Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    We have a manual that explains all the features 

    Records 1 - 20 / 480

    • help
    • print

      Print search results

    • export
      A maximum of 250 titles can be exported. Please, refine your queryYou can also select and export up to 30 titles via your marked list.
    Check title to add to marked list
    Predation and survival in reintroduced populations of the Common hamster Cricetus cricetus in the Netherlands
    Haye, Maurice J.J. La; Kats, Ruud J.M. van; Müskens, Gerard J.D.M. ; Hallmann, Caspar A. ; Jongejans, Eelke - \ 2020
    Mammalian Biology - Zeitschrift für Säugetierkunde (2020). - ISSN 1616-5047
    Predation - Reintroduction - Reproduction - Rodent - Survival - Transmitter

    European populations of Common hamster (Cricetus cricetus) have dramatically declined in the last decades, and in many EU countries, the species is on the brink of extinction. In the Netherlands, a research and reintroduction program was started in three areas with hamster-friendly management to reverse the decline of the species. Since 2002, more than 800 captive-bred and wild-born hamsters were monitored using implant radiotransmitters to quantify survival rates and discover the main causes of death after release compared to those of wild individuals. Individuals with a transmitter were regularly checked at their burrow. Predation by foxes, birds of prey, and small mustelids was the most important cause of mortality of this medium-sized rodent, while crop type and harvest regime were also likely to be important drivers as they influenced survival rates through the presence or absence of protective cover. The fitted weekly survival model showed that male hamsters had much lower survival rates during the active season than females, which corresponds with the ‘risky male hypothesis’. Survival rates of females appeared too low to keep populations at a stable level. To establish a viable population, more optimal environmental conditions for both survival and reproduction of the hamsters are necessary. Using electric fences around fields with hamsters significantly increased the survival of females. However, hamster conservationists need to consider not just subadult and adult survival rates, but also habitat connectivity, weather effects on reproduction, and alternative agricultural practices on a landscape scale.

    Maternal Fecal Microbiota Transplantation in Cesarean-Born Infants Rapidly Restores Normal Gut Microbial Development : A Proof-of-Concept Study
    Korpela, Katri ; Helve, Otto ; Kolho, Kaija Leena ; Saisto, Terhi ; Skogberg, Kirsi ; Dikareva, Evgenia ; Stefanovic, Vedran ; Salonen, Anne ; Andersson, Sture ; Vos, Willem M. de - \ 2020
    Cell 183 (2020)2. - ISSN 0092-8674 - p. 324 - 334.
    cesarean section - clinical trial - colonization - early-life health - fecal microbiota transplantation - maternal seeding - microbiota development - newborn - selective outgrowth - vertical transmission

    A proof-of-concept safety study shows that oral fecal transplantation can shift the microbiome composition of infants who are born via cesarean section to a profile that is more similar to those born via vaginal delivery.

    A Hitchhiker’s guide to the potato wart disease resistance galaxy
    Prodhomme, Charlotte ; Arkel, Gert van; Plich, Jarosław ; Tammes, Jasper E. ; Rijk, Johan ; Eck, Herman J. van; Visser, Richard G.F. ; Vossen, Jack H. - \ 2020
    Theoretical and Applied Genetics 133 (2020)12. - ISSN 0040-5752 - p. 3419 - 3439.

    Key message: Two novel major effect loci (Sen4 and Sen5) and several minor effect QTLs for potato wart disease resistance have been mapped. The importance of minor effect loci to bring full resistance to wart disease was investigated. Using the newly identified and known wart disease resistances, a panel of potato breeding germplasm and Solanum wild species was screened. This provided a state-of-the-art “hitch-hikers-guide” of complementary wart disease resistance sources. Abstract: Potato wart disease, caused by the obligate biotrophic soil-born fungus Synchytrium endobioticum, is the most important quarantine disease of potato. Because of its huge impact on yield, the lack of chemical control and the formation of resting spores with long viability, breeding for resistant varieties combined with strict quarantine measures are the only way to efficiently and durably manage the disease. In this study, we set out to make an inventory of the different resistance sources. Using a Genome-Wide Association Study (GWAS) in the potato breeding genepool, we identified Sen4, associated with pathotypes 2, 6 and 18 resistance. Associated SNPs mapped to the south arm of chromosome 12 and were validated to be linked to resistance in one full-sib population. Also, a bulked segregant analysis combined with a Comparative Subsequence Sets Analysis (CoSSA) resulted in the identification of Sen5, associated with pathotypes 2, 6 and 18 resistance, on the south arm of chromosome 5. In addition to these two major effect loci, the GWAS and CoSSA allowed the identification of several quantitative trait loci necessary to bring full resistance to certain pathotypes. Panels of varieties and Solanum accessions were screened for the presence of Sen1, Sen2, Sen3, Sen4 and Sen5. Combined with pedigree analysis, we could trace back some of these genes to the ancestral resistance donors. This analysis revealed complementary resistance sources and allows elimination of redundancy in wart resistance breeding programs.

