
    Welk voersysteem moet u kiezen als u zeugen in groepen gaat huisvesten? Dit is een vraag die menig varkenshouder bezighoudt. Het voerstation, de voerligbox met binnenuitloop en het biofixsysteem zijn bekende systemen. Hierover is redelijk veel informatie aanwezig. Er zijn echter ook systemen op de markt waarover veel minder bekend is. Hierdoor is het voor de varkenshouder moeilijk om een afgewogen keuze te maken
    Herculesstal toont technieken van de toekomst
    Wagenberg, V. van; Zonderland, J. ; Smolders, M.M.A.H.H. ; Klooster, K. van 't - \ 2003
    Praktijkkompas. Varkens 17 (2003)4. - ISSN 1570-8578 - p. 2 - 3.
    varkenshouderij - huisvesting, dieren - stallen - dierenwelzijn - duurzaamheid (sustainability) - milieubeheer - voedering - technieken - innovaties - experimentele uitrusting - economische haalbaarheid - voedersystemen - mestverwerking - proefboerderijen - pig farming - animal housing - stalls - animal welfare - sustainability - environmental management - feeding - techniques - innovations - experimental equipment - economic viability - feeding systems - manure treatment - experimental farms
    In de Herculesstal op Praktijkcentrum Sterksel worden vele nieuwe grensverleggende technieken samengebracht in één vleesvarkensstal. Dierenwelzijn, kostprijsbeheersing en milieu staan centraal. Daartoe worden speciaal ontwikkelde strodosators gebruiktsensorvoedering wordt geoptimaliseerd en de mest wordt met een nieuw type indamper/luchtwasser verwerkt tot hoogwaardige mestproducten. Kortom, veel interessante ontwikkelingen voor de varkenshouderij van de toekomst.
    Groepshuisvesting zeugen: brijvoedering met lange trog
    Hoofs, A.I.J. ; Mheen, H. van der - \ 2003
    Praktijkkompas. Varkens 17 (2003)3. - ISSN 1570-8578 - p. 16 - 17.
    varkenshouderij - zeugen - varkensvoeding - zeugenvoeding - voedering - gemeenschappelijke voeding - brijvoedering - troggen - voertroggen - varkensstallen - agrarische bedrijfsvoering - voedersystemen - groepshuisvesting - vloeibare voedering - pig farming - sows - pig feeding - sow feeding - feeding - communal feeding - wet feeding - troughs - feed troughs - pig housing - farm management - feeding systems - group housing - liquid feeding
    Brijvoedering via een lange trog combineert de managementvoordelen van gelijktijdig vreten, en stabiele groepen met de economische voordelen van het voeren van brijvoedering met brijproducten. Dit voersysteem geniet dan ook veel belangstelling vanuit de praktijk.
    Onbeperkt voeren drachtige zeugen beinvloedt reproductie niet
    Peet-Schwering, C.M.C. van der; Plagge, J.G. - \ 2003
    Praktijkkompas. Varkens 17 (2003)3. - ISSN 1570-8578 - p. 10 - 11.
    varkenshouderij - zeugen - zeugenvoeding - varkensvoeding - voer - onbeperkte voedering - voedering - gerantsoeneerde voeding - zwangerschap - prestatieniveau - worpresultaten - biggenproductie - zeugvoortplanting - voortplanting - voortplantingsvermogen - gewicht - gewichtstoename - lichaamsvet - rugspek - vetdikte - groepshuisvesting - voedersystemen - pig farming - sows - sow feeding - pig feeding - feeds - unrestricted feeding - feeding - restricted feeding - pregnancy - performance - litter performance - piglet production - sow reproduction - reproduction - reproductive performance - weight - weight gain - body fat - backfat - fat thickness - group housing - feeding systems
    Het gedurende drie opeenvolgende pariteiten onbeperkt voeren van drachtige zeugen met een aangepast voer beonvloedt de reproductieresultaten niet in vergelijking met het beperkt voeren van een gangbaar zeugenvoer. Na drie worpen zijn de onbeperkt gevoerde zeugen wel 25 kg zwaarder dan de beperkt gevoerde zeugen en hebben ze 3 mm meer spek aangezet.
    Scholeksters en hun voedsel in de Oosterschelde; rapport voor deelproject D2 thema 1 van EVA II, de tweede fase van het evaluatieonderzoek naar de effecten van schelpdiervisserij op natuurwaarden in de Waddenzee en Oosterschelde 1999-2003
    Rappoldt, C. ; Ens, B.J. ; Berrevoets, C.M. ; Geurts van Kessel, A.J.M. ; Bult, T.P. ; Dijkman, E.M. - \ 2003
    Wageningen : Alterra (Alterra rapport 883) - 137
    vogels - voedingsgedrag - schaal- en schelpdierenvisserij - mossels - charadriiformes - schaaldieren - voedering - populatie-ecologie - nederland - waddenzee - oosterschelde - birds - feeding behaviour - shellfish fisheries - mussels - charadriiformes - shellfish - feeding - population ecology - netherlands - wadden sea - eastern scheldt
    Les oiseaux piscivores comme indicateurs de la qualité de l'environnement marin: suivi des effets de la plche littorale en Afrique du Nord-Ouest
    Veen, J. ; Peeters, J. ; Leopold, M.F. ; Damme, C.J.G. van; Veen, T. - \ 2003
    Wageningen : Alterra (Alterra-rapport 666) - 190
    zeevogels - vogels - vissen - visserij - milieueffect - noord-afrika - senegal - biologische indicatoren - populatiedynamica - voedering - sea birds - birds - fishes - fisheries - environmental impact - north africa - senegal - biological indicators - population dynamics - feeding
