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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    Grasraffinage en gebruik van grasvezel in de rundveevoeding
    Klop, A. ; Durksz, D.L. ; Zonderland, A. ; Koopmans, B. - \ 2015
    Wageningen : Wageningen UR, Livestock Research (Livestock Research rapport 790) - 26
    veevoeding - melkveevoeding - kalvervoeding - bioraffinage - grasmaaisel - vezels - eiwit - proeven - melkveehouderij - livestock feeding - dairy cattle nutrition - calf feeding - biorefinery - grass clippings - fibres - protein - trials - dairy farming
    In 2012 is een proef met melkkoeien uitgevoerd met als doel de waarde van grasvezel te onderzoeken. In het rantsoen van de koeien werd een deel van de graskuil vervangen door grasvezel. De grasvezel kwam beschikbaar na de raffinage van gras. De resultaten van de proef vielen tegen. De voeropname van de koeien die grasvezel kregen was namelijk lager dan van de (controle)koeien die het gangbare rantsoen kregen. De melkgift was eveneens lager op het rantsoen met grasvezel. De oorzaak van de lagere voeropname heeft waarschijnlijk te maken met de versheid en daarmee de smakelijkheid van grasvezel. Daarom is in 2013 besloten om eerst te kijken naar de mogelijkheid om grasvezel te conserveren (in te kuilen), waardoor de kwaliteit en de houdbaarheid mogelijk werd verbeterd. In 2012 is eveneens een oriënterend onderzoek gedaan met graseiwit verstrekt aan kalveren. Graseiwit is het eiwit dat gewonnen wordt uit het grassap en in de proef werd het in gelvorm verstrekt. De resultaten van de proef met kalveren waren uitermate positief. De dieren namen het graseiwit graag op. De groei van de kalveren was vergelijkbaar met de controlegroep.
    A field trial on the effects of algae addition to calf feed. Project T2014
    Elissen, H.J.H. ; Berg, W. van den; Kootstra, A.M.J. - \ 2015
    Lelystad : Wageningen UR, PPO/Acrres (Rapport / PPO-AGV 662) - 41
    calves - calf feeding - feed formulation - feeds - veal calves - liveweight - animal health - feed conversion - algae - kalveren - kalvervoeding - voersamenstelling - voer - vleeskalveren - levend gewicht - diergezondheid - voederconversie - algen
    This report describes a field trial that took place between 1 July and 2 October 2015 at a Dutch rose veal farm in which a group of 30 calves was fed with formula milk of which 2% of the dry matter was substituted with concentrated freshwater algae. The control group consisted of 25 calves. The farm owners collected the data, which were statistically analyzed and reported at ACRRES. During the trial the following parameters were monitored: calf weight, amounts of formula milk, water, solid feeds, feed additions and medication, deviations in manure structure, and disease incidence. Individual calf weights were determined at arrival and four weighing dates. The main conclusion of this field trial is that the addition of algae to the formula milk of rose veal calves during a period of 44 to 51 days did not have a statistically significant effect on calf weight increase up to 13 weeks after the start of the trial.
    Replacing lactose from calf milk replacers : effects on digestion and post-absorptive metabolism
    Gilbert, M.S. - \ 2015
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Walter Gerrits; Henk Schols. - Wageningen : Wageningen University - ISBN 9789462576032 - 171
    vleeskalveren - lactose - kunstmelk - polysacchariden - glucose - fructose - glycerol - zetmeelvertering - metabolisme - fermentatie - kalvervoeding - diervoeding - voedingsfysiologie - veal calves - lactose - filled milk - polysaccharides - glucose - fructose - glycerol - starch digestion - metabolism - fermentation - calf feeding - animal nutrition - nutrition physiology

    Summary PhD thesis Myrthe S. Gilbert

    Replacing lactose from calf milk replacers – Effects on digestion and post-absorptive metabolism

    Veal calves are fed milk replacer (MR) and solid feed. The largest part of the energy provided to veal calves originates from the MR. Calf MR contains 40 to 50% lactose, originating from whey, a by-product from cheese production. High and strongly fluctuating dairy prices are a major economic incentive to replace lactose from the calf MR by alternative energy sources. The objective of this thesis was to study the effects of replacing lactose from calf MR on nutrient digestion and fermentation and post-absorptive metabolism.

    In Chapter 2 and 3, four starch products (SP) were evaluated for replacing lactose. The four SP differed in size and branching, and consequently required different ratios of starch-degrading enzymes for their complete hydrolysis to glucose. Gelatinized starch required α-amylase and (iso)maltase; maltodextrin required (iso)maltase and α-amylase; maltodextrin with α-1,6-branching required isomaltase, maltase and α-amylase and maltose required maltase. In Chapter 2, adaptation to these SP was assessed during 14 weeks, using a within-animal titration study. Forty male Holstein-Friesian calves (n = 8 per treatment) were assigned to either a lactose control MR or one of four titration strategies, each testing the stepwise exchange of lactose for one of the SP. For control calves, fecal dry matter (DM) content and fecal pH did not change over time. The response in fecal DM content and fecal pH in time did not differ between SP treatments and decreased linearly with 0.57% and 0.32 per week, respectively, where one week corresponded to an increase in SP inclusion of 3%. This indicates that the capacity for starch digestion was already exceeded at low inclusion levels, resulting in SP fermentation. All SP required maltase to achieve complete hydrolysis to glucose and it was, therefore, suggested that maltase is the rate-limiting enzyme in starch digestion in milk-fed calves.

