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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    The tree under which you sit : district-level management and leadership in maternal and newborn health policy implementation in the Greater Accra Region, Ghana
    Kwamie, A. - \ 2016
    Wageningen University. Promotor(en): Han van Dijk; I.A. Agyepong. - Wageningen : Wageningen University - ISBN 9789462576742 - 158
    health policy - birth - pregnancy - policy - management - administration - ghana - west africa - gezondheidsbeleid - geboorte - zwangerschap - beleid - bedrijfsvoering - bestuur - ghana - west-afrika

    Health system governance has to do with decision-making – who makes decisions, when, where, how and why. At the district level – the level of care which operationalises health policies – governance is critical, yet remains little understood. Governance has the ability to influence health system performance, and this is essential in maternal and newborn health, where timely decisions are required to support policy implementation. In this regard, district managers are particularly important. They are the link in the middle of the health system, connecting top-end policy formulation to bottom-end implementation. Their abilities to interpret, translate, support and challenge policy will have an effect on what gets operationalised. However, capacity weaknesses in district management and leadership are often cited as a factor in poor health system performance.

    This thesis seeks to deepen understandings of district-level management, leadership and decision-making for policy and programme management and implementation for maternal and newborn health. Within this, the thesis also seeks to understand the scope for change that an intervention to strengthen management and leadership capacities can bring.

    This thesis contributes to the applied field of health policy and systems research by drawing on policy implementation theory, organisational management theory and complexity theory as its theoretical basis. A realist approach methodology was undertaken to understand the contexts in which district managers are embedded, how this influences their decision-making, and what the effects of a managerial intervention are, given these contexts. The thesis followed an embedded case study flexible design. The first case study was an exploratory qualitative case study to understand how and why district managers make decisions in maternal and newborn health policy implementation. The second case study was an historical case study of district manager decision-space over time. The third case study was an explanatory qualitative case study of the management and leadership intervention. The final validation of our theorising throughout the cases was achieved through the administration of a questionnaire across all district health management teams of the Great Accra Region.

    This thesis demonstrates that district managers find themselves in contexts of strong hierarchical authority and resource uncertainty – in particular, lacking financial transparency. This promotes a management and leadership typology which attunes managers towards serving the health system bureaucracy, resulting in reduced district-level responsiveness to maternal and newborn health challenges. The outcome is that district manager decision-space is narrow surrounding resource allocation decisions, and this in turn affects local planning programming and management.

    The thesis further demonstrates that broader patterns of centralised governmental decision-making have affected the development of the district health system over time. Particularly, the sequencing of decentralisation processes has ensured that national-level decision-making has remained empowered in contrast to district-level decision-making. System fragmentation – through reduced Government of Ghana funds and increasingly verticalised donor funds – has also been a contributor. This accounts for the observed hierarchical authority and resource uncertainty which affects district managers. As a result of these contexts, this thesis also showed that an intervention to strengthen management and leadership capacities was limited in its sustainability.

    This thesis raises the issues of health system organisation as critical to the potential of district management and leadership effectiveness. It provides evidence that weaknesses in district management and leadership arise out of the organisational governance mismatches in autonomy and responsibility. It suggests that in strengthening management and leadership, approaches which seek to address organisational capacities, not only individual capacities, are needed to convey sustainable change. Advancements in this regard have the scope to improve district manager decision-making for maternal and newborn health policy and programme implementation in the future.