    Enduring Behavioral Effects Induced by Birth by Caesarean Section in the Mouse
    Morais, Livia H. ; Golubeva, Anna V. ; Moloney, Gerard M. ; Moya-Pérez, Angela ; Ventura-Silva, Ana Paula ; Arboleya, Silvia ; Bastiaanssen, Thomaz F.S. ; O'Sullivan, Orla ; Rea, Kieran ; Borre, Yuliya ; Scott, Karen A. ; Patterson, Elaine ; Cherry, Paul ; Stilling, Roman ; Hoban, Alan E. ; Aidy, Sahar El; Sequeira, Ana M. ; Beers, Sasja ; Moloney, Rachel D. ; Renes, Ingrid B. ; Wang, Shugui ; Knol, Jan ; Ross, R.P. ; O'Toole, Paul W. ; Cotter, Paul D. ; Stanton, Catherine ; Dinan, Timothy G. ; Cryan, John F. - \ 2020
    Current Biology 30 (2020)19. - ISSN 0960-9822 - p. 3761 - 3774.e6.
    behavior - Caesarean section - co-housing - gut-brain axis - microbiota - microbiota gut-brain axis - prebiotics - probiotics

    Birth by Caesarean (C)-section impacts early gut microbiota colonization and is associated with an increased risk of developing immune and metabolic disorders. Moreover, alterations of the microbiome have been shown to affect neurodevelopmental trajectories. However, the long-term effects of C-section on neurobehavioral processes remain unknown. Here, we demonstrated that birth by C-section results in marked but transient changes in microbiome composition in the mouse, in particular, the abundance of Bifidobacterium spp. was depleted in early life. Mice born by C-section had enduring social, cognitive, and anxiety deficits in early life and adulthood. Interestingly, we found that these specific behavioral alterations induced by the mode of birth were also partially corrected by co-housing with vaginally born mice. Finally, we showed that supplementation from birth with a Bifidobacterium breve strain, or with a dietary prebiotic mixture that stimulates the growth of bifidobacteria, reverses selective behavioral alterations in C-section mice. Taken together, our data link the gut microbiota to behavioral alterations in C-section-born mice and suggest the possibility of developing adjunctive microbiota-targeted therapies that may help to avert long-term negative consequences on behavior associated with C-section birth mode.

