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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    Exploration of variance, autocorrelation, and skewness of deviations from lactation curves as resilience indicators for breeding
    Poppe, M. ; Veerkamp, R.F. ; Pelt, M.L. van; Mulder, H.A. - \ 2020
    Journal of Dairy Science 103 (2020)2. - ISSN 0022-0302 - p. 1667 - 1684.
    automatic milking system - dairy cow - milk yield - resilience - variance

    The ability of a cow to cope with environmental disturbances, such as pathogens or heat waves, is called resilience. To improve resilience through breeding, we need resilience indicators, which could be based on the fluctuation patterns in milk yield resulting from disturbances. The aim of this study was to explore 3 traits that describe fluctuations in milk yield as indicators for breeding resilient cows: the variance, autocorrelation, and skewness of the deviations from individual lactation curves. We used daily milk yield records of 198,754 first-parity cows, recorded by automatic milking systems. First, we estimated a lactation curve for each cow using 4 different methods: moving average, moving median, quantile regression, and Wilmink curve. We then calculated the log-transformed variance (LnVar), lag-1 autocorrelation (rauto), and skewness (Skew) of the daily deviations from these curves as resilience indicators. A genetic analysis of the resilience indicators was performed, and genetic correlations between resilience indicators and health, longevity, fertility, metabolic, and production traits were estimated. The heritabilities differed between LnVar (0.20 to 0.24), rauto (0.08 to 0.10), and Skew (0.01 to 0.02), and the genetic correlations among the indicators were weak to moderate. For rauto and Skew, genetic correlations with health, longevity, fertility, and metabolic traits were weak or the opposite of what we expected. Therefore, rauto and Skew have limited value as resilience indicators. However, lower LnVar was genetically associated with better udder health (genetic correlations from −0.22 to −0.32), better longevity (−0.28 to −0.34), less ketosis (−0.27 to −0.33), better fertility (−0.06 to −0.17), higher BCS (−0.29 to −0.40), and greater dry matter intake (−0.53 to −0.66) at the same level of milk yield. These correlations support LnVar as an indicator of resilience. Of all 4 curve-fitting methods, LnVar based on quantile regression systematically had the strongest genetic correlations with health, longevity, and fertility traits. Thus, quantile regression is considered the best curve-fitting method. In conclusion, LnVar based on deviations from a quantile regression curve is a promising resilience indicator that can be used to breed cows that are better at coping with disturbances.

    Intramammary antimicrobial treatment of subclinical mastitis and cow performance later in lactation
    Borne, Bart H.P. van den; Schaik, Gerdien van; Lam, Theo J.G.M. ; Nielen, Mirjam ; Frankena, Klaas - \ 2019
    Journal of Dairy Science 102 (2019)5. - ISSN 0022-0302 - p. 4441 - 4451.
    antimicrobial - clinical mastitis - dairy cow - milk yield - somatic cell count

    The aim of this study was to evaluate long-term therapeutic effects of antimicrobial treatment of recently acquired subclinical mastitis (RASCM) during lactation. Quarter-level clinical mastitis (CM) follow-up, composite somatic cell counts (SCC), and cow-level milk yield later in lactation were evaluated using follow-up data from 2 previously published linked randomized field trials. The first trial randomly assigned antimicrobial treatment with any intramammary product or negative control to culture-positive quarters of cows having a first elevated composite SCC after 2 consecutive low composite SCC measurements. Untreated cows that had a second elevated composite SCC at the next measurement and were staphylococci-positive (i.e., Staphylococcus aureus or non-aureus staphylococci) were randomly assigned to treatment or control. Quarter-level CM cases were reported by the participating herd personnel, and milk yield and composite SCC data were obtained from the regular test-day recording. Frailty survival models were used to evaluate the long-term therapeutic effects of antimicrobial treatment of RASCM on quarter-level CM follow-up. Mixed linear regression models were applied to quantify the effect on milk yield and composite SCC. Data of 638 quarters from 486 cows in 38 herds were available for statistical analyses, of which 229 quarters of 175 cows received antimicrobial treatment for RASCM. Antimicrobial treatment culminated in reduced composite SCC levels later in lactation but did not result in different milk yield levels or CM follow-up compared with control cows. Antimicrobial treatment of cows with RASCM should therefore only be considered in exceptional situations given the current focus on antimicrobial usage reduction in animal husbandry.

    Production, partial cash flows and greenhouse gas emissions of simulated dairy herds with extended lactations
    Kok, A. ; Lehmann, J.O. ; Kemp, B. ; Hogeveen, H. ; Middelaar, C.E. van; Boer, I.J.M. de; Knegsel, A.T.M. van - \ 2019
    Animal 13 (2019)5. - ISSN 1751-7311 - p. 1074 - 1083.
    dairy cow - lactation length - lactation persistency - milk yield - simulation model

