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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    Influence of pectin supplementation on feed fermentation characteristics in rats and pigs
    Tian, L. - \ 2016
    Wageningen University. Promotor(en): Harry Gruppen; Henk Schols. - Wageningen : Wageningen University - ISBN 9789462577282 - 142
    pigs - rats - pectins - feed supplements - dietary fibres - digestion - digestive tract - carbohydrates - microbial flora - nutrition physiology - animal nutrition - food chemistry - varkens - ratten - pectinen - voedersupplementen - voedingsvezels - spijsvertering - spijsverteringskanaal - koolhydraten - microbiële flora - voedingsfysiologie - diervoeding - voedselchemie

    The physiological effects of dietary fiber (DFs) depend on several factors including structural features of the DFs, composition and activity of colonic microbiota, and products formed during fermentation. In this thesis, the influence of pectin supplementation to feed fermentation characteristics in rats and pigs was studied. The non-starch polysaccharides (NSP) present in the selected feed ingredient oats were characterized. Distinct populations of arabinoxylans (AXs) were observed in oats, compared to those reported for other cereals like wheat and barley. The fate of cereal AXs and soybean pectin during fermentation and the consequent effects on appetite regulation and fat accumulation were studied in rats as a model. Oat AXs were fermented less rapidly than wheat AXs in the caecum of rats. Soy pectin was fermented more early and efficiently than cereal AXs. A significant inverse correlation between rat retroperitoneal fat-pad weight and concentration and relative SCFA proportion of butyrate was observed. In a following in vivo rat experiment, commercial soy pectin together with three other soluble pectins originating from citrus and sugar beet and differing in their methyl esterification were individually supplemented to the diets. Their effects on the utilization of the different DFs present in the feed and the consequent effect on the microbial community in the colon of rats was studied. All pectins were fermented rapidly and consequently shifted fermentation of other consumed DFs (e.g. cereal AXs) to more distal part of colon, although low-methyl esterified pectin was more efficiently fermented by the microbiota than high-methyl esterified pectin. Results suggested that pectins can confer beneficial health effects through modulation of the gut microbiota. In a last in vivo experiment, citrus pectins together with a hydrothermal treated soybean meal were supplemented to pig diets to study their effect on the digestion and fermentation of carbohydrates in both the small and large intestine. Pectins, and more particularly low-methyl esterified pectin, decreased the ileal digestibility of digestible starch resulting in more starch to be fermentated in the proximal colon of pigs. Consequently, also the fermentation patterns of DFs and the microbiota composition was affected. All pectins tested shaped the colonic microbiota from a Lactobacillus-dominated microbiota to a Prevotella-dominated community, with potential health-promoting effects.

    Linking early life conditions to osteochondrosis prevalence in gilts
    Koning, D.B. de - \ 2015
    Wageningen University. Promotor(en): Bas Kemp, co-promotor(en): Ilse van Grevenhof; Wouter Hazeleger. - Wageningen : Wageningen University - ISBN 9789462575042 - 234
    gelten - osteochondritis - varkensvoeding - vloertypen - bouw (dier) - voortbeweging - antilichamen - koolhydraatrijk voedsel - arginine - voedersupplementen - diergezondheid - gilts - osteochondritis - pig feeding - floor type - conformation - locomotion - antibodies - carbohydrate-rich foods - arginine - feed supplements - animal health

    Osteochondrosis (OC) involves the development of necrotic growth cartilage near the surface of a joint and is suggested to be associated with lameness in sows. Development of OC in pigs occurs at young age in a relatively short time frame of several weeks around 10 weeks of age. Due to this time dependency, one may wonder whether there are time dependent effects of factors or conditions associated with OC. The aim of this thesis was to assess whether OC prevalence is associated with conditions encountered in early life such as dietary restriction, floor type, conformation and locomotive characteristics (CLC), natural (auto-) antibodies (N[A]Ab), and carbohydrate levels. Indications for time dependent effects were found for dietary restriction on OC prevalence. This indicated that gilts receiving restricted feeding from 4 to 10 weeks of age and switched to ad libitum feeding until 26 weeks of age had a significantly higher prevalence of OC when compared to gilts receiving restricted feeding after 10 weeks of age. Time dependent effects of floor type were not clearly present, but gilts housed on a deep litter type system using wood shavings after weaning had a higher prevalence of severe OC when compared to gilts kept on a concrete partially slatted floor. Feed with a lower carbohydrate level increased OC prevalence compared to feed with a higher carbohydrate level. We hypothesized that the effects of dietary restriction, floor type, and dietary carbohydrate levels were mediated through loading of the joints either by, respectively, a short rapid increase in weight gain, higher incidence of play behaviors, or by an overall increased body weight. Although OC has been suggested to be associated with various CLC such as lameness, a consistent association of CLC at young age with OC at slaughter could not be found. This is likely due to CLC and OC both varying over time, making associations between the 2 entities complicated. There were indications that a component of the immune system is associated with OC as N(A)Ab against several antigens were found after weaning in association with OC. However, as with the CLC, associations with OC were not consistent over time, making it difficult to discern the exact associations between N(A)Ab and OC. To conclude, several early life conditions were found to affect or be associated with OC prevalence in gilts. This indicates that if one wants to reduce OC prevalence, one needs to start early after weaning. However, the exact implications of OC on CLC such as lameness and, therefore, welfare remain uncertain and require further studies into the long term welfare effects of OC.

