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The aim of the current experiment was to determine the aP requirements in modern broilers by performing a dose-response experiment. This study showed that for realizing maximal performance, in phase 1 (d1-d10) 5.4 g aP per kg of feed was required, in phase 2 (d11-d21) 4.3 g aP per kg of feed, and in phase 4 (d31-d38) 2.6 g aP per kg of feed. In phase 3 (d22-d30), performance of the broilers was not affected by dietary aP content. For realizing maximal tibia ash content in phase 3, an aP-level of 3.8 g/kg was required.

The aim of the current experiment was to determine the aP requirements in modern broilers by performing a dose-response experiment. This study showed that for realizing maximal performance, in phase 1 (d1-d10) 5.4 g aP per kg of feed was required, in phase 2 (d11-d21) 4.3 g aP per kg of feed, and in phase 4 (d31-d38) 2.6 g aP per kg of feed. In phase 3 (d22-d30), performance of the broilers was not affected by dietary aP content. For realizing maximal tibia ash content in phase 3, an aP-level of 3.8 g/kg was required. Dit experiment is uitgevoerd met als doel de behoefte aan opneembaar fosfor (oP) bij huidige vleeskuikens vast te stellen op basis van een dosis-respons studie. Deze studie geeft aan dat het voer voor het realiseren van maximale dierprestaties in fase 1 (d1-d10) 5,4 g oP per kg dient te bevatten, in fase 2 (d11-d21) 4,3 g oP per kg en in fase 4 (d31-d38) 2,6 g oP per kg. In fase 3 (d22-d30) had het oP-gehalte geen effect op de dierprestaties. Voor het realiseren van een maximaal tibia-asgehalte was in deze fase een oP-gehalte van 3.8 g/kg noodzakelijk.

No potassium no plant: A huge number of processes are dependent on this element. Luckily, hardly any problems occur because the plant is good at looking after itself in this respect.

Er is geen voedingselement waarvan de plant zoveel nodig heeft als stikstof. Het gehalte kan wel 5% van de drogestof uitmaken. Behalve als essentieel onderdeel van veel plantonderdelen en inhoudsstoffen, wordt ook steeds meer duidelijk dat stikstof een signaalstof is, die processen aanstuurt, bijna zoals een hormoon.

Goal of this literature study is to define the uncertainties related to P requirement models and ways to make them more precise and more reliable than current systems and to find biomarkers to monitor P balance in living animals. Milk P is an important factor in P balance, and concentration may vary between individual cows. Bone represents a large P reserve and can have a profound impact on cow P balance and plasma P regulation. Plasma P concentration is still the most commonly used diagnostic measurement available to judge the P status of an animal, with all restrictions for good interpretation; new biomarkers defining P status are needed. Further research into mechanisms and quantification of the is needed to improve our understanding of P metabolism. Het doel van deze literatuurstudie is de onzekerheden en aannames binnen de huidige P behoeftemodellen in kaart te brengen, suggesties te doen voor verbetering om nauwkeuriger en met meer zekerheid naar behoefte te kunnen voeren, en biomarkers te zoeken om de P balans bij levende dieren te monitoren. Het P-gehalte van melk is een belangrijke factor op de totale P balans, maar kan sterk variëren tussen individuele koeien. In het skelet ligt een zeer groot aandeel van de totale P voorraad opgeslagen, en botweefsel kan een belangrijke invloed hebben op de P balans en de plasma P regulatie. Plasma P is nog altijd de meest gebruikte diagnostische parameter om de P status te beoordelen, ondanks alle beperkingen die een goede interpretatie moeilijk maken; nieuwe biomarkers zijn daarom hard nodig. Verder onderzoek naar achterliggende mechanismes met de bijbehorende kwantificering is noodzakelijk om de kennis over de P stofwisseling te verbeteren.