    The transition period is the most critical period in the lactation cycle of dairy cows. Extended lactations reduce the frequency of transition periods, the number of calves and the related labour for farmers. This study aimed to assess the impact of 2 and 4 months extended lactations on milk yield and net partial cash flow (NPCF) at herd level, and on greenhouse gas (GHG) emissions per unit of fat- and protein-corrected milk (FPCM), using a stochastic simulation model. The model simulated individual lactations for 100 herds of 100 cows with a baseline lactation length (BL), and for 100 herds with lactations extended by 2 or 4 months for all cows (All+2 and All+4), or for heifers only (H+2 and H+4). Baseline lactation length herds produced 887 t (SD: 13) milk/year. The NPCF, based on revenues for milk, surplus calves and culled cows, and costs for feed, artificial insemination, calving management and rearing of youngstock, was k€174 (SD: 4)/BL herd per year. Extended lactations reduced milk yield of the herd by 4.1% for All+2, 6.9% for All+4, 1.1% for H+2 and 2.2% for H+4, and reduced the NPCF per herd per year by k€7 for All+2, k€12 for All+4, k€2 for H+2 and k€4 for H+4 compared with BL herds. Extended lactations increased GHG emissions in CO2-equivalents per t FPCM by 1.0% for All+2, by 1.7% for All+4, by 0.2% for H+2 and by 0.4% for H+4, but this could be compensated by an increase in lifespan of dairy cows. Subsequently, production level and lactation persistency were increased to assess the importance of these aspects for the impact of extended lactations. The increase in production level and lactation persistency increased milk production of BL herds by 30%. Moreover, reductions in milk yield for All+2 and All+4 compared with BL herds were only 0.7% and 1.1% per year, and milk yield in H+2 and H+4 herds was similar to BL herds. The resulting NPCF was equal to BL for All+2 and All+4 and increased by k€1 for H+2 and H+4 due to lower costs for insemination and calving management. Moreover, GHG emissions per t FPCM were equal to BL herds or reduced (0% to -0.3%) when lactations were extended. We concluded that, depending on lactation persistency, extending lactations of dairy cows can have a positive or negative impact on the NPCF and GHG emissions of milk production.

    Dynamic forecasting of individual cow milk yield in automatic milking systems
    Jensen, Dan B. ; Voort, Mariska van der; Hogeveen, Henk - \ 2018
    Journal of Dairy Science 101 (2018)11. - ISSN 0022-0302 - p. 10428 - 10439.
    dairy cow - dynamic linear model - milk yield - somatic cell count

    Accurate forecasting of dairy cow milk yield is useful to dairy farmers, both in relation to financial planning and for detection of deviating yield patterns, which can be an indicator of mastitis and other diseases. In this study we developed a dynamic linear model (DLM) designed to forecast milk yields of individual cows per milking, as they are milked in milking robots. The DLM implements a Wood's function to account for the expected total daily milk yield. It further implements a second-degree polynomial function to account for the effect of the time intervals between milkings on the proportion of the expected total daily milk yield. By combining these 2 functions in a dynamic framework, the DLM was able to continuously forecast the amount of milk to be produced in a given milking. Data from 169,774 milkings on 5 different farms in 2 different countries were used in this study. A separate farm-specific implementation of the DLM was made for each of the 5 farms. To determine which factors would influence the forecast accuracy, the standardized forecast errors of the DLM were described with a linear mixed effects model (lme). This lme included lactation stage (early, middle, or late), somatic cell count (SCC) level (nonelevated or elevated), and whether or not the proper farm-specific version of the DLM was used. The standardized forecast errors of the DLM were only affected by SCC level and interactions between SCC level and lactation stage. Therefore, we concluded that the implementation of Wood's function combined with a second-degree polynomial is useful for dynamic modeling of milk yield in milking robots, and that this model has potential to be used as part of a mastitis detection system.

    Shortening or omitting the dry period in dairy cows : effects on milk yield, energy balance, metabolic status, and fertility
    Chen, Juncai - \ 2016
    Wageningen University. Promotor(en): Bas Kemp, co-promotor(en): Ariette van Knegsel. - Wageningen : Wageningen University - ISBN 9789462579088 - 205
    dairy cows - dairy cattle - dry period - milk yield - energy balance - metabolism - lactation - melkkoeien - melkvee - gustperiode - melkopbrengst - energiebalans - metabolisme - lactatie

    During early lactation, dairy cows typically experience negative energy balance (EB) caused by the high energy requirement for milk yield, which cannot be met by feed intake. Severity of negative EB has been associated with an increased incidence of metabolic disorders and infectious diseases, subfertility, and increased culling rates. Shortening or omitting the dry period (DP) and feeding glucogenic diet could possibly improve EB in dairy cows. The objective of this thesis was to study the effects of shortening or omitting the DP on milk yield, energy balance, metabolism, and fertility over two subsequent lactations in dairy cows fed a lipogenic or glucogenic diet during early lactation. In the current study, 167 cows were assigned to three DP lengths (0, 30, or 60 days) and two early lactation diets (glucogenic or lipogenic diet), and cows were planned to have same DP length and diet over two subsequent lactations. In the first lactation after DP length and dietary treatments, shortening or omitting the DP improved EB due to a decreased milk yield in the early lactation compared with a conventional DP of 60 days. Omitting the DP or feeding a glucogenic diet improved metabolic status in early lactation. Moreover, omitting the DP increased the percentage of cows with normal resumption of ovarian cyclicity. Shortening the DP to 30 d did not influence metabolic status and fertility compared with conventional DP in dairy cows. In the first lactation, the cows with a 0-d DP had less milk but similar energy intake, leading to excessive weight gain and, therefore, high body condition score (BCS) at onset of the second lactation after DP length and dietary treatments. In the second lactation, improvement of EB in cows with a 0-d DP was less pronounced than the first lactation, which could be related to the high BCS at onset of lactation and reduced milk yield losses. Shortening or omitting the DP did not influence uterine health status, ovarian activity, and reproductive performance in the second lactation. In second lactation, feeding a glucogenic diet improved metabolic status and shortened the interval from calving to first ovulation compared with a lipogenic diet without affecting EB independent of DP length. Furthermore, shortening or omitting the DP decreased peak yield but did not influence lactation persistency in both lactations after implementation of DP treatment. In conclusion, omitting the DP improved metabolic status and resumption of ovarian activity, which was related to an improved EB in early lactation. Shortening the DP for two subsequent lactations could be achieved for most cows with limited milk yield losses. Independent of DP length, glucogenic diet improved EB and metabolic status compared with lipogenic diet in early lactation.