    Phosphorus requirement in laying hens
    Lambert, W. ; Krimpen, M.M. van; Star, L. - \ 2014
    Lelystad : Schothorst Feed Research (Report / Schothorst Feed Research 1362-2) - 48
    hennen - fosfor - voedingsstoffenbehoeften - pluimveevoeding - voedersupplementen - diergezondheid - pluimveehokken - hens - phosphorus - nutrient requirements - poultry feeding - feed supplements - animal health - poultry housing
    It was hypothesized that P supply by feed in alternative housing systems can be lowered without negative effects on bone quality and production performance. Therefore, the objectives of the current study were 1) to update the retainable phosphorus (rP) needs of two modern laying hen breeds from 36 to 90 weeks of age housed in an aviary system, 2) to investigate the influence of dietary rP levels on Ca and P content in eggs, manure, carcasses and bones.
    Actuele ontwikkelingen in de preventie en bestrijding van maagdarmwormen bij schapen : Kernpunten uit een literatuurstudie
    Bokma-Bakker, M.H. ; Antonis, A.F.G. ; Ploeger, H. ; Vellema, P. ; Verkaik, J.C. - \ 2014
    Wageningen UR/Universiteit Utrecht
    schapenhouderij - maagdarmziekten - wormen - dierparasitaire nematoden - nematodirus battus - haemonchus contortus - teladorsagia circumcincta - schapenziekten - gastheer parasiet relaties - graslandbeheer - ziektebestrijding - dierveredeling - selectief fokken - voedersupplementen - schapenvoeding - sheep farming - gastrointestinal diseases - helminths - animal parasitic nematodes - nematodirus battus - haemonchus contortus - teladorsagia circumcincta - sheep diseases - host parasite relationships - grassland management - disease control - animal breeding - selective breeding - feed supplements - sheep feeding
    De schapensector gaat de parasitaire resistentie-ontwikkeling terugdringen. Ze wil dat doen door verbetering van de preventie en de bestrijding van maagdarmwormen. Experts hebben in 2013 een literatuurstudie uitgevoerd. Hierin zijn de belangrijkste binnen- en buitenlandse innovatieve ontwikkelingen voor verlaging van de infectiedruk opgenomen en vertaald naar toepasbaarheid onder de Nederlandse omstandigheden. Bekeken zijn de gebieden fokkerij, voeding, vaccinatie, beweiding, inzet van natuurlijke middelen en diagnostiek. In deze brochure zijn de belangrijkste bevindingen samengevat.
    Nutritional regulation of stearoyl-CoA desaturase in the bovine mammary gland
    Jacobs, A.A.A. - \ 2011
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Jan Dijkstra; Jurgen van Baal. - [s.l.] : S.n. - ISBN 9789461730954 - 176
    melkkoeien - melkklieren - acyl-coa desaturase - voedersupplementen - plantaardige oliën - onverzadigde vetzuren - genexpressie - rundveevoeding - diervoeding - dairy cows - mammary glands - acyl-coa desaturase - feed supplements - plant oils - unsaturated fatty acids - gene expression - cattle feeding - animal nutrition

