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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Genetic improvement of feed intake and methane emissions of cattle
Manzanilla Pech, Coralia I.V. - \ 2017
Wageningen University. Promotor(en): Roel Veerkamp, co-promotor(en): Yvette de Haas. - Wageningen : Wageningen University - ISBN 9789463430692 - 199
cattle - feed intake - methane production - genetic improvement - genetic parameters - conformation - breeding value - animal genetics - rundvee - voeropname - methaanproductie - genetische verbetering - genetische parameters - bouw (dier) - fokwaarde - diergenetica

Feed costs represent half of the total costs of dairy production. One way to increase profitability of dairy production is to reduce feed costs by improving feed efficiency. As DMI is a trait that varies significantly during and across lactations, it is imperative to understand the underlying genetic architecture of DMI across lactation. Moreover, phenotypes of DMI are scarce, due to the difficulty of recording them (expensive and labor-intensive). Some predictor traits have been suggested to predict DMI. Examples of these predictor traits are those related to production (milk yield (MY) or milk content) or to the maintenance of the cow (body weight (BW) or conformation traits). The ability to determine when predictor traits ideally should be measured in order to achieve an accurate prediction of DMI throughout the whole lactation period is thus important. Recently, with the use of information of single nucleotide polymorphism (SNP) markers, together with phenotypic data and pedigree, genomically estimated breeding values (GEBV) of scarcely recorded traits, such as DMI, have become easier to accurately predict. This approach, combined with predictor traits, could contribute to an increased accuracy of predictions of GEBV of DMI. Methane (CH4) is the second important greenhouse gas, and enteric CH4 is the largest source of anthropogenic CH4, representing 17% of global CH4 emissions. Furthermore, methane emissions represent 2-12% of feed energy losses. Selecting for lower CH4 emitting animals and more feed-efficient animals would aid in mitigating global CH4 emissions. To identify the impact on CH4 emissions of selecting for lower DMI animals, it is important to determine the correlations between DMI and CH4 and to identify whether the same genes that control DMI affect CH4. Therefore, the general objectives of this thesis were to (1) explore the genetic architecture of DMI during lactation, (2) study the relationship of DMI to conformation, production and other related traits, (3) investigate the correlations between DMI and methane traits, and determine the SNP in common between DMI and CH4 through a genome-wide association study (GWAS), and (4) investigate the accuracy of predictions of DMI using predictor traits combined with genomic data.

Documentatierapport Koemodel : de werking van het koemodel samengevat
Zom, R.L.G. - \ 2016
Wageningen : Wageningen Livestock Research (Livestock Research rapport 1005) - 9
rundvee - melkveehouderij - voeropname - melkproductie - diermodellen - leeftijdsstructuur - melkveestapel - cattle - dairy farming - feed intake - milk production - animal models - age structure - dairy herds
Het effect van een verhoogde ammoniak concentratie in het water op fysiologie, groei en voeropname van Europese paling (Anguilla anguilla)
Abbink, W. ; Blom, E. ; Pelgrim, Thamar ; Vries, P. de; Vis, J.W. van de; Schram, E. - \ 2015
Yerseke : IMARES (Rapport / IMARES C187/15) - 18 p.
european eels - ammoniak - dierfysiologie - groei - voeropname - visteelt - aquacultuur - dierenwelzijn - dierlijke productie - kweekvis - palingen - huisvesting, dieren - diergezondheid - ammonia - animal physiology - growth - feed intake - fish culture - aquaculture - animal welfare - animal production - farmed fish - eels - animal housing - animal health
Culturing soles on ragworms: growth and feeding behaviour
Ende, S.S.W. - \ 2015
Wageningen University. Promotor(en): Johan Verreth, co-promotor(en): Johan Schrama. - Wageningen : Wageningen University - ISBN 9789462575622 - 128
solea - soleidae - kweekvis - voeropname - groei - prooi - wormen - foerageren - voedingsgedrag - prestatieniveau - vijverteelt - aquacultuur - farmed fish - feed intake - growth - prey - helminths - foraging - feeding behaviour - performance - pond culture - aquaculture

Ende, S.S.W. (2015). Culturing soles on ragworms: Growth and feeding behaviour. PhD thesis, Wageningen University, The Netherlands.