    Pupping habitat ofd grey seals in the Dutch Wadden Sea
    Brasseur, S.M.J.M. ; Groot, A.V. de; Aarts, G.M. ; Dijkman, E.M. ; Kirkwood, R.J. - \ 2015
    Den Burg : IMARES (Report / IMARES C009/15) - 104
    halichoerus grypus - habitats - whelping - birth - vegetation - geomorphology - wadden sea - halichoerus grypus - habitats - jongen werpen - geboorte - vegetatie - geomorfologie - waddenzee
    Atlantic grey seals (Halichoerus grypus grypus) started recolonising Dutch coastal haul-outs in the 1950s, after practically 500 years of rarity in the Dutch coastal zone which was caused mainly by human hunting. The first pup-birth was recorded in 1985 at the Wadden Sea sandbank of Engelschhoek. Sandbanks in the Wadden Sea may form and recede in periods of decades, but may change abruptly as a result of a single storm. These rapidly evolving places are not the perfect breeding habitat for grey seals, which exhibit long-term fidelity to breeding sites and only reluctantly shift. Little is known of the geomorphology of the currently utilised pupping sites, nor the implications of change in structure on future occupation and selection of new sites.
    Regio heeft grote invloed op levensvatbaarheid
    Pellikaan, F. ; Ouweltjes, W. ; Windig, J.J. ; Muskens, J. ; Linden, R. van der; Pelt, M.L. van; Calus, M.P.L. - \ 2014
    Veeteelt 31 (2014)14. - ISSN 0168-7565 - p. 10 - 13.
    melkveehouderij - kalveren - levensvatbaarheid - geboorte - vaarzen - grote landbouwbedrijven - bedrijfsgrootte in de landbouw - landbouwstatistieken - bedrijfsvergelijking in de landbouw - invloeden - dairy farming - calves - viability - birth - heifers - large farms - farm size - agricultural statistics - farm comparisons - influences
    Een afname van zes procent levend geboren kalveren van vaarzen tussen 1995 en 2010 was aanleiding voor nieuw sectoronderzoek. Uit de inventarisatie blijkt dat naast bekende factoren als draagtijd en geboorteverloop de regio waar het bedrijf is gehuisvest en het seizoen van afkalven zorgen voor opmerkelijke verschillen in levensvatbaarheid van kalveren.
    Naar een probleemloos afkalvende dikbilkoe = Towards an easy-calving double-muscled cow
    Napel, J. ten; Hoving, A.H. ; Bohte-Wilhelmus, D.I. ; Hannewijk, P. - \ 2012
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 648) - 40
    rundveehouderij - vleesvee - dierenwelzijn - keizersnede - dierveredeling - selectief fokken - geboorte - dierlijke productie - diergezondheid - vleesveerassen - cattle husbandry - beef cattle - animal welfare - caesarean section - animal breeding - selective breeding - birth - animal production - animal health - beef breeds
    A measuring and breeding programme has been developed for easy calving doublemuscled beef cattle.
    Vijftig procent natuurlijk kalven is economisch te verantwoorden. Een kwestie van durf?
    Eilers, C.H.A.M. - \ 2012
    Veeteeltvlees (2012). - ISSN 1570-3312 - p. 10 - 13.
    rundveehouderij - vleesproductie - geboorte - dierenwelzijn - kosten-batenanalyse - agrarische bedrijfsvoering - cattle husbandry - meat production - birth - animal welfare - cost benefit analysis - farm management
    Meer natuurlijk afkalven vergt een gericht fokkerijbeleid en een andere houding van vleesveehouders ten opzichte van natuurlijk afkalven. In onderzoek is nagegaan of een gedeeltelijke omschakeling de economische resultaten in de praktijk onder druk zet.
    Natuurlijke geboorte extreme vleesrassen
    Napel, J. ten - \ 2012
    V-focus 9 (2012)5a. - ISSN 1574-1575 - p. 15 - 17.
    rundveehouderij - vleesvee - verbeterd roodbont - belgisch witblauw - dierveredeling - fokwaarde - geboorte - dierenwelzijn - dierlijke productie - cattle husbandry - beef cattle - improved red pied - belgian blue - animal breeding - breeding value - birth - animal welfare - animal production
    Dikbilkoeien die probleemloos natuurlijk afkalven is geen utopie. Na drie jaar voorbereidend onderzoek en vier jaar onderzoek in de praktijk binnen het project Natuurlijke Luxe is duidelijk hoe dat moet. Het belangrijkste is om met fokkerij de ruimte in het geboortekanaal te vergroten. Of dat ook gebeurt, is nu een kwestie van willen en doen.
    Lammerensterfte, leverbot en ureum bij melkschapen
    Verkaik, J.C. ; Smolders, G. - \ 2010
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 417) - 27
    biologische landbouw - schapenhouderij - mortaliteit - lammeren - schapen - leverbot - ureum - geboorte - agrarische bedrijfsvoering - quarantaine - eiwitopname - zware metalen - organic farming - sheep farming - mortality - lambs - sheep - liver flukes - urea - birth - farm management - quarantine - protein uptake - heavy metals
    The monitored lamb mortality at organic dairy sheep farms is relativly high with big differences. Mortality over 10% is caused by poor management and infectious abortions. Short term improvements needs a structured approach. Treatment of the dairy sheep is limited to the dry period. Avoiding infection by housing ewes in early lactation appears effective. Liver fluke is well predictable on the prognosis and the fluke and grazing history. The time between infection intake and appearance in blood or dung makes these researches risky. Urea appears dependable upon the amount of protein fed. Protein wastage reduces when more energy is fed.