    Increasing the proportion of unsaturated fatty acids (UFA) in milk is believed to be beneficial in terms of human health, thereby increasing the nutritional quality of milk. The proportion of UFA in milk is mainly dependent on the proportion of UFA in the diet, the degree of biohydrogenation of UFA in the rumen, and on activity of the stearoyl-CoA desaturase (SCD) enzyme in the mammary gland. This thesis focuses on SCD in the mammary gland of dairy cows, and how SCD can be influenced by nutrition. In the first study it was shown that supplementing the diet of dairy cows with soybean oil significantly decreases mammary SCD1 expression compared with rapeseed oil or linseed oil and this was partly reflected by the lower desaturase indices in milk. In contrast, mammary SCD5 expression was much lower (<103) than that of SCD1 and was not affected by dietary plant oil supplementation. To study the changes in genome-wide expression of genes in response to dietary UFA supplementation, mammary tissue samples of the same experiment were used for micro-array analysis. It was found that 972 genes were significantly affected through UFA supplementation, indicating that large transcriptional adaptations occurred in the mammary gland when diets of dairy cows were supplemented with unprotected dietary UFA. Since biopsy of the mammary gland is an invasive and costly method which presents a risk of udder infection, the use of milk somatic cells as a non-invasive, alternative source of mRNA was investigated in the second experiment. Since there was a significant relationship between SCD1 expression in milk somatic cells and mammary tissue, it can be concluded that milk somatic cells can be used as a source of mRNA to study SCD1 expression in dairy cows. To study the effects of acetate (Ac) and β-hydroxybutyrate (BHBA) as well as various long-chain fatty acids (LCFA) on mammary SCD expression, a bovine mammary epithelial cell line (MAC-T) was used in the third experiment. This study showed that Ac up-regulates expression of SCD1 and acetyl-CoA carboxylase in MAC-T cells, which indicates that Ac may increase desaturation and de novo synthesis of fatty acids in the bovine mammary gland. In addition it was shown that expression of sterol regulatory binding protein 1 (SREBP-1) and insulin-induced gene 1 protein (INSIG-1) was related to the expression of several lipogenic genes, thereby strengthening the support for the role of SREBP-1 and INSIG-1 as central regulators of lipogenesis in the bovine mammary gland. Overall, it can be concluded that saturated LCFA have little or no effect on SCD1 expression in the bovine mammary gland, whereas unsaturated LCFA inhibit mammary SCD1 expression. The regulation of SCD1 in the bovine mammary gland by LCFA appears to be, at least partly, regulated by the transcription factors SREBP-1 and INSIG-1. Based on the in vitro research it appears that short-chain fatty acids, in particular Ac, upregulate mammary SCD1 expression, although further research is needed to verify if short-chain fatty acids induce SCD1 expression in the bovine mammary gland. The recently discovered isoform SCD5 is expressed in bovine mammary tissue, although contribution to ∆9-desaturation of fatty acids appears to be quite low.

    Efficacy and safety of dietary N,N-dimethylglycine in broiler production
    Kalmar, I.D. - \ 2011
    Wageningen University. Promotor(en): Wouter Hendriks; Martin Verstegen, co-promotor(en): G.P.J. Janssens. - S.l. : s.n. - ISBN 9789085858751
    vleeskuikens - aminozuurderivaten - metabolieten - pluimveevoeding - voedertoevoegingen - voedersupplementen - vleeskuikenresultaten - verteerbaarheid - karkasopbrengst - oxidatieve stress - ascites - voederveiligheid - voedselveiligheid - voedingsfysiologie - diervoeding - broilers - amino acid derivatives - metabolites - poultry feeding - feed additives - feed supplements - broiler performance - digestibility - carcass yield - oxidative stress - ascites - feed safety - food safety - nutrition physiology - animal nutrition

    N,N-dimethylglycine (DMG), the dimethyl derivative of the amino acid glycine, is a naturally occurring intermediary metabolite in the choline to glycine metabolism. The molecule was first reported in 1943 and is currently used for a variety of applications, including the enhancement of athletic performances in both man and racing animals. With respect to its biological activities, DMG is for instance suggested to enhance oxygen utilisation and to posses non-enzymatic anti-oxidant properties. The studies described in this thesis aimed to evaluate DMG as a feed additive in chickens for fattening.

    In a pilot study, broilers were challenged with both cold stress and a high energy feed in order to incite broiler ascites syndrome. This metabolic disease results from an imbalance between oxygen requirement and supply, and is an important cause of financial losses and a major welfare issue in the modern broiler industry. A low dosage of dietary DMG effectively attenuated progression towards ascites. We hypothesize that this effect results from reduction in endothelial damage and dysfunction caused by plasma free fatty acids, which were substantially lowered by DMG supplementation. Furthermore, DMG improved nutrient digestibility and reduced nitrogen emission, which can be attributed to an emulsifying effect of DMG at the gut level. A subsequent trial revealed dose-dependent effects of dietary DMG on technical performance, carcass yield, oxidative stress parameters and broiler ascites syndrome. However, the nature and magnitude of the effects depended on fatty acid profile of the basal ration. Herein, effects were most pronounced when fed a diet rich in
    poly-unsaturated fatty acids. Generally, effects showed a linear relationship with dose, except for progression towards broiler ascites syndrome, which showed a quadratic relationship with dietary DMG content. Next, a series of efficacy trials were performed on farms at different European locations, using broiler strains and rearing conditions common to each region. Basal flock efficiency showed a wide range between trials; still, DMG systematically improved broiler performance. Finally, a safety and tolerance trial demonstrated a wide safety range of DMG in the target species. Moreover, DMG did not accumulate in consumer parts of broilers when included in diets at the recommended dosage, and bioaccumulation in meat at tenfold dosage did not exceed DMG content in for instance spinach.

    In conclusion, current investigations clearly demonstrate a wide applicability of DMG as a new feed additive in broiler production, in which both economic efficiency and environmental load as well as animal welfare is enhanced without compromising consumer safety.