    Sainfoin (Onobrychis viciifolia) : a forgotten crop for dairy cows with future potential
    Huyen, Nguyen Thi - \ 2016
    Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Wilbert Pellikaan; Martin Verstegen. - Wageningen : Wageningen University - ISBN 9789462577268 - 160
    onobrychis viciifolia - dairy cows - fodder legumes - fodder crops - legume silage - rumen digestion - nutrition physiology - methane production - milk yield - dairy performance - animal nutrition - onobrychis viciifolia - melkkoeien - voederpeulvruchten - voedergewassen - peulvruchtenkuilvoer - pensvertering - voedingsfysiologie - methaanproductie - melkopbrengst - melkresultaten - diervoeding

    Sainfoin (Onobrychis viciifolia): a forgotten crop for dairy cows with future potential


    The world population growth and rising incomes are expected to increase the consumption of animal-derived foods such as meat, eggs and milk. However, livestock production should not only be directed towards increasing productivity but should also incorporate environmental, food safety and animal welfare aspects. Therefore, farm businesses have to respond to the high environment impact of their activities, by using low-input systems including the use of forage legumes. Recent studies have demonstrated that forage legumes with moderate levels of condensed tannins (CT) are beneficial for animal nutrition and animal health. Sainfoin (Onobrychis viciifolia Scop.) is a tanniniferous forage legume containing CT that has potential nutritional and health benefits, i.e. preventing bloating, reducing nematode larval establishment, improving nitrogen (N) utilization and reducing greenhouse gas and N emissions (Chapter 1). However, the use of sainfoin as a fodder crop in dairy cow rations in northwestern Europe is still rather unknown. This thesis investigated the potential of sainfoin in the dairy cow diets and the effect of CT structural properties on rumen fermentation and biohydrogenation (BH).

    Chapter 2 reports a study where the effect of sainfoin silage on nutrient digestibility, animal performance, energy and N utilization and methane (CH4) production in dairy cows was investigated. Six rumen cannulated, lactating dairy cows were randomly assigned to either a control (CON) or sainfoin based (SAIN) diet. The CON diet was a mixture of grass silage, corn silage, concentrate and linseed. In the SAIN diet, 50% of the grass silage DM in the CON diet was exchanged by sainfoin silage. Total daily dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) intake did not differ between the two diets. The apparent digestibility of DM, OM, NDF and acid detergent fiber (ADF) were respectively, 5.7, 4.0, 15.7 and 14.8% lower for the SAIN diet. Methane production per kg DM intake was lowest for the SAIN diet and CH4 production as a percentage of gross energy intakes tended to be lower while milk yield was greater for the SAIN diet. Nitrogen intake, N retention and energy retained in body protein were greater for the SAIN than the CON diet. Nitrogen retention as a percentage of N intake tended to be greater for the SAIN diet. These results showed that inclusion of sainfoin silage at the expense of grass silage in dairy cow rations reduced CH4 per kg DM intake. Although nutrient digestibility was decreased, sainfoin silage improved milk production and redirected metabolism towards body protein accretion at the expense of body fat.

    In Chapter 3, reticular fatty acid (FA) flow and ruminal BH of C18:3n-3 is reported using the reticular sampling technique (Cr-EDTA and Yb-acetate as digesta flow markers) in the lactating cows fed the SAIN and CON diet in Chapter 2. The reticular flows of DM, OM and N were not affected by dietary treatment. However, NDF flow was higher (1.87 vs. 1.40 kg/d) where the cows were fed the SAIN diet. A higher mono-unsaturated FA flow was caused by the higher trans-9-C18:1 and cis-9-C18:1 flow for the SAIN compared to the CON fed cows. The flows of trans-9,trans-12-C18:2 and cis-12,trans-10 C18:2 were higher in the SAIN diet fed cows, but total poly-unsaturated FA flow was not affected by the different diet treatments. The SAIN diet fed cows had a significant lower ruminal BH of cis-9-C18:1 and C18:3n-3, compared to the CON fed cows and tended to a lower ruminal BH in case of cis-9,cis-12-C18:2. These results show that inclusion of sainfoin silage at the expense of grass silage in dairy cow rations reduces ruminal BH of dietary cis-9-C18:1 and C18:3n-3.

    The effects of replacing grass silage by sainfoin silage in a TMR on milk production and FA in milk fat of the dairy cows in Chapter 2 is reported in Chapter 4. Milk yield reported in Chapter 4 was highest for the SAIN diet with every kg of OM digested of the SAIN diet resulting, on average, in 0.2 kg more milk production. The SAIN diet fed cows had a higher C18:3n-3 and cis-9,cis-12-C18:2 proportion in milk fat compared to the CON diet fed cows. A higher proportion of total trans-C18:1 was found in the cows fed the SAIN diet. There were no differences in proportion of total saturated and unsaturated FA in milk fat between the two diets. Our results showed that replacing grass silage by sainfoin silage improved milk yield and milk FA profile of dairy cows.