    Les recherches rapportées ici avaient pour objectif d'établir un systOme de suivi permettant de mesurer les effets futurs de la plche devant la côte ouest-africaine. Les recherches concernaient le comportement dans les sites de reproduction et la nourriture des oiseaux de mer pour avoir une idée de la composition des espOces et de la taille des populations piscicoles. On a étudié quatre espOces parmi celles qui se reproduisent en colonies (Mouette u tlte grise, Goéland railleur, Sterne caspienne et Sterne royale) dans deux régions situées au Sénégal. Il s'est avéré que les changements annuels dans la taille des populations reproductrices des Sternes royales étaient en rapport avec la présence de certaines espOces de poissons. La condition physique des jeunes (de toutes les espOces) était relativement bonne dans toutes les années. La nourriture du Goéland railleur, de la Sterne caspienne et de la Sterne royale) différait par espOce d'oiseau, par colonie et par année d'observation. Toutes les espOcesmentionnées avaient un régime varié et, en conséquence, elles donnent des informations différentes sur la présence de populations piscicoles. On conseille de réaliser le systOme de suivi développé ici, dans toutes les grandes colonies d'oiseaux de mer situées de la Mauritanie jusqu'en Guinée. De préférence, on devrait agrandir le nombre d'espOces d'oiseaux u étudier en ajoutant des représentants de différents groupes écologiques, caractérisés par des différences dans leur biotope alimentaire et leur technique de gagnage.
    Welzijn (opfok) vleeskuikenouderdieren
    Haar, J. van der; Voorst, S. van - \ 2001
    Praktijkonderzoek. Pluimvee 15 (2001)1. - ISSN 1570-2537 - p. 21 - 25.
    voedering - diervoedering - dierenwelzijn - diergedrag - diergezondheid - opfoktechnieken - vleeskuikenouderdieren - feeding - animal feeding - animal welfare - animal behaviour - animal health - rearing techniques - broiler breeders
    Praktijkcentrum 'Het Spelderholt' heeft in samenwerking met ID-Lelystad onderzocht of tweemaal in plaats van eenmaal per dag voeren in de opfokperiode het welzijn van vleeskuikenouderdieren verbetert. Hiermee werd niet het verwachte effect op het gedrag verkregen.
    Triticale voor melkvee en jongvee
    Duinkerken, G. van; Bleumer, E.J.B. - \ 2000
    Lelystad : Praktijkonderzoek Rundvee, Schapen en Paarden (Publicatie / Praktijkonderzoek Rundvee, Schapen en Paarden (PR) 142) - 36
    rundvee - melkvee - kalveren - triticale - oogsten - voedering - cattle - dairy cattle - calves - triticale - harvesting - feeding
    Ten opzichte van een rantsoen met snijmaos en graskuil werd geen effect op voeropname en meetmelkproductie gevonden. Het rantsoen met triticale als enig ruwvoer leidde wel tot verminderde productieresultaten.
    Korte termijn advies voedselreservering Oosterschelde; samenvattende rapportage in het kader van EVAII
    Bult, T.P. ; Ens, B.J. ; Lanters, R.L.P. ; Smaal, A.C. ; Zwarts, L. - \ 2000
    [Den Haag] [etc.] : RIKZ [etc.] - 60
    schaaldieren - mossels - vogels - voedering - nederland - oosterschelde - aquatische ecologie - fauna - schelpdieren - watervogels - Zeeland - shellfish - mussels - birds - feeding - netherlands - eastern scheldt - fauna
    In 1999 is na een tussentijdse evaluatie het beleidsbesluit Schelpdiervisserij Kustwateren 1999-2003 vastgesteld. Dit hield o.a. in dat het voedselreserveringsbeleid dat in de periode 1993-1998 van kracht was voor de Oosterschelde, werd gewijzigd: De hoeveelheid voedsel die in de periode voor 1999 werd gereserveerd voor vogels in de Oosterschelde, was gerelateerd aan de gemiddelde voedselbehoefte van de vogels die eind jaren 80 in dit gebied aanwezig waren. Deze gemiddelde voedselbehoefte was vastgesteld op 3,4 miljoen kilo kokkelvlees en 1,3 miljoen kilo mosselvlees
    Fosforbehoefte rose vleeskalveren
    Plomp, M. ; Heeres-van der Tol, J.J. ; Schonewille, J.Th. - \ 1999
    Lelystad : Praktijkonderzoek Rundvee, Schapen en Paarden (Publicatie / Praktijkonderzoek Rundvee, Schapen en Paarden (PR) 139) - 27
    kalfsvlees - voedering - voeding - fosfor - veal - feeding - nutrition - phosphorus
    Op basis van de onderzoeksresultaten wordt voor rosé kalveren een P-gehalte in het rantsoen geadviseerd van 4 gram per kg ds over de totale afmestperiode, of een rantsoen met 4,5 g P per kg ds in de leeftijd van 14 tot 22 weken en 3,5 g P per kg ds vanaf 22 weken. Met deze rantsoenen kan het fosfaatoverschot op bedrijven met 25 tot 30 verminderen.
    Effects of thrips feeding on tospovirus transmission in chrysanthemum
    Wetering, F. van de - \ 1999
    Agricultural University. Promotor(en): R.W. Goldbach; S.B.J. Menken; D. Peters; C. Mollema. - S.l. : S.n. - ISBN 9789058080103 - 120
    chrysanthemum - thrips - voedering - plantenvirussen - plantenziekten - ziekteoverdracht - vectoren, ziekten - chrysanthemum - thrips - feeding - plant viruses - plant diseases - disease transmission - disease vectors