    Evaluation of the optimum protein requirements for Vietnamese pigs
    Pham, K.T. - \ 2010
    Wageningen University. Promotor(en): Martin Verstegen; Wouter Hendriks, co-promotor(en): N. Le Duc. - [S.l. : S.n. - ISBN 9789085856115 - 188
    varkens - eiwitbehoefte - varkensvoeding - voer - voedingseiwit - lysine - voedersupplementen - prestatieniveau - diervoeding - vietnam - pigs - protein requirement - pig feeding - feeds - dietary protein - lysine - feed supplements - performance - animal nutrition - vietnam

    The studies reported in this thesis were carried out in Central Vietnam where pig production plays an important role and pig farmers face a general dietary protein shortage for their animals. The objectives of the work presented were (1) to investigate the crude protein (CP) supply to local Mong Cai (MC) pigs as well as lean type pigs (including crossbreds); (2) to derive CP requirements under high temperature conditions in the tropics; (3) to determine optimal lysine content in the diet of lactating Mong Cai (MC) sows and their piglets; (4) to evaluate the effects of floor types and dietary CP content on performance of sows and piglets. An interview based study of smallholders farmers showed that poor nutritive value of the diets for fattening pigs and sows is observed in three agro–ecological zones (Upland, Lowland and Coastal) in Central Vietnam. Pig on smallholder farms can produce more lean meat if they feed their pigs a higher dietary CP level. The optimum dietary CP level for the different breeds of pigs investigated (MC; F1, Large White Mong Cai and F2, (Landrace Mong Cai) Large White) were found to be 13 % for MC, 15 % for F1 and 16 % for F2 pigs. High dietary CP levels (>19 % CP) for MC, F1 and F2 negatively affected growth performance. The optimum dietary CP content for lean type pigs kept under the hot humid tropical climate of Central Vietnam to ascertain the maximum growth performance and carcass characters in Large White (LW) and Landrace (LD) pigs must be more than 16 % CP. The other study indicated that increasing dietary lysine level from 0.7 to 1.2 % reduced the sows weight loss during lactation. No effect was found on the number of piglets born nor piglet survival at 7 days. The number of piglets weaned was improved by lysine levels of over 1.02 %. Using raised wooden floors resulted in a higher number of piglets and litter weight at weaning compared to piglets on ground clay and concrete floor. In conclusion, the current work indicates that improving protein quantity and quality in traditional diets for Vietnamese pigs kept by smallholder farmers can significantly improve productivity of MC, F1 and F2 pigs, and as such improve the income of farmers.


    Feeding and management strategies for rural poultry production in Central Tanzania
    Goromela, E.H. - \ 2009
    Wageningen University. Promotor(en): Martin Verstegen, co-promotor(en): Rene Kwakkel; A.M. Katule. - [S.l.] : S.n. - ISBN 9789085853244 - 223
    pluimvee - pluimveehouderij - platteland - dorpen - bedrijfsvoering - pluimveevoeding - diervoeding - voedingsstoffen - voedersupplementen - legresultaten - tanzania - poultry - poultry farming - rural areas - villages - management - poultry feeding - animal nutrition - nutrients - feed supplements - laying performance - tanzania
    Keywords: Central Tanzania, rural poultry, scavengeable feed resources, nutrient composition, crop
    contents, season, farming system, chemical composition, supplementary feeding, weaning, egg production,
    growth rate, survival rate, laying management, indigenous chickens