Despite the high market demand and intensive research efforts since the 1960s commercial culture of common sole (Solea solea L.) has been unsuccessful. Problems related to availability and price of suitable raw materials (invertebrates) and the low tolerance to crowding have hampered the development of intensive sole culture. Alternative extensive pond cultures systems are currently explored where common sole can graze on natural food. The general aim of this study was to get insight into which factors limit growth of common sole foraging on ragworms in ponds. The results did not show any nutritional effects that may hamper the growth of common sole. At non-limiting conditions, i.e. when fed chopped ragworms and when housed in sediment free tanks, common sole showed higher food intake, higher growth rates and higher nutrient utilization efficiencies than when fed mussels or a formulated diet. The results however suggest that growth in a pond with ragworms was limited by reduced foraging capabilities of common sole. To explore this hypothesis, the effect of prey size, predator size and prey density were tested. Overall, intake of buried ragworms was reduced by more than half in contrast to intake of unburied ragworms. Intake of buried ragworms was reduced regardless of ragworm size or common sole size. Increasing ragworm density only resulted in satiation intake values in smaller common sole. Our results additionally indicate that the presence of common sole hampers ragworm performance in a pond. Ragworms reduced their feeding activities when receiving water from tanks which contained common sole and ragworms, i.e. when common sole could graze on ragworms. Results from this PhD study suggest that the growth of common sole in ponds is not limited by nutritional but by their foraging abilities. However, the results of this study are too incomplete to fully predict growth performance of common sole in a pond. Factors such as temperature, oxygen supply or feeding activity need to be investigated to make comprehensive growth predictions.