    Following the titration, a fixed inclusion level of 18% of the SP in the MR was applied. Effects on starch-degrading enzyme activity, nutrient disappearance, SP fermentation and jugular glucose appearance were measured (Chapter 3). Lactase activity in the brush border was high in the proximal small intestine of all calves, resulting in a high apparent ileal disappearance of lactose (≥ 99% of intake). Maltase and isomaltase activities in the brush border were not increased for any of the SP treatments. Luminal α-amylase activity was lower in the proximal small intestine but greater in the distal small intestine of SP-fed calves compared to control calves. This amylase activity in the distal small intestine of SP-fed calves might have been of microbial origin. Apparent SP disappearance did not differ between SP treatments. The difference between apparent ileal (62%) and total tract (99%) SP disappearance indicated substantial SP fermentation in the large intestine (37% of intake). In addition, total tract SP fermentation was quantified using fecal 13C excretion which originated from the naturally 13C-enriched corn SP. Total tract SP fermentation averaged 89% of intake, regardless of SP treatment. MR leaking into the reticulorumen was measured as the recovery of Cr in the reticulorumen at slaughter after feeding MR pulse-dosed with Cr 4h prior to slaughter. MR leaking into the reticulorumen averaged 11% for SP-fed calves. By difference, this leaves 41% of the SP intake fermented in the small intestine. This coincided with increased fecal nitrogen (N) and DM losses for SP-fed calves. However, apparent total tract crude fat disappearance tended to increase when replacing lactose with SP. The substantial SP fermentation indicates that only 10% of the SP intake was enzymatically hydrolyzed and absorbed as glucose. This was in agreement with the marginal increase in 13C enrichment in peripheral plasma glucose after feeding naturally 13C-enriched gelatinized starch and maltose, compared to a clear increase after feeding naturally 13C-enriched lactose to control calves. It was concluded that fermentation, rather than enzymatic digestion, is the main reason for small intestinal starch disappearance in milk-fed calves. The expected decrease in growth performance with such extensive SP fermentation is partially compensated by the greater crude fat digestion and possibly by a reduced urinary glucose excretion when replacing lactose with SP.

    Glucose, fructose and glycerol do not require enzymatic hydrolysis and can be absorbed directly from the small intestine. However, these lactose replacers might differentially affect glucose and insulin metabolism and with that energy partitioning. The effects of partly replacing lactose with glucose, fructose or glycerol on energy and N partitioning and glucose homeostasis and insulin sensitivity were, therefore, studied in Chapter 4 and 5. Forty male Holstein-Friesian calves either received a lactose control MR or a MR in which one third of the lactose was replaced with glucose, fructose or glycerol (n = 10 per treatment). Energy and N retention were not affected by MR composition. Fructose absorption from the small intestine was incomplete resulting in fructose fermentation. This resulted in fecal losses of DM, energy and N and the lowest numerical energy and N retention for fructose-fed calves. Postprandial plasma concentrations of glucose exceeded the renal threshold for glucose in glucose-fed calves and control calves, which resulted in urinary glucose excretion. Glycerol was likely excreted with the urine of glycerol-fed calves. Oxidation of glucose, fructose and glycerol was quantified by feeding a single dose of [U-13C]glucose, [U-13C]fructose or [U-13C]glycerol with the MR and subsequently measuring 13CO2 production. Oxidation of lactose replacers did not differ between lactose replacers and averaged 72% of intake. However, the time at which the maximum rate of oxidation was reached was delayed for fructose-fed compared to glucose-fed and glycerol-fed calves, indicating that fructose was converted into other substrates before being oxidized. Conversion of fructose and glycerol into glucose was confirmed by an increase in 13C enrichment of peripheral plasma glucose after feeding [U-13C]fructose and [U-13C]glycerol, respectively. Insulin sensitivity did not differ between MR treatments, but was already low at the start of the experiment at 15 weeks of age and remained low throughout the experiment. It was concluded that glucose and glycerol can replace one third of the lactose from the calf MR, but that inclusion of fructose should be lower to prevent incomplete absorption from the small intestine.

    In literature and the studies in this thesis, high inter-individual variation in growth performance was found in veal calves. The experiment described in Chapter 6 was, therefore, designed to assess the predictability of later life growth performance by charactering calves in early life. In addition, it was examined whether the ability of calves to cope with MR in which lactose is partially replaced by alternative energy sources can be predicted. From 2 to 11 weeks of age, male Holstein-Friesian calves were fed a lactose control MR and solid feed according to a practical feeding scheme and were characterized individually using targeted challenges related to feeding motivation, digestion, post-absorptive metabolism, immunology, behavior and stress. Based on the results in Chapter 4, a combination of glucose, fructose and glycerol in a 2:1:2 ratio was used to replace half of the lactose from the MR (GFG). From 11 to 27 weeks of age, calves received a lactose control MR or the GFG MR (n = 65 per treatment). Growth performance from 11 to 27 weeks of age tended to be lower for GFG-fed than for control calves (-25 g/d). Measurements in early life explained 12% of the variation in growth performance in later life. However, this was mainly related to variation in solid feed refusals. When growth performance was adjusted to equal solid feed intake, only 4% of the variation in standardized growth performance in later life, reflecting feed efficiency, could be explained by early life measurements. This indicates that > 95% of the variation in feed efficiency in later life could not be explained by early life characterization. It is hypothesized that variation in health status explains substantial variation in feed efficiency in veal calves. Significant relations between fasting plasma glucose concentrations, fecal dry matter and fecal pH in early life and feed efficiency in later life depended on MR composition. These measurements are, therefore, potential tools for screening calves in early life on their ability to cope with a MR in which half of the lactose is replaced by glucose, fructose and glycerol (in a 2:1:2 ratio).