    Minder keizersneden bij dikbillen
    Napel, J. ten - \ 2010
    Kennis Online 7 (2010)nov. - p. 8 - 8.
    rundveehouderij - vleesvee - keizersnede - geboorte - dierveredeling - cattle husbandry - beef cattle - caesarean section - birth - animal breeding
    Vrijwel alle dikbilkoeien komen met een keizersnee ter wereld. Wageningen UR Livestock Research werkt in het project ‘Natuurlijke luxe’ met de Federatie van Vleesveestamboeken Nederland aan meer natuurlijke geboorten.
    Cultuuromslag nodig : natuurlijke Luxe bij Verbeterd Roodbont : dier & welzijn
    Napel, J. ten - \ 2010
    V-focus 7 (2010)5A. - ISSN 1574-1575 - p. 24 - 25.
    dierenwelzijn - geboorte - rundveerassen - rundveehouderij - rassen (dieren) - verbeterd roodbont - animal welfare - birth - cattle breeds - cattle husbandry - breeds - improved red pied
    Het streven naar meer natuurlijke geboorten bij Verbeterd Roodbont is in een nieuwe fase gekomen. Het stamboek heeft de trekkende rol overgenomen van Wageningen UR Livestock Research en stimuleert en ondersteunt zijn leden met concreet advies. Het doel wat het stamboek voor ogen heeft is 50 procent natuurlijke geboorten in 2020. Een portret van een cultuuromslag.
    Meetprogramma dikbilrassen biedt veel perspectief
    Napel, J. ten - \ 2010
    V-focus 7 (2010)5. - ISSN 1574-1575 - p. 42 - 43.
    rundveehouderij - vleesvee - vleesveerassen - belgisch witblauw - geboorte - dierveredeling - selectief fokken - bekken - verbeterd roodbont - cattle husbandry - beef cattle - beef breeds - belgian blue - birth - animal breeding - selective breeding - pelvis - improved red pied
    De inwendige bekkenhoogte van een koe vertoont veel variatie, is sterk erfelijk en hangt nauw samen met de kans op een natuurlijke geboorte van het kalf. Dit maakt selectie voor een grotere inwendige bekkenhoogte een geschikt instrument om bij Verbeterd Roodbont en Belgisch Witblauw vleesvee te selecteren voor natuurlijke geboorten.
    Sensor signaleert naderende geboorte
    Ipema, A.H. ; Hogewerf, P.H. ; Bleumer, E.J.B. - \ 2009
    V-focus 2009 (2009)12. - ISSN 1574-1575 - p. 24 - 25.
    melkveehouderij - melkkoeien - sensors - geboorte - kalven - dairy farming - dairy cows - sensors - birth - calving
    Met de nieuwe generatie draadloze sensoren, die momenteel in ontwikkeling is en langzaam voor de praktijk beschikbaar komt, kunnen steeds meer signalen van het individuele dier automatisch worden vastgelegd, zoals een naderende geboorte
    Ruimere koe... lichter kalf
    Napel, J. ten - \ 2008
    V-focus 5 (2008)2. - ISSN 1574-1575 - p. 36 - 37.
    rundveehouderij - vleesvee - geboorte - keizersnede - bevallingscomplicaties - dierenwelzijn - probleemoplossing - werkgroepen - cattle husbandry - beef cattle - birth - caesarean section - parturition complications - animal welfare - problem solving - working groups
    Hoe buig je de cultuur van systematisch toepassen van een keizersnede om naar meer natuurlijke geboorten? Wageningen UR begeleidt dit proces door vleesveehouders in werkgroepen zelf te laten zoeken naar oplossingen
    Baren op Beveland : vruchtbaarheid en zuigelingensterfte in Goes en omliggende dorpen gedurende de 19e eeuw
    Hoogerhuis, O.W. - \ 2003
    Wageningen University. Promotor(en): A.M. van der Woude. - Wageningen : S.n. - ISBN 9789058088581 - 333
    demografie - geschiedenis - geboorte - zuigelingensterfte - bevolkingsstatistieken - borstvoeding - zuigelingenvoedsel - nederland - menselijke vruchtbaarheid - zeeland - demography - history - birth - infant mortality - vital statistics - breast feeding - human fertility - infant foods - netherlands - zeeland
    This study deals with the high infant mortality on Zuid-Beveland, a region which is situated in the middle of the province of Zeeland in the south western part of the Netherlands. The study describes on a micro-level the development of infant mortality during the period 1811-1900 in Goes, a small market town, and four neighbouring villages. This research is based on family reconstitution data. The analyses show that infant-feeding practices were the most important determinants of fertility and mortality levels, followed by the season in which children were born. This study shows that women were likely to cease breastfeeding during the months betweenJulyto October. The increasing demand for women's time by agricultural activities, especially during the harvest season and in the summer-months, caused the absence of the mother in the family.Which led to inferior food for the infants and to an increase of infant mortality rate.High temperatures in hot summers also raised the mortality rate. Exploration of the relationship between fertility and mortality at the micro-level further showed that the probability of conception during the first year following giving birth was greater when the infant died than when the infant survived. The evidence of 'replacing' children who had died, casts new light on this apparent change in the balance between fertility and infant mortality in the middle of the nineteenth century.