Effect van voersysteem op technische resultaten en gezondheid van gespeende biggen
Peet-Schwering, C.M.C. van der; Pas, P.A. van de; Binnendijk, G.P. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 870) - 23
varkens - biggen - voedersystemen - drinkwater - diergezondheid - varkenshouderij - veehouderij - kweken - voeropname - groei - pigs - piglets - feeding systems - drinking water - animal health - pig farming - livestock farming - rearing - feed intake - growth
Op Varkens Innovatie Centrum Sterksel is onderzocht wat het effect is van het verstrekken van voer en drinkwater via een geoptimaliseerd voer- en drinkwatersysteem (Feeder) of via 2-vaksdroogvoerbakken en drinkbakjes (controlegroep) op de groei, voeropname, waterverbruik, voederconversie, eet- en drinkgedrag en gezondheid van gespeende biggen. De resultaten van het onderzoek zijn in dit rapport beschreven.
Effect van voerniveau bij drachtige lacterende zeugen op reproductie en conditie = Effect of feeding level in gestating lactating sows on reproduction and condition
Peet-Schwering, C.M.C. van der; Rommers, J.M. ; Troquet, L.M.P. ; Soede, N.M. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research report 861) - 39
zeugen - voeropname - varkensvoeding - varkenshouderij - lichamelijke fitheid - zogen - voortplantingsvermogen - biggen - lactatie - sows - feed intake - pig feeding - pig farming - physical fitness - suckling - reproductive performance - piglets - lactation
Op VIC Sterksel is onderzocht wat het effect is van het voerniveau van zeugen tijdens de laatste 8 dagen van een zes weekse lactatie waarin ze ook drachtig zijn op de gewichts- en spekdikte ontwikkeling van de zeugen, de resultaten van de biggen en het aantal levend en dood geboren biggen in de volgende worp. De resultaten van het onderzoek zijn in dit rapport beschreven.
Pilot inkuilen Grote waternavel ten behoeve van veevoeding
Hoving, I.E. ; Schooten, H.A. van - \ 2015
Wageningen : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 853) - 26
veevoeding - varkensvoeding - conservering - varkens - voeropname - voedingswaarde - kuilvoer - hydrocotyle - kuilvoerbereiding - ingekuilde planten - livestock feeding - pig feeding - conservation - pigs - feed intake - nutritive value - silage - silage making - silage plants
This report describes the results of a practical ensiling experiment with Greater water pennywort, in which the processing of the plant material and the effect of drying on the ensiling result and nutrition value has been investigated. The conservation of the ensiled product was very poor (even after drying) due to the high water content, low sugar content and soil contamination. The intake of the wet product by pigs seem to be good. The poor preservation proved no obstacle. Greater water pennywort has potential as fodder for pigs given the nutritional and good intake. What is needed are methods to harvest cleaner and to ferment the product better.
Fokwaarde voeropname : introductie van fokwaarde voor voeropname in Nederland
Haas, Y. de; Veerkamp, R.F. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 837) - 17
fokwaarde - melkveehouderij - melkproductie - voeropname - dierveredeling - rundveehouderij - rundveevoeding - breeding value - dairy farming - milk production - feed intake - animal breeding - cattle husbandry - cattle feeding
Feed costs represent above 50% of the total costs of dairy production, so reducing costs by improving dairy cow feed efficiency is a way to increase profitability. Therefore it is important to improve efficiency of that dairy cattle population. This project has shown that it is possible to breed for more efficient animals, resulting in permanent and cumulative changes in the genetic merit of dairy cows. The breeding value for feed intake is currently integrated in the Better Life Efficiency index for all sires of CRV, and it is under discussing if it will be included in the national index (published by GES) for all bulls in the Netherlands and Flanders.
Body composition and reproduction in broiler breeders: impact of feeding strategies
Emous, R.A. van - \ 2015
Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Rene Kwakkel; Marinus van Krimpen. - Wageningen : Wageningen University - ISBN 9789462572386 - 173
vleeskuikenouderdieren - vleeskuikens - lichaamssamenstelling - gevogeltevoeding - voer - voedingseiwit - voeropname - diergedrag - corticosteron - voortplanting - vrouwelijke vruchtbaarheid - prestatieniveau - diervoeding - broiler breeders - broilers - body composition - fowl feeding - feeds - dietary protein - feed intake - animal behaviour - corticosterone - reproduction - female fertility - performance - animal nutrition


Key words: broiler breeder, feeding strategies, body composition, reproduction, behavior

Nowadays, welfare issues in broiler breeders associated with nutrition and reproductive characteristics, are becoming increasingly challenging. Due to genetic selection on broilers, body composition of breeders has changed dramatically during the last 50 years to less fat and more breast muscle. It is postulated that a certain amount of body fat in broiler breeders at the onset of lay is necessary for maximum performance and offspring quality. Body composition of breeders can be influenced by different feed allowances during rearing and lay, as well as by changes in nutrient composition of the diet. However, little is known about the effects of body composition on reproduction of broiler breeders. In this thesis, we investigated the effects of different feeding strategies during the rearing period on body composition at the end of rearing. Moreover, the effects of differences in body composition at the end of rearing, and feeding strategies during lay were evaluated on breeder performance, incubation traits, offspring performance, behavior and feather cover. From this study, it can be concluded that feeding a low protein diet during rearing decreased breast muscle and increased abdominal fat pad, whereas providing an increased feeding schedule, which resulted in a high growth pattern, only increased abdominal fat pad, at the end of rearing. The higher abdominal fat pad content resulted in an increased hatchability during the first phase of lay and a larger number of eggs during the second phase of lay. For maintaining growth pattern, broiler breeders had to provide a higher amount of feed with an increased energy to protein ratio compared to broiler breeders that were fed a diet with a standard energy to protein ratio. This resulted in an increased eating time and less stereotypic object pecking, which may indicate a reduced hunger and frustration. On the other hand, a low daily protein intake during the rearing and first phase of lay can lead to a poor feather cover. Feeding a high-energy diet during the second phase of lay resulted in increased hatchability, decreased embryonic mortality and more first grade chicks.

