Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    We have a manual that explains all the features 

    Records 1 - 20 / 150

    • help
    • print

      Print search results

    • export

      Export search results

    • alert
      We will mail you new results for this query: wurpublikatie/titelbeschrijving/classificatie/trefwoord/cab/engels==milk
    Check title to add to marked list
    Milk progesterone measures to improve genomic selection for fertility in dairy cows
    Tenghe, Amabel Manyu Mefru - \ 2017
    Wageningen University. Promotor(en): R.F. Veerkamp; B. Berglund, co-promotor(en): D. J. de Koning; A.C. Bouwman. - Wageningen : Wageningen University - ISBN 9789463431330 - 179
    dairy cows - fertility - progesterone - milk - genomics - genetic improvement - heritability - genetic parameters - dairy performance - reproductive traits - animal genetics - animal breeding - dairy farming - melkkoeien - vruchtbaarheid - progesteron - melk - genomica - genetische verbetering - heritability - genetische parameters - melkresultaten - voortplantingskenmerken - diergenetica - dierveredeling - melkveehouderij

    Improved reproductive performance has a substantial benefit for the overall profitability of dairy cattle farming by decreasing insemination and veterinary treatment costs, shortening calving intervals, and lowering the rate of involuntary culling. Unfortunately, the low heritability of classical fertility traits derived from calving and insemination data makes genetic improvement by traditional animal breeding slow. Therefore, there is an interest in finding novel measures of fertility that have a higher heritability or using genomic information to aid genetic selection for fertility. The overall objective of this thesis was to explore the use of milk progesterone (P4) records and genomic information to improve selection for fertility in dairy cows. In a first step, the use of in-line milk progesterone records to define endocrine fertility traits was investigated, and genetic parameters estimated. Several defined endocrine fertility traits were heritable, and showed a reasonable repeatability. Also, the genetic correlation of milk production traits with endocrine fertility traits were considerably lower than the correlations of milk production with classical fertility traits. In the next step 17 quantitative trait loci (QTL) associated with endocrine fertility traits, were identified on Bos taurus autosomes (BTA) 2, 3, 8, 12, 15, 17, 23, and 25 in a genome-wide association study with single nucleotide polymorphisms. Further, fine-mapping of target regions on BTA 2 and 3, identified several associated variants and potential candidate genes underlying endocrine fertility traits. Subsequently, the optimal use of endocrine fertility traits in genomic evaluations was investigated; using empirical and theoretical predictions for single-trait models, I showed that endocrine fertility traits have more predictive ability than classical fertility traits. The accuracy of genomic prediction was also substantially improved when endocrine and classical fertility traits were combined in multi-trait genomic prediction. Finally, using deterministic predictions, the potential accuracy of multi-trait genomic selection when combining a cow training population measured for the endocrine trait commencement of luteal activity (C-LA), with a training population of bulls with daughter observations for a classical fertility trait was investigated. Results showed that for prediction of fertility, there is no benefit of investing in a cow training population when the breeding goal is based on classical fertility traits. However, when considering a more biological breeding goal for fertility like C-LA, accuracy is substantially improved when endocrine traits are available from a limited number of farms.

    Background analysis for a Temporary Measure (State aid) aimed at restructuring the Dutch Dairy Sector
    Jongeneel, Roel ; Silvis, Huib ; Daatselaar, Co ; Everdingen, Walter van - \ 2017
    Wageningen : Wageningen Environmental Research (Wageningen Economic Research memorandum 2017-054) - 20
    dairy farming - agricultural sector - milk - markets - crises - agricultural crises - netherlands - melkveehouderij - landbouwsector - melk - markten - crises - landbouwcrises - nederland
    The EU dairy sector is facing a crisis, which also affects Dutch dairy farmers. Low milk prices have negatively affected dairy farm profitability. At the same time, the structural adjustment in the Dutch dairy sector has slowed down: the reduction in the rate of farm exits was below normal levels and in contrast with the pattern observed in several other EU Member States. Now the Dutch government would like to consider a temporary support programme aimed at restructuring the dairy sector. The Ministry of Economic Affairs has requested Wageningen Economic Research to provide a background analysis with respect to such a temporary measure. This analysis is requested because the proposed measure would imply state aid to the Dutch dairy sector, which is only allowable in case a number of criteria are satisfied. This research should provide insight into this matter.
    Dry period length of dairy cows : milk composition and quality
    Vries, Ruben de - \ 2017
    Wageningen University. Promotor(en): Toon van Hooijdonk; K. Holtenius, co-promotor(en): Kasper Hettinga; H.L.M. Lindmark-Månsson. - Wageningen : Wageningen University - ISBN 9789463430463 - 141
    dairy cows - dry period - milk composition - milk quality - milk - casein - micelles - melkkoeien - gustperiode - melksamenstelling - melkkwaliteit - melk - caseïne - micellen

    A dry period of dairy cows is historically seen as a period during which the cow can restore its body condition and regenerate its mammary epithelium in order to be high yielding in the successive lactation. Recent work has indicated that high yielding cows generally experience a severe negative energy balance in early lactation. Dry period reduction is a strategy to improve the energy balance of dairy cows in early lactation. This thesis aimed at evaluating the influence of dry period length on milk composition and milk quality. Milk composition parameters indicate the processing quality of milk for the dairy plant, and may also reflect the physiological condition and energy status of the cow.