    Extra dietary starch in late-pregnant sows fed a high fibre diet: effect on litter weight at birth
    Peet-Schwering, C.M.C. van der; Binnendijk, G.P. ; Verstegen, M.W.A. - \ 2002
    Lelystad : Praktijkonderzoek Veehouderij (Praktijkboek / Praktijkonderzoek Veehouderij 19) - 13
    zeugenvoeding - samenstelling - zetmeel - vet - voeropname - worpgewicht - geboorte - zeugen - zwangerschap - sow feeding - composition - starch - fat - feed intake - litter weight - birth - sows - pregnancy
    An experiment with 141 multiparous pregnant sows was conducted to investigate whether the supply of glucogenic energy at the end of pregnancy may be insufficient for an optimal growth of the foetuses in sows that are fed a diet with a high level of non-starch polysaccharides (NSP) and low level of starch. Sows were fed one of three diets from day 85 of pregnancy until parturition: : :Sows were fed a high NSP low starch diet. The daily intake of starch and sugar was 500 g. : :Sows were fed the same diet in the same amount as the sows in treatment 1 plus an extra daily amount of 500 g starch from wheat starch (is glucogenic energy). This means that the sows were fed 0.58 kg/d extra wheat starch (is 6.73 MJ glucogenic NE) during the last month of pregnancy. : :Sows were fed the same diet in the same amount as the sows in treatment 1 plus an extra daily amount of 200 g soya oil (is 6.73 MJ lipogenic NE). This treatment was added because otherwise it will not be clear whether energy or glucogenic energy is thelimiting factor. : :From day 1 of day 85 of pregnancy all sows were fed the high NSP low starch diet. During lactation all sows were fed the same lactation diet. Effects on litter performance, on changes in body weight and backfat thickness of the sows, and on feed intakeduring lactation were studied. The supply of extra dietary starch or extra dietary fat in late-pregnant sows that were fed a high NSP low starch diet did not increase litter weight at birth. This suggests that sows that were fed the high NSP low starch diet received sufficient glucogenic energy for foetal development. : :The number of stillborn piglets was numerically higher in sows that received extra dietary fat at the end of pregnancy. Sows that were fed extra dietary starch or extra dietary fat increased more in weight and backfat thickness during late pregnancy than sows that were fed the high NSP low starch diet. Decreases in weight and backfat thickness during lactation were similar for the three experimental treatments. Voluntary feed intake during lactation was slightly decreased in sows that were fed extra starch or extra fat in late pregnancy. :The present study shows that late-pregnant sows can be fed a high NSP low starch diet without adverse effects on litter weight at birth. A daily intake of 500 to 600 g starch and sugar in latepregnant sows seems sufficient for optimal growth of the foetuses.
    De invloed van geboorte-inductie en het tijdstip van vlekziekte-parvo-vaccinatie tijdens de zoogperiode op het interval spenen-bronst van zeugen
    Binnendijk, G. ; Vesseur, P. ; Vonk, M. - \ 1999
    Praktijkonderzoek varkenshouderij 13 (1999)1. - ISSN 1382-0346 - p. 22 - 24.
    zeugen - geboorte - zogen - oestrus - lactatieduur - drachtigheidsperiode - vaccinatie - parvoviridae - erysipelothrix - infectieziekten - sows - birth - suckling - oestrus - lactation duration - gestation period - vaccination - parvoviridae - erysipelothrix - infectious diseases
    Het effect van het al dan niet toepassen van geboorte-inductie in combinatie met het tijdstip van het toedienen van een vlekziekte-parvo-vaccinatie is onderzocht. Geboorte-inductie heeft effect op de drachtduur, het geboortegewicht van de biggen en het percentage biggen met spreidzit.
    Wederom goede aflamresultaten in het Low-inputsysteem!
    Verkaik, J. - \ 1998
    Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 11 (1998)6. - ISSN 1386-8470 - p. 4 - 5.
    schapen - low input landbouw - scharrelhouderij - milieueffect - geboorte - ontwikkeling - productiviteit - sheep - low input agriculture - free range husbandry - environmental impact - birth - development - productivity
    Het Low-input systeem, gekenmerkt door het ontbreken van huisvesting en het niet verstrekken van krachtvoer, heeft wederom goede aflamresultaten behaald.
    Thyroid hormones and iodide in the near-term pregnant rat
    Versloot, P. - \ 1998
    Agricultural University. Promotor(en): D. van der Heide. - S.l. : Versloot - ISBN 9789054858065 - 133
    metabolisme - schildklierhormonen - jodide - hormonale controle - voortplanting - ontwikkeling - schildklier - bevruchting - zwangerschap - geboorte - ratten - metabolism - thyroid hormones - iodide - hormonal control - reproduction - development - thyroid gland - fertilization - pregnancy - birth - rats

