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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Hoe ziet trips zijn omgeving?
Tol, Rob van - \ 2018
Kleuren, geuren en andere factoren die gedrag beïnvloeden. Titel: Kruip in de huid van trips De glastuinbouwsector worstelt al jaren met de bestrijding van trips. De laatste jaren zijn mooie resultaten behaald met biologische bestrijding, maar in diverse teelten zorgt trips nog voor grote problemen. In deze workshop willen we terug naar de basis en in de huid van trips kruipen. Hoe en wanneer vliegt trips? Hoe kijkt een trips? Welke geuren vinden ze lekker en welke niet? Hoe planten ze zich voort? Hoe gedraagt een trips zich op de plant? Onderzoekers Rob van Tol en Gerben Messelink van Wageningen University & Research nemen je mee in de wereld van trips en presenteren de meest recente kennis over het gedrag van trips. Meer basiskennis helpt om deze plaag gerichter en effectiever te bestrijden. De workshop zal starten met een interactieve tripsquiz om uw kennis over deze belangrijke plaag te testen. Deelnemers aan deze workshop worden aangeraden de app kahoot alvast te downloaden op mobiel of tablet.
Het burgerinitiatief en de overheid hebben elkaar nodig
Breman, B.C. - \ 2014
Arnhem : RUIMTEVOLK
Na een dag vol inspirerende voorbeelden van bottom-up initiatieven en bijzonder ‘goede gesprekken‘ over de kracht van burgers in Noord-Groningen tijdens het Dorpenlab van het kennisprogramma van het Ministerie van Infrastructuur en Milieu en RUIMTEVOLK kruip ik diezelfde avond toch met enigszins gemengde gevoelens in bed.
The Effect of Low-Density Diets on Broiler Breeder Performance During the Laying Period and on Embryonic Development of their Offspring
Enting, H. ; Kruip, T.A.M. ; Verstegen, M.W.A. ; Aar, P.J. van de - \ 2007
Poultry Science 86 (2007). - ISSN 0032-5791 - p. 850 - 856.
quantitative food restriction - egg weight - feed restriction - parental age - recommended levels - chick-embryo - in-vitro - females - growth - hen
The effect of low-density diets on bird performance, egg composition, and embryonic development was studied with 2,100 female and 210 male Cobb broiler breeders from 25 to 60 wk of age. The experiment included 5 treatments. These included a control group with a normal density diet (ND, 2,800 kcal of AME/kg). Treatments 2 (LD11) and 3 (LD21) had a 11 and 21% lower nutrient density. Treatment 4 (LD11OP) had a 11% less dense diet, which was obtained by inclusion of other feed ingredients. In these 4 treatments similar diets were given during the rearing and the laying period. Treatment 5 combined LD12 in the rearing period and ND diets during the laying period (LD12-ND). Egg composition and embryonic development were measured in eggs of ND and LD21 birds at 29 and 41 wk of age. During the laying period from wk 25 to 60, live weights did not differ among treatments, except that birds fed LD11OP had lower live weights. A significantly higher rate of lay was provided by LD11 compared with ND. Egg weights were significantly higher when low-density diets were fed, particularly in LD11OP. Percentage of fertile eggs did not differ among treatments. Compared with the other treatments, LD11OP provided a significantly lower hatchability. We found that LD21 resulted in a better development of the area vitellina externa and heart and embryo weight at 29 wk of age. It was concluded that this was related to a higher egg weight and egg white proportion. This suggests that the amount of egg white in eggs of hens fed ND was limiting for embryonic development, particularly in eggs of young broiler breeders.
Associations between Energy Metabolism, LH Pulsatility and First Ovulation in early Lactating Cows
Jorritsma, R. ; Langendijk, P. ; Kruip, T.A.M. ; Wensing, T.H. ; Noordhuizen, J.P.T.M. - \ 2005
Reproduction in Domestic Animals 40 (2005)1. - ISSN 0936-6768 - p. 68 - 72.