    In this work, omission of the dry period was related to a reduced β-casein fraction in early lactation milk. Applying a short (4 weeks) instead of a conventional (8 weeks) dry period resulted in increased plasmin activity in milk, but did not affect the β-casein fraction. Increased plasmin activity in relation to a shortened dry period was particularly found in milk of cows of third or higher parity, that generally had relatively high somatic cell count. At low somatic cell counts, dry period reduction or omission only tended to result in an increased plasmin activity due a higher casein concentration in milk. From increased concentrations of a number of low abundant proteins in colostrum of cows with a short dry period it was hypothesized that a short dry period was related to increased proliferation of mammary epithelial cells during the first days in lactation.

    Although the casein composition of milk was related to both plasmin activity in milk and the metabolic status of cows, which are both influenced by dry period length, quantitative differences in casein composition of cows with different dry period length were small. It was concluded that shortening or omitting the dry period of cows with good mammary health obtains milk with a higher protein content with little differences in protein composition.

    The role of casein micelles and their aggregates in foam stabilization
    Chen, Min - \ 2016
    Wageningen University. Promotor(en): Erik van der Linden; Toon van Hooijdonk, co-promotor(en): Marcel Meinders; Guido Sala. - Wageningen : Wageningen University - ISBN 9789462579842 - 124
    foams - foaming - milk - casein - micelles - physical properties - stabilization - schuim - schuimen - melk - caseïne - micellen - fysische eigenschappen - stabilisatie

    Many foam products derived from milk or specific dairy ingredients suffer from drainage, coalescence and/or disproportionation. Previous studies indicated that foam properties of milk are strongly influenced by the composition of the milk as well as by the processing conditions during foam production. The aim of this research was to get a better understanding of these two factors. Interestingly, the presence of aggregates of casein micelles was found to result in very stable foams. The interfacial properties (adsorption speed, adsorption energy, dynamical interfacial tension, interfacial dilatational moduli), thin film stability (rupture time) and foam properties (foamability, drainage, coalescence) of casein micelle dispersions were determined. Based on these data, the very stable foams were concluded to result from properties of the thin films in the foam, which were affected drastically by the presence of the large aggregates of casein micelles.

    Impact of microbial variability on food safety and quality
    Aryani, D.C. - \ 2016
    Wageningen University. Promotor(en): Marcel Zwietering, co-promotor(en): Heidy den Besten. - Wageningen : Wageningen University - ISBN 9789462577381 - 190
    listeria monocytogenes - lactobacillus plantarum - growth analysis - kinetics - growth models - inactivation - heat stress - strain differences - food safety - milk - ham - microbial diversity - food quality - listeria monocytogenes - lactobacillus plantarum - groeianalyse - kinetica - groeimodellen - inactivatie - warmtestress - stamverschillen - voedselveiligheid - melk - ham - microbiële diversiteit - voedselkwaliteit
    Grondstofefficiëntie in de zuivel-, varkensvlees-, aardappel- en suikerketen
    Baltussen, W.H.M. ; Dolman, M.A. ; Hoste, R. ; Janssens, S.R.M. ; Reijs, J.W. ; Smit, A.B. - \ 2016
    LEI Wageningen UR (Nota / LEI Wageningen UR 2016-013) - 85
    agro-industriële ketens - efficiëntie - duurzaamheid (sustainability) - melk - varkensvlees - aardappelen - suiker - productie - nederland - agro-industrial chains - efficiency - sustainability - milk - pigmeat - potatoes - sugar - production - netherlands
    In opdracht van het ministerie van Economische Zaken en Topsector Agri & Food heeft LEIWageningen UR de state-of-the-art in kaart gebracht op het gebied van de duurzaamheidsprestatiesvoor vier belangrijke grondstoffen van de aardappel-, suiker-, varkensvlees- en zuivelketen. De viergrondstoffen zijn: land, water, energie en fosfaat. De focus in dit rapport ligt op de kansen enuitdagingen die er zijn op het gebied van efficiënter grondstofgebruik.
    New tools in modulating Maillard reaction from model systems to food
    Troise, A.D. - \ 2015
    Wageningen University. Promotor(en): Vincenzo Fogliano, co-promotor(en): Claire Berton-Carabin; P. Vitaglione. - Wageningen : Wageningen University - ISBN 9789462575455 - 129
    maillard-reactie - maillard-reactieproducten - modulatie - controle - inkapselen - olijfolie - melk - emulsies - modellen - voedsel - gereedschappen - maillard reaction - maillard reaction products - modulation - control - encapsulation - olive oil - milk - emulsions - models - food - tools
    New tools in modulating Maillard reaction from model systems to food