Voorspellen van de voeropname van droogstaande melkkoeien
Zom, R.L.G. ; Riel, J.W. van - \ 2014
Wageningen : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 794) - 17
melkkoeien - melkveevoeding - melkveehouderij - voeropname - drachtigheidsperiode - modellen - gustperiode - dairy cows - dairy cattle nutrition - dairy farming - feed intake - gestation period - models - dry period
The feed intake module of the Dairy Cow Model is extended with an adjustment factor to predict the feed intake capacity of dairy cows in the dry period. This adjustment factor is described as a function of day before calving (t) using an exponential model. This model is derived from a dataset with data on the feed intake of dairy cows in the dry period. The feed intake capacity of dry dairy cows (VOCDROOGSTAND) is estimated by multiplication of the uncorrected feed intake capacity (VOC0), as predicted by the Dairy Cow Model) with the adjustment factor. In addition to that, the t model includes a fixed discount factor “correction factor”, to account for the depression in feed intake 1 and 0 days before parturition.
The development of a model for the prediction of feed intake and energy partitioning in dairy cows
Zom, R.L.G. - \ 2014
Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Ad van Vuuren. - Wageningen : Wageningen University - ISBN 9789462570443 - 176
dieren - melkkoeien - melkveehouderij - voeropname - modelleren - verteerbare energie - animals - dairy cows - dairy farming - feed intake - modeling - digestible energy

Balancing the supply of on-farm grown forages with the production targets of the dairy herd is a crucial aspect of the management of a dairy farm. Models which provides a rapid insight of the impact of the ration, feed quality and feeding management on feed intake and performance of dairy cows are indispensable to optimize feeding strategies, allocation of feeds and purchased concentrates, in order to find the best compromise between milk performance, nutrient use efficiency, manure excretion, gaseous emissions and profitability. This thesis describes the development of the Wageningen UR Dairy Cow Model (Wageningen DCM), a model for the prediction of feed intake and performance of dairy cows. The Wageningen DCM is constructed from two modules: a feed intake model and an energy partitioning model which describes the partitioning of the ingested net energy to milk energy output and body reserves. For the development of the feed intake model a calibration dataset was compiled with 38515 weekly records of ration feed composition, diet composition, individual feed intakes, milk yield and composition, parity, days in lactation and days pregnant from 1507 cows. The feed intake model predicts dry matter intake (DMI) from feed and animal characteristics. Data of standard feed analysis were used to estimate the satiety value (SV) of numerous feeds. The SV is the measure of the extent to which a feed limits intake. The cows’ ability to process the intake-limiting satiety value-units is expressed as the feed intake capacity (FIC). The FIC is estimated from parity, days in milk and days of pregnancy which are indicators of the size and physiological state of the cow. An evaluation of the feed intake model was performed using an independent dataset containing 8974 weekly means of DMI from 348 cows. On the basis of mean square prediction error (MSPE) and relative prediction error (RPE) as criteria, it was concluded that feed intake model was robust and can be applied to various diets and feeding management situations in lactating HF cows.

A second model was developed to predict the partitioning of ingested net energy (NEL) to milk energy and body reserves. This energy partitioning model describes the baselines of daily NEL intake and milk energy output (MEO) during successive lactation cycles of a ‘reference’ cow. The MEO and change in body energy of a cow is estimated from deviation of NEL intake from the baseline. A NEL intake above the baselines results in a higher predicted MEO and reduced mobilization of body energy reserves. Whereas, a NEL intake below the baseline results in a lower predicted MEO and increased mobilization. The proportion of ingested NEL partitioned to MEO depends parity number, days in lactation and pregnant, reflecting the changes in priority in energy partitioning during successive lactation cycles of a dairy cow

The feed intake model and energy partitioning model are integrated in the Wageningen DCM. Model simulations showed that the Wageningen DCM is able to simulate the effects of diet composition, nutritional strategies and effects of cow characteristics (parity, days in milk and pregnancy) on dry matter and nutrient intake, and the partitioning of ingested NEL into MEO and body energy. The Wageningen DCM requires easily available input data. Validation of the Wageningen DCM with external data indicated a good accuracy of the prediction of intake and milk energy output with relatively low prediction errors ≤ 0.1. The Wageningen DCM enables users to analyse and compare different feeding strategies, identify limitations of feeding strategies, formulate diets, calculate feed budgets and to develop economic and environmental sustainable feeding strategies.