There is large variation in the production performance of commercial growing-finishing pig farms. This variation even exists when pigs have a similar genetic background and fed similar diets. The health status is one of the major factors contributing to this large variation in pig performance, as activation of the immune system can decrease feed intake, body weight gain and increase nutrient utilisation for immune system functioning. As a consequence, amino acids (AA) are repartitioned from skeletal muscle deposition towards utilisation for immune system functioning. Current requirement estimates for growing-finishing pigs are formulated to maximize protein deposition for growth and do not take into account the increased utilization of AA for immune functioning as induced by health challenging conditions. This lack of knowledge hampers the ability of feed manufacturers to optimize diets and improve pig performance. The main objective of the present thesis was to quantify the effect of health status on AA requirements for body protein deposition and for immune system functioning of growing pigs. A health status web was developed as a tool to categorize growing-finishing pig farms on the basis of their health status. The health status web can be of use for feed manufacturers to develop targeted strategies to accommodate the nutritional requirements of pigs belonging to particular groups of farms sharing a common health status. A dose-response technique was developed, which is a simple, accurate technique to quantitatively estimate changes in AA requirements of individual meal-fed pigs. Nevertheless, a minimum time period of 21 days is required for each individual, which makes the technique inappropriate for studying the effect of immune system activation on AA requirements. The combined measurements of whole body N retention, plasma irreversible loss rate (ILR, i.e. the amount of free AA that disappears per unit of time from the plasma pool for protein synthesis or oxidation), urea entry and appearance of 13C into plasma proteins, provided insight into the consequences of immune system activation on AA metabolism. Pigs selected from a farm with a suboptimal health status had greater serum haptoglobin, lower serum albumin concentrations, and greater leukocyte counts in blood at the start of the experiment than pigs selected from a farm with a high health status, indicating a higher level of immune system activation. The occurrence of compensatory gain in pigs from a farm characterized as having a suboptimal health status proves, however, that it is difficult to maintain a contrast in health status, and that pigs can adapt quickly to a change in housing conditions. In the absence of effects on feed intake, health challenging conditions may affect performance due to alterations in post-absorptive AA metabolism, as also indicated by increased urinary N losses, and a tendency for a reduced N retention and a lower utilization of digestible N for N retention in pigs with a systemic inflammation, or by a reduction in faecal nutrient digestibility as indicated for dry matter and N in pigs from a farm with a suboptimal health status. The observed changes in protein and AA metabolism after immune stimulation imply that especially tryptophan may become limiting during immune system activation, whereas lysine becomes excessive. Furthermore, the utilization of methionine, tyrosine, and valine for immune system functioning seems to increase in pigs with a systemic lung inflammation. In addition, the dietary AA or protein supply was able to modulate the acute phase response pre- and post-challenge, stressing the importance of an adequate dietary AA supply for appropriate functioning of the immune system of growing-finishing pigs. Before implementing targeted feeding strategies for farms sharing a common health status, future research should be conducted to study the possible beneficial effects of increasing the dietary supply of particularly tryptophan, methionine, tyrosine, and valine relative to lysine for immune system function and for body protein deposition in pigs from farms with a different health status.

The aim of the present study is to update the requirements for the essential amino acids of laying hens, both on a AFD and SID basis, by performing a meta-analysis on dose-response studies used to derive requirement values for essential amino acids (lysine, methionine+cysteine, threonine and tryptophan) in laying hens as presented in the literature. In this meta-analysis, the data are fitted by use of the Wood equation (see paragraph 2.4). The amino acid intake levels for realizing maximal rate of lay, egg mass and feed efficiency are provided. The amino acid requirements for use in practice are based on the amino acid intake levels at which 95% of these maximum responses were reached.