    The studies reported in this thesis demonstrate that glycerol, glucose and a combination of glucose, fructose and glycerol in a 2:1:2 ratio are promising lactose replacers. The effects of replacing lactose by other carbohydrate or energy sources described in this thesis are required to evaluate the potential of lactose replacers for inclusion in calf milk replacers and provide input for feed evaluation for calves and ruminants.

    Food for rumination : developing novel feeding strategies to improve the welfare of veal calves
    Webb, L.E. - \ 2014
    Wageningen University. Promotor(en): Imke de Boer, co-promotor(en): Eddy Bokkers; Kees van Reenen. - Wageningen : Wageningen University - ISBN 9789462570955 - 250
    vleeskalveren - kalvervoeding - voer - kunstmelk - concentraten - ruwvoer (roughage) - abnormaal gedrag - herkauwen - voedingsvoorkeuren - dierenwelzijn - diergezondheid - veal calves - calf feeding - feeds - filled milk - concentrates - roughage - abnormal behaviour - rumination - feeding preferences - animal welfare - animal health

    Summary of thesis entitled: “Food for Rumination – Developing novel feeding strategies to improve the welfare of veal calves”, Laura Webb

    Veal calves are typically fed high levels of milk replacer supplemented with solid feed, which tends to contain a relatively small roughage component. Feeding strategies used in veal production have been associated with welfare issues, including the development of abnormal oral behaviours (AOB) and poor gastrointestinal health. AOB include tongue playing, excessive oral manipulation of the environment, grazing of the coat of other calves, and sham chewing, and are thought to develop in calves when chewing activity (i.e. eating and rumination) is not adequately stimulated. Common gastrointestinal health issues include poor rumen development and lesions in the abomasum.

    The aim of this thesis was to develop novel feeding strategies to improve the welfare of veal calves, i.e. to minimise the development of AOB and gastrointestinal health disorders as well as maximise chewing activity.

    The EU legislation stipulates a minimum of 250 g of `fibrous feed' for 20 week-old calves, but this amount does not seem supported by previous research in terms of it optimising calf welfare. In addition, it does not specify what fibrous feed refers to in terms of source and particle length of roughage. Developing novel feeding strategies for calves necessitates a better understanding of how different roughage characteristics might affect behaviour and gastrointestinal health, and this is what was investigated in Chapter 2. Because none of the single roughage sources investigated were able to improve both behaviour and health, it is likely that a combination of roughage sources would be optimal. For example, an appropriate diet choice may include a combination of roughage sources that facilitate good ruminal papillae development (e.g. maize silage), minimise plaque formation, and encourage both rumen muscularisation and rumination (e.g. straw). This chapter also suggested that hay, as a roughage source with both high levels of structure and high levels of fermentable fibre, could achieve both objectives of encouraging rumination and rumen development. Hay, however, is not used in veal production due to its high iron content that would lead to darker meat colour, which is less preferred by consumers.

    In Chapter 3, different amounts of a solid feed mixture were fed to calves and behaviour was monitored. The results showed that calves fed no solid feed on top of their milk replacer still displayed a rumination-like behaviour, which was in previous literature referred to as `sham chewing'. This result gives an indication as to the importance of rumination in calves. Moreover, this chapter failed to find a straightforward linear relationship between amount of solid feed provided and level of AOB displayed. Certain amounts of solid feed were found to initially stimulate chewing activity to a high level, but later, as calves grew older and more experienced with roughage, failed to stimulate chewing above the level displayed by calves fed no solid feed. Providing such an amount of roughage seemed to be more detrimental in terms of behaviour than providing an amount that results in a constant level of chewing activity throughout the fattening period.

    In order to develop animal-friendly feeding strategies, it is important to know what the animals would choose when given free choice. Therefore, in Chapter 4, the feed preferences of calves for milk replacer, concentrate, hay, straw and maize silage were investigated. This study showed that at 6 months, calves selected on average approximately 1250 g dry matter (DM) milk replacer, 1000 g DM roughage and 2000 g DM concentrate. Although all calves with free choice showed high levels of chewing activity and subsequently low levels of AOB, large individual differences existed in intake levels and feed preferences. Moreover, outcomes were dependent on the variable used to assess preferences: i.e. intake (in g DM relative to metabolic body weight), duration of feeding, or number of visits to each diet component. On average, however, calves showed a preference for milk replacer, concentrate and hay, over straw and maize silage.

    In contrast to free choice testing, as was used in Chapter 4, double demand operant conditioning gives an indication as to the strength of a preference. In Chapter 5, different methods to analyse data collected from double demand operant conditioning studies were investigated. Due to the dependence level between the two resources presented simultaneously, i.e. at any given time the test animal can only work for one resource, it would seem that proportions of rewards achieved for one resource over the total number of rewards achieved for both resources would be an adequate dependent variable in this type of analysis.