dairy-cows - ovarian activity - dry period - postpartum - cattle - balance - secretion - hormone - leptin - number
This study was designed to elucidate associations between energy metabolism and LH pulsatility characteristics in early lactation, and days to first ovulation, in order to explain the relationship between energy balance and fertility observed in epidemiological studies. To this end, 10 multiparous HF cows were monitored during lactation, after the application of two different feeding strategies during the dry period. Days to first ovulation was assessed using blood progesterone measurements and LH pulsatility was measured in 8-h windows in the third week postpartum. The association between depth of negative energy balance and days to ovulation was confirmed. However, this study does not support the idea that LH pulsatility characteristics in early lactation are predictive for the interval between parturition and first ovulation
Metabolic homeostasis in postpartum dairy cows hampered by fatty livers
Jorritsma, R. ; Murondoti, A. ; Vos, P. ; Noordhuizen, J.P.T.M. ; Kruip, T.A.M. ; Wensing, T. - \ 2004
Veterinary Record 155 (2004)5. - ISSN 0042-4900 - p. 151 - 152.
hepatic triacylglycerol - dry period - lipidosis - herds
Effects of non-esterified fatty acids on bovine granulosa cells and developmental potential of oocytes in vitro
Jorritsma, R. ; Cesar, M.L. ; Hermans, J. ; Kruitwagen, C. ; Vos, P. ; Kruip, T.A.M. - \ 2004
Animal Reproduction Science 81 (2004)3-4. - ISSN 0378-4320 - p. 225 - 235.
growth-factor-i - dairy-cows - energy-balance - early lactation - body condition - progesterone - postpartum - heifers - cattle - follicles
High yielding dairy cows experience a negative energy balance (NEB) shortly after parturition, which is accompanied by high concentrations of non-esterified fatty acids (NEFA) in blood up to approximately 3 weeks post partum. We hypothesized that the elevated plasma NEFA concentration causes lower fertility by exerting negative effects on grarnulosa cells and oocytes in the ovary, leading to less viable embryos and insufficient corpora lutea. In two series of experiments, we studied the effects of a realistic NEFA (C18:1) concentration on both the proliferation and the progesterone production of follicular granulosa cells in vitro (part I) and on maturation, fertilization and developmental potential of oocytes (part II). For part I, granulosa cells were added to 4 groups of dishes with four different media and cultured for nine consecutive days. After a preculture period of 42 h, the presence of NEFA had a negative effect on the proliferation of granulosa cells. No effect of NEFA on the amount of progesterone production per cell was observed. For part II, a total of 1804 cumulus-oocyte-complexes were collected from slaughterhouse ovaries. Using a subgroup of 690 COC, maturation medium with NEFA caused a delay in maturation. Using another 1114 COC, fertilization, cleavage, and embryonic development after maturation in presence of NEFA were significantly reduced. We concluded that the presence of NEFA in follicular fluid and blood of postpartum cows may reduce fertility due to hampered embryonic development and subnormal CL function. (C) 2003 Elsevier B.V. All rights reserved.
Follicular dynamics around the recruitment of the first follicular wave in the cow
Hendriksen, P.J.M. ; Gadella, B.M. ; Vos, P. ; Mullaart, E. ; Kruip, T.A.M. ; Dieleman, S.J. - \ 2003
Biology of Reproduction 69 (2003)6. - ISSN 0006-3363 - p. 2036 - 2044.
bovine ovarian-follicles - growth-factor system - side-chain cleavage - estrous-cycle - luteinizing-hormone - dominant follicle - developmental competence - aromatase-activity - antral follicles - granulosa-cells
The present study aimed to test the generally accepted view that a follicular wave starts with follicles newly recruited from the population smaller than 3 mm, which later compete for dominance. According to this view, subordinate follicles are expected to be too atretic to join the next follicular wave. Ten cows were ovariectomized shortly prior to the LH surge, thus around the start of the first follicular wave of the cycle. Per cow, on average, 14.4 follicles of ¿3 mm were dissected. Follicular health was determined on the basis of four parameters: 1) judgment of the degree of atresia by stereomicroscope, 2) incidence of apoptotic nuclei among the granulosa cells, 3) estradiol and progesterone concentrations, and 4) insulin-like growth factor-I (IGF-I) binding proteins (IGFBPs)-2, -4, and -5 concentrations in the follicular fluid. In addition to the preovulatory follicle, 3.1 other follicles, mainly sized 3¿4.5 mm, were found to be healthy based on the proportion of apoptotic nuclei, and concentrations of estradiol/progesterone, and IGFBPs. The ability of these follicles to respond with growth on the preovulatory and periovulatory FSH surges was supported by a comparison to the follicular population of four cows 31¿68 h after the LH surge. The present results point to an alteration of the view on the follicular wave. The larger follicles during the first days of the follicular wave are, in general, derived from follicles that also joined the previous wave. A portion of these growing follicles are estradiol active and compete for dominance. Other growing follicles lack estradiol production and are probably derived from rather atretic follicles. The first newly recruited follicles do not reach the size of 3 mm before 31 h after the preovulatory FSH surge. At that time, the larger follicles are already competing for dominance.