    Thyroid hormones, thyroxine (T4) and 3,5,3'-triiodothyronine (T3), are produced by the thyroid gland. To synthesize thyroid hormones the thyroid needs iodide. The uptake of iodide as well as the production and secretion of T4 and T3 by the thyroid gland is regulated by thyrotropin (TSH), which is produced by the pituitary. However, most of the biologically active form, T3, is produced from T4 via monodeiodination in peripheral tissues.

    This reaction is catalyzed by the deiodinases, type I (ID-I) in liver and kidney, and type II (ID-II) in the central nervous system and brown adipose tissue (BAT). T4 and T3 concentrations differ in the various tissues, like the contribution of T3 produced locally from T4. A large portion of the T3 produced in the liver enters the circulation, whereas T3 produced in the brain and cerebellum is mainly used locally.

    The production, distribution and transport of thyroid hormones are influenced by several (patho)physiological conditions. In this study we concentrated on the effects of pregnancy on maternal thyroid hormone metabolism. It is well known that thyroid hormones are very important for normal fetal development, especially of the central nervous system. During development thyroid hormones produced by the mother, mainly T4, contribute to the fetal thyroid hormone pools before and also after onset of fetal thyroid function. Insufficient production of maternal thyroid hormones during pregnancy can result in permanent brain damage in the offspring.

    At the end of gestation the concentrations of T4 and T3 in maternal plasma and tissues have decreased. In order to gain more insight into the effects of pregnancy on the production, distribution, and transport of thyroid hormones in the mother we performed kinetic experiments with T4 and T3 using nonpregnant and near-term pregnant rats (chapter 2). A bolus injection of [125I]T4 and [131I]T3 was given, and blood samples were taken at regular times during the next twenty-four hours.

    Physiological para-meters of the production, interpool transport, distribution and metabolism of T4 and T3 were estimated by means of a three-compartment model. According to this model three compartments can be distinguished: 1. the plasma; 2. the fast pool; and 3. the slow pool. Liver and kidney are considered to be the main components of the fast pool, whereas skin, muscles and brain belong to the slow pool.