    The introduction and rapid spread of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in Western Europe since the 1980s led to a considerable increase of losses in different, mainly ornamental crops due to tomato spotted wilt tospovirus (TSWV) infections. Besides the losses inflicted by TSWV, F. occidentalis itself is also an important pest on many of these crops. Chrysanthemum is one of those crops which is affected by both TSWV and its vector. Breeding and selection of this plant species has resulted in the identification of a few chrysanthemum cultivars with some partial resistance to thrips. However, resistant cultivars to TSWV have not been successfully developed yet, meaning that the control of TSWV has to rely on other strategies. Besides sanitation programs, other successful strategies to control TSWV or F. occidentalis are currently not available.

    To develop durable and effective control measures and integrated pest management strategies, more detailed knowledge of the precise interactions between the virus, its vector and the threatened crop is required. Since transmission of TSWV is associated with ingestion of food, the feeding behaviour of thrips is one of the most determining factors in virus transmission. This study was therefore aimed to analyse the interactions between virus, vector and (chrysanthemum) plant in relation to thrips feeding.

    Tospovirus is acquired by larvae and transmitted by old second instar larvae and adults after their emergence. As a first feature, the ability of larvae to acquire TSWV was analysed in relation to their age. The results obtained in a study with several F. occidentalis populations showed that the ability to acquire virus (defined as ingestion of virus by larvae, subsequently developing in viruliferous adults), dropped with the age of larvae. A notable result was obtained with one of the populations (NL3), which could only acquire TSWV when larvae were in their first larval (L1) stage.