    Transforming knowledge systems for life on Earth: Visions of future systems and how to get there
    Fazey, Ioan ; Schäpke, Niko ; Caniglia, Guido ; Hodgson, Anthony ; Kendrick, Ian ; Lyon, Christopher ; Page, Glenn ; Patterson, James ; Riedy, Chris ; Strasser, Tim ; Verveen, Stephan ; Adams, David ; Goldstein, Bruce ; Klaes, Matthias ; Leicester, Graham ; Linyard, Alison ; McCurdy, Adrienne ; Ryan, Paul ; Sharpe, Bill ; Silvestri, Giorgia ; Abdurrahim, Ali Yansyah ; Abson, David ; Adetunji, Olufemi Samson ; Aldunce, Paulina ; Alvarez-Pereira, Carlos ; Amparo, Jennifer Marie ; Amundsen, Helene ; Anderson, Lakin ; Andersson, Lotta ; Asquith, Michael ; Augenstein, Karoline ; Barrie, Jack ; Bent, David ; Bentz, Julia ; Bergsten, Arvid ; Berzonsky, Carol ; Bina, Olivia ; Blackstock, Kirsty ; Boehnert, Joanna ; Bradbury, Hilary ; Brand, Christine ; Böhme (born Sangmeister), Jessica ; Bøjer, Marianne Mille ; Carmen, Esther ; Charli-Joseph, Lakshmi ; Choudhury, Sarah ; Chunhachoti-ananta, Supot ; Cockburn, Jessica ; Colvin, John ; Connon, Irena L.C. ; Cornforth, Rosalind ; Cox, Robin S. ; Cradock-Henry, Nicholas ; Cramer, Laura ; Cremaschi, Almendra ; Dannevig, Halvor ; Day, Catherine T. ; Lima Hutchison, Cathel de; Vrieze, Anke de; Desai, Vikas ; Dolley, Jonathan ; Duckett, Dominic ; Durrant, Rachael Amy ; Egermann, Markus ; Elsner (Adams), Emily ; Fremantle, Chris ; Fullwood-Thomas, Jessica ; Galafassi, Diego ; Gobby, Jen ; Golland, Ami ; González-Padrón, Shiara Kirana ; Gram-Hanssen, Irmelin ; Grandin, Jakob ; Grenni, Sara ; Lauren Gunnell, Jade ; Gusmao, Felipe ; Hamann, Maike ; Harding, Brian ; Harper, Gavin ; Hesselgren, Mia ; Hestad, Dina ; Heykoop, Cheryl Anne ; Holmén, Johan ; Holstead, Kirsty ; Hoolohan, Claire ; Horcea-Milcu, Andra Ioana ; Horlings, Lummina Geertruida ; Howden, Stuart Mark ; Howell, Rachel Angharad ; Huque, Sarah Insia ; Inturias Canedo, Mirna Liz ; Iro, Chidinma Yvonne ; Ives, Christopher D. ; John, Beatrice ; Joshi, Rajiv ; Juarez-Bourke, Sadhbh ; Juma, Dauglas Wafula ; Karlsen, Bea Cecilie ; Kliem, Lea ; Kläy, Andreas ; Kuenkel, Petra ; Kunze, Iris ; Lam, David Patrick Michael ; Lang, Daniel J. ; Larkin, Alice ; Light, Ann ; Luederitz, Christopher ; Luthe, Tobias ; Maguire, Cathy ; Mahecha-Groot, Ana Maria ; Malcolm, Jackie ; Marshall, Fiona ; Maru, Yiheyis ; McLachlan, Carly ; Mmbando, Peter ; Mohapatra, Subhakanta ; Moore, Michele Lee ; Moriggi, Angela ; Morley-Fletcher, Mark ; Moser, Susanne ; Mueller, Konstanze Marion ; Mukute, Mutizwa ; Mühlemeier, Susan ; Naess, Lars Otto ; Nieto-Romero, Marta ; Novo, Paula ; ÓBrien, Karen ; O'Connell, Deborah Anne ; O'Donnell, Kathleen ; Olsson, Per ; Pearson, Kelli Rose ; Pereira, Laura ; Petridis, Panos ; Peukert, Daniela ; Phear, Nicky ; Pisters, Siri Renée ; Polsky, Matt ; Pound, Diana ; Preiser, Rika ; Rahman, Md Sajidur ; Reed, Mark S. ; Revell, Philip ; Rodriguez, Iokiñe ; Rogers, Briony Cathryn ; Rohr, Jascha ; Nordbø Rosenberg, Milda ; Ross, Helen ; Russell, Shona ; Ryan, Melanie ; Saha, Probal ; Schleicher, Katharina ; Schneider, Flurina ; Scoville-Simonds, Morgan ; Searle, Beverley ; Sebhatu, Samuel Petros ; Sesana, Elena ; Silverman, Howard ; Singh, Chandni ; Sterling, Eleanor ; Stewart, Sarah Jane ; Tàbara, J.D. ; Taylor, Douglas ; Thornton, Philip ; Tribaldos, Theresa Margarete ; Tschakert, Petra ; Uribe-Calvo, Natalia ; Waddell, Steve ; Waddock, Sandra ; Merwe, Liza van der; Mierlo, Barbara van; Zwanenberg, Patrick van; Velarde, Sandra Judith ; Washbourne, Carla Leanne ; Waylen, Kerry ; Weiser, Annika ; Wight, Ian ; Williams, Stephen ; Woods, Mel ; Wolstenholme, Ruth ; Wright, Ness ; Wunder, Stefanie ; Wyllie, Alastair ; Young, Hannah R. - \ 2020
    Energy Research & Social Science 70 (2020). - ISSN 2214-6296
    Climate and energy research - Epistemology - Knowledge - Social-technical transitions - Sustainability science - Transformation