    The Maillard reaction (MR) supervises the final quality of foods and occupies a prominent place in food science. The first stable compounds, the Amadori rearrangement products (APs) and Heyns rearrangement products (HPs), represent the key molecules from which a myriad of reactions takes place and each of them contributes to the formation of Maillard reaction end-products (MRPs) or advanced glycation end products (AGEs).

    Several papers have dealt with the control of the MR in foods ranging from the thermal loading reduction, to the use of alternative process technologies, reactants impact or enzymes, as well as to the monitoring of the end-products formation by multiresponse modeling. The strategies used up to now aim at common goals: the reduction of potentially toxic compounds and the promotion of desired molecules formation as well as flavor, aroma, color and texture attributes. In other words the ultimate target is the promotion of food quality by tuning the MR.

    This thesis introduces four alternative strategies that are able to control the final extent of the MR in foods.

    The possibility to segregate reactants by encapsulating some minor components and thus delaying the MR was highlighted in Chapter 2. The encapsulation of sodium chloride, ascorbic acid, PUFA and iron inside hydrophobic capsules was used as a possible example: the core material release over the time delayed the reaction rates.

    The results obtained through the treatment with the enzyme fructosamine oxidase (Faox) I and II which is able to deglycate free Amadori products and capitalize the local unfolding of lysine peptide bound residues were reported in Chapter 3. Data showed that Faox can reduce the formation ofNε-(Carboxymethyl)-L-lysine and bound hydroxymethylfurfural in model system and in low lactose milk.

    The effects obtained with the addition of spray-dried olive oil mill wastewaters in milk was illustrated in Chapter 4. This ingredient acts as a source of phenylethanoids, which can trap a-hydroxycarbonyls and a-dicarbonyls and can form adducts with amino groups after the oxidation of phenolic rings into quinone. The use of this functional ingredient before milk thermal treatment resulted in a reduction of off-flavor, reactive carbonyls species and bound MRPs.

    The possibilities offered by the location of MR reactants in microemulsion was investigated in Chapter 5. The oil/water partition coefficient of amino acids played a key role in the formation of Amadori compounds. The anchoring effect of tricaprylin and Tween 20 toward aliphatic amino acids in microemulsion systems was evaluated and compared to a control aqueous solution of amino acids and glucose. Results confirmed the hypothesis: the higher the partition coefficient the lower the formation of aliphatic amino acids Amadori compounds.

    All of the four proposed strategies involved location and interaction of reagents, reactants, intermediates and final products. As a result each strategy depicted a specific route for the control of the final extent of the MR. Many steps are still necessary to scale up these methodologies into the food production chain, however new ways for obtaining foods of superior quality have been paved.

    Dynamics of the proteome in human and farm animal milk
    Zhang, L. - \ 2015
    Wageningen University. Promotor(en): Toon van Hooijdonk, co-promotor(en): Kasper Hettinga; Jacques Vervoort. - Wageningen : Wageningen University - ISBN 9789462574199 - 193
    moedermelk - melk - kamelenmelk - proteomen - melkeiwit - melkeiwitten - lactatie - melksamenstelling - melkbewerking - kwantitatieve analyse - kwalitatieve analyse - human milk - milk - camel milk - proteomes - milk protein - milk proteins - lactation - milk composition - milk processing - quantitative analysis - qualitative analysis


    The milk proteome changes due to many factors, such as lactation, individual, health status, processing, and species differences. The objective of the work described in this thesis was to increase our understanding of the dynamics of proteome in human and farm animal milk, and its contributions on the improvement of infant formula. This study shows that milk proteome not only differs qualitatively and quantitatively but also differs in their changing rate over lactation between species, especially for immune-related proteins. In addition, milk proteome shows different stability under different processing within and between species. It is concluded that although milk proteome differs between species, the function of milk proteins is essentially the same for all newborns, in providing nutrients and immunity for their growth and development. Both enriching specific milk proteins and mild processing of milk proteins should be considered for the improvement of infant formula.