    In Chapter 6 the statistical method developed in Chapter 5 was used to assess the preference of calves for long and chopped hay and straw, and their preference for hay versus straw. Two to five month-old calves learned the double demand operant task and were motivated to work for roughage on top of a high energy diet of milk replacer and concentrate. They showed a preference for long over chopped hay, but not for long over chopped straw, and showed a strong preference for hay over straw.
    In Chapter 7 it was investigated whether temperament might affect learning of a double demand operant task in calves. Studies in horses and voles previously found that certain individuals seemed unable to learn certain tasks. If one could find out why, individual training programs could be designed and non-learners would not be removed from studies, potentially avoiding biases in data due to only certain temperament profiles making it through the learning criteria. Chapter 7 gave some indication that temperament may affect learning in calves, and it is the first study in calves to do so. However, due to the low number of animals used, further research is necessary to confirm which temperamental traits affect learning ability in calves.

    Relationships between tongue playing and: 1) hypothesised measures of chronic stress, and 2) hypothesised temperamental traits were investigated in Chapter 8. Large individual differences in the performance of tongue playing in calves subjected to similar husbandry conditions were found. This suggests that although tongue playing might well be a warning sign for chronic stress, and hence poor welfare, individual variation in the propensity to tongue play in response to stressful conditions exists. This could be due to differences in temperament. In contrast to what theoretical papers suggest, calves that showed more tongue playing showed characteristics of a reactive coping style. This result is, however, consistent with previous experimental papers on calves and other species.

    Results from Chapters 2 to 8 were combined into the design of the experiment described in Chapter 9. In this chapter, various feeding strategies (i.e. different amounts of solid feed combined with different concentrate to roughage ratios, different types of ad libitum choice diets, and feeding milk replacer via an open bucket or automated milk dispenser[AMD]) were applied and the effect on behaviour was recorded. Rumination was mainly affected by roughage provision, regardless of concentrate provision. Therefore, increasing solid feed provision without increasing the roughage content would most likely have little effect on rumination, although it would probably increase eating time to a certain extent. Because of the timing of tongue playing and oral manipulation of the environment (found in both Chapters 3 and 9), we suggest that the first of these two AOB is related to chewing activity in general, whereas the second may be more related to anticipation of an upcoming meal and positive reinforcement of feeding behaviours following an unsatisfactory meal. Calves provided ad libitum access to long straw in racks showed high levels of chewing activity and low levels of AOB relative to calves that did not have access to a straw rack but otherwise received the same diet. Six-month-old calves with ad libitum access to straw, maize silage and concentrate (but a restricted milk replacer allowance of 1050 g DM/d) consumed on average approximately 900 g DM/d roughage and 2300 g DM concentrate at 6 months of age. Feeding milk replacer via an AMD seemed to have little impact on behaviour, although it led to lower levels of tongue playing at 15 wk relative to bucket-fed calves.

    In Chapter 10, I first reflect on possible underlying mechanisms of AOB and on the best methods to assess animal preferences. AOB seem to develop in veal calves due to a number of factors, starting with the thwarting of chewing activity, of which rumination at least is most likely a behavioural need. Other factors involved in the development of AOB include chronic stress resulting from the thwarting of chewing activity, anticipation of an upcoming meal, and positive reinforcement of feeding behaviours following a meal that was unsatisfactory. Of great importance is the understanding of individual variation in the propensity to develop AOB, because stereotypic behaviours in sub-optimal environments have been linked to improvements in welfare (relative to non-stereotyping animals). Ruminants seem to be able to select a diet that maximises their comfort. Developing feeding strategies to improve veal calf welfare, therefore, requires the assessment of calf feed preferences. Choice tests and cross point analysis of double demand functions are two possible methods for the assessment of animal preferences, and both these methods include drawbacks and benefits. In contrast to choice tests, double demand offers a setting that closer mimics the complexity of natural environments by imposing a cost on access to resources and enables quantification of the strength of preferences. However, this procedure requires appropriate statistical methods, which take into account the dependence structure between the two simultaneously available resources. Finally, practical implications of the research presented in this thesis are described in Chapter 10. The development of novel feeding strategies to improve the welfare of veal calves is challenged by individual differences in feed preferences, chewing efficiency, and behavioural response to chronic stress caused by inadequate feeding. The latter is demonstrated by only certain calves developing AOB when chewing activity is not stimulated enough by the feeding strategy, whilst others do not develop such behaviours. This complicates the evaluation of the effects of feeding strategy on veal calf behaviour. However, based on the results of this thesis and previous research it seems that young calves should first receive a diet that optimises rumen development, before receiving coarser roughages that stimulate chewing activity, rumen muscularisation, and minimise plaque and hairball prevalence in the rumen. Adequate amounts of roughage and concentrate at 6 months of age seem to be 1000 and 2000-3000 g DM, based on voluntary intake.