    The main objective of the present study was to develop feeding and management strategies that would
    help to increase the overall productivity of rural poultry production in Tanzania. The first study which aimed at
    analyzing the existing poultry production systems in developing countries with special reference to the village
    poultry production showed that the productivity of village chickens is generally low. The second study
    showed that scavengeable feed resources (SFR) play a critical role in the village poultry production systems.
    SFR such as cereal grains and their by-products, oil seeds and oil seed cakes were the most important
    scavengeable feed resources (SFR) during the dry season; whereas forage leaves, flowers, seeds, garden
    vegetables, insects and worms were the most important SFR during the wet season. Nevertheless, the
    availability of the SFR varied with seasonal conditions, farming activities, land size available for scavenging
    and the flock size. The third study showed that the amount and physical composition of the crop/gizzard
    contents varied between the seasons and farming systems. The chemical compositions of the crop contents
    showed a higher crude protein (10.1%) and ash (24.9%) in the rainy season and higher metabolizable energy
    (12.2 MJ/kgDM-1) in the dry season. The study also showed that quantity and nutrient contents did not meet
    the birds’ requirements. Studies four and five were carried out on-farm with growing chicks and their mother
    hens to evaluate the effect of protein and energy supplementation and management practices (i.e.
    weaning and laying) on growth and carcass yield of chicks and the performance of broody hens. Chicks
    and hens supplemented with either high protein or low energy diets showed a higher body weight gain and
    high egg output respectively, than non-supplemented chicks and hens. Chicks weaned at 4 and 8 weeks of
    age had shorter length of reproduction cycles which increased the laying performances of scavenging hens
    without compromising chicks’ survival or growth rate. Similarly, hens supplemented with either high protein or
    low energy diets showed a higher body weight gain and high egg output than non-supplemented hens.
    Hens in Lay-hatch-rear group produced only about 30 eggs on average compared to the 53 eggs from the
    Lay-hat group and 73 eggs from the Lay group. It is concluded that the commonly observed low production
    performance of indigenous chickens is mainly due to inappropriate management conditions under which
    the birds are raised. Thus the productivity of indigenous hens under traditional management systems can be
    increased by supplementary feeding and relieving the hens from some aspects of the reproductive burden
    such as from brooding and rearing.
    Fyto-V eindrapport, Ontwikkelen van fytotherapie als middel bij het reduceren van en/of behandelen van dierziekten
    Groot, M.J. ; Noordam, M.Y. ; Kleter, G.A. ; Asseldonk, A.G.M. ; Kleijer-Ligtenberg, E. ; Halkes, S.B.A. ; Fink-Gremmels, J. ; Osch, H.H. van - \ 2009
    Wageningen : RIKILT (Rapport / RIKILT, Instituut voor Voedselveiligheid 2008.010) - 1009
    medicinale planten - veeartsenijkunde - vee - diervoedering - voedertoevoegingen - voedersupplementen - wetgeving - regelingen - nederland - europa - medicinal plants - veterinary medicine - livestock - animal feeding - feed additives - feed supplements - legislation - regulations - netherlands - europe
    This report describes the current legislation in the Netherlands, Europe and in a number of other important countries regarding the use of herbs in animals and in humans; the bottlenecks in current legislation as noticed by the registration authorities, the industry and the animal production sector; the recommendations of the project group to solve these bottlenecks.
    Multipurpose fodder trees in Ethiopia : farmers'perception, constraints to adoption and effect of long-term supplementation on sheep performance
    Mekoya, A. - \ 2008
    Wageningen University. Promotor(en): Akke van der Zijpp; Seerp Tamminga, co-promotor(en): Simon Oosting. - [S.l.] : S.n. - ISBN 9789085048183 - 207
    bomen voor meerdere doeleinden - veevoeder - houding van boeren - perceptie - beperkingen - voedersupplementen - schapenvoeding - prestatieniveau - bedrijfssystemen - ethiopië - bomen als veevoer - multipurpose trees - fodder - farmers' attitudes - perception - constraints - feed supplements - sheep feeding - performance - farming systems - ethiopia - fodder trees
    Many organizations in Ethiopia have promoted exotic multipurpose fodder tree species particularly Sesbania sesban for livestock feed and soil improvement. Despite the apparent benefits, the number of farmers planting these trees was low. Moreover, some farmers feeding Sesbania sesban reported reproduction problems in sheep. The latter was supported by a few short term reproduction studies conducted in Ethiopia. The present thesis was conducted to assess farmers’ perceptions about multipurpose fodder trees and about constraints to adoption, and to study effects of long-term feeding of Sesbania sesban on sheep performance. The farmers’ perception was studied by a field survey among 235 farm households from three district with different dominant farming systems (wheat, teff or coffee as the major crop) and the sheep performance studies were a series of experiments at the International Livestock Research Centre in Debre Zeit, Ethiopia.

    Farmers planted exotic multipurpose fodder trees for their feed value. The valuation for other purposes (soil and water conservation, use as fuel wood) depended on cropping system, vegetation cover and availability of alternative local fodder trees. Major constraints to adoption were agronomic problems, low multipurpose value, and land shortage. Farmers’ decision making criteria to adopt multipurpose fodder trees encompassed multiple objectives: farmers preferred local fodder trees to exotics for biomass production, multi-functionality, life span, and compatibility to the cropping system. In terms of feed value, ease of propagation, and growth potential local fodder trees were ranked lower than or comparable to exotics. A significant correlation was observed between farmers’ feed value score of a fodder tree species and the crude protein content assessed in the laboratory. The number of Sesbania sesban trees currently planted on-farm was about 30% of the recommended number for meat or milk production. Despite some farmers (11.8% of users) reported reproduction problems in sheep, the feed value of Sesbania sesban was appreciated across farming systems. However, the feed value was appreciated more in the wheat- and the teff-based farming systems than in the coffee-based farming system. From the results of the series of on-station experiments conducted for one whole reproductive cycle from post-weaning up to first lactation it was observed that supplementation of Sesbania sesban at 30% of the ration (0.98% of body weight) improved basal and total feed intake and digestibility, growth rate and the overall reproductive performance of sheep. No observable adverse effects of possible anti-nutritional factors in Sesbania sesban were found in this long term study.

    We conclude that the introduction of exotic multipurpose fodder trees need consideration of farmers multiple criteria, of local resources and knowledge and of the diversity of the farming systems. Introduction should be accompanied by practical training of farmers and of extension agents. The studies show that Sesbania sesban is a potential protein supplement that can be used to substitute commercial concentrates for smallholder farmers in the Ethiopian highlands.