    Effects of the structural properties of CT, i.e. average polymer size (or mean degree of polymerization, mDP); percentage of cis flavan-3-ols (%cis) and percentage of prodelphinidins (%PD) in CT extracts on CH4 production and fermentation characteristics of rumen fluid using an in vitro gas production technique was investigated in Chapter 5. Extracts of CT from eight plants; black currant leaves, goat willow leaves, goat willow twigs, pine bark, red currant leaves, sainfoin plants, weeping willow catkins and white clover flowers were extracted, in order to obtain CT with a wide range in mDP, %PD and %cis. All CT extracts reduced CH4 concentration, decreased the maximum rate of fermentation for CH4 production and rate of substrate degradation. The correlation between CT structure on the one hand and CH4 production and fermentation characteristics on the other hand showed that the %PD within CT had the largest effect on fermentation characteristics, followed by mDP and %cis.

    Chapter 6 reports results of an in vitro study to investigate the effects of the structural properties CT (mDP, %cis and %PD) on rumen fermentation and BH end-products. The total volatile FA (VFA), ammonia concentration and the proportion of branched chain VFA was reduced in all CT extracts, compared to the control. The proportion of cis-9-C18:1; cis-9,cis-12-C18:2; cis-9,cis-12,cis-15-C18:3 were numerically higher in all CT sources, while the proportion of C18:0 and fractional rate of BH of C18:3n-3 were numerically lower in all CT sources, compared to the control. The correlation between CT structural properties on the one hand and fermentation and BH end-products on the other hand showed that the CT with a high %PD and smaller mDP had the largest effect on fermentation end-products. However, mDP was found to be the most important factor affecting rumen BH.

    Chapter 7 provides a general synthesis on the major findings of the studies presented in the preceding chapters. In addition, results are reported of a further in vitro as well as an in situ study in which I investigated the mechanisms of CT action in the rumen, in the post-rumen compartments and digestive tract. In the in situ study, fresh sainfoin (Esparcette) was incubated in the rumen and in the abomasum before digested during passage through the digestive tract. For the in vitro study, sainfoin (Ambra) was incubated with rumen fluid buffer for 1, 2, 4, 8, 12, 24 hours. After incubation in situ and in vitro, the incubated material was analyzed for tannin content by butanol-HCl assay. The results showed that the soluble CT dramatically reduced upon introduction in the digestive tract. Additional analyses showed that CT had bound to the fiber and protein (diet and microbes) fractions in the digestive tract.

    The present work showed that sainfoin silage can be used in dairy cow rations to improve milk production and N utilization and reduce CH4 emissions per kg DM intake. Moreover, sainfoin silage, when replacing part of the grass silage in a TMR of dairy cows, increases ruminal unsaturated FA flow into the reticulum and reduces ruminal BH of dietary cis-9-C18:1 and C18:3n-3. Cows fed sainfoin silage at the expense of grass silage in a TMR increase the proportion of unsaturated FA in milk fat. In terms of condensed tannin structure, mDP and %PD appear to be the most important properties of CT that affect fermentation and BH end-products. Condensed tannins with a mDP ranging from 5 to 10 monomeric units and a %PD > 70.0% seem to have the highest biological activity in the rumen.