    From Milk By-Products to Milk Ingredients : Upgrading the Cycle
    Boer, Ruud De - \ 2014
    Wiley-Blackwell - ISBN 9780470672228 - 269 p.
    milk - milk products

    Milk is a complex substance, and a variety of constituents can be extracted from it for use as ingredients in other foods. The main ingredients from milk are milk fat, cheese and serum, but this range is continually expanding as food companies, dairies and dairy scientists seek to utilize as many raw materials and by-products as possible, to reduce waste, maximize efficiency, and increase productivity. Ingredients from Milk is a concise, fresh approach to ingredients derived from milk, containing guidance and new techniques for dairy industry professionals and scientists. has a structure is designed to mirror the process of extracting ingredients from milk, beginning with the basic concepts and following through the processes until finally arriving at the consumer products which constitute the end uses of ingredients from milk. This book is primarily targeted at the dairy industry, but also provides a valuable insight for academics and students seeking an industry perspective.

    Smediger kaas door juiste voer
    Hettinga, K.A. ; Dijkstra, J. - \ 2014
    De zelfkazer 66 (2014)6. - ISSN 0166-4549 - p. 10 - 11.
    kazen - smaak - eiwitgehalte - vetgehalte - voersamenstelling - onverzadigde vetten - vetzuren - melk - melkvet - cheeses - taste - protein content - fat content - feed formulation - unsaturated fats - fatty acids - milk - milk fat
    Veel kaasmakers willen smedige (zachte, smeuïge) kaas maken, want de gemiddelde consument vindt die kaas het lekkerst. Kasper Hettinga en Jan Dijkstra van Wageningen Universiteit vertellen hoe de smedigheid van kaas kan worden beïnvloed door de samenstelling van het veevoer.
    Genetic variation of milk fatty acid composition between and within dairy cattle breeds
    Maurice - Van Eijndhoven, M.H.T. - \ 2014
    Wageningen University. Promotor(en): Johan van Arendonk; Roel Veerkamp, co-promotor(en): Mario Calus. - Wageningen : Wageningen University - ISBN 9789462571488 - 184
    dierveredeling - melkkoeien - vetzuren - melk - genetische variatie - rundveerassen - heritability - melkvet - genetische bronnen van diersoorten - melkveehouderij - animal breeding - dairy cows - fatty acids - milk - genetic variation - cattle breeds - heritability - milk fat - animal genetic resources - dairy farming


    Maurice – Van Eijndhoven, M.H.T. (2014). Genetic variation of milk fatty acid composition between and within dairy cattle breeds. PhD thesis, Wageningen University, the Netherlands

    Fat is one of the main components in bovine milk and comprises a large number of individual fatty acids (FA). The composition of FA in milk varies considerably due to differences in the genetics and nutrition of cows and an increasing interest in the possibilities for modifying FA composition can be noticed nowadays. In this thesis two fields of interest were combined, namely: production of milk with specific milk fat composition and conservation of native cattle breeds. Therewith, the overall objective of this thesis was to investigate the variability of detailed milk FA composition between and within different dairy cattle breeds, including the mainstream Holstein Friesian (HF) and Jersey, and the native dual purpose breeds Meuse-Rhine-Yssel (MRY), Groningen White Headed (GWH) and Dutch Friesian (DF) in the Netherlands. For this study the accuracy of mid-infrared (MIR) spectrometry was evaluated for predicting FA composition in different breeds. Differences of milk FA composition within and between breeds were investigated using MIR and Gas Chromatography (GC) information. Finally, similarities in genomic variation associated with detailed milk fat composition between the mainstream HF breed and native dual purpose breeds were studied. Results show that MIR is an accurate method for predicting FA composition among different breeds and countries. Evaluating the FA composition in different breeds, differences were found in milk FA composition among herds using different cattle breeds in the Netherlands, based on detailed milk FA measurements using GC. Evaluating the FA composition in milk between and within breeds using a large dataset that included MIR spectra of milk from cows from a range of farms using one or more breeds, in general, only minor breed differences in FA composition were found and HF showed more genetic variation in FA composition compared to MRY. Furthermore, differences were detected between the native breeds MRY, DF and GWH in genomic variations of regions that are associated with FA composition in HF, while most variation in these main regions was clearly observed in HF. Overall, it was concluded that no large differences existed in milk FA composition among the native Dutch dual purpose breeds and the mainstream HF breed. It is suggested, however, that selecting specific FA composition differences in farms using different breeds in the Netherlands can attribute to modifying the FA composition in bovine milk production.