Flyer cockpit vleesvarkens
Dirx-Kuijken, N.C.P.M.M. ; Peet-Schwering, C.M.C. van der - \ 2014
Wageningen UR Livestock Research
varkenshouderij - slachtdieren - voeropname - diergezondheid - lichaamsgewicht - pig farming - meat animals - feed intake - animal health - body weight
Het project ‘Vitale vleesvarkens’ richt zich op het verbeteren van de resultaten in de (vlees)varkenshouderij. Binnen het project is o.a. onderzoek uitgevoerd naar het effect van grondstoffen- en nutriëntensamenstelling en van bigkwaliteit op de technische en financiële resultaten van het vleesvarken. Daarnaast is gewerkt aan de ont-wikkeling van nieuwe voersystemen voor biggen en vleesvarkens en de ontwikkeling van een cockpit at-tentiesysteem voor (vlees)varkens.
Effect geboortegewicht en voeropname op S. suis
Peet-Schwering, C.M.C. van der; Troquet, L.M.P. ; Smith, H. ; Hout, J. van - \ 2014
V-focus 11 (2014)3. - ISSN 1574-1575 - p. 32 - 33.
varkenshouderij - biggen - biggenziekten - streptococcus suis - geboortegewicht - biggenvoeding - voeropname - invloeden - ziekte-incidentie - pig farming - piglets - piglet diseases - birth weight - piglet feeding - feed intake - influences - disease incidence
Er is geen duidelijk effect van geboortegewicht en van voeropname vóór spenen op het aantal biggen met klinische verschijnselen van een Streptococcus suis (S. suis) infectie. Dit blijkt uit onderzoek dat is uitgevoerd in opdracht van het Productschap Vee en Vlees en het ministerie van Economische Zaken.
Hoe giftig zijn ammonia en nitraat voor snoekbaars?
Schram, E. ; Roques, J.A.C. ; Kuijk, T. van; Abbink, W. ; Heul, J.W. van der; Vries, P. de; Bierman, S.M. ; Vis, J.W. van de; Flik, G. - \ 2014
Aquacultuur 29 (2014)1. - ISSN 1382-2764 - p. 12 - 17.
snoekbaars - recirculatie aquacultuur systemen - aquacultuur - nitraat - ammoniak - voeropname - pike perch - recirculating aquaculture systems - aquaculture - nitrate - ammonia - feed intake
In intensieve recirculatiesystemen lopen vissen het risico blootgesteld te worden aan ammonia en nitraat. Hoe hoog mogen de nitraat- en ammoniaconcentratie zijn zonder dat dit negatieve effecten heeft op de vissen? IMARES onderzocht dit in samenwerking met de Radboud Universiteit Nijmegen en de Universiteit van Amsterdam voor juveniele snoekbaars. Conclusie: de ammonia (NH3) concentratie moet onder de 0.05 mg NH3-N/I gehouden worden. Van nitraat lijken juveniele snoekbaarzen zelfs bij 358 mg NO3-N/I nog weinig hinder te ondervinden.
Effect van geboortegewicht en voeropname voor spenen op het aantal gespeende biggen met Streptococcus suis verschijnselen = Effect of birth weight and feed intake before weaning on the number of weaned piglets with clinical signs of Streptococcus suis
Peet-Schwering, C.M.C. van der; Troquet, L.M.P. ; Smith, H.E. ; Greeff, A. de; Hout, J. van; Faber, I. - \ 2014
Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 761)
varkenshouderij - biggen - biggenziekten - streptococcus suis - geboortegewicht - biggenvoeding - voeropname - pig farming - piglets - piglet diseases - birth weight - piglet feeding - feed intake
At Swine Innovation Centre Sterksel the effects of birth weight and feed intake before weaning on the number of weaned piglets with clinical signs of an infection with S. suis were investigated. The results are described in this report.
Feed intake and oxygen consumption in fish
Subramanian, S. - \ 2013
Wageningen University. Promotor(en): Johan Verreth, co-promotor(en): Johan Schrama; S.J. Kaushik; I. Geurden. - Wageningen : Wageningen UR - ISBN 9789461737571 - 163
vissen - voeropname - zuurstofconsumptie - energieopname - voer - samenstelling - energiemetabolisme - macronutriënten - visvoeding - visteelt - aquacultuur - voedingsfysiologie - fishes - feed intake - oxygen consumption - energy intake - feeds - composition - energy metabolism - macronutrients - fish feeding - fish culture - aquaculture - nutrition physiology