    Besides the age of the larvae at which they acquire virus, other parameters such as the F. occidentalis population involved, the feeding behaviour by the amount of food ingested, the virus species acquired and the host plant involved were studied for their effect on virus acquisition and transmission. Large and significant differences were found in TSWV transmission competencies between fourteen F. occidentalis populations which originated from different countries all over the world. These differences were not affected by the amount of virus ingested or the host used as virus source. However, the use of another tospovirus species, impatiens necrotic spot virus (INSV), influenced the transmission differences between populations. The transmission efficiencies found appeared to be rather constant, supporting the view that the competence of a population to transmit TSWV is a stable, and, therefore, inherited property.

    The efficiency at which the F. occidentalis populations transmitted INSV was higher than that of TSWV. This observation confirms earlier reports that the different tospovirus species are transmitted at distinct rates by the same thrips population. It is likely that various isolates of TSWV will also be transmitted at different rates by one and the same F. occidentalis population as has been shown for some Thrips tabaci populations. In contrast to TSWV, INSV is acquired by L1s as well as second larval instars (L2s) of the NL3 population.

    Further studies revealed that males of F. occidentalis are more efficient TSWV transmitters than females. This feature was found for all fourteen F. occidentalis populations tested. The differences in virus transmission competencies between both sexes can be explained by differences in their feeding behaviour. Males produce less silvery scars and make more frequent inoculation punctures than females. These punctures may represent the event during which the virus is successfully transmitted, as cells remain viable allowing virus to be replicated after virus-containing saliva injection. In addition, cells which are pierced and drained in the feeding process (resulting in silvery scars) are probably so destroyed that they will not support virus replication.

    The different efficiencies by which males and females transmit virus may have an impact on the spread of the virus in a crop. Males may infect more plants than females as they show a higher mobility and the sex ratios in flights are male-biased. However, the contribution of males to the spread may be compensated or outweighed by the greater life expectation of females. Quantification of the development of an epidemic in terms of which part is caused by males and which by females, will be extremely difficult as the ratio between males and females will change continuously and their age can not accurately be determined.

    To analyse whether thrips resistant chrysanthemum cultivars could effectively be used to control TSWV spread in this crop, fifteen cultivars were assessed for their susceptibility for this virus. All cultivars were susceptible, irrespective their degree of thrips resistance. However, the number of plants that attracted an infection varied for each cultivar. lt appeared in this study that the infection proceeds poorly in the infected plants and that the virus became unevenly distributed over the plant. A consequence of these observations is that in the chrysanthemum crop the virus will disperse slowly from primary infected plants. No L1s emerging on such plants, or only a small proportion of them, will acquire virus. With the development of the infection in the plant and development of the thrips population, more larvae will be able to acquire virus and thus become transmitters. This means that the early developing population of thrips found on primary infected plants by incoming (dispersing) adults will hardly contribute to the (intercrop) spread of the virus an that, with time, the infection pressure may increase from these primary infected plants. Studies on assessing the development of viruliferous thrips in a population on a primary infected chrysanthemum plant should enhance our understanding of TSWV spread in chrysanthemum.

    In most cases, tospovirus infections have been attributed to virus introduction from sources located outside the crop, and less to secondary (intercrop) spread in the crop as reported for groundnut, tomato and pepper. The incidence of TSWV infections in the Dutch chrysanthemum crops is low, despite the fact that TSWV transmission to chrysanthemum occurs highly efficiently. Since the virus is not seed transmitted, the first infections may arise as a result from primary infections, subsequently followed by some secondary spread.

    Using plants in testing the susceptibility of chrysanthemum for TSWV and vector resistance is a time- and labour-consuming activity. An expeditious leaf disk assay was introduced to assess this susceptibility. This assay was also used to quantify TSWV transmission to a partially vector-resistant and a susceptible cultivar. It was shown that the inoculation access period in which 50% of the disks became infected (IAP 50 ) was shorter for a partially vector-resistant cultivar than for a susceptible cultivar, indicating that TSWV is more efficiently transmitted to the more vector resistant cultivar. This may be the result of a different feeding behaviour on the less preferred, partially resistant cultivar, resulting in a higher frequency of inoculation punctures in a unit of time, and subsequently in greater probability of successful transmission.