Antony Jesu Prabhu, P. (2015). Minerals in fish: does the source matter? PhD thesis. Wageningen University, The Netherlands.Minerals are a group of micro-nutrients essential to fish. Meta-analysis of literature data was performed to identify the appropriate response criterion to determine the mineral requirement of fish. The meta-analysis revealed that, vertebral mineral concentrations or specific enzyme activities provide stringent requirement estimates compared to weight gain. Dietary intake forms the major route of mineral supply to fish; however fish are also capable of acquiring dissolved minerals from the rearing water. Changes in the dietary composition or mineral concentration of rearing water could have an impact on the mineral balance in fish. In this thesis, high fat diets, diets devoid, or low in fish meal and rearing systems with high water mineral concentrations were studied for their impact on the mineral balance in rainbow trout or common carp. Increased available phosphorus levels were needed (0.4% vs. 0.8%) in high fat diets to improve whole body and vertebral mineralisation as indicated by ash, P and Ca concentrations. However, supplementing phosphorus to complete plant ingredient based diets negatively affected the absorption and utilisation of micro-minerals namely Zn, Cu and Se. In rainbow trout that received complete plant ingredient based diets, the endogenous loss of Zn was higher and of Cu was lower resulting in Zn depletion and Cu accumulation in the body. Further, the hepatic metabolism of Fe and Cu was affected in rainbow trout fed the plant ingredient based diets, possibly due to the alterations in bile or cholesterol metabolism. With regard to the minimal dietary levels required, supplementation of Zn and Se were required beyond the levels recommended by NRC (2011) to maintain body balance in rainbow trout and common carp when fed complete plant ingredient based diets. Common carp reared in recirculation aquaculture systems (RAS) with high concentration of minerals in the water was able to acquire and retain minerals from water. However, only in the case of Se, they were able to compensate for a part of the dietary requirement. On the whole, higher dietary levels of P and Ca are required in the diet of fast growing rainbow trout; dietary levels of Zn and Se have to be increased beyond present recommended levels in plant ingredient based diets for rainbow trout and common carp. Low water exchange RAS has multiple effects on the whole animal physiology of fish and requires further research for better understanding.

This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?

The aim of the present study is to update the requirements for the essential amino acids of laying hens, both on a AFD and SID basis, by performing a meta-analysis on dose-response studies used to derive requirement values for essential amino acids (lysine, methionine+cysteine, threonine and tryptophan) in laying hens as presented in the literature. In this meta-analysis, the data are fitted by use of the Wood equation (see paragraph 2.4). The amino acid intake levels for realizing maximal rate of lay, egg mass and feed efficiency are provided. The amino acid requirements for use in practice are based on the amino acid intake levels at which 95% of these maximum responses were reached. Dit rapport geeft een update van de behoefte aan aminozuren (lysine, methionine+cysteine, threonine en tryptofaan) van leghennen, zowel op basis van schijnbaar fecaal verteerbare als gestandaardiseerd ileaal verteerbare aminozuurgehalten van het voer. Hiervoor is een meta-analyse uitgevoerd op peer reviewed dosis-response studies. Studies moesten voldoen aan een vooraf bepaalde set van criteria, voordat ze bij deze analyse betrokken werden.

Goal of this literature study is to define the uncertainties related to P requirement models and ways to make them more precise and more reliable than current systems and to find biomarkers to monitor P balance in living animals. Milk P is an important factor in P balance, and concentration may vary between individual cows. Bone represents a large P reserve and can have a profound impact on cow P balance and plasma P regulation. Plasma P concentration is still the most commonly used diagnostic measurement available to judge the P status of an animal, with all restrictions for good interpretation; new biomarkers defining P status are needed. Further research into mechanisms and quantification of the is needed to improve our understanding of P metabolism.