Acute fasting in heifers as a model for assessing the relationship between plasma and follicular fluid NEFA concentrations.
Jorritsma, R. ; Groot, M.W. de; Vos, P.L.A.M. ; Kruip, T.A.M. ; Wensing, T. ; Noordhuizen, J.P.T.M. - \ 2003
Theriogenology 60 (2003)1. - ISSN 0093-691X - p. 151 - 161.
growth-factor-i - preovulatory lh surge - energy-balance - dairy-cows - beef heifers - ovarian follicle - bovine follicles - milk-production - body condition - holstein cows
It is known from epidemiological studies that negative energy balance in early lactating dairy cows is related to a depression in reproductive performance. Elevated plasma concentrations of non-esterified fatty acids (NEFA) are a typical metabolic characteristic of these animals and are proposed as the possible link. The suggestion is that NEFA might have a direct effect on the ovary, by affecting development of the oocyte or the granulosa cells. However, no data is available concerning the relationship between the concentration of NEFA in follicular fluid and plasma. Therefore, a cross-over study with 10 heifers around 15 months of age was conducted to analyze this relationship and examine the suggested effects of the negative energy balance on follicular growth. Investigation of these effects was performed on fasted heifers. The experimental treatment consisted of feeding hay with a subsequent period of fasting, to induce elevated plasma NEFA concentrations. Sampling of follicular fluid was performed using transvaginal aspiration of follicles, which were standardized using a synchronization protocol. In addition, concentrations of glucose, insulin, NEFA, and estradiol were measured in plasma. Follicular estradiol and progesterone concentrations were also measured to assess the quality of the dominant follicle. Fasting resulted in significantly lower plasma glucose (P=0.0006) and plasma insulin (P
Metabolic changes in early lactation and impaired reproductive performance in dairy cows.
Jorritsma, R. ; Wensing, T. ; Kruip, T.A.M. ; Vos, P.L.A.M. ; Noordhuizen, J.P.T.M. - \ 2003
Veterinary Research 34 (2003)1. - ISSN 0928-4249 - p. 11 - 26.
growth-factor-i - early postpartum period - energy-balance - first ovulation - holstein cows - luteinizing-hormone - milk-production - body condition - fatty liver - food-intake
This review addresses the suggestion that the decline in dairy reproductive performance, as increasingly observed these days, may be due to a hampered process of metabolic adaptation in early lactating cows. In our opinion, adaptation to the negative energy balance is a gradual process. Because almost all cows do adapt in the long run, it is not possible to classify animals as adapted or non-adapted. The use of risk factors is more appropriate in this case and is discussed in this review. Among them are the body condition score and its derivatives, feed intake, the calculated negative energy balance, and metabolic parameters like the plasma concentration of insulin or the triacylglycerol content in the liver. Moreover, factors that play a role in the link between declined reproductive performance and the metabolic situation of the cow during the early lactating period are discussed. Among these are insulin, insulin-like growth factors, leptin, neuropeptide Y, non-esterified fatty acids, thyroid hormones, urea, and ammonia.
Lack of association of Mycobacterium avium subsp. paratuberculosis with oocytes and embryos from moderate shedders of the pathogen.
Kruip, T.A.M. ; Muskens, J. ; Roermund, H.J.W. van; Bakker, D. ; Stockhofe, N. - \ 2003
Theriogenology 59 (2003)7. - ISSN 0093-691X - p. 1651 - 1660.