    WHYDRY; Verkorten van de droogstand van melkvee: effecten op de melkproductie, energiebalans en koe- en kalfgezondheid
    Knegsel, A.T.M. van - \ 2014
    Wageningen : Wageningen University, leerstoelgroep Adaptatiefysiologie - 156
    melkproductie - energiebalans - diergezondheid - koeien - kalveren - experimenten - melkopbrengst - lactatie - melkinterval - melkveehouderij - gustperiode - milk production - energy balance - animal health - cows - calves - experiments - milk yield - lactation - milking interval - dairy farming - dry period
    Van Knegsel, A.T.M. (Editor), 2014. WHYDRY: Verkorten van de droogstand van melkvee: effecten op de melkproductie, energiebalans en koe- en kalf-gezondheid. Wageningen University, Wageningen, Nederland. 156 blz. Sinds het begin van de 20ste eeuw worden melkkoeien enkele weken voor de verwachte kalfdatum drooggezet, d.w.z. niet meer gemolken. Het doel van deze droogstand is om de melkproductie in de daaropvolgende lactatie te maximaliseren. Daarnaast kunnen koeien met subklinische mastitis tijderns de droogstand behandeld worden met antibiotica. Recent is er discussie ontstaan of een droogstand van 6 tot 8 weken nog wel optimaal is vanwege een aantal redenen. Ten eerste is de vraag of een maximale melkproductie nog steeds wenselijk is, omdat een hoge melkproductie in begin lactatie wordt geassocieerd met een hoge ziekte-incidentie. Ten tweede is het droogzetten van hoogproductief melkvee met nog een hoge dagproductie bij droogzetten een risico voor uiergezondheid. Ten derde is sinds 2013 in Nederland het gebruik van antibiotica in de veehouderij sterk gelimiteerd. Dit geldt ook voor de antibiotica gebruikt in de droogstand, zgn. droogzetters. Deze antibiotica bepalen mede de lengte van de toegepaste droogstand, vanwege de wachttijd na gebruik van droogzetters voor de levering van melk. Het doel van WHYDRY was om via een integrale aanpak te onderzoeken wat de consequenties zijn van het verkorten van de droogstand voor melkproductie, melksamenstelling, energiebalans en koe- en kalfgezondheid. Het onderzoeksproject WHYDRY bestond hoofdzakelijk uit een groot dierexperiment waarin koeien 2 lactaties zijn gevolgd onder gecontroleerde omstandigheden. Binnen dit experiment zijn 168 Holstein-Friesian koeien random toegewezen aan een van de drie droogstandslengtes (0, 30 of 60 dagen) en een van twee lactatierantsoenen (glucogeen of lipogeen). Daarnaast is er een separaat experiment uitgevoerd naar pensontwikkeling van koeien met verschillende droogstandslengtes en zijn de melkcontrolegegevens geanalyseerd van 11 praktijkbedrijven die al een verkorte droogstand toepasten. De resultaten van WHYDRY laten zien dat het verkorten of weglaten van de droogstand resulteert in een verschuiving van de melkproductie van de kritische periode na afkalven naar de periode vóór afkalven wanneer de koe makkelijk in haar energiebehoefte kan voorzien. De verschillen in melkproductie en energiebalans tussen koeien met verschillende droogstandslengtes waren aanzienlijk. Verkorten van de droogstand resulteerde in beperkte reductie in melkproductie en melkopbrengst, maar met een duidelijke verbetering van de energiebalans in de daaropvolgende lactatie. Verkort droog zetten had geen gevolgen voor het celgetal in de melk, biestkwaliteit, antistofconcentratie in het bloed van de kalveren of groei van de kalveren. Een tweede lactatie opnieuw verkort droogzetten was goed mogelijk. Daarmee kan het verkorten van de droogstand naar 30 dagen een interessante strategie zijn om de energiebalans in vroege lactatie te verbeteren zonder dat het gevolgen heeft voor de totale lactatieproductie. Dit geldt zeker wanneer geen rekening gehouden hoeft te worden met de wachttijd van eventuele droogzetters en het gewenst is de melkproductie van koeien met een hoge dagproductie op 60 dagen voor afkalven de lactatieperiode te verlengen. Weglaten van de droogstand resulteerde in een sterke reductie in melkproductie en melkopbrengst, maar de energiebalans (qua duur en diepte) en metabole gezondheid werden sterk positief beïnvloed. Biestkwaliteit was significant minder, wat ook resulteerde in een lagere concentratie antistoffen in het bloed van de kalveren tot 6 weken leeftijd, maar daarna niet meer. Verder bestond het risico dat koeien vervetten en niet persistent genoeg waren om een tweede lactatie tot 4 aan afkalven gemolken te worden. Voor bepaalde koeien leek deze strategie echter wel succesvol. Koeien met een hoge dagproductie enkele maanden voor afkalven kenden geen negatieve gevolgen voor de melkproductie in de totale volgende lactatie wanneer zij gemolken werden tot aan afkalven. Onafhankelijk van droogstandslengte was ook het voeren van een glucogeen rantsoen in vroege lactatie gunstig voor de energiebalans en metabole gezondheid, in vergelijking met een meer lipogeen rantsoen.
    Economische winst te halen bij voerproductie
    Doornewaard, G.J. ; Haan, M.H.A. de - \ 2014
    V-focus 11 (2014)2. - ISSN 1574-1575 - p. 29 - 31.
    melkveehouderij - melkopbrengst - melkveevoeding - kosten-batenanalyse - efficiëntie - agrarische bedrijfsvoering - bedrijfsvergelijking in de landbouw - duurzaamheid (sustainability) - dairy farming - milk yield - dairy cattle nutrition - cost benefit analysis - efficiency - farm management - farm comparisons - sustainability
    Door een efficiënte bedrijfsvoering scoort Koeien & Kansen-deelnemer Adrian Houbraken economisch bovengemiddeld goed. Hij bewijst dat lage mineralenverliezen naar het milieu (door een hoge benutting) goed samengaan met economie. Verdere verbetering van de efficiëntie lijkt vooral mogelijk bij de voerproductie.
    Diarrhea and loss of production on Dutch dairy farms caused by the Schmallenberg virus
    Muskens, J. ; Smolenaars, A.J. ; Poel, W.H.M. van der; Mars, M.H. ; Wuijckhuise, L. van; Holzhauer, M. ; Weering, H. van; Kock, P. - \ 2012
    Tijdschrift voor Diergeneeskunde 137 (2012)2. - ISSN 0040-7453 - p. 112 - 115.