Antony Jesu Prabhu, P. (2015). Minerals in fish: does the source matter? PhD thesis. Wageningen University, The Netherlands.Minerals are a group of micro-nutrients essential to fish. Meta-analysis of literature data was performed to identify the appropriate response criterion to determine the mineral requirement of fish. The meta-analysis revealed that, vertebral mineral concentrations or specific enzyme activities provide stringent requirement estimates compared to weight gain. Dietary intake forms the major route of mineral supply to fish; however fish are also capable of acquiring dissolved minerals from the rearing water. Changes in the dietary composition or mineral concentration of rearing water could have an impact on the mineral balance in fish. In this thesis, high fat diets, diets devoid, or low in fish meal and rearing systems with high water mineral concentrations were studied for their impact on the mineral balance in rainbow trout or common carp. Increased available phosphorus levels were needed (0.4% vs. 0.8%) in high fat diets to improve whole body and vertebral mineralisation as indicated by ash, P and Ca concentrations. However, supplementing phosphorus to complete plant ingredient based diets negatively affected the absorption and utilisation of micro-minerals namely Zn, Cu and Se. In rainbow trout that received complete plant ingredient based diets, the endogenous loss of Zn was higher and of Cu was lower resulting in Zn depletion and Cu accumulation in the body. Further, the hepatic metabolism of Fe and Cu was affected in rainbow trout fed the plant ingredient based diets, possibly due to the alterations in bile or cholesterol metabolism. With regard to the minimal dietary levels required, supplementation of Zn and Se were required beyond the levels recommended by NRC (2011) to maintain body balance in rainbow trout and common carp when fed complete plant ingredient based diets. Common carp reared in recirculation aquaculture systems (RAS) with high concentration of minerals in the water was able to acquire and retain minerals from water. However, only in the case of Se, they were able to compensate for a part of the dietary requirement. On the whole, higher dietary levels of P and Ca are required in the diet of fast growing rainbow trout; dietary levels of Zn and Se have to be increased beyond present recommended levels in plant ingredient based diets for rainbow trout and common carp. Low water exchange RAS has multiple effects on the whole animal physiology of fish and requires further research for better understanding.

This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?

There is large variation in the production performance of commercial growing-finishing pig farms. This variation even exists when pigs have a similar genetic background and fed similar diets. The health status is one of the major factors contributing to this large variation in pig performance, as activation of the immune system can decrease feed intake, body weight gain and increase nutrient utilisation for immune system functioning. As a consequence, amino acids (AA) are repartitioned from skeletal muscle deposition towards utilisation for immune system functioning. Current requirement estimates for growing-finishing pigs are formulated to maximize protein deposition for growth and do not take into account the increased utilization of AA for immune functioning as induced by health challenging conditions. This lack of knowledge hampers the ability of feed manufacturers to optimize diets and improve pig performance. The main objective of the present thesis was to quantify the effect of health status on AA requirements for body protein deposition and for immune system functioning of growing pigs. A health status web was developed as a tool to categorize growing-finishing pig farms on the basis of their health status. The health status web can be of use for feed manufacturers to develop targeted strategies to accommodate the nutritional requirements of pigs belonging to particular groups of farms sharing a common health status. A dose-response technique was developed, which is a simple, accurate technique to quantitatively estimate changes in AA requirements of individual meal-fed pigs. Nevertheless, a minimum time period of 21 days is required for each individual, which makes the technique inappropriate for studying the effect of immune system activation on AA requirements. The combined measurements of whole body N retention, plasma irreversible loss rate (ILR, i.e. the amount of free AA that disappears per unit of time from the plasma pool for protein synthesis or oxidation), urea entry and appearance of 13C into plasma proteins, provided insight into the consequences of immune system activation on AA metabolism. Pigs selected from a farm with a suboptimal health status had greater serum haptoglobin, lower serum albumin concentrations, and greater leukocyte counts in blood at the start of the experiment than pigs selected from a farm with a high health status, indicating a higher level of immune system activation. The occurrence of compensatory gain in pigs from a farm characterized as having a suboptimal health status proves, however, that it is difficult to maintain a contrast in health status, and that pigs can adapt quickly to a change in housing conditions. In the absence of effects on feed intake, health challenging conditions may affect performance due to alterations in post-absorptive AA metabolism, as also indicated by increased urinary N losses, and a tendency for a reduced N retention and a lower utilization of digestible N for N retention in pigs with a systemic inflammation, or by a reduction in faecal nutrient digestibility as indicated for dry matter and N in pigs from a farm with a suboptimal health status. The observed changes in protein and AA metabolism after immune stimulation imply that especially tryptophan may become limiting during immune system activation, whereas lysine becomes excessive. Furthermore, the utilization of methionine, tyrosine, and valine for immune system functioning seems to increase in pigs with a systemic lung inflammation. In addition, the dietary AA or protein supply was able to modulate the acute phase response pre- and post-challenge, stressing the importance of an adequate dietary AA supply for appropriate functioning of the immune system of growing-finishing pigs. Before implementing targeted feeding strategies for farms sharing a common health status, future research should be conducted to study the possible beneficial effects of increasing the dietary supply of particularly tryptophan, methionine, tyrosine, and valine relative to lysine for immune system function and for body protein deposition in pigs from farms with a different health status.