    Formalised knowledge systems, including universities and research institutes, are important for contemporary societies. They are, however, also arguably failing humanity when their impact is measured against the level of progress being made in stimulating the societal changes needed to address challenges like climate change. In this research we used a novel futures-oriented and participatory approach that asked what future envisioned knowledge systems might need to look like and how we might get there. Findings suggest that envisioned future systems will need to be much more collaborative, open, diverse, egalitarian, and able to work with values and systemic issues. They will also need to go beyond producing knowledge about our world to generating wisdom about how to act within it. To get to envisioned systems we will need to rapidly scale methodological innovations, connect innovators, and creatively accelerate learning about working with intractable challenges. We will also need to create new funding schemes, a global knowledge commons, and challenge deeply held assumptions. To genuinely be a creative force in supporting longevity of human and non-human life on our planet, the shift in knowledge systems will probably need to be at the scale of the enlightenment and speed of the scientific and technological revolution accompanying the second World War. This will require bold and strategic action from governments, scientists, civic society and sustained transformational intent.

    Morphological changes in secondary, but not primary, sensory cortex in individuals with life-long olfactory sensory deprivation
    Peter, Moa G. ; Mårtensson, Gustav ; Postma, Elbrich M. ; Nordin, Love Engström ; Westman, Eric ; Boesveldt, Sanne ; Lundström, Johan N. - \ 2020
    NeuroImage 218 (2020). - ISSN 1053-8119
    Anosmia - Area - Cortical thickness - Curvature - Morphometry - Plasticity - Voxel-based

    Individuals with congenital sensory deprivation usually demonstrate altered brain morphology in areas associated with early processing of the absent sense. Here, we aimed to establish whether this also applies to individuals born without a sense of smell (congenital anosmia) by comparing cerebral morphology between 33 individuals with isolated congenital anosmia and matched controls. We detected no morphological alterations in the primary olfactory (piriform) cortex. However, individuals with anosmia demonstrated gray matter volume atrophy in bilateral olfactory sulci, explained by decreased cortical area, curvature, and sulcus depth. They further demonstrated increased gray matter volume and cortical thickness in the medial orbital gyri; regions closely associated with olfactory processing, sensory integration, and value-coding. Our results suggest that a lifelong absence of sensory input does not necessarily lead to morphological alterations in primary sensory cortex and extend previous findings with divergent morphological alterations in bilateral orbitofrontal cortex, indicating influences of different developmental processes.

    Experimental Coxiella burnetii infection in non-pregnant goats and the effect of breeding
    Roest, Hendrik I.J. ; Dinkla, Annemieke ; Koets, Ad P. ; Post, Jacob ; Keulen, Lucien Van - \ 2020
    Veterinary Research 51 (2020)1. - ISSN 0928-4249

    Q fever is a zoonosis caused by the intracellular bacterium Coxiella burnetii. In Europe, small ruminants are the main source of human Q fever. Small ruminant herds can be infectious during several lambing seasons. However, it is not clear how infection is maintained in a herd and what role non-pregnant animals play in the transmission of C. burnetii. We therefore inoculated nulliparous goats with C. burnetii, isolated from the outbreak of Q fever in the Netherlands, to gain a better understanding of the role of non-pregnant goats. Seroconversion and excretion of C. burnetii were monitored after inoculation. To study the effect of breeding on the excretion of C. burnetii, the goats were naturally bred and monitored during gestation and after lambing. Our results indicate that C. burnetii infection prior to breeding did not result in infection of the placenta nor did it affect the gestation length or the number of kids born. However, one of the ten does did excrete C. burnetii in the colostrum post-partum and the bacterium was detected in the mammary gland and associated lymph nodes at necropsy. This result indicates that non-pregnant goats might play a role in maintaining Q fever in a goat herd as persistent carriers of infection.