    melkveehouderij - melkopbrengst - diarree - schmallenbergvirus - rundveeziekten - orthobunyavirus - virusziekten - bloedmonsters verzamelen - dairy farming - milk yield - diarrhoea - schmallenberg virus - cattle diseases - orthobunyavirus - viral diseases - blood specimen collection - adult cattle - coronavirus
    At the end of August and the first two weeks of September 2011 dozens of veterinary practitioners reported to GD Veekijker (Animal Health Service) several dairy herds with cows with sudden decreased milk production, watery diarrhea and sometimes fever. In the beginning these reports came from the Eastern region of the Netherlands, after that also from the other three regions. The percentages of diseased herds per veterinary practice varied from a few till dozens per cent. Extensive bacteriological, virological and parasitological testing of the feces of sick cows did not reveal an infectious cause of the clinical problems. Recently, 50 stored blood samples of clinically diseased cattle were tested for the Schmallenbergvirus using a PCR, and 36% (18/50) tested positive. A large group of control cows (n=115) was also tested with the PCR and all cattle tested negative. Likely the Schmallenbergvirus was the primary cause of the clinical symptoms in the Dutch dairy herds. Further research will be done to confirm this.
    Effect of increased maturity of silage maize at harvest on conservation, dairy cow performance and methane emission
    Zom, R.L.G. ; Bannink, A. ; Goselink, R.M.A. - \ 2012
    Lelystad : Wageningen UR Livestock Research (Report / Wageningen UR Livestock Research 578) - 16
    melkveehouderij - rundveevoeding - krachtvoeding - maïskuilvoer - rijpingsfase - droge stof - melkopbrengst - voeropname - verteerbaarheid - voersamenstelling - dairy farming - cattle feeding - force feeding - maize silage - ripening stage - dry matter - milk yield - feed intake - digestibility - feed formulation
    Increasing maturity at harvest is evaluated as a cost-free method to increase starch concentration and rumen by-pass starch of maize silage, reducing methane emission. Results showed no effect on cow performance or silage stability, but the calculated effect on methane emission was low with the maize cultivar used.
    Adaptive models for operational use in dairy farming : increasing economic results utilising individual variation in response
    Andre, G. - \ 2011
    Wageningen University. Promotor(en): Alfons Oude Lansink, co-promotor(en): Paul Berentsen; Bastiaan Engel. - [S.l.] : S.n. - ISBN 9789085858812 - 169
    melkveehouderij - melkresultaten - bedrijfsresultaten in de landbouw - melkopbrengst - melkkoeien - dynamische modellen - melkinterval - melkproductie - voeropname - melktempo - nederland - dairy farming - dairy performance - farm results - milk yield - dairy cows - dynamic models - milking interval - milk production - feed intake - milking rate - netherlands
    During the last century in the Netherlands milk production per cow has almost tripled. Accordingly, the amount of concentrates yearly fed per cow strongly increased. Furthermore, automation and robotisation has changed dairy management, especially by the introduction of automatic concentrate feeders and milking systems. A new management concept, emerging in the last decades, is Precision Livestock Farming (PLF). The objective of PLF is to optimize livestock production, by on-line monitoring and control of the production process, utilizing the technical possibilities of automation and robotisation. Nowadays, individual settings for daily concentrate supply and milking frequency are based on standards, ignoring individual variation in milk yield response on concentrate intake and milking frequency. This leads to the main hypothesis for this thesis research that profitability of dairy farming can be improved by utilizing information on individual variation in response. The first objective of this research was to quantify the individual variation in milk yield response to concentrate intake and milking interval length, in order to assess the economic prospects of applying individual optimal settings for concentrate supply and milking frequency. The second objective was the development and testing of adaptive models for on-line estimation of the actual individual response in milk yield to concentrate intake and milking interval length. The conclusion is that on-line estimation of the actual individual response in milk yield and milking duration is possible following a Bayesian approach for time series using an adaptive dynamic model. Besides estimation of the actual response the Bayesian approach adequately detects process deteriorations. Therefore, adaptive dynamic models provide a useful tool for control and monitoring of the dairy production process.
    Feeding and grazing management for dairy cattle: opportunities for improved production
    Abrahamse, P.A. - \ 2009
    Wageningen University. Promotor(en): Seerp Tamminga, co-promotor(en): Jan Dijkstra. - [S.l. : S.n. - ISBN 9789085854548 - 158
    melkveehouderij - melkkoeien - rundveevoeding - beweidingssystemen - voeropname - melkopbrengst - melksamenstelling - melkresultaten - verbetering - begrazingsbeheer - dairy farming - dairy cows - cattle feeding - grazing systems - feed intake - milk yield - milk composition - dairy performance - improvement - grazing management
    An adequate feed intake is an important prerequisite to realize high milk production in
    dairy cows, especially during grazing. The analysis of feed intake behaviour can assist in
    understanding variation in daily intake and in improving its prediction. Indeed, our results
    indicated that differences in feed intake behaviour were more pronounced when varying
    the type of roughage than when varying the type of concentrate. Dry matter intake (DMI)
    was reduced when a ration high in grass silage was fed, but milk production was only