    Jongveeopfok: een investering in de toekomst
    Mourits, Monique - \ 2013
    dairy farming - calves - rearing techniques - calf feeding - management information systems - agricultural education
    Praktijk weerbarstig bij aanpak kalverdiarree
    Cappellen, J. van; Boumans, I.J.M.M. ; Stassen, E.N. - \ 2013
    Veeteelt 30 (2013)7. - ISSN 0168-7565 - p. 38 - 39.
    melkveehouderij - kalveren - kalverziekten - diarree - kalvervoeding - colostrum - maatregelen - dairy farming - calves - calf diseases - diarrhoea - calf feeding - colostrum - measures
    Veehouders weten goed welke maatregelen er zijn tegen kalverdiarree, maar passen ze in de praktijk vaak niet toe. ‘Geen noodzaak’, ‘te weinig tijd’ of ‘te onpraktisch voor de eigen situatie’ zijn veelgehoorde argumenten om geen actie te ondernemen.
    Kosten jongveeopfok berekenen met Jonkos
    Evers, A.G. ; Haan, M.H.A. de - \ 2011
    V-focus 8 (2011)5. - ISSN 1574-1575 - p. 44 - 45.
    melkveehouderij - kalveren - opfoktechnieken - kalvervoeding - voer - kosten - bedrijfsinformatiesystemen - dairy farming - calves - rearing techniques - calf feeding - feeds - costs - management information systems
    Wageningen UR Livestock Research, DLV, Wageningen UR Leerstoelgroep Bedrijfseconomie en de Universiteit Utrecht faculteit Diergeneeskunde hebben samen het rekenprogramma Jonkos ontwikkeld. Deze software brengt de kosten voor jongveeopfok in beeld. Er is een versie voor de melkveehouder en één voor de opfokker van jongvee gemaakt.
    Olifantsgras voor het opwarmen van kalvermelk
    Kasper, G.J. - \ 2008
    V-focus 5 (2008)april (2). - ISSN 1574-1575 - p. 26 - 27.
    rundveehouderij - kalveren - vleesvee - kalvervoeding - kunstmelk - verwarming - miscanthus - energetische waarde - cattle husbandry - calves - beef cattle - calf feeding - filled milk - heating - miscanthus - energy value
    Veehouderijbedrijven zoeken naar alternatieven voor energie-bronnen. Op het vleeskalverbedrijf van de familie Henken te Rhenen wordt Miscanthus geteeld, ofwel olifantsgras, als vervanger voor fossiele energie
    Energiebehoefte en N-excretie van kalveren van zoogkoeien
    Tamminga, S. - \ 2007
    cattle husbandry - nurse cows - meat production - calves - calf feeding - growth - body weight
    Nutrient synchrony in preruminant calves
    Borne, J.J.G.C. van den - \ 2006
    Wageningen University. Promotor(en): Martin Verstegen, co-promotor(en): Walter Gerrits. - [S.l.] : S.n. - ISBN 9789085045243 - 197
    vleeskalveren - diermodellen - kalvervoeding - voedingsstoffenbeschikbaarheid - tijd - eiwitmetabolisme - energiemetabolisme - aminozuren - glucose - synchronisatie - groei - mestresultaten - veal calves - animal models - calf feeding - nutrient availability - time - protein metabolism - energy metabolism - amino acids - glucose - synchronization - growth - fattening performance
    In animal nutrition, the nutrient composition of the daily feed supply is composed to match the nutrient requirements for the desired performance. The time of nutrient availability within a day is usually considered not to affect the fate of nutrients. The aim of this thesis was to evaluate effects of the time of nutrient availability within a day (i.e. nutrient synchrony) on the protein and energy metabolism in preruminant calves. Two types of nutrient synchrony were studied: (1) synchrony between total nutrient supply and requirements within a day, and (2) synchrony between protein and carbohydrate availability. The studies were mainly conducted in heavy preruminant calves, because those animals have a very low efficiency of protein utilization for growth compared with other farm animals, such as pigs and lambs, allowing a large potential for improvement. Increasing the feeding frequency increased the efficiency of protein utilization in preruminant calves. This was however not detected when short-term measurements of amino acid metabolism (12 h urea production and oral leucine oxidation) were considered. Dietary carbohydrates were almost completely oxidized, unaffected by feeding level, in heavy preruminant calves. Glucose homeostasis improved with increasing feeding frequency. In pigs, an asynchronous availability of glucose and amino acids within a day reduced protein utilization but did not affect fat retention. In preruminant calves, however, an asynchronous availability of glucose and amino acids did not decrease the efficiency of protein utilization but substantially increased fat retention. Separating the intake of protein and lactose over meals inhibited postprandial plasma insulin responses, but increased glucose excretion in urine. Intramuscular fat content and oxidative enzyme activity increased with decreasing nutrient synchrony in an oxidative muscle in calves. Oxidative enzyme activity is not an appropriate indicator of whole-body heat production in growing calves.
    Rumen development in veal (preruminant) calves
    Suárez, B.J. - \ 2006
    Wageningen University. Promotor(en): Seerp Tamminga, co-promotor(en): Walter Gerrits; Jan Dijkstra. - [S.l.] : S.n. - ISBN 9789085045366 - 174
    vleeskalveren - pensontwikkeling - pensfermentatie - concentraten - ruwvoer (roughage) - voer - samenstelling - koolhydraten - enzymactiviteit - mestresultaten - kalvervoeding - veal calves - rumen development - rumen fermentation - concentrates - roughage - feeds - composition - carbohydrates - enzyme activity - fattening performance - calf feeding
    Historically, veal calves were fed until slaughter weight with only milk replacer and, in absence of solid feed the physiological development of the forestomachs was limited. In 1997, a new EU legislation stipulated that a minimum amount of solid feed (fiber) has to be provided for the welfare of the calves (solid feed supply reduce abnormal oral behaviors in veal calves; Van Putten, 1982; Veissier et al., 1998); however, no specifications were made about the type and source of feed.