    Animal health and immunomodulation of natural resistance = Diergezondheid en immunomodulatie van de natuurlijke weerstand
    Savelkoul, H.F.J. ; Tijhaar, E. - \ 2007
    Tijdschrift voor Diergeneeskunde 132 (2007)19. - ISSN 0040-7453 - p. 764 - 766.
    immunomodulatoren - immunostimulerende middelen - immunostimulatie - immuunsysteem - diergezondheid - dierziekten - dierhouderij - veevoeding - voedersupplementen - immunomodulators - immunostimulants - immunostimulation - immune system - animal health - animal diseases - animal husbandry - livestock feeding - feed supplements
    De huidige dierhouderij kent een aantal hardnekkige gezondheidsproblemen. Bij melkvee zijn dat met name mastitis, klauw- en reproductieproblemen. Bij varkens zijn dat intra-uterine sterfte en speendiarree en bij kippen is dat vooral het voorkomen van ascites. Deze gezondheidsproblemen zijn in het algemeen niet via gerichte vaccinaties te voorkomen. Bij sommige ziekten zijn vaccinaties wel degelijk zeer effectief maar dan kunnen andere overwegingen van maatschappelijke of handelspolitieke aard aanleiding zijn om deze niet uit te voeren. Bij fokkerij, houderij en voeding gaat het in het algemeen om slechts een productieparameter waarop wordt geoptimaliseerd. Daarna wordt door specifieke aanpassingen geprobeerd de gezondheidsconditie van de individuele dieren te verbeteren, hetgeen meestal veel tijd vergt. In dit artikel wordt ingegaan op het verbeteren van duurzame gezondheidscondities voor productiedieren en immunomodulatie
    WP3: wettelijke regelingen over gebruik van kruiden bij landbouwhuisdieren
    Groot, M.J. ; Noordam, M.Y. ; Kleter, G.A. - \ 2007
    Wageningen : RIKILT (Rapport / RIKILT 2007.017) - 70
    geneeskrachtige kruiden - voedertoevoegingen - voedersupplementen - voer - veevoeding - recht - regelingen - farmacologie - veeartsenijkunde - Nederland - herbal drugs - feed additives - feed supplements - feeds - livestock feeding - law - regulations - pharmacology - veterinary medicine - Netherlands
    Dit rapport is geschreven in het kader van het LNV onderzoeksproject FYTO-V ( en beschrijft de wettelijke regelingen voor het gebruik van kruiden bij landbouwhuisdieren. Er wordt onderscheid gemaakt tussen gebruik van kruiden als onderdeel van diervoeder, als aanvullend diervoeder, als diervoederadditief en als diergeneesmiddel. Ook is aandacht geschonken aan de toepassingsmogelijkheden binnen de biologische landbouw en de wetgeving in het buitenland.
    Proceedings of the Frontis workshop on fresh herbage for dairy cattle : the key to a sustainable food chain
    Elgersma, A. ; Dijkstra, J. ; Tamminga, S. - \ 2006
    Dordrecht : Springer (Wageningen UR Frontis series vol. 18) - ISBN 9781402054518
    melkvee - grasbestand - begrazing - soortenrijkdom - lolium perenne - voeropname - voedingsstoffen - voedersupplementen - graslandbeheer - stikstofmetabolisme - lipiden - melkkwaliteit - diervoeding - duurzaamheid (sustainability) - dairy cattle - herbage - grazing - species richness - lolium perenne - feed intake - nutrients - feed supplements - grassland management - nitrogen metabolism - lipids - milk quality - animal nutrition - sustainability
    Product quality and a sustainable food chain of ruminant products are largely determined by animal nutrition, in which forage is the major feed source. Forages and grasslands play a unique role in agriculture because they contribute through animals to our food supply and to the abatement of environmental problems. Interest in grassland management and grass utilization for dairy production in temperate and subtropical regions has recently led to considerable research efforts. In the past this research often emphasized on plant and animal aspects separately. However, the interrelationship between pasture and the grazing ruminant is a dynamic, two-way process. Many people are not aware of these complex relations, and scientists often focus on either soil-plant interactions, plant production, animal nutrition, animal production or product quality issues. This book contains the contributions of researchers and experts in the field of grassland management and grass utilization. Chapters are arranged in an order that allows progressive development within the food chain, moving from the big picture to basic principles of grassland management and effects on herbage quality, intake and nutrient flows.
    Consequences of different strategies of free amino acid supplementation to dietary proteins for physiological utillization
    Gas, M. - \ 2006
    Wageningen University. Promotor(en): Martin Verstegen, co-promotor(en): Victor Schreurs; J. Bujko. - s.n. : S.n. - ISBN 9789085043355 - 150
    ratten - diermodellen - diëten - voer - vrije aminozuren - voedersupplementen - voedingseiwit - katabolisme - oxidatie - voedingsfysiologie - rats - animal models - diets - feeds - free amino acids - feed supplements - dietary protein - catabolism - oxidation - nutrition physiology
    The efficiency of using free amino acids (AAs) as dietary constituent is sometimes lower than that of AAs derived from intact protein. The aim of the project was to evaluate dietary management conditions, which can determine the efficiency of utilization of crystalline AAs in animal diets or in clinical nutrition. The studies in this thesis were focused mainly on differences in short-term catabolism between protein bound and free AAs during the post prandial phase of a meal. The stable isotope technique was used in model studies with laboratory Wistar (WU) rats. In different experiments, so-called [ 13 CO 2 ]-breath test studies were used to compare the metabolic fate of free and protein-bound [1- 13 C]-labeled AAs in a meal in various nutritional situations. The influence of free AA supplementation strategies on weight gain development was also studied. Moreover, protein and fat content in the liver and carcass were analysed.