In fish, the voluntary feed intake is influenced by dietary, environmental and/or physiological factors. It is well known that under hypoxia the concentration of oxygen in the water (DO) determines the feed intake of fish. However at non-limiting water DO levels (normoxia), several other mechanisms might play a role in feed intake regulation. Under hypoxia feed intake and oxygen consumption are interrelated. In this thesis we proposed the ‘oxystatic’ concept of feed intake regulation, which states that even at normoxia and in the absence of other constraints, the long term (weeks) voluntary feed intake of fish can be constrained by a set-point value of oxygen consumption. Dietary macronutrient composition affects the ‘dietary oxygen demand’ (i.e., amount of O2 consumed per unit of feed). This oxystatic concept implies that fish fed to satiation with diets differing in ‘dietary oxygen demand’ (mg O2/ g or kJ feed) will have a different digestible energy intake but a similar oxygen consumption. The validity of the oxystatic concept was assessed in two species, Nile tilapia and rainbow trout. These fish were fed diets which had large contrasts in nutrient composition (i.e., protein to energy ratio; type of the non-protein energy source (starch vs. fat); amino acid composition) in order to create contrasts in dietary oxygen demand. In all conducted studies with both species, the digestible energy intake was affected by the diet composition. However, in some studies oxygen consumption was similar and in others it differed between the diets, which respectively supports and contradicts the oxystatic concept. In all studies with both species, the digestible energy intake of tilapia and trout was negatively related to dietary oxygen demand and positively related to efficiency of oxygen utilization for energy retention. Furthermore it was observed in tilapia that the within-day variation in feed intake was affected by dietary macronutrient composition. The variation in within-day feed intake was related to pre-feeding oxygen levels. Based on the combined results, it is suggested that even at normoxia voluntary feed intake in fish is limited/determined by oxygen consumption and/or the oxidative metabolism. Overall, the oxystatic concept appears to be valid for certain conditions, but its generic application remains questionable. Yet, the oxystatic concept enables the combination of dietary, environmental and fish factors into one concept. Further it provides a conceptual insight for better understanding of feed intake regulation in fish.

Optimizing genomic selection for scarcely recorded traits
Pszczola, M.J. - \ 2013
Wageningen University. Promotor(en): Johan van Arendonk, co-promotor(en): Mario Calus; T. Strabel. - Wageningen : Wageningen UR - ISBN 9789461737663 - 158
melkvee - genomen - selectief fokken - genetische verbetering - fokwaarde - fenotypen - genotypen - kenmerken - voeropname - dierveredeling - dairy cattle - genomes - selective breeding - genetic improvement - breeding value - phenotypes - genotypes - traits - feed intake - animal breeding