    Rumen development is triggered by the production of VFA resulting from fermentation ofOMin the rumen (Flatt et al., 1958). Butyrate, and to a lesser extent propionate stimulate the development of the rumen mucosa; mostly because of their use as energy sources by the rumen epithelium (Sander et al., 1959; Tamate et al., 1962). In rearing calves, information on rumen fermentation of different sources of dietary carbohydrates is relatively well documented (Davis and Drackley, 1998; Lesmeister and Heinrichs, 2004) but only a few experiments have been conducted in veal calves.

    Based on earlier research (Blokhuis et al., 2000) it was hypothesized that stimulating early rumen development in veal calves would be beneficial to their subsequent performance and health. Therefore in vivo experiments were designed to establish the effects of stimulating an early rumen development in veal calves, aiming to optimize nutrient utilization from rumen fermentation and to prevent health problems in the lower gastrointestinal tract (e.g. ulcers in abomasum). In addition the potential interactions of feeding solid feed with a milk replacer based diet were investigated. Finally but not least, the development and evaluation (comparison) of techniques for estimating fermentation characteristics of different substrates, to facilitate the choice of feed ingredient for veal calves diets was also carried out. 

    Chapter 2:This study was conducted to evaluate the effects of concentrate intake, differing in carbohydrates composition in addition to a milk replacer, on growth performance and rumen fermentation characteristics in veal calves. Accordingly, 160 Holstein Friesian x Dutch Friesian male calves, were fed with one of the following treatments: 1) milk replacer control (CONTROL), 2) pectin-based concentrate (PECTIN), 3) neutral detergent fiber (NDF) based concentrate, 4) starch-based concentrate (STARCH) and 5) mixed concentrate (MIXED) (equal amounts of concentrates of treatments 2, 3, and 4). Concentrate diets were provided in addition to a commercial milk replacer Results: Calves showed an ADG varying between 0.70 and 0.78 kg/d, with a rumen fermentation in concentrates fed calves characterized by a low pH (4.9 - 5.2), relatively low VFA concentrations between 100 and 121 mmol/L and high concentrations of reducing sugars (33-66 g/kg DM). Calves fed the CONTROL diet had higher lactate concentration (21mmol/L) than concentrate fed calves (between 5 and 11 mmol/L). Results indicated that the carbohydrate source can influence intake, growth rate and rumen fermentation in young veal calves.

    Chapter 3:This experiment aimed to gain an insight into the effects of age (calves were euthanized either at the end of 8 or 12 weeks of age) and concentrate supplementation, differing in carbohydrates composition, on rumen development in young veal calves. Moreover, some selected plasma metabolites as predictors of rumen development were evaluated. Diets treatments correspond to those described in Chapter 2. Results: Feeding concentrates differing in carbohydrate composition to veal calves promoted rumen development compared with calves fed milk replacer only. In most calves, a poorly developed rumen mucosa was observed. Coalescing rumen papillae with embedded hair, feed particles and cell debris were found in all calves fed concentrate diets. Calves fed concentrates had significantly heavier rumens than calves fed CONTROL. Although the variation in carbohydrate composition caused variation in rumen development, the latter was generally small. In the dorsal location of the rumen, calves fed concentrate diets showed an increased ratio of mucosa to serosa length (RMSL) than calves fed CONTROL. Mucosa thickness (MCT) and muscle thickness (MST) were bigger in the ventral and in the dorsal locations of the rumen, respectively.

    At 8 weeks, calves fed concentrate diets had higher plasma acetate concentrations than calves on the CONTROL treatment. However, at 12 weeks, only NDF fed calves showed significantly higher plasma acetate concentrations. For plasma BHBA concentration no differences were observed among treatments at 12 weeks. Results from a principal component analysis indicated that veal calves, in addition to rumen volatile fatty acids (VFA) concentrations, other factors are likely to affect rumen development.  