    In the near-term pregnant rat the production and distribution of T4 remained unchanged. The transport of T4 from plasma to the fast pool was more than tripled, whereas transport to the slow pool remained constant. We suggest that in the near-term pregnant rat available T4 was distributed between the maternal and fetal compartments by means of very fast transport. This hypothesis is based on the fact that it seems unlikely that the transport of T4 to maternal liver and kidney, which are considered to be the main components of the fast pool, will have increased that much in the near-term pregnant rat. This was confirmed by the results of steady-state, double isotopic experiments using nonpregnant and near-term pregnant rats (chapter 3).

    In this study, the rats received a continuous simultaneous infusion of [125I]T4 and [131I]T3 in order to achieve equilibrium in all tissues. With this method it was possible to calculate the T4 and T3 concentrations, the relative contributions of plasma-derived vs. locally produced T3, the thyroidal T4 and T3 secretion rates, and the plasma-to-tissue ratios for T4 and T3. Indeed, the transport of T4 to liver and kidney, as well as almost all other maternal organs, was diminished. Since the production of T4 remained unchanged this implies that T4 is transported to another compartment, i.e. the feto-placental compartment. This compartment was not measured in these studies.

    The plasma appearance rate for T3 remained constant in the near-term pregnant rat. This was accomplished by an increase in the secretion of T3 by the thyroid and a decrease in locally produced T3. Less T3 was transported from plasma to liver, kidney, BAT and pituitary. ID-I activity in liver, and ID-II activity in the brain both increased during pregnancy. However, this did not result in an increase in the local conversion of T4 to T3 in these tissues. In the liver the contribution of T3 produced locally remained constant, while in the brain even a decrease was found.

    The insufficient availability of T4 in maternal tissues, as demonstrated by the lower T4 concentrations, might explain the discrepancy between deiodinase activities and the local production of T3. The transport of T4 to the feto-placental compartment resulted indirectly in a deficiency of T3 in the maternal organs. We can conclude that pregnancy affects maternal thyroid hormone metabolism. The mother has to share the available thyroid hormones, especially T4, with the fetuses.

    Iodide is an essential element for the synthesis of thyroid hormones. In rats the fetal thyroid is capable of producing thyroid hormones on day 18 of gestation. Iodide is transported across the placenta from the maternal to the fetal circulation. In chapter 4 we assessed iodide uptake by the maternal thyroid, while the iodide uptake by the fetal thyroid was estimated. We measured the in vivo uptake of 125I by the thyroid continuously. By using the specific activity of iodide in the urine we were able to calculate the absolute iodide uptake in the thyroid.

    Pregnancy resulted in a decrease in the absolute thyroidal iodide uptake. On day 20 of pregnancy the fetal thyroid is already capable of concentrating iodide. However, the difference in absolute iodide uptake by the maternal thyroid, compared to nonpregnant controls, cannot fully be explained by the transport of iodide to the fetal compartment and/or the mammary glands. The decrease in iodide uptake by the maternal thyroid has no impact on the thyroidal production of thyroid hormones.

    Iodine deficiency can lead to disturbed physical and mental development. In large populations in the world iodine intake is marginally deficient. For this reason a marginal iodine deficiency, instead of the more common severe iodine deficiency, was induced in our rats. We used this model to study the effects of marginal iodine deficiency on iodide metabolism (thyroidal iodide uptake; chapter 4) and thyroid hormone metabolism (kinetic experiments; chapter 5) in near-term pregnant rats.

    The absolute iodide uptake by the maternal thyroid was not affected by marginal iodine deficiency. The decreased plasma inorganic iodide was compensated by an increase in thyroidal clearance. A similar compensation was not found for the fetus; the uptake of iodide by the fetal thyroid decreased by 50 % during marginal iodine deficiency. During this marginal iodine deficiency plasma T4 and T3 remained constant in nonpregnant as well as near-term pregnant rats. The production rate and the plasma clearance rate for T4 were both decreased.