    Variance estimates are similar using pedigree or genomic relationships with or without the use of metafounders or the algorithm for proven and young animals
    Aldridge, Michael N. ; Vandenplas, Jérémie ; Bergsma, Rob ; Calus, Mario P.L. - \ 2020
    Journal of Animal Science 98 (2020)3. - ISSN 0021-8812
    pigs - restricted maximum likelihood - single step - variance components

    With an increase in the number of animals genotyped there has been a shift from using pedigree relationship matrices (A) to genomic ones. As the use of genomic relationship matrices (G) has increased, new methods to build or approximate G have developed. We investigated whether the way variance components are estimated should reflect these changes. We estimated variance components for maternal sow traits by solving with restricted maximum likelihood, with four methods of calculating the inverse of the relationship matrix. These methods included using just the inverse of A (A-1), combining A-1 and the direct inverse of G (HDIRECT-1), including metafounders (HMETA-1), or combining A-1 with an approximated inverse of G using the algorithm for proven and young animals (HAPY-1). There was a tendency for higher additive genetic variances and lower permanent environmental variances estimated with A-1 compared with the three H-1 methods, which supports that G-1 is better than A-1 at separating genetic and permanent environmental components, due to a better definition of the actual relationships between animals. There were limited or no differences in variance estimates between HDIRECT-1, HMETA-1, and HAPY-1. Importantly, there was limited differences in variance components, repeatability or heritability estimates between methods. Heritabilities ranged between <0.01 to 0.04 for stayability after second cycle, and farrowing rate, between 0.08 and 0.15 for litter weight variation, maximum cycle number, total number born, total number still born, and prolonged interval between weaning and first insemination, and between 0.39 and 0.44 for litter birth weight and gestation length. The limited differences in heritabilities suggest that there would be very limited changes to estimated breeding values or ranking of animals across models using the different sets of variance components. It is suggested that variance estimates continue to be made using A-1, however including G-1 is possibly more appropriate if refining the model, for traits that fit a permanent environmental effect.

    Bridging youth and gender studies to analyse rural young women and men's livelihood pathways in Central Uganda
    Rietveld (Anne), A.M. ; Burg, M. van der; Groot, J.C.J. - \ 2020
    Journal of Rural Studies 75 (2020). - ISSN 0743-0167 - p. 152 - 163.
    Agriculture - Gender norms - Intersectionality - Migration - Opportunity space - Rural economy - Young people

    Many development countries are currently undergoing major demographic shifts as the percentage of young people of the total population rapidly increases. This shift is associated with high rates of migration, unemployment and instability. In policy discourses, engaging youth in commercial agricultural is often presented as a measure to control or even counter these trends. In Uganda, a country with one of the youngest populations in the world, we investigated whether young people themselves see a career in farming as an option. We studied the livelihood pathways of rural-born young men and women from Central Uganda and in particular; 1) their aspirations, 2) the extent to which these aspirations are associated with agriculture, and 3) the importance of gender in shaping their opportunity spaces. Data consisted of in-depth interviews with 8 young men and 8 young women originating from the same rural community in Central Uganda (2017) and was supported by three additional datasets collected between 2010 and 2014; one qualitative case-study conducted in the same site (2014) and two survey datasets collected in three rural sites in Central Uganda in 2010 (N = 199) and 2012 (N = 54). Our findings suggest a large proportion of youth out-migrating from the rural communities, with young women migrating more often than young men. Farming was seldom an aspiration but irrespective of sex or residence most young men and women did remain engaged in agriculture in some way. The nature of the engagement was different for men and women though, with young women specifically refraining from commercial agriculture. By analyzing the opportunity space of young men and women, we uncovered how their livelihood pathways were linked to a set of normative and structural constraints maintaining gender inequality. Examples were young women's weaker resource base (land) and gender norms which discourage young women's independent commercial (agricultural) activities. To advance the engagement of young men and especially women in commercial agriculture, it is important to acknowledge these patterns and their underlying structural gender differences.

    Estimation of litter size variability phenotypes in Large White sows
    Dobrzański, Jan ; Mulder, Han A. ; Knol, Egbert F. ; Szwaczkowski, Tomasz ; Sell-Kubiak, Ewa - \ 2020
    Journal of Animal Breeding and Genetics 137 (2020)6. - ISSN 0931-2668 - p. 559 - 570.
    pigs - reproductive traits - total number born - trait's variation