Het network of excellence EURRECA heeft tien micronutriënten geselecteerd die prioriteit verdienen bij de Europese harmonisatie van de voedingsaanbevelingen. Voor veel van de micronutrienënten zijn melk en zuivelproducten belangrijke bronnen. Zo bleek tijdens een symposium in Parijs.

Op verschillende locaties in Nederland werd gedurende de jaren 1993-1999 onderzoek gedaan naar de geschiktheid van miscanthus en hennep als akkerbouwmatig geteeld energiegewas. De resultaten wat betreft gewasproductiviteit (biomassa-opbrengst) bij verschillende stikstofbemestingsniveaus en plantdichtheden, de minerale samenstelling en minerale behoeften van het gewas, gewasopkomst en gewasvestiging bij variërende plantleeftijd, poottijd en rhizoomgrootte (voor miscanthus), en voor beide gewassen de economische perspectieven. Ondanks goede opbrengsten kan het saldo niet tippen aan het gemiddelde van de gewassen in een normaal bouwplan; ook hier zijn weer subsidies nodig

Door verminderde industriële depositie van zwavel en minder verontreinigde meststoffen kan de zwavelvoorziening van landbouwgewassen in gevaar komen., met name op lichte gronden. PPO onderzocht in bemestingsproeven met wintertarwe in verschillende regio's en op verschillende grondsoorten het effect van zwavelbemesting op de zwavelopname en het zwavelgehalte in verschillende groeistadia en de uiteindelijke korrelopbrengst. Voor een goede stikstofvoorziening zijn vooral zwavelhoudende stikstofmeststoffen gunstig die bij het begin van de groei van het gewas worden gegeven

Door het Minas-beleid probeert Nederland te voldoen aan de Europese nitraatrichtlijn. De vraag is echter wat de voorspellende waarde is van de volgens Minas berekende stikstofoverschotten voor de werkelijke uitspoeling van nitraat naar het grondwater. In het kader van het project 'Sturen op nitraat' (Alterra, PPO, PRI, PV en CLM) worden voor een groot aantal teelten en gewassen de Minas-maatstaven vergeleken met mogelijke andere maatstaven voor nitraatuitspoeling: het werkelijke N-overschot (waarin de N-depositie uit de lucht en neerslag is meegenomen, evenals de berekende werkelijke N-afvoer), de minerale stikstof in de bodem na de oogst (risico van nitraatuitspoeling is in de winter het grootst), en de minerale stikstof in de bodem in de late herfst (1 december). De bepalende factoren voor de aan- en afvoer van stikstof, de correlaties tussen de verschillende maatstaven en de voorspellende waarde worden besproken

No potassium no plant: A huge number of processes are dependent on this element. Luckily, hardly any problems occur because the plant is good at looking after itself in this respect.

Er is geen voedingselement waarvan de plant zoveel nodig heeft als stikstof. Het gehalte kan wel 5% van de drogestof uitmaken. Behalve als essentieel onderdeel van veel plantonderdelen en inhoudsstoffen, wordt ook steeds meer duidelijk dat stikstof een signaalstof is, die processen aanstuurt, bijna zoals een hormoon.

Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Livestock Research to determine the bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens. A precise estimate of the bioavailability of zinc sources is required both for fulfilling the zinc requirements of the animal and to reduce zinc excretion in excreta and the environment.