    Nutrient utilization, dietary preferences, and gastrointestinal development in veal calves : interactions between solid feed and milk replacer
    Berends, H. - \ 2014
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Walter Gerrits; Joost van den Borne. - Wageningen : Wageningen University - ISBN 9789462570436 - 239
    dieren - koeien - vleeskalveren - diervoeding - voedingsstoffen - groei - ontwikkeling - diervoedering - vaste voeding - melk - animals - cows - veal calves - animal nutrition - nutrients - growth - development - animal feeding - solid feeding - milk

    Solid feeds (SF), comprising roughages and concentrates, represent an increasingly important source of nutrients for veal calves. From a welfare and economic perspective, there is a strong incentive to replace a considerable portion of the milk replacer (MR) by SF in the diet. However, interactions between MR and SF complicate the prediction of the nutritional value of these ration components, and adverse effects on health may occur when combining MR and SF. To investigate these interactions, various combinations of MR, concentrates, and roughages were tested in a series of large-scale studies.

    When provided with unrestricted access to MR, concentrates, maize silage, hay, and straw over a 6-month period, calves markedly changed their preferences over time, and individual differences appeared very large. However, the ratio between digestible crude protein and digestible energy in the diet of choice appeared remarkably constant between calves. Another set of studies aimed at defining age-related changes in utilization efficiency of SF. It was demonstrated that stimulating early rumen development (before 12 wk of age) improves the nutritional value of each kg of SF in later life. In another study, it was shown that the nutritional value of SF increases with age. This effect is likely related to improved fermentation of fibrous SF. Increasing SF intake lead to an increase in the passage rates of concentrates and straw through the rumen.

    Compared to the feeding of MR alone, nitrogen (N) economy of veal calves can be improved by feeding a low-protein SF, creating a N shortage in the rumen. Urea-N, likely originating from the MR, was demonstrated to recycle back into the rumen for microbial protein production. In a subsequent study, it appeared that the feeding of a high-protein SF improved ruminal degradation of fibrous SF relative to a low-protein SF at equal protein intake, balanced via the MR. Urea recycling was demonstrated to be unable to completely compensate a N shortage in the rumen. An important interaction between MR and SF can be the influence of SF on the proportion of MR flowing in the rumen, where it is fermented and potentially causes health problems. The current standard to measure this so-called ‘ruminal drinking’ is the Co recovery method, which requires sacrificing the calves. Several non-terminal methods to quantify ruminal drinking were evaluated in three consecutive experiments. From a meta-analysis of Co recovery data, it was shown that on average 17% of the MR fed flows into the rumen instead of the abomasum. No associations with SF or MR intake related variables were found. Potential adverse effects of replacing MR by SF include abomasal damage, particularly in the pyloric area. This generally increases with the intake of SF, particularly in the presence of sharp, abrasive particles, and more so with a 20:80 than with a 50:50 mixture of roughage:concentrate. Results indicated that early rumen development can offer some protection in later life.

    In conclusion, when taking interactions between MR and SF into account, it appeared possible to replace a considerable portion of MR by SF without compromising calf performance and health.

    White Gold : Opportunities for Dairy Sector Development Collaboration in East Africa
    Makoni, N. ; Mwai, R. ; Redda, T. ; Zijpp, A.J. van der; Lee, J. van der - \ 2014
    Wageningen : Centre for Development Innovation, Wageningen UR (CDI report 14-006) - 150
    zuivelindustrie - oost-afrika - waardeketenanalyse - melk - vee - rundvee - ontwikkelingssamenwerking - kenya - ethiopië - tanzania - uganda - rwanda - burundi - dairy industry - east africa - value chain analysis - milk - livestock - cattle - development cooperation - kenya - ethiopia - tanzania - uganda - rwanda - burundi
    A study of the dairy sector in six East African countries was followed by a dairy expert consultation in Uganda in April 2014. The objective of the initiative was to explore possibilities to improve coordination among development agencies, investors and other value chain stakeholders and governments, and for creating synergy within and between the different countries. This report describes outcomes of both study and consultation and is intended to serve as a reference document for all stakeholders. It includes recommendations and priority actions that should enable stakeholders to capitalize on the opportunities in the East African dairy sector and clarify the roles of various partners in this endeavour (donors, public sector, and private sector). Study and consultation were initiated by the Inter-Agency Donor Group (IADG) on pro-poor livestock research and development. Report CDI-14-006
    Decision support modeling for milk valorization
    Banaszewska, A. - \ 2014
    Wageningen University. Promotor(en): Jack van der Vorst, co-promotor(en): Frans Cruijssen. - Wageningen : Wageningen University - ISBN 9789461739261 - 182
    operationeel onderzoek - modelleren - melk - beslissingsondersteunende systemen - beslissingsmodellen - rentabiliteit - zuivelindustrie - rauwe melk - melkbewerking - nederland - efficiëntie - operations research - modeling - milk - decision support systems - decision models - profitability - dairy industry - raw milk - milk processing - netherlands - efficiency

    The research presented in this thesis concerns decision problems in practice that require structured, precise, scientific studies to provide strong, reliable answers. An opportunity to contribute to both practice and science emerged in 2008 when two large, Dutch dairy companies merged, creating FrieslandCampina (FC), which was the fourth largest dairy company in the world at that time. In 2009, a new Milk Valorization & Allocation (MVA) department was created at the corporate level to optimally utilize raw milk (the main raw material) in all business units. The main goal of this research was the development and application of decision support models to help MVA attain its mission of “getting more out of milk.”