    The results of the present study confirm literature that showed a higher post prandial catabolic losses of the tracer when dietary protein is replaced with crystalline AAs. In some, but not all situations a lower weight gain was observed for growing animals. Our results showed that short-term catabolic losses of endogenous leucine were modulated by exogenous AA supply. It increased or decreased depending on the adequacy of the dietary supply.

    The common practice for free AA supplementation is to mix it with the deficient protein. In our study we showed that during the post prandial period the best utilization of methionine deficient protein did not occur when methionine supplement was given simultaneously with methionine deficient meal. The best utilisation occurred when there was a delay between the supply of deficient meal and free methionine. Therefore, introducing time interval of free amino acid supplementation to poor quality protein should be considered as a factor with potential to improve physiological utilization of dietary amino acids.A 1h time interval for free methionine supplementation influenced the weight gain, but differently depending on the protein level. Animals fed very deficient protein diet (5%) showed higher weight gain when supplementation of the deficient free methionine was provided with a 1h delay (1h interval). With protein deficient diets and less than 7.5 % protein we found fatty livers in our experiment. We concluded that post prandial AA oxidation influences the post absorptive AA catabolism. This does not always mean effect on growth. For growth in rats lysine deficiency is most limiting but it seems that even a 34% methionine deficiency below the NRC recommendation did not limit growth. We found that methionine deficiency influenced fat metabolism and from the literature we concluded that the mechanism probably works via choline and carnitin
    Phytase studies in pigs and poultry: effect on protein digestion and energy utilization
    Kies, A.K. - \ 2005
    Wageningen University. Promotor(en): Martin Verstegen, co-promotor(en): Walter Gerrits. - s.l. : S.n. - ISBN 9789085042228 - 148
    varkens - pluimvee - fytase - voedersupplementen - eiwitvertering - energiegebruik - varkensvoeding - pluimveevoeding - diervoeding - voedingsfysiologie - pigs - poultry - phytase - feed supplements - protein digestion - energy consumption - pig feeding - poultry feeding - animal nutrition - nutrition physiology
    Phytase is applied for improving digestibility of phosphorus in pig and poultry diets. Indepen-dently, phytase also improves animal performance. The mechanisms to explain this effect were investigated and quantified. Protein can be complexed with phytate, especially under the acid conditions that occurs in the stomach of animals. Dietary phytase supplementation pre-vents formation of such complexes or, if such complexes are formed, helps to release protein faster and to a larger extent from phytate. Consequently, protein digestibility may increase. This effect was confirmed in a meta-analysis of digestibility experiments, both in poultry and pigs. The higher protein digestibility explains, only in part, the improved performance. In poultry, the apparent metabolizable energy level increased with dietary phytase, mainly as the result of higher protein and fat digestion. Because in literature no effect of phytase on energy digestibility in pigs was shown, post-absorptive energy utilization was investigated. Using indirect calorimetry, no clear effect of phytase could be shown on energy partitioning. Phytase improved, however, energy utilization during the first two weeks post-weaning of ad libitum fed piglets. This may indicate that adaptation of piglets is somewhat facilitated by phytase. In an experiment with restrictedly-fed piglets, three weeks post-weaning, energy digestibility increased with phytase, but not energy metabolizability. A number of observations indicated, however, that energy metabolism of the piglets was affected. Processes that increase or de-crease heat production balance each other out. Phytase increased digestibility of minerals considerably, including the monovalent cations sodium and potassium. Mineral absorption and excretion are, in part, active processes, increasing heat production. Using a mathematical model, this effect was estimated at about 1% of energy requirements for maintenance. A lower energy requirement may result from a reduced produc-tion of endogenous protein. In growing pigs, dietary phytase supplementation decreased gastric mucin production. Possibly, the for-mation of inositol mono-, di- or tri-phosphates may act positively on the growth of animals, but this remains to be confirmed. In conclusion, phytase improved digestibility of amino acids, both in poultry and pigs. It also improved energy metabolizability in poultry. Energy utilization in pigs is probably affected, but the mechanism needs further clarification and quantification.