    The objective of this study was to obtain new phenotypes of phenotypic variability for the total number born (TNB) in pigs using the residual variance of TNB. The analysis was based on 246,799 Large White litter observations provided by Topigs Norsvin. Three animal models were used to obtain estimates of residual variance for TNB: the basic model (BM) containing fixed effects of farm–year and season and random effects of animal and permanent environmental sow, the basic model with an additional fixed effect of parity (BMP) and a random regression model (RRM). The within-individual variance of the residuals was calculated and log-transformed to obtain three new variability traits: LnVarBM, LnVarBMP and LnVarRRM. Then, (co)variance components, heritability, the genetic coefficient of variation at the standard deviation level (GCVSDe) and genetic correlations between the three LnVar's and between the LnVar's and mean total number born (mTNB) were estimated with uni-, bi- and trivariate models. Results indicated that genetically LnVar's are the same trait and are positively correlated with the mTNB (~0.60). Thus, both traits should be included in breeding programmes to avoid an increase in TNB variability while selecting for increased TNB. Heritability of the LnVar's was estimated at 0.021. The GCVSDe for LnVar's showed that a change of 8% in residual standard deviation of TNB could be obtained per generation. Those results indicate that phenotypic variability of litter size is under genetic control, thus it may be improved by selection.

    In utero behavioral imprinting to predation risk in pups of the bank vole
    Sievert, Thorbjörn ; Kerkhoven, Arjane ; Haapakoski, Marko ; Matson, Kevin D. ; Ylönen, Olga ; Ylönen, Hannu - \ 2020
    Behavioral Ecology and Sociobiology 74 (2020)2. - ISSN 0340-5443
    Alarm pheromone - Cross-generational effects - Odor - Olfaction - Predation risk

    Abstract: In the predator–prey arms race, survival-enhancing adaptive behaviors are essential. Prey can perceive predator presence directly from visual, auditory, or chemical cues. Non-lethal encounters with a predator may trigger prey to produce special body odors, alarm pheromones, informing conspecifics about predation risks. Recent studies suggest that parental exposure to predation risk during reproduction affects offspring behavior cross-generationally. We compared behaviors of bank vole (Myodes glareolus) pups produced by parents exposed to one of three treatments: predator scent from the least weasel (Mustela nivalis nivalis); scent from weasel-exposed voles, i.e., alarm pheromones; or a control treatment without added scents. Parents were treated in semi-natural field enclosures, but pups were born in the lab and assayed in an open-field arena. Before each behavioral test, one of the three scent treatments was spread throughout the test arena. The tests followed a full factorial design (3 parental treatments × 3 area treatments). Regardless of the parents’ treatment, pups exposed to predator odor in the arena moved more. Additionally, pups spend more time in the center of the arena when presented with predator odor or alarm pheromone compared with the control. Pups from predator odor–exposed parents avoided the center of the arena under control conditions, but they spent more time in the center when either predator odor or alarm pheromone was present. Our experiment shows that cross-generational effects are context-sensitive, depending on the perceived risk. Future studies should examine cross-generational behavioral effects in ecologically meaningful environments instead of only neutral ones. Significance statement: We exposed bank voles to odors signaling predation risk to assess the effects parental predation exposure on the behavior of their offspring. Besides predator odor, we also assessed the role of a conspecific alarm cue as a novel way of spreading the predation risk information. Pup behaviors were assessed in the open-field arena, a standard way of assessing animal behavior in a wide range of contexts. We found that also alarm pheromone increased the time pups spend in the center of the arena similarly to predator odor. While previous studies suggested that offspring would be more fearful, our results indicate that the cross-generational effects are very context-dependent; i.e., they differ significantly depending on which scent cue is presented in the open-field arena. This shows the need for better tools or measurements to translate laboratory results into ecologically meaningful frameworks.

    Machine learning to further improve the decision which boar ejaculates to process into artificial insemination doses
    Kamphuis, Claudia ; Duenk, Pascal ; Veerkamp, Roel Franciscus ; Visser, Bram ; Singh, Gurnoor ; Nigsch, Annette ; Mol, Rudi Maria De; Broekhuijse, Marleen Leonarda Wilhelmina Johanna - \ 2020
    Theriogenology 144 (2020). - ISSN 0093-691X - p. 112 - 121.
    Boar semen - Fertility phenotypes - Machine learning - Prediction model