    numericaly affected. Grazing management might result in increased herbage intake and
    higher intake of nutrients from herbage by improved nutritional composition of herbage.
    In the first grazing experiment, herbage DMI was indeed increased when allocating cows
    daily (1Da) to a new grazing plot compared to every four days (4D) allocation, but only
    when pasture mass on offer and sward surface height (SSH) were high. Grazing time
    increased numerically and ruminating time decreased between days in the 4D treatment,
    coinciding with differences in rumen fermentation characteristics and milk composition.
    Milk yield was greater in 1Da than in 4D, but milk fatty acid (FA) composition, potentially
    influencing human health, showed hardly any difference. In a subsequent experiment,
    herbage DMI was again greater when allocating twice daily (2D) compared to once daily
    (1Db), especially when SSH was high. Grazing behaviour was more equally distributed
    in 1Db than in 2D and milk yield was increased in 2D compared to 1Db at high SSH,
    but as before milk FA composition hardly differed between treatment. The last grazing
    experiment aimed to take advantage of the higher sugar contents of grass in the afternoon
    than in the morning. It showed that grazing behaviour and herbage intake were similar
    between morning (MA) and afternoon allocation (AA), but cows receiving a fresh plot in
    the afternoon had a longer evening meal than cows receiving a fresh plot in the morning.
    This, in combination with differences in diurnal chemical composition of the grass between
    treatments probably caused higher intake of sugars in AA, resulting in a higher milk fat
    content. However, milk production remained unaffected. In conclusion, the results of
    this thesis indicate that short-term feed intake behaviour is related to DMI and therefore
    may be a helpful tool in optimizing DMI and milk production in high-production dairy
    cows. Increased pasture allocation frequency improves intake and milk yield in grazing
    dairy cows, especially when offered SSH is high enough. In intensive stripgrazing systems,
    reallocation of dairy cows following afternoon milking instead of morning milking has no
    added value.
    Oudere koeien voor een duurzame houderij
    Gosselink, J.M.J. ; Bos, A.P. ; Bokma, S. ; Groot Koerkamp, P.W.G. - \ 2008
    V-focus 5 (2008)4. - ISSN 1574-1575 - p. 30 - 31.
    melkveehouderij - melkkoeien - leeftijd - melkopbrengst - bedrijfsresultaten in de landbouw - agrarische bedrijfsvoering - agrarische bedrijfsplanning - dairy farming - dairy cows - age - milk yield - farm results - farm management - farm planning
    Een oudere veestapel blijkt economisch gunstig te zijn. Wat moet er gebeuren om de leeftijd van de melkkoe omhoog te krijgen?
    Kostprijs van melk: uitkomsten 2005 en methodewijzigingen
    Blokland, P.W. - \ 2007
    Agri-monitor 2007 (2007)februari. - ISSN 1383-6455 - 3
    melkveebedrijven - melk - melkproductiekosten - melkopbrengst - bedrijfsresultaten in de landbouw - kostenanalyse - rentabiliteit - bedrijfsgrootte in de landbouw - compensatiebedragen - dairy farms - milk - milk production costs - milk yield - farm results - cost analysis - profitability - farm size - compensatory amounts
    In 2005 hebben zuivere melkveebedrijven een gemiddelde kostprijs van ruim 41 euro per 100 kg melk gerealiseerd. Op grotere bedrijven is de kostprijs beduidend lager dan op kleinere bedrijven. De methode van de kostprijsberekening is begin 2007 aangepast vanwege het toenemende aandeel van de EU-inkomenstoeslagen in de totale opbrengsten.
    Eerste kwartaal melkvee: melk- en veeprijzen lager, krachtvoer duurder
    Jager, J.H. ; Bolhuis, J. - \ 2007
    Agri-monitor 2007 (2007)april. - ISSN 1383-6455 - 2
    melkveehouderij - melkveebedrijven - rundvee - melkproductie - landbouwprijzen - bedrijfsresultaten in de landbouw - agrarische economie - melkopbrengst - dairy farming - dairy farms - cattle - milk production - agricultural prices - farm results - agricultural economics - milk yield
    In het eerste kwartaal van 2007 ligt de melkproductie zowel in Nederland als in de EU hoger dan in dezelfde maanden van 2006. De zuivelproducten konden goed worden afgezet op de markt, maar toch daalde de voorschotprijs van melk licht. Ook kalveren brachten veel minder op, waardoor 2007 minder goed is begonnen dan 2006.
    Mondiale verspreiding HF-genen: spermahandel jaarlijks goed voor 100 miljoen euro
    Oldenbroek, J.K. ; Fikse, J.K. ; Hiemstra, S.J. - \ 2007
    Veeteelt 24 (2007)21. - ISSN 0168-7565 - p. 12 - 15.
    melkveehouderij - rundveerassen - melkopbrengst - dierveredeling - dierenhandel - markteconomie - duurzaamheid (sustainability) - internationale handel - rundvee - dairy farming - cattle breeds - milk yield - animal breeding - trade in animals - market economics - sustainability - international trade - cattle
    Hoogproductieve rassen, zoals Holstein Friesian, verdrijven de lokale rassen door wereldwijde handel in fokvee en sperma. Een actieplan moet ervoor zorgen dat genetische diversiteit behouden blijft. Aan de hand van cijfermateriaal laten onderzoekers zien dat Amerika toonaangevend is in de wereldwijde spermamarkt en dat Duitsland en Nederland de grootste exporteurs zijn van levend vee. Tevens wordt op het belang van duurzaamheid in de fokkerij gewezen
    Hoeveelheid melk bepaalt kostprijs
    Evers, A.G. - \ 2007
    V-focus 4 (2007)2. - ISSN 1574-1575 - p. 2 - 2.
    melkveehouderij - melkopbrengst - kosten - prijsvorming - quota's - onderzoeksinstituten - proefbedrijven - agrarische bedrijfsvoering - landbouwkundig onderzoek - bedrijfsvergelijking in de landbouw - productiekosten - dairy farming - milk yield - costs - price formation - quotas - research institutes - pilot farms - farm management - agricultural research - farm comparisons - production costs