    Variatie in rantsoen verkleint kans op tekort aan vitaminen
    Smolders, E.A.A. - \ 2005
    V-focus 2 (2005)4. - ISSN 1574-1575 - p. 14 - 15.
    vitaminegehalte - diervoeding - voedersupplementen - vitaminetoevoegingen - vitaminetekorten - vitaminen - melkveehouderij - rundveevoeding - diergezondheid - vitamin content - animal nutrition - feed supplements - vitamin supplements - vitamin deficiencies - vitamins - dairy farming - cattle feeding - animal health
    In de EU is de discussie over het wel of niet toestaan van synthetische vitamines in veevoer weer opgelaaid. Met name de noordelijke EU-landen willen af van het verbod op deze stoffen omdat zij vrezen voor diergezondheidsklachten. Op vijf melkveebedrijven waar al jaren geen vitamines worden bijgevoerd, zijn de gevolgen onderzocht. Onderzoek is gedaan naar de vitaminegehalten in het voer, de bloedwaarden van de koeien, de diergezondheid en de vruchtbaarheid
    Tibiale dyschondroplasie bij kalkoenen: Hy.D in voer vermindert TD niet aantoonbaar
    Veldkamp, T. ; Voorst, S. van - \ 2004
    De Pluimveehouderij 34 (2004)21. - ISSN 0166-8250 - p. 18 - 19.
    kalkoenen - pluimveeziekten - bewegingsstoornissen - dyschondroplasie - botziekten - voedersupplementen - vitaminetoevoegingen - fosfor - calcium - kalkoenvoeding - turkeys - poultry diseases - movement disorders - dyschondroplasia - bone diseases - feed supplements - vitamin supplements - phosphorus - calcium - turkey feeding
    In zes experimenten onderzocht het Praktijkonderzoek het effect van verschillendede genetische, omgevings- en voedingsfactoren op het vóórkomen van tibiale dyschondroplasie (TD) en de ernst ervan bij vleeskalkoenen. In dit artikel de resultaten van de zesde en laatste proef. Hieruit bleek dat toevoeging van Hy.D (een vitamin D3-bron) bij laag of hoog calcium- en opneembaar fosfor-gehalte in de voeders (Ca en oP) geen effect had op het aantal qevallen van TD of de ernst ervan
    Kunnen biologische herkauwers zonder synthetische vitaminen
    Smolders, E.A.A. ; Kan, C.A. - \ 2004
    Praktijkkompas. Rundvee 18 (2004)2. - ISSN 1570-8586 - p. 2 - 3.
    melkkoeien - biologische landbouw - rundveevoeding - voedersupplementen - vitaminetoevoegingen - dairy cows - organic farming - cattle feeding - feed supplements - vitamin supplements
    Uit berekeningen blijkt dat er voor koeien in de stalperiode soms een tekort dreigt aan vitamine D en E. Voor vitamine A geldt dat alleen in rantsoenen met uitsluitende hooi. Gehalten van vitamine A in voordroogkuilen van gras/klaver op Bioveembedrijven komen redelijk overeen met literatuurgegevens. Die van vitamine E waren de helft van wat verwacht werd en het gehalte aan vitamine D was in de Nederlandse kuilen veel hoger dan wat elders gevonden is.
    Lactobacillus plantarum 44a as a live feed supplement for freshwater fish
    Bucio Galindo, A. - \ 2004
    Wageningen University. Promotor(en): Frans Rombouts; Johan Verreth, co-promotor(en): Ralf Hartemink. - Wageningen : - ISBN 9789058089434 - 132
    lactobacillus plantarum - zoetwatervissen - probiotica - voedersupplementen - visvoeding - lactobacillus plantarum - freshwater fishes - probiotics - feed supplements - fish feeding
    Calprona-P en Exenta kruidentinctuur
    Rodenburg, T.B. ; Smolders, M.M.A.H.H. - \ 2003
    Praktijkkompas. Varkens 17 (2003)4. - ISSN 1570-8578 - p. 10 - 10.
    varkenshouderij - biggen - varkensvoeding - groeibevorderaars - voedertoevoegingen - groei - voedersupplementen - prestatieniveau - dierenwelzijn - wetgeving - vergelijkend onderzoek - Nederland - pig farming - piglets - pig feeding - growth promoters - feed additives - growth - feed supplements - performance - animal welfare - legislation - comparative research - Netherlands
    In de varkenshouderij wordt op dit moment gebruik gemaakt van antimicrobiële groeibevorderaars (AMGB's) in het voer. Het gebruik van AMGB's wordt vanaf 2006 wellicht volledig verboden, omdat het kan leiden tot resistentie van humane bacteriepopulaties. Vooruitlopend op dit verbod onderzoekt het Praktijkonderzoek in opdracht van het bedrijfsleven de werkzaamheid van alternatieven voor AMGB's in biggenvoeders.
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