    Current artificial insemination (AI) laboratory practices assess semen quality of each boar ejaculate to decide which ones to process into AI doses. This decision is aided with two, world-wide used, motility parameters that come available through computer assisted semen analysis (CASA). This decision process, however, still results in AI doses with variable and sometimes suboptimal fertility outcomes (e.g., small litter size). The hypothesis was that the decision which ejaculates to process into AI doses can be improved by adding more data from CASA systems, and data from other sources, in combination with a data-driven model. Available data consisted of ejaculates that passed the initial decision, and thus, were processed into AI doses and used to inseminate sows. Data were divided into a training set (6793 records) and a validation set (1191 records) for model development, and an independent test set (1434 records) for performance assessment. Gradient Boosting Machine (GBM) models were developed to predict four fertility phenotypes of interest (gestation length, total number born, number born alive, and number of stillborn piglets). Each fertility phenotype was considered as a numeric and as a binary outcome parameter, totaling to eight different fertility phenotypes. Data used to further improve the decision process originated from four sources: 1) CASA information, 2) boar ejaculate information, 3) breeding value estimations, and 4) weather information. These data were used to create seven prediction sets, where each new set added parameters to the ones included in the previous set. The GBM models predicted fertility phenotypes with low correlations (for numeric phenotypes) and area under the curve values (for binary phenotypes) on the test data. Hence, results demonstrated that a combination of more data and GBM did not enable further improvement of the AI dose quality checks, resulting in the rejection of our hypothesis. However, our study revealed parameters affecting boar ejaculate fertility which were not used in today's decision process. These parameters (listed in the top 10 in at least four GBM models) included one parameter associated with boar ejaculate information, two with breeding value estimations, five with CASA information, and one with weather information. These parameters, therefore, should be further investigated for their potential value when assessing the quality of boar ejaculates in daily routine AI doses processing.

    Improvisation and harm avoidance: An ethnographic study of adherence to postnatal care protocols in two hospitals in Southern Ghana
    Yevoo, Linda L. ; Agyepong, Irene A. ; Gerrits, Trudie ; Dijk, Han van - \ 2020
    Midwifery 82 (2020). - ISSN 0266-6138
    Ethnography - Harm avoidance - Improvisation - Postnatal care - Protocols

    Providers’ adherence to case management protocols can affect quality of care. However, how and why protocols are adhered to by frontline health workers in low- and middle-income countries is not always clear. This study explored midwives’ adherence to national postnatal care protocols in two public hospitals in Southern Ghana using an ethnographic study design. Ninety participant observations and 88 conversations were conducted over a 20-months period, and two group interviews held with the midwives in the two hospitals. Data was analysed using a grounded theory approach. Findings: Midwives collectively decided when to adhere, modify or totally ignore postnatal care protocols. Adherence often occurred if required resources (equipment, tools, supplies) were available. Modification occurred when midwives felt that strict adherence could have negative implications for patients and they could be seen as acting ‘unprofessionally’. Ignoring or modifying protocols also occurred when midwives were uncertain of the patient's health condition; basic supplies, logistics and infrastructure needed for adherence were unavailable or inappropriate; or midwives felt they might expose themselves or their clients to physical, psychological, emotional, financial or social harm. Regardless of the reasons that midwives felt justified to ignore or modify postnatal care protocols, it appeared in many instances to lead to the provision of care of suboptimal quality. Conclusion and recommendations: Providing clinical decision-making protocols is not enough to improve mother and new born care quality and outcomes. Faced with constraining conditions of work, providers are likely to modify guidelines as part of coping behaviour. Addressing constraining conditions of work must accompany guidelines. This includes adequate risks protection for health workers and clients; and resolution of deficits in essential equipment, infrastructure, supplies and staffing.

    Born migrators: Historical biogeography of the cosmopolitan family Cannabaceae
    Jin, Jian Jun ; Yang, Mei Qing ; Fritsch, Peter W. ; Velzen, Robin van; Li, De Zhu ; Yi, Ting Shuang - \ 2020
    Journal of Systematics and Evolution 58 (2020)4. - ISSN 1674-4918 - p. 461 - 473.
    ancestral geographical range analysis - Cannabaceae - dispersal - molecular dating - Northern Hemisphere - phylogeny