    The dairy processing industry is a specific and challenging research field. This is related to the fact that the raw milk is transformed into thousands of end products via highly interrelated production processes. These processes are affected by uncertainties related to supply, processing capacities, and demand. Attaining high profitability requires a central, integral planning process that facilitates the optimal allocation of raw milk to a large range of products. Optimal allocation of raw milk is achieved when it is successfully allocated to the most profitable end products and all important constraints are taken into account. This process is defined as milk valorization. Contribution to the improvement of milk valorization in the dairy industry was the main objective of this thesis. We approached the problem from a Logistics Management perspective. We focused on decisions supporting the optimal flow of raw materials to end products, from farmers to consumer markets. With the use of Operations Research techniques, we developed quantitative models and frameworks to improve the mid-term milk valorization process.

    As the first step towards the improvement of milk valorization we developed a mid-term Dairy Valorization Model (DVM). The model creates optimal plans for the allocation of milk, and the production of end products and byproducts. It captures the dynamics of dairy production and incorporates all relevant elements and constraints. The following elements were indicated as important and included in the DVM: recipes based on raw milk composition (dry matter, fat, and protein content); seasonality of raw milk composition and supply; a complete dairy product portfolio; by-product utilization; network of supply regions and production locations; by-product and raw milk transportation; and changes in sale prices. Including all relevant elements assures DVM comprehensiveness. This important aspect achieves truly integral valorization of milk. Furthermore, the developed DVM also fosters understanding of complex, underlying production processes. Moreover, by means of additional analysis we have also shown that the seasonality of raw milk components (dry matter, fat and protein) plays an important role in the valorization process. It considerably affects decisions regarding milk allocation to end products (up to 50% difference in production volumes of clustered end products) and company profit (up to 4% difference in monthly profit).

    Given the complexity of the dairy system, the development of a high class valorization model required a gradual approach. The developed DVM focuses on the valorization of milk-based end products (main milk products). The production of those products, however, results in large volumes of byproducts.In the second step of this research we investigated the effect of whey valorization (byproduct of cheese) on the valorization of main milk products, as well as the added value of integral valorization (simultaneous valorization of both main and byproducts). We developed a new Integral Dairy Valorization model (IDVM) to allow for an integral milk valorization. We also developed a three-step evaluation approach to compare results of stepwise valorization (in which whey valorization only follows after main milk products valorization) and integral valorization. The results show that the explicit valorization of whey flows leads to significant economic gains for FC. Profit obtained from post processing of whey byproducts amounts to circa 20% of the total profit. Furthermore, the effect of integrating both valorization processes is currently small (on average 0.0089% increase in monthly profit). There is, however, a potential in the integration of two processes. In case demand for, and sale prices of, whey-based products, sale prices of milk powders or processing capacity for whey increases, the gain from the integration can be considerably larger (up to 1200% stronger effect in comparison to the current situation). We have also shown that currently whey products are not profitable enough to drive the production of milk products that are the source of the whey by-product.

    In the next step we focused on the accuracy of solutions obtained with the DVM. Because the DVM is a deterministic model, uncertainties present in input are not incorporated, and as such the stability of valorization plans is affected. Stability of plans is often referred as to the ‘robustness’ of plans: the degree to which the optimal solution might change if realization of certain input parameters turn out to be different than the forecasted values. The robustness is important, because the valorization plans that are initially indicated as optimal can easily become sub-optimal or costly. Therefore, the overall goal of the third study was to develop a framework for robustness evaluation of valorization plans obtained with deterministic models. We developed a five-step framework comprised of the following: (1) definition of Key Performance Indicators (KPIs), (2) selection of relevant input parameters, (3) definition of scenarios, (4) evaluation of robustness, and (5) extraction of conclusions. The output from Step 4 of the framework is multidimensional, and thus to arrive at the final robustness degree, a number of decisions must be made a priori: acceptable KPIs limits (robustness bounds); evaluation time (month or year); evaluation depth (parameter or element); and the grouping approach of KPIs. The results show that depending on the selection of these aspects different conclusions regarding robustness of valorization plans are obtained, (average robustness degree varied from 48% to 92%), and thus the final conclusions regarding the robustness degree of plans is affected. The overall robustness degree of valorization plans (at FC) obtained with the DVM was 90% and was indicated by FC as sufficiently high to attain successful milk valorization. The calculated robustness degrees also identified the parameters with the greatest effect on robustness (composition and supply of milk).