    The spread of TSWV will certainly be affected by the attractiveness of the plant as food source of the thrips. The lower development rate of viruliferous thrips and the shorter life expectancy on partially vector-resistant cultivars likely reduces secondary spread. On the contrary, the mobility and dispersal of thrips and subsequent TSWV transmission in enhanced on partially resistant vector plants, and hence, the use of vector-resistant cultivars may not under all circumstances lead to an effective control of TSWV spread.

    Management, milk production level and economic performance : an explorative study on dairy farms
    Rougoor, C.W. - \ 1999
    Agricultural University. Promotor(en): A.A. Dijkhuizen; R.B.M. Huirne; A. Kuipers. - S.l. : Rougoor - ISBN 9789054859734 - 145
    melkvee - koeien - melkproductie - melkopbrengst - melkveebedrijven - agrarische bedrijfsvoering - agrarische economie - graslandbeheer - weiden - voedering - mastitis - vruchtbaarheid - modellen - economische evaluatie - dairy cattle - cows - milk production - milk yield - dairy farms - farm management - agricultural economics - grassland management - pastures - feeding - mastitis - fertility - models - economic evaluation

    The research described in this thesis focuses on the relation between dairy herd management, milk production per cow, and gross margin per 100 kg of milk. The study was carried out as an explorative and empirical study. The thesis is composed of five parts.

    First, relations between technical data, including milk production, economic performance and nutrient losses were determined for a group of 478 farms. This part serves as the empirical basis for the study. Second, literature was reviewed as to the definition of management and management research.

    Third, based on this knowledge a field study was set up with 38 dairy farms. Technical and economic data were gathered during one year. Repeatability of economic data and milk production data was determined to get insight into the usefulness of one year of data. As could be expected, ranking over years of farms was not completely random. However, the ranking changed over time as well. This indicated that one year of data could be used to determine the influence of fixed effects on technical and economic performance, but year-effects cannot be separated.

    Fourth, two methodologies that were available to analyse this kind of data were described: Principal Components Regression (PCR) and Partial Least Squares (PLS). An overview of these two methodologies showed the advantage of using PLS for the current study, with a relatively large number of variables and complex relations that have to be determined.

    Fifth, the results of the analyses of the data set were described. Data were available on management, technical and economic performance. Ma-nagement data were acquired by questionnaires, observations, and a workshop. PLS-models were constructed to determine the relationships between pasture and feeding management and gross margin, milk production level and nitrogen loss. The models were used to define hypotheses for the relationship between pasture and feeding management and gross margin and milk production. Also two models were set up to determine the relationships between mastitis and fertility management and gross margin and milk production.

    In the concluding chapter, a schematic overview is given of management characteristics that are clearly related to gross margin per 100 kg of milk and milk production per cow. Characteristics of the farmer are a central element of 'the key to success'. A high production per cow is not the best economic option for each farmer. High production per cow should only be advised when the farmer is able to give the herd the detailed attention and interest that are needed.

    Comparison of four housing systems for non-lactating sows
    Backus, G.B.C. ; Vermeer, H.M. - \ 1997
    Rosmalen : Research Institute for Pig Husbandry (Report / Research Institute for Pig Husbandry P 5.1) - 12
    varkenshouderij - huisvesting, dieren - varkensstallen - varkens - zeugen - diergedrag - diergezondheid - productiviteit - voedering - vergelijkend onderzoek - pig farming - animal housing - pig housing - pigs - sows - animal behaviour - animal health - productivity - feeding - comparative research
    From January 1994 to March 1996, a comparative study was conducted to determine whether group housing of dry sows can be advised as an alternative for individual housing. In the study three group housing systems (free access stalls, trickle feeding and the electronic sow feeding) and one individual housing system (stalls) were considered. The four systems were compared on different aspects: i.e. animal behaviour, reproduction and replacement, health, feeding, labour and control, and economics
    Optimaliseringsmodel voor afstemming van voer- en klimaatschema bij vleesvarkens
    Otte, M.A. - \ 1996
    Wageningen : IMAG-DLO [etc.] (Nota / DLO-Instituut voor Milieu- en Agritechniek P 96-01) - 91
    varkens - vlees - voedering - klimaat - pigs - meat - feeding - climate
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