    Een evaluatie van de totstandkoming van de melkprijs in 2006 voor het High-techbedrijf, ook in vergelijking met een vergelijkingsgroep van LEI-bedrijven
    Estimation of genotype × environment interaction for yield, health and fertility in dairy cattle
    Calus, M.P.L. - \ 2006
    Wageningen University. Promotor(en): Johan van Arendonk, co-promotor(en): Roel Veerkamp. - [S.l. ] : S.n. - ISBN 9789085043751 - 181
    melkvee - genotype-milieu interactie - melkopbrengst - diergezondheid - vruchtbaarheid - fokwaarde - genetische parameters - wiskundige modellen - dierveredeling - dairy cattle - genotype environment interaction - milk yield - animal health - fertility - breeding value - genetic parameters - mathematical models - animal breeding
    In dairy cattle breeding,health and fertility traits have recently been included in a large number of national breeding goals.The effectiveness of breeding decisions and management changes to improve health and fertility possibly interact through genotype × environment interaction (G×E). G×E is a phenomenon in which different genotypes respond differently to changes in an environment. It can consist of the following effects: heterogeneous genetic variances across environments, genetic correlation of a trait expressed in different environments being less than 1.0 (reranking), and heterogeneous genetic correlations between traits across environments. In this thesis, G×E for health andfertiltity, as well as for yield, has been investigated using reaction norm models. In the reaction norm models, breeding values and genetic parameters were modeled as a function of an environmental descriptor using random regression. The dimensions of the model were expanded from linear random regressions to higher order random regressions, to include two parameters to define the environment, and to multivariate reaction norm models.Many environmental descriptors were investigated in this thesis, such as production level, farm size, average somatic cell score and calving interval, however, it appears that the herd parameters linked to nutrition and energy balance are most important for G×E.Significant G×E was detected in 86% of the situations for yield traits, but only in 14% of the situations for health and fertility traits, although significantrerankingwas found for SCS, mastitis and survival. Estimated G×E effects mainly consisted of heterogeneous genetic variances with limitedreranking. As a result of heterogeneous variances in different traits, the relative importance of fertility compared to yield doubled across environments. Estimated G×E effects for SCS indicated morererankingof animals based on analysis of test day records, than on lactation averages. It was shown that selection for increased yield is expected to lead to increased environmental sensitivity for yield, while selection for better fertility is expected to lead to decreased environmental sensitivity for fertility. The models presented in this thesis can be used to account for the effect of herd environment on a trait and the relations between traits, and therefore enable to make accurate predictions of breeding values across environments.
    Prototype van een dynamisch krachtvoer advies systeem voor melkvee
    Duinkerken, G. van; André, G. ; Zom, R.L.G. - \ 2003
    Lelystad : Praktijkonderzoek Veehouderij (PraktijkRapport / Animal Sciences Group, Praktijkonderzoek : Rundvee ) - 54
    melkvee - melkveehouderij - rundveevoeding - concentraten - melkproductie - melkopbrengst - lineaire modellen - diervoeding - diervoedering - dairy cattle - dairy farming - cattle feeding - concentrates - milk production - milk yield - linear models - animal nutrition - animal feeding
    Een zogenaamd dynamisch krachtvoeradvies houdt rekening met de individuele melkproductierespons van dieren op het opgenomen krachtvoer en benut daarmee de verschillen tussen dieren voor wat betreft de efficiëntie waarmee het (kracht)voer wordt benut. Daarbij wordt uitgegaan van de zogenaamde krachtvoercoëfficiënt, die aangeeft hoeveel kg melk extra is te verwachten indien van een bepaald dier de krachtvoeropname met één kg/dag stijgt. Ook houdt het dynamische model rekening met de variatie binnen de dieren als gevolg van veranderingen die tijdens de lactatie optreden. Het prototype dynamisch model bleek goed bruikbaar om schattingen te geven van zowel het basisniveau (van de melkgift) als de krachtvoercoëfficiënt. Zodoende is het mogelijk om goede voorspellingen te geven van de verwachte melkgift op korte termijn en daar een krachtvoeradvies aan te koppelen. Ook de monitoringfunctie van het model, waarbij onverwachte afwijkingen in de melkgift direct worden gesignaleerd en gemeld op basis waarvan de veehouder kan nagaan of er oorzaken voor de afwijkingen te vinden zijn, zoals bijvoorbeeld kreupelheid of tochtigheid van de betreffende koe, functioneerde goed in de uitgevoerde proef
    Normale veevervanging en hoge gezondheidskosten op high-techbedrijf
    Thomassen, I. ; Kamp, A. van der - \ 2002
    Praktijkkompas. Rundvee 16 (2002)6. - ISSN 1570-8586 - p. 31 - 33.
    melkveehouderij - melkvee - melkkoeien - diergezondheid - vervanging - verbetering van de veestapel - dierziekten - preventie - ziektepreventie - ziektebestrijding - veeartsenijkunde - kosten - agrarische bedrijfsvoering - bedrijfsvergelijking in de landbouw - melkproductie - melkopbrengst - proefbedrijven - demonstratiebedrijven, landbouw - proefboerderijen - dairy farming - dairy cattle - dairy cows - animal health - replacement - herd improvement - animal diseases - prevention - disease prevention - disease control - veterinary medicine - costs - farm management - farm comparisons - milk production - milk yield - pilot farms - demonstration farms - experimental farms
    Vergelijking van de veevervanging op het high-techbedrijf in de jaren 1999 - 2001 met het gemiddelde van de proefbedrijven over 1992-1999 laat een normale veevervanging zien op het high-techbedrijf.
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