    No effects of marginal iodine deficiency on pool sizes and transport rates were found for nonpregnant rats. In the near-term pregnant rat marginal iodine deficiency resulted in a marked decrease in the transport of T4 from plasma to the fast pool. For T3 an increase in the production rate and plasma clearance rate was found for nonpregnant, marginally iodine- deficient rats, while these parameters were slightly decreased in near-term pregnant rats. Marginal iodine deficiency induced a 50 % decrease in the interpool transport rates of T3 between plasma and the fast pool in near-term pregnant rats. The hepatic activity of ID-I was increased as a result of marginal iodine deficiency in nonpregnant as well as near-term pregnant rats.

    On the basis of the results of thyroid hormone studies in normal pregnant rats (chapter 2 and 3) we suggest that during marginal iodine deficiency less maternal T4 is available for the fetal compartment. Together with the lower uptake of iodide by the fetal thyroid this can lead to diminished levels of thyroid hormone of maternal and fetal origin in the fetal organs. In this case, marginal iodine deficiency will have a negative effect on fetal development, especially of the brain.

    Another situation which irreversibly affects fetal brain development is maternal hypothyroidism. Two different levels of hypothyroidism were induced in female rats, by giving thyroidectomized rats two different doses of T4 and T3. The effects of hypothyroidism on maternal thyroid hormone metabolism in near-term pregnant rats (kinetic experiment, chapter 6) were studied. Plasma T4 and T3 levels were very low severely hypothyroid animals, whereas only plasma T3 was decreased in the mildly hypothyroid group. Even during this mild hypothyroidism profound alterations in the transport rates of T4 were found compared to intact, pregnant rats. The transport of T4 from plasma to the fast pool was decreased. Therefore, it appears that even during mild hypothyroidism the transport of T4 to the feto-placental compartment is affected.

    In conclusion: Pregnancy seriously affects the maternal thyroid hormone status. Despite an unchanged thyroidal production of T4, all maternal T4 tissue levels are decreased. Less T4 is available for the mother because of the transport of T4 to the feto-placental compartment. Indirectly this results in a T3-deficiency in most maternal organs. During marginal iodine deficiency and maternal hypothyroidism the transport of maternal T4 to the feto-placental compartment is diminished, whereas during marginal iodine deficiency the availability of iodine for fetal thyroid hormone syn-thesis is also decreased. Eventually this can result in impaired development of the fetal central nervous system.

    Van geboorte tot slacht in een hok
    Vermeer, H. ; Plagge, G. ; Binnendijk, G. ; Backus, G. - \ 1997
    Praktijkonderzoek varkenshouderij 11 (1997)1. - ISSN 1382-0346 - p. 4 - 5.
    huisvesting, dieren - dierhouderij - dierenwelzijn - geboorte - biggen - productiviteit - rentabiliteit - slachtgewicht - spenen - animal housing - animal husbandry - animal welfare - birth - piglets - productivity - profitability - slaughter weight - weaning
    De technische resultaten van varkens die van geboorte tot slacht niet worden verplaatst en gemengd zijn beter dan die van varkens die tweemaal verplaatst en eenmaal gemengd worden. Het laatste is in de praktijk gebruikelijk.
    Lammersterfte gedaald door aanpassingen Low-inputsysteem
    Boer, J. de - \ 1997
    Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 10 (1997)5. - ISSN 1386-8470 - p. 30 - 32.
    geboorte - schapen - lammeren - groei - ontwikkeling - extensieve landbouw - birth - sheep - lambs - growth - development - extensive farming
    De aanpassingen in het Low-inputsysteem die halverwege de aflamperiode van 1996 zijn ingevoerd zijn in 1997 verder verfijnd. De aanpassingen rondom aflammeren zijn bijzonder effectief. Dit jaar is de sterfte teruggelopen tot 12,1%. Het sterftepercentage is gelijk aan het landelijk gemiddelde.
    Sterftepercentage bij aflammen 'Low-input systeem' nog te hoog
    Boer, J. de - \ 1996
    Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 9 (1996)5. - ISSN 1386-8470 - p. 30 - 33.
    geboorte - ontwikkeling - groei - lammeren - massa - gewicht - voedergrassen - birth - development - growth - lambs - mass - weight - fodder grasses
    De verwachting was dat door een evenrediger leeftijdsopbouw en het verlagen van het geboortegewicht door het sturen van het grasaanbod de sterfte met 5 tot 8% verlaagd kon worden. Dit doel is niet gerealiseerd.
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