    Chapter 4:This experiment was designed based on the results obtained in experiment 1 (Chapter 2 and 3) where in concentrate-fed veal calves a rumen environment, characterized by a sub clinical acidosis (pH< 5.2), relatively low VFA concentrations (100-120 mmol/L) and a rumen mucosa characterized by poorly shaped papillae with feed and cell debris embedded between them (referred as plaque formation) were observed. Feeding only roughage to young calves generally does not promote rapid papillae development (Nocek and Kesler, 1980); however, roughage consumption and its inherent coarseness stimulate the development of the rumen wall (Tamate et al., 1962) and rumination (Hodgson, 1971) and the healthiness of the rumen mucosa (Haskins et al., 1969). Information concerning the effects of roughage intake on veal calves performance and rumen development is scarce (Blokhuis et al., 2000; Cozzi et al., 2002). Therefore, it was hypothesized that adding small amount of roughage to a concentrate diet will improve and stimulates the development of the rumen wall, without having negative effects on calf's performance. Sixty four male Holstein Friesian x Dutch Friesian veal calves (46 kg ± 3.0 kg), were fed on of the following diets: 1) C100= concentrate only, 2) C70-S30= concentrate (70%) with straw (30%), 3) C70-G30= concentrate (70%) with dried grass (30%), 4) C70-G15-S15= concentrate (70%) with dried grass (15%) and straw (15%), 5) C70-CS30= concentrate (70%) with corn silage (30%), 6) C40-CS60= concentrate (40%) with corn silage (60%), 7) C70-CS30-AL= concentrate (70%) with corn silage (30%) ad libitum, 8) C70-G15-S15-AL= concentrate (70%) with dried grass (15%) and straw (15%) ad libitum. All dietary treatments were provided in addition to a commercial milk replacer. Concentrate was provided as pellets and roughage was chopped. Results: Roughage and intake level affects rumen fermentation and rumen development of veal calves. Substitution of part of the concentrate by roughage did not affect DMI and ADG, but among roughage sources feeding straw reduced DMI and ADG. The addition of roughage did not affect rumen pH (pH >5.3). Rumen fermentation was characterized by high total volatile fatty acids (VFA) and reducing sugars (RS) concentrations. Cobalt recovery, as an indication of milk leakage was found in the rumen, varying between 20.5 and 34.9 %, but it was not affected by dietary treatments. Roughage addition decreased the incidence of plaque formation and the incidence of calves with poorly developed rumen mucosa. However, morphometric parameters of the rumen wall were hardly influenced by the type and level of roughage. Results indicated that in veal calves, the addition of roughage to concentrate diets did not affect growth performance and positively influenced the macroscopic appearance of the rumen wall.

    Chapter 5:Several methodologies have been developed to characterize feedstuffs in terms of digestibility and degradability, comprising in vivo , in situ and in vitro methods.

    The gas production technique (GPT) provides gas production profiles that give an indication of the fermentative characteristics of the feed. The objective of this experiment was to estimate fermentation kinetic parameters of various solid feeds supplied to veal calves using the GPT, and to study the effect of adaptation of the rumen microflora to these solid feeds on their subsequent fermentation patterns. Thus, from the in vivo experiment described in Chapter 2 and 3; three out of five dietary treatments were selected as inoculum sources: pectin ( PECTIN ), neutral detergent fiber ( NDF ), and starch ( STARCH ). Sugar beet pulp ( SBP ), sugar beet pectin ( SBPec) , native corn starch ( NCS ), soy bean hulls ( SBH ) and crystalline cellulose ( AVICEL) were selected as substrates. For the second in vitro experiment, three out of eight dietary treatments (from the in vivo experiment described in Chapter 4) were selected as inocula. The selected diet treatments were: C100= concentrate only, C70-S30 = concentrate (70%) with straw (30%) and C70-CS30 = concentrate (70%) with corn silage (30%). For this gas production experiment, straw ( STRAW ), soy bean hulls ( SBH ), native corn starch ( NCS ) and sugar beet pectin ( SBPec ) were chosen as in vitro substrates.

    For both in vivo experiments, cumulative gas production was measured over time (72 h) as an indicator of the kinetics of fermentation. Fermentation end-products, including volatile fatty acids and ammonia, and organic matter loss, were also measured. Results : In both experiments significant differences between the inoculum sources, in terms of both fermentation kinetics characteristics and end-products of fermentation were observed. Similarly, significant effects were also observed for substrate compositions. Differences between the fermentation characteristics of NCS, SBPec and SBH, were consistent for both experiments. The total VFA production was not different among these substrates in both experiments. Finally, for both experiments, there was a significant inocula and substrate interaction which may indicate differences in the microbial activity occurring between the calves. Therefore, it was concluded that rumen inoculum from adapted animals should be used to obtain a more accurate assessment of feed ingredients in veal calf diets.