para-tuberculosis - cattle - cows
Paratuberculosis is a chronic and progressive disease of the intestine in ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map). The bacterium is transmitted to young animals, becomes manifest in adulthood and leads to economic losses. The aim of this study is to investigate if cows shedding Map possess oocytes and embryos that are carriers of the bacterium. New genetical material can enter the dairy farm using embryo transfer but the question as to whether this technique is safe with respect to transmission of paratuberculosis has yet to be addressed. We selected and bought 16 cows, all proven to be moderate shedders of the bacterium in the faeces immediately prior to the experiment but none were clinically sick. One sample of uterine content was collected from each animal by flushing the uterus on the day of heat and five samples of homogenised uterine tissue were collected on the eighth day of the same cycle by biopsy. In addition, 217 cumulus-oocyte complexes (COCs), ranging from 3 to 35 COCs per animal, were collected using ultrasound guided transvaginal puncture of the ovarian follicles (OPU). On the seventh day of the subsequent cycle 31 embryos were obtained using the classic technique of super ovulation induction, artificial insemination (AI), followed by flushing of the uterus. These embryos have been washed and trypsinised. Fourteen of the 16 cows were treated again for super ovulation in the subsequent cycle and 19 foetuses were collected by opening of the uterus after euthanasia on Days 35-49 of the cycle. All samples were cultured for presence of Map and checked every 2 months during 1 year for bacterial growth. None of the samples showed growth of Map after 12 months of culture. Pathological examination of the cows revealed different degrees of severity of pathological alterations of the intestinal tract and mesenteric lymph nodes. However, the results suggest that neither in vivo embryo's nor oocytes are carriers of the bacteria and do not form an extra risk at transfer. However, due to the limited size of the experiment (sample size of 16 cows), a certain margin for error remains.
Post-partum supplementation with rumen undegradable protein not reduce fatty acid liver development in dairy cows as induced by overfeeding during the dry period
Murandot, A. ; Rukkwamsuk, T. ; Kruip, T.A.M. ; Wensing, T. ; Meijer, G.A.L. ; Beynen, A.C. - \ 2002
Journal of Animal Physiology and Animal Nutrition (2002). - ISSN 0931-2439
Cellular and molecular deviations in bovine in vitro-produced embryos are related to the large offspring syndrome
Lazzari, G. ; Wrenzycki, C. ; Herrmann, D. ; Duchi, R. ; Kruip, T. ; Niemann, H. ; Galli, C. - \ 2002
Biology of Reproduction 67 (2002). - ISSN 0006-3363 - p. 767 - 775.
The large offspring syndrome (LOS) is observed in bovine and ovine offspring following transfer of in vitro-produced (IVP) or cloned embryos and is characterized by a multitude of pathologic changes, of which extended gestation length and increased birthweight are predominant features. In the present study, we used bovine blastocysts to analyze cellular parameters, i.e., the number of cells in Day 7 blastocysts and the size of Day 12 elongating blastocysts, and molecular parameters, i.e., the relative abundance of developmentally important genes: glucose transporter (Glut) 1, Glut-2, Glut-3, Glut-4, heat shock protein (Hsp) 70.1, Cu/Zn-superoxide dismutase (SOD), histone H4.1, basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF) I receptor (R), and IGFII-R. Some blastocysts were produced by in vitro maturation and fertilization followed by in vitro culture in synthetic oviduct fluid medium supplemented with BSA or human serum or by in vivo culture in the sheep oviduct. Other blastocysts were derived in vivo from the uterine horns of superovulated donors. The findings made in the early embryos were related to a representative number of calves obtained from each production system and from artificial insemination (AI). In vitro culture of bovine embryos in the presence of high concentrations of serum or BSA significantly increased the number of cells in Day 7 blastocysts, the size of blastocysts on Day 12, and the relative abundance of the transcripts for Hsp70.1, Cu/Zn-SOD, Glut-3, Glut-4, bFGF, and IGFI-R when compared with embryos from the in vivo production groups. Birthweights of calves derived from IVP embryos were significantly higher than those of calves derived from sheep oviduct culture, superovulation, or AI. The results support the hypothesis that persistence of early deviations in development is causally involved in the incidence of LOS, in particular in increased birthweights. The cellular and molecular parameters analyzed in this study can be considered early markers of LOS in cattle.
Biotechnology of reproduction and farm animals welfare
Kruip, T.A.M. ; Reenen, C.G. van - \ 2002
Animal Welfare and Animal Health (FAL) (2002). - p. 57 - 62.
Robotic milking and its effect on fertility and cell counts
Kruip, T.A.M. ; Morice, H. ; Robert, M. ; Ouweltjes, W. - \ 2002
Journal of Dairy Science 85 (2002)10. - ISSN 0022-0302 - p. 2576 - 2581.