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.

Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Livestock Research to determine the bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens. A precise estimate of the bioavailability of zinc sources is required both for fulfilling the zinc requirements of the animal and to reduce zinc excretion in excreta and the environment.

Vruchtensappen zijn minder gezond dan gedacht. Sommige producten bevatten minder voedingsstoffen dan ze beloven, zijn slecht voor het gebit of zetten de consument met hun natuurlijke uitstraling op het verkeerde been. Vruchtensap is geen volwaardig alternatief voor vers fruit. Sommige sappen bevatten voornamelijk (vruchten)suikers en leveren slechts 'lege' calorieën

Adequate methods with known performance characteristics for the assessment of the concentration of nutrients in infant and follow-on formula (referred to as "formula") are essential in the evaluation whether the composition deviates from the compositional provisions as laid down by law. Many standardized analytical methods for the analysis of nutrients in infant formula are internationally available.

Fertilisers received a lot of attention when growers first started using substrates. Since then the nutritional requirements of the plant have been largely driven by the need to reduce runoff emissions. In addition, more efficient use of fertilisers is playing a role. Until now growers went along with standerd fertiliser strategies. Now they are starting to adjust the nutrients given to suit the plant's needs.

The demand for agricultural products (food, feed, fibre, and biomass for other purposes) produced in Sub-Saharan Africa (SSA) will increase for the coming decades. In addition, the global climate change will largely impact on the agricultural sector in Sub-Saharan Africa. Major challenges for the agricultural sector in SSA are that agricultural production systems depend on resources that are for a large part non-renewable, and that the current agricultural practices in SSA are major contributors to environmental degradation. The Government of the Netherlands addresses food security and sustainable agricultural production in Sub-Saharan Africa. In order to support this process, the Ministry of EL&I has asked for ‘a concept’ to evaluate options for agricultural developments, which are aimed at increasing productivity and improving livelihoods, whilst safeguarding or improving ecosystems. This report presents analyses of yield gaps in Africa, nutrient use and requirements for crop land, and of fresh water production and crop evapotranspiration. The yield gap analysis was based on spatial databases and simulations of potential (irrigated) and water-limited maize yields with a crop growth model. The yield gap in Africa varies largely, ranging from 5 to 60%. The potential improvement for land productivity is large (up to 7 times the actual production levels), even without the help of irrigation. The analysis of nutrient use and requirements for cropland in Africa showed that closing the yield gap requires a higher N and P availability to crops. The analysis of the fresh water production per capita and evapotranspiration from cropland revealed that changes in cropland management, e.g. targeted to increase crop yields and evapotranspiration, can have a dramatic effect on fresh water production and may call for cropping systems that are efficient in water use. From a water use perspective the intensification of agriculture should be assessed at the regional (river basin) level, taking account of the spatial position of the country with respect to water-stressed basins. In the allocation of water resources, priority should be given to the areas where the highest return on water resources can be achieved in terms of types of water use or production systems. The report presents a tool to presented to evaluate strategic plans for the development of agriculture to increase food security in Sub-Saharan Africa. The tool can assist in identifying and evaluating alternative strategies for agricultural intensification in a participatory process. Apart from the Ministry of EL&I, other potential actors and stakeholders in such a process are the Dutch embassies in the pilot countries, governmental planning agencies, the private sector (local and foreign investors), NGOs (local and international NGOs), and knowledge institutes.

Goede voeding kan helpen ouderdomskwalen te voorkomen, ook voor wie al 50-plus is. En tot die categorie behoren steeds meer mensen, in Nederland en daarbuiten. Ook gaat met de jaren de behoefte aan sommige voedingsstoffen omhoog. Volop kansen voor productontwikkeling dus.