Animal breeding aims to genetically improve animal populations by selecting the best individuals as parents of the next generation. New traits are being introduced to breeding goals to satisfy new demands faced by livestock production. Selecting for novel traits is especially challenging when recording is laborious and expensive and large scale recording is not possible. Genetic improvement of novel traits may be thus limited due to the small number of observations. New breeding tools, such as genomic selection, are therefore needed to enable the genetic improvement of novel traits. Using the limited available data optimally may, however, require alternative approaches and methodologies than currently used for conventional breeding goal traits. The overall objective of this thesis was to investigate different options for optimizing genomic selection for scarcely recorded novel traits. The investigated options were: (1) genotype imputation for ungenotyped but phenotyped animals to be used to enlarge the reference population; (2) optimization of the design of the reference population with respect to the relationships among the animals included in it; (3) prioritizing genotyping of the reference population or the selection candidates; and (4) using easily recordable predictor traits to improve the accuracy of breeding values for scarcely recorded traits. Results showed that: (1) including ungenotyped animals to the reference population can lead to a limited increase in the breeding values accuracy; (2) the reference population is designed optimally when the relationship within the reference are minimized and between reference population and potential selection candidates maximized; (3) the main gain in accuracy when moving from traditional to genomic selection is due to genotyping the selection candidates, but preferably both reference population and selection candidates should be genotyped; and (4) including the predictor traits in the analysis when it is recorded on both reference population and selection candidates can lead to a significant increase in the selection accuracy. The key factors for successful implementation of selection for a novel trait in a breeding scheme are: (1) maximizing accuracy of genotype prediction for ungenotyped animals to be used for updating the reference population; (2) optimizing the design of the reference population; (3) determining easy to record indicator traits that are also available on the selection candidates (4) developing large scale phenotyping techniques; and (5) establishing strategies and policies for increasing the engagement of farmers in the recording of novel traits.

Minder eiwit, goed gedrag
Emous, R.A. van; Krimpen, M.M. van; Kwakkel, R.P. - \ 2013
De Pluimveehouderij 43 (2013)5. - ISSN 0166-8250 - p. 28 - 29.
pluimveehouderij - pluimveevoeding - eiwitgehalte - diergedrag - vleeskuikenouderdieren - vleeskuikens - dierenwelzijn - voeropname - poultry farming - poultry feeding - protein content - animal behaviour - broiler breeders - broilers - animal welfare - feed intake
Een lager eiwitgehalte in het voer van vleeskuikenouderdieren bevordert natuurlijk gedrag, zo blijkt uit onderzoek van Wageningen UR.
Verbazingwekkende groei na spenen: studieavond 'Grote korrel voor kleine big'
Nederhoff, T. ; Brand, H. van den; Kemps, A. ; Alderliesten, E. - \ 2013
De Molenaar 116 (2013)2. - ISSN 0165-4284 - p. 7 - 9.
biggen - biggenvoeding - korrels - voeropname - spenen - piglets - piglet feeding - granules - feed intake - weaning
Toen dr. Henry van den Brand (Wageningen University) beweerde dat grote korrels bij zogende biggen voor hogere voeropname en groei leiden, geloofde niemand hem. Inmiddels produceert Coppens diervoeding een korrel van 15 millimeter doorsnee voor jonge biggen. Resultaten van de eerste praktijkproeven tonen aan dat de groei na spenen hoog is
Voer van invloed op biggensterfte
Makkink, C.A. ; Wientjes, J.G.M. - \ 2013
De Molenaar 116 (2013)7. - ISSN 0165-4284 - p. 18 - 19.
varkenshouderij - dierenwelzijn - mortaliteit - biggen - varkensvoeding - biggenvoeding - voeropname - insuline - colostrum - varkens - dierlijke productie - diergezondheid - diervoeding - pig farming - animal welfare - mortality - piglets - pig feeding - piglet feeding - feed intake - insulin - pigs - animal production - animal health - animal nutrition
Marginale verschillen in voeding en metabolisme vóór inseminatie kunnen leiden tot grote verschillen in prenatale en postnatale biggensterfte. Dit was een van de conclusies tijdens het seminar van de leerstoelgroep Adaptatiefysiologie in Wageningen University.
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