    The effectiveness of valorization models is mainly linked to the optimality, feasibility and robustness of obtained plans. However, even if these three aspects are satisfied, the success of the valorization process is still very much dependent on the performance level of actors and units that are involved in the process. Given the fact that processing units (factories) are the most important units in the supply chain of a processing company, because they can easily affect the value of each ton of raw milk used in the production process, the last study investigated the performance of processing units. We developed two Data Envelopment Analysis models for performance measurement and improvement, and applied it to the case study of TNT Express. The models allowed us to identify: inefficient units (30%); parts of efficiency levels (of inefficient units) that result from either management practices (85%) or a favorable external environment (15%); potential reductions in consumed input resources that allow for the same output levels (17% less labor and subcontractors could be used); and role models that can be treated as master units in efficient use of certain inputs and thus should play leading roles in setting benchmarks.

    We concluded that in order to successfully valorize raw materials, companies should: develop their own valorization model, possess a comprehensible overview of the complete production system; and have access to necessary input data. Furthermore, there is a potential in integrating main product and by-product valorization processes. The added value, however, depends on the information on market and production capacities of by-products and related to them main products. To ensure that possible future integration of both valorizations processes occurs correctly, companies should investigate future market developments and the possibility of increasing production capacity. Moreover, we have also shown that robustness of solutions obtained with deterministic valorization models can be sufficiently high to obtain reliable plans. This means that it is not always necessary to implement complex modeling techniques (such as stochastic programming). To ensure accurate solutions, companies should also focus on improving forecast accuracies of parameters affecting the robustness. The robustness degree should also be regularly assessed with the developed framework. Finally, managers should also focus on performance levels of processing units. A DEA model should be developed to identify inefficient factories and provide new insights to improve performance.

    In order to properly valorize milk or other food resources to its maximum an integral point of view should be chosen. Operations Research techniques should be used because the complexity of many processing industries makes applying practical rules of thumb insufficient and often inadequate. The models and frameworks developed in this thesis provide new perspective on and new insights into the complex problem of milk valorizations. We have shown that analyses of results obtained with the developed methods can answer many managerial questions, and thus support the decision making process within a company. This improves overall raw material valorization, creates more value for companies, and leads to more sustainable dairy chains.

    Natural variation in casein composition of milk
    Bijl, E. - \ 2014
    Wageningen University. Promotor(en): Toon van Hooijdonk, co-promotor(en): T. Huppertz; Hein van Valenberg. - Wageningen : Wageningen University - ISBN 9789461739445 - 145
    melk - caseïne - melksamenstelling - variatie - milk - casein - milk composition - variation

    Bovine milk contains 3-4 % protein and almost 80% of the milk protein fraction consist of four caseins; αs1-casein, β-casein, αs2-casein and κ-casein. Most of the caseins in milk are assembled in casein micelles, which consist of several thousands of individual casein molecules and salts. The unique structure of casein micelles allows the delivery of large amounts of calcium and phosphate to the neonate. Considerable natural variation in casein content and composition exists between milk samples from individual cows, however the impact of these variations on casein micelle structure and technological properties of dairy products are largely unknown. This study showed that the expression of caseins and their post-translational modification as well as inclusion of calcium in casein micelles are well-balanced processes. Analysis of the genetic background of phosphorylation of αs1-casein with eight or nine phosphate groupsshowed that αs1-casein phosphorylation was regulated by a different set of genes. Also, variation in αs1-casein phosphorylation resulted in changes in the core of casein micelles and was associated with a difference in degradation efficiency by chymosin in milk gels. Another post-translational modification, glycosylation of κ-casein, resulted in changes in the surface of casein micelles. Natural variation in αs1-CN phosphorylationand glycosylation of κ-casein are both relevant factors to consider for optimization of dairy products and the design of future breeding strategies.

    MOOI : melkveehouderij opent, onderneemt en innoveert
    Zijlstra, J. - \ 2013
    Leeuwarden [etc.] : Hogeschool VHL - ISBN 9789081742689 - 48
    melkveehouderij - opleiding melkveehouderij - ondernemerschap - agrarisch onderwijs - melk - zuivelbedrijven - zuivelindustrie - dairy farming - dairy education - entrepreneurship - agricultural education - milk - dairies - dairy industry
    Rede lectoraat melkveehouderij Hogeschool VHL.
    Variation of milk urea in dairy cattle : a study on factors that affect the relationship between urea concentration in milk and urea excretion in urine
    Spek, J.W. - \ 2013
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Jan Dijkstra; Andre Bannink. - S.l. : s.n. - ISBN 9789461736642 - 156
    melkkoeien - melkvee - ureum - melk - concentratie - urinering - excretie - stikstof - meta-analyse - natriumchloride - opname (intake) - diervoeding - rundveevoeding - voedingsfysiologie - dairy cows - dairy cattle - urea - milk - concentration - urination - excretion - nitrogen - meta-analysis - sodium chloride - intake - animal nutrition - cattle feeding - nutrition physiology