The aim of this study was to analyze the effect of robotic milking (RM) on fertility and somatic cell counts (SCC) among dairy herds participating in the national Dutch milk recording system. It was hypothesized that RM, and a higher milking frequency in general, would have negative effects on fertility, due to expected and supposed deeper negative energy balance (NEB). Herds increasing milking frequency from two to three times daily consistently had increased production. Milk production during RM was intermediate between the amounts obtained by milking twice versus three times a day. Milking three times a day and the associated higher production had no significant effect on reproductive measures such as nonreturn rate at 56 d post insemination (NR56) or days to first service. Although RM did not affect NR56, use of the robot was associated with an increase in days to first service. An increase in milking frequency from two to three times daily did not affect SCC, but SCC were significantly increased after milking with the robot. Robotic milking has a significant positive effect on production and no negative effect on fertility as measured by NR56. The effect of RM in increasing days to first service appears due to reasons other than increased production and a more NEB. Increased SCC during RM is potentially of concern. From the data available, the relationship of RM to clinical mastitis could not be determined but this aspect needs further attention.
Case study van een granulosa-thecaceltumor bij het rund [Case report of a granulosa-theca tumour in a cow]
Jorritsma, R. ; Antonis, A.F.G. ; Stockhofe, N. ; Kruip, T.A.M. - \ 2002
Tijdschrift voor Diergeneeskunde 127 (2002). - ISSN 0040-7453 - p. 286 - 288.
Effects of in vivo prematuration and in vivo final maturation on developmental capacity and quality of pre-implantation embryos
Dieleman, S.J. ; Hendriksen, P.J.M. ; Viuff, D. ; Thomsen, P.D. ; Hyttel, P. ; Knijn, H.M. ; Wrenzycki, C. ; Kruip, T.A.M. ; Niemann, H. ; Gadella, B.M. ; Bevers, M.M. ; Vos, P.L.A.M. - \ 2002
Theriogenology 57 (2002). - ISSN 0093-691X - p. 5 - 20.
Transgenesis may affect farm animal welfare: a case for systematic risk assessment
Reenen, C. van; Meuwissen, T.H.E. ; Hopster, H. ; Oldenbroek, K. ; Kruip, T.A. ; Blokhuis, H.J. - \ 2001
Journal of Animal Science 79 (2001). - ISSN 0021-8812 - p. 1763 - 1779.
This paper considers (potentially) harmful consequences of transgenesis for farm animal welfare and examines the strategy of studying health and welfare of transgenic farm animals. Evidence is discussed showing that treatments imposed in the context of farm animal transgenesis are by no means biologically neutral and may compromise animal health and welfare. Factors posing a risk for the welfare of transgenic farm animals include integration of a transgene within an endogenous gene with possible loss of host gene function (insertional mutations), inappropriate transgene expression and exposure of the host to biologically active transgene-derived proteins, and in vitro reproductive technologies employed in the process of generating transgenic farm animals that may result in an increased incidence of difficult parturition and fetal and neonatal losses and the development of unusually large or otherwise abnormal offspring (large offspring syndrome). Critical components of a scheme for evaluating welfare of transgenic farm animals are identified, related to specific characteristics of transgenic animals and to factors that may interact with the effects of transgenesis. The feasibility of an evaluation of welfare of transgenic farm animals in practice is addressed against the background of the objectives and conditions of three successive stages in a long-term transgenic program. Concrete steps with regard to breeding and testing of transgenic farm animals are presented, considering three technologies to generate transgenic founders: microinjection, electroporation and nuclear transfer, and gene targeting including gene knockout. The proposed steps allow for unbiased estimations of the essential treatment effects, including hemi- and homozygous transgene effects as well as effects of in vitro reproductive technologies. It is suggested that the implementation of appropriate breeding and testing procedures should be accompanied by the use of a comprehensive welfare protocol, specifying which parameters to monitor, at which stages of the life of a farm animal, and in how many animals. Some prerequisites and ideas for such a protocol are given. It is anticipated that systematic research into the welfare of farm animals involved in transgenesis will facilitate the use of the safest experimental protocols as well as the selection and propagation of the healthiest animals and, thereby, enable technological progress that could be ethically justified.
Epidemiological evidence of effects of EDC on ruminant reproduction
Kruip, T.A. - \ 2001
In: 'Proceedings of the British Society of Animal Science 2001,' p. 229 (abstr)
Effect van xeno-oestrogenen op de genitaaltractus van het rund
Kruip, T.A. ; Hoving-Bolink, A.H. ; Postma, A. ; Boerjan, M.L. ; Meijer, G.A.L. - \ 2001
Lelystad : ID-Lelystad - 23 p.
The high yielding cow and her endangared fertility
Kruip, T.A. - \ 2001
In: 'EAAP, Budapest (Hungary),' p. Abstract N1,2
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