Primary goals of this thesis were to: 1) examine the in vivo digestion of macronutrients from conventional or alternative feed ingredients used in practical diets of juvenile gadoids (Atlantic cod and haddock), 2) document growth potential of fish at the juvenile grower phase given varying levels of dietary protein and energy and 3) assess the potential of in vitro pH-Stat methods for rapid screening protein quality of feed ingredients, specifically for gadoids. All primary research questions were linked to and built upon one another with the goal of gaining a better understanding of protein and energy utilization of juvenile grower phase gadoids. Studies showed that cod and haddock have a high capacity to utilize a wide range of dietary feed ingredients, such as fish meals, zooplankton meal, soybean products (meal, concentrate and isolate) and wheat gluten meal. New dietary formulations for gadoids may also utilize pulse meals, corn gluten meal, canola protein concentrate and crab meal. Digestibility data in this thesis is currently the only research that examined both in vivo and in vitro macronutrient digestibility of a large number and wide range of individual ingredients, specifically for gadoids. This is essential to gain new knowledge on protein and energy utilization as well as for least-cost ration formulations and effective substitution of ingredients into new formulations. Data has demonstrated a dietary digestible protein/digestible energy (DP/DE)ratio of 30 g DP/MJ DE is required for gadoids during the juvenile phase (

Goede voeding kan helpen ouderdomskwalen te voorkomen, ook voor wie al 50-plus is. En tot die categorie behoren steeds meer mensen, in Nederland en daarbuiten. Ook gaat met de jaren de behoefte aan sommige voedingsstoffen omhoog. Volop kansen voor productontwikkeling dus.

Adequate methods with known performance characteristics for the assessment of the concentration of nutrients in infant and follow-on formula (referred to as "formula") are essential in the evaluation whether the composition deviates from the compositional provisions as laid down by law. Many standardized analytical methods for the analysis of nutrients in infant formula are internationally available.

Primary goals of this thesis were to: 1) examine the in vivo digestion of macronutrients from conventional or alternative feed ingredients used in practical diets of juvenile gadoids (Atlantic cod and haddock), 2) document growth potential of fish at the juvenile grower phase given varying levels of dietary protein and energy and 3) assess the potential of in vitro pH-Stat methods for rapid screening protein quality of feed ingredients, specifically for gadoids. All primary research questions were linked to and built upon one another with the goal of gaining a better understanding of protein and energy utilization of juvenile grower phase gadoids. Studies showed that cod and haddock have a high capacity to utilize a wide range of dietary feed ingredients, such as fish meals, zooplankton meal, soybean products (meal, concentrate and isolate) and wheat gluten meal. New dietary formulations for gadoids may also utilize pulse meals, corn gluten meal, canola protein concentrate and crab meal. Digestibility data in this thesis is currently the only research that examined both in vivo and in vitro macronutrient digestibility of a large number and wide range of individual ingredients, specifically for gadoids. This is essential to gain new knowledge on protein and energy utilization as well as for least-cost ration formulations and effective substitution of ingredients into new formulations. Data has demonstrated a dietary digestible protein/digestible energy (DP/DE)ratio of 30 g DP/MJ DE is required for gadoids during the juvenile phase (