    The aim of this thesis was to increase the applicability of milk urea nitrogen concentration (MUN) as a predictor of urinary urea nitrogen excretion (UUN) by identifying and quantifying factors that can explain variation in MUN that is not related to UUN. A literature study was conducted in order to identify these factors that affect the relationship between MUN and UUN. In this literature review a number of factors were established that affect the relationship between MUN and urinary N-excretion (UN) or UUN, such as dietary crude protein content (CP), intake of dietary salt and water, body weight, diurnal variation in plasma urea nitrogen concentration (PUN), exchange of urea between blood and milk, and heritability of MUN. Results of a quantitative meta-analysis where the effect of various physiological and dietary factors on the relationship between MUN and UN or UUN were studied confirmed the fact that CP affects the relationship between MUN and UUN and showed that by using information on MUN and CP more variation in UUN could be explained compared to using information on either MUN or CP alone. One of the factors established in the literature review that can affect the relationship between MUN and UUN is dietary salt content or drink water intake. In order to quantify the effect of dietary salt on MUN and UUN an experiment was carried out that investigated the effect of four dietary levels of sodium chloride (NaCl) on urea levels in blood plasma and milk and on UN and UUN. The results from this trial clearly showed a negative relationship between dietary NaCl content and MUN whereas UUN was not affected by NaCl intake and UN was slightly increased by increasing NaCl intake levels. The question arose whether the effect of dietary salt on MUN would be similar at high and low dietary protein levels as the renal mechanism of excretion and reabsorption of urea is affected by both dietary protein and salt intake. Therefore, the interaction between dietary salt and protein on UUN was tested in an experiment with two CP levels and two dietary NaCl levels. No interaction between dietary NaCl and CP on MUN was observed. However, the relationship between MUN and UUN was altered by the effect of salt intake. The literature review showed that diurnal variation in PUN and MUN can be substantial, and that this variation depends on factors such as time and frequency of feeding and milking. Insight in the dynamics of urea transport between blood of milk is important in order to model and predict variation in MUN over time under various feeding and milking regimes. To obtain quantitative insight in urea fluxes between blood and milk two experiments were conducted in which urea transport from blood to milk and vice versa was investigated by means of pulse dose injections of labeled [15N15N]urea in milk cisterns at various time intervals before milking. The results showed a rapid distribution of injected labeled urea throughout the milk in the mammary gland and substantial urea transport from milk to blood.

    It is concluded that various factors that are discussed in this thesis contribute to variation in MUN that is not related to UUN. Taking these factors into account increases the applicability of MUN as a predictor of UUN.

    Genomica in de melkveehouderij : de praktische toepassingen
    Haas, Yvette de - \ 2012
    dairy farming - dairy cattle - animal breeding - genomics - dna - milk
    Foaming behaviour of organic and regular milk
    Pijnenburg, J. ; Sala, G. ; Valenberg, H.J.F. van; Meinders, M.B.J. - \ 2012
    Wageningen : Wageningen UR - 23
    melk - biologische voedingsmiddelen - schuimen - stabiliteit - melkproducten - milk - organic foods - foaming - stability - milk products
    Organic milk is used more and more by consumers to froth milk that is used e.g. for the preparation of a capuccino. Frequently, organic milk turns out not to foam properly. This report describes a study to find the main couse of this bad foamability of organic milk. The focus of the research was to get insight in the foaming behaviour of a specific brand, indicated as A. The foamability and stability of different milk, both organic and regular, as well as skimmed, semi-skimmed, and full fat, were tested. The foamability of the different milk varieties appeared to be about equal. However, differences were observed for the foam stability. Foams made from A showed the lowest stability of all tested milk varieties. The reason for this is not yet clear, but the bad foam stability of this milk might be probably due to a higher fatty acid content.
    Aan melk is steeds meer af te lezen
    Arendonk, J.A.M. van - \ 2012
    Kennis Online 9 (2012)april. - p. 5 - 5.
    melkveehouderij - diergezondheid - ziekteresistentie - pens - melk - methaanproductie - dairy farming - animal health - disease resistance - rumen - milk - methane production
    In de melk en de pens van koeien wordt gezocht naar aanwijzingen die moeten leiden naar dieren met een grotere natuurlijke weerstand en minder methaanuitstoot.
    Check title to add to marked list
    << previous | next >>

    Show 20 50 100 records per page

    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.