    Chapter 6 (General discussion) focused in four points: a) Factors influencing rumen development in rearing and veal calves; b) The importance of ruminal drinking in veal calves fed solids feeds; c) Effects of feeding strategies on ruminal pH and buffering capacity of rumen contents in veal calves; d) comparative analysis of the results obtained from the GPT (results presented in Chapter 5) and the PDE activities (results presented in Chapter 2 and 4).
    Mineralenbehoefte : koper en selenium vragen aandacht op Bioveembedrijven
    Smolders, E.A.A. ; Plomp, M. - \ 2005
    Veeteelt 22 (2005)3. - ISSN 0168-7565 - p. 67 - 67.
    melkveehouderij - biologische landbouw - rundveevoeding - voer - voersamenstelling - mineralen - koper - selenium - kalveren - kalvervoeding - voedingsstoffentekorten - mineraaltekorten - agrarische bedrijfsvoering - dairy farming - organic farming - cattle feeding - calves - calf feeding - feeds - feed formulation - minerals - copper - selenium - nutrient deficiencies - mineral deficiencies - farm management
    Bij het streven naar zelfvoorziening en het telen van eigen krachtvoer is op biologische bedrijven extra aandacht nodig voor de mineralen en spoorelementen. Het jongvee heeft de grootste kans op tekorten, zo blijkt uit resultaten van het project Bioveem
    Perspectief van eiwitrijke krachtvoedergewassen voor rosékalveren: een deskstudie = Prospects for protein-rich crops as concentrates substitutes for pink veal calves: a desk study
    Gotink, G.J. - \ 2003
    Lelystad : Praktijkonderzoek Veehouderij (PraktijkRapport / Animal Sciences Group, Praktijkonderzoek : Rundvee ) - 33 p.
    vleeskalveren - gewassen - eiwitconcentraten - erwten - lupinen - tuinbonen - teelt - voedingswaarde - mineraalovermaat - agrarische economie - kalvervoeding - diervoeding - veal calves - crops - protein concentrates - peas - lupins - faba beans - cultivation - nutritive value - mineral excess - agricultural economics - calf feeding - animal nutrition
    Bij de wijziging van de Meststoffenwet (september 2000) hebben rosékalveren eigen forfaitaire N-normen gekregen. Als vervolg hierop zullen naar verwachting rosé vleeskalverbedrijven met een verfijnde mineralenaangifte worden geconfronteerd. Via managementmaatregelen kan de kalverhouder het mineralenoverschot proberen te beperken. Een van deze maatregelen is de voeding. Een mogelijkheid is de aanvoer van mineralen van buiten het bedrijf zo veel mogelijk te beperken door op het eigen bedrijf eiwitrijke voedergewassen te telen als vervanging van eiwit uit mengvoer. In deze deskstudie is het perspectief van erwten, lupinen en veldbonen (Vicia faba L.) als krachtvoederteelt op het rosékalverbedrijf teelttechnisch, voedertechnisch, economisch en mineralentechnisch bestudeerd. Een deskstudie heeft aangetoond dat de eigen teelt van eiwitrijke krachtvoedergewassen als vervanger van eiwitrijk krachtvoer geen oplossing is voor het verlagen van het mineralenoverschot op het rosékalverbedrijf. Dit is toe te schrijven aan te lage drogestofopbrengsten van de eiwitrijke teelten
    Een vaarskalfje meer of minder : extra opfok jongvee op extensief bedrijf aantrekkelijker dan op intensief bedrijf
    Saatkamp, H.W. ; Ouweltjes, W. ; Walle, K. van der; Hogeveen, H. - \ 2003
    Veeteelt 20 (2003)11. - ISSN 0168-7565 - p. 28 - 30.
    melkveehouderij - melkvee - kalveren - vaarzen - kalvervoeding - agrarische bedrijfsvoering - bedrijfsvergelijking in de landbouw - intensieve veehouderij - extensieve veehouderij - dairy farming - dairy cattle - calves - heifers - calf feeding - farm management - farm comparisons - intensive livestock farming - extensive livestock farming
    In dit 2e artikel van een serie over jongvee en vervangingsbeleid aandacht voor 't opfokbeleid met cijfers over het aanhouden van verschillende aantallen jongvee op zowel een extensief als op een intensief melkveebedrijf
    Ruwvoerverstrekking en watergift bij witvleeskalveren
    Ruis-Heutinck, L.F.M. ; Reenen, C.G. van; Heeres-van der Tol, J.J. - \ 2002
    Lelystad : Praktijkonderzoek Veehouderij (PraktijkRapport. Rundvee, paarden, schapen, geiten / Praktijkonderzoek Veehouderij 2) - 28
    vleeskalveren - kalveren - ruwvoer (roughage) - kalvervoeding - drinkwater - melk - groei - karkaskwaliteit - vleeskwaliteit - diergedrag - abnormaal gedrag - diergezondheid - dierpathologie - dierenwelzijn - veal calves - calves - roughage - calf feeding - drinking water - milk - growth - carcass quality - meat quality - animal behaviour - abnormal behaviour - animal health - animal pathology - animal welfare
    In dit eerste PraktijkRapport vindt u de resultaten van vier jaar onderzoek naar het effect van het verstrekken van ruwvoer op het gedrag van witvleeskalveren, hun diergezondheid en technische prestaties en de kwaliteit van kalfsvlees. Daarnaast is nagegaan in hoeverre het kalf, wanneer het ruwvoer krijgt, nog behoefte heeft aan extra water boven de waterverstrekking via de melk
    Goede start kalf noodzaak voor minder medicijngebruik
    Heeres-van der Tol, J. - \ 2001
    Rundvee praktijkonderzoek 14 (2001)5. - ISSN 1569-805X - p. 30 - 31.
    diervoedering - kalvervoeding - kalveren - voer - veevoeding - veevoeder - ruwvoer (forage) - ruwvoer (roughage) - dierenwelzijn - diergezondheid - diergedrag - vleeskalveren - kalfsvlees - vlees - vleeskwaliteit - kwaliteit - rundvleeskwaliteit - vleeseigenschappen - malsheid - animal feeding - calf feeding - calves - feeds - livestock feeding - fodder - forage - roughage - animal welfare - animal health - animal behaviour - veal calves - veal - meat - meat quality - quality - beef quality - meat characteristics - tenderness
    Antibioticagebruik in de veehouderij wordt door de buitenwereld kritisch gevolgd.
    Automatisering bij de voedering van vleeskalveren : verslag van een werkgroep
    Harmsen, W.L. ; Werkgroep, - \ 1976
    Lelystad : Proefstation voor de Rundveehouderij (Rapport / Proefstation voor de Rundveehouderij 45) - 38
    rundvee - kalveren - vleesproductie - kalvervoeding - drinkbakken - voedersysteem voor kalveren - automatisering - cattle - calves - meat production - calf feeding - drinkers - bucket calf feeders - automation
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