The demand for agricultural products (food, feed, fibre, and biomass for other purposes) produced in Sub-Saharan Africa (SSA) will increase for the coming decades. In addition, the global climate change will largely impact on the agricultural sector in Sub-Saharan Africa. Major challenges for the agricultural sector in SSA are that agricultural production systems depend on resources that are for a large part non-renewable, and that the current agricultural practices in SSA are major contributors to environmental degradation. The Government of the Netherlands addresses food security and sustainable agricultural production in Sub-Saharan Africa. In order to support this process, the Ministry of EL&I has asked for ‘a concept’ to evaluate options for agricultural developments, which are aimed at increasing productivity and improving livelihoods, whilst safeguarding or improving ecosystems. This report presents analyses of yield gaps in Africa, nutrient use and requirements for crop land, and of fresh water production and crop evapotranspiration. The yield gap analysis was based on spatial databases and simulations of potential (irrigated) and water-limited maize yields with a crop growth model. The yield gap in Africa varies largely, ranging from 5 to 60%. The potential improvement for land productivity is large (up to 7 times the actual production levels), even without the help of irrigation. The analysis of nutrient use and requirements for cropland in Africa showed that closing the yield gap requires a higher N and P availability to crops. The analysis of the fresh water production per capita and evapotranspiration from cropland revealed that changes in cropland management, e.g. targeted to increase crop yields and evapotranspiration, can have a dramatic effect on fresh water production and may call for cropping systems that are efficient in water use. From a water use perspective the intensification of agriculture should be assessed at the regional (river basin) level, taking account of the spatial position of the country with respect to water-stressed basins. In the allocation of water resources, priority should be given to the areas where the highest return on water resources can be achieved in terms of types of water use or production systems. The report presents a tool to presented to evaluate strategic plans for the development of agriculture to increase food security in Sub-Saharan Africa. The tool can assist in identifying and evaluating alternative strategies for agricultural intensification in a participatory process. Apart from the Ministry of EL&I, other potential actors and stakeholders in such a process are the Dutch embassies in the pilot countries, governmental planning agencies, the private sector (local and foreign investors), NGOs (local and international NGOs), and knowledge institutes.

Het network of excellence EURRECA heeft tien micronutriënten geselecteerd die prioriteit verdienen bij de Europese harmonisatie van de voedingsaanbevelingen. Voor veel van de micronutrienënten zijn melk en zuivelproducten belangrijke bronnen. Zo bleek tijdens een symposium in Parijs.

Bij de introductie van de eerste substraten kreeg de bemesting veel belangstelling. Daarna bleef de behoefte van de plant aan voedingsstoffen lange tijd onderbelicht. Nu is er sprake van een revival. Verlaging van de emissies is een motor achter de hernieuwde belangstelling. Maar een effectiever gebruik van meststoffen begint ook mee te spelen. Tot nu toe voorzagen de telers het systeem van meststoffen. Nu beginnen ze de voedingsgift op de plant af te stemmen.

De mestwetgeving en problemen met uitspoeling maken veredeling van aardappels op stikstofefficiëntie steeds interessanter. Met een lowinputaardappel kunnen veredelaars ook nieuwe markten in ontwikkelingslanden bedienen. Onderzoekers speuren naar manieren om de complexe eigenschap voor veredelaars grijpbaar te maken.

Bij de introductie van de eerste substraten kreeg de bemesting veel belangstelling. Daarna bleef de behoefte van de plant aan voedingsstoffen lange tijd onderbelicht. Nu is er sprake van een revival. Verlaging van de emissies is een motor achter de hernieuwde belangstelling. Maar een effectiever gebruik van meststoffen begint ook mee te spelen. Tot nu toe voorzagen de telers het systeem van meststoffen. Nu beginnen ze de voedingsgift op de plant af te stemmen.

De mestwetgeving en problemen met uitspoeling maken veredeling van aardappels op stikstofefficiëntie steeds interessanter. Met een lowinputaardappel kunnen veredelaars ook nieuwe markten in ontwikkelingslanden bedienen. Onderzoekers speuren naar manieren om de complexe eigenschap voor veredelaars grijpbaar te maken.

In proeven op vier locaties met verschillende tarwerassen onderzocht PPO de werking van de chlorophylmeter, waarmee de groenheid van een tarwegewas wordt vastgesteld en vervolgens daarmee de stikstofbemesting wordt afgestemd op de behoefte. Met het systeem blijkt het goed mogelijk de optimale tweede en derde stikstofgift te bepalen (resp. aan het begin van de strekkingsfase en bij het in aar komen)

Gastcolumn van Prof. dr. Edith Feskens, hoogleraar Voeding en Metabool Syndroom aan Wageningen Universiteit. De energiedichtheid van onze voeding is belangrijk, omdat een te hoge calorie inneming gecombineerd met lage fysieke activiteit de oorzaak is van de huidige obesitasepidemie. Maar ook de nutriëntendichtheid is belangrijk.