    Dispersal scenarios have been favored over tectonic vicariance as an explanation for disjunct distributions in many plant taxa during the last two decades. However, this argument has been insufficiently addressed in cosmopolitan groups showing disjunct patterns in both the temperate and tropical regions. In this study, we used the Cannabaceae, an angiosperm family distributed in tropical and temperate regions of both the New World and the Old World, to explore the role of dispersal in shaping disjunct patterns and species diversification of cosmopolitan plants. We reconstructed the phylogenetic relationships of all 10 genera and 75 species of Cannabaceae (ca. 64.1% of recognized species) based on eight DNA regions. Based on fossil calibrations, we estimated the divergence times and net diversification rates. We further inferred the ancestral geographical ranges with several models and compared the fitness of different models. The Cannabaceae and most genera were strongly supported as monophyletic except for the Parasponia being embedded within the Trema. The Celtis were resolved into two strongly supported clades primarily corresponding to temperate and tropical regions. We inferred that the Cannabaceae originated at ca. 93 Ma, and that subsequent rampant and widespread dispersals shaped the intercontinentally disjunct distribution of the Cannabaceae. Dispersal coincides with adaptation to drier and colder climate in the Northern Hemisphere, or humid and warm climate in the tropical regions, followed by rapid species diversification. This study advances our understanding as to the formation of distribution patterns and species diversification of a plant family with tropical to temperate disjunct distributions.

    Youngest versus oldest child: why does mothers’ snack choice differ?
    Damen, Femke W.M. ; Steenbekkers, Bea L.P.A. ; Fogliano, Vincenzo ; Luning, Pieternel A. - \ 2020
    Appetite 144 (2020). - ISSN 0195-6663
    Birth order - Child dietary behavior - Family structure - Food choice - Sibling - Snack foods

    Young children frequently consume energy dense snacks, which is one of the factors contributing to childhood overweight. The consumption of more healthy snacks could help in meeting the dietary intake requirements of children. Previous research suggested that mothers of first children showed more health-conscious food behavior compared to mothers of not-first children. However, what is missing from earlier research is an in-depth exploration of differences in considerations to choose a snack and the reasons connected. Therefore, this study aims to characterize differences in mothers' snack choice for their youngest child at 2–3 years and their oldest child when he/she was of the same age. Moreover, this study aims to identify reasons for these differences. A grounded theory approach was used for data collection and analysis. Semi-structured interviews were carried out with 17 Dutch mothers with two or three children. All mothers indicated differences between snacks provided to their youngest child (2–3 years) and their oldest child when it was of the same age. Most frequently mentioned differences were youngest children receive unhealthy snacks at a younger age, the structure regarding snack providing is more fixed, and that youngest children receive less age-specific snacks. Most frequently mentioned reasons for these differences were role-modelling, novelty of the first-born, availability of other types of snacks at home, and school hours of the oldest child. The study provided insights into the possible role of siblings in shaping snack consumption. Results might be relevant for the development of intervention strategies to increase mothers' awareness and to help to meet children's dietary requirements.

    Genome-wide association study in newborn calf serum reveals QTL for natural antibodies in Swedish dairy cattle
    Cordero Solorzano, Juan ; Wensman, J.J. ; Tråvén, M. ; Arts, J.A.J. ; Parmentier, H.K. ; Bovenhuis, H. ; Koning, Dirk Jan De - \ 2019
    Failure of passive transfer (FPT) occurs when a newborn calf does not absorb enough antibodies (<10 g/l of IgG) from the colostrum. Some calves absorb antibodies very effectively while others do not. This difference in uptake cannot be explained solely by the time, amount and quality of the colostrum given. Natural antibodies (NAb) are produced without any antigenic stimulation and target self-antigens and pathogen-associated molecular patterns (PAMPs). Our objective was to estimate genetic parameters and detect quantitative trait loci (QTL) for three NAb isotypes (IgG, IgM and IgA) in newborn calf serum binding keyhole limpet hemocyanin (KLH) and muramyl dipeptide (MDP). Two experimental farms were included in the study. Serum samples were collected from 831 calves between 2 to 7 days old, born from January 2015 to April 2017. 70% of the animals were Swedish Red and 30% Swedish Holstein. Antibodies were measured from serum using indirect ELISAs. To estimate genetic parameters, a linear mixed model was run, correcting for antibody concentration of colostrum given, volume of first meal, time of birth to blood sampling time, weight at birth and breed, including genetic effect, maternal effect and Herd-Year-Season of calving with sample storage plate as random effects. An imputed 50K SNP array from a LD 7K array was used for the Genome-wide association study (GWAS), running the same model but including the SNP genotype as a fixed effect. Heritabilities for NAb isotypes in newborn calf serum ranged from 0.20 to 0.53, with a maternal effect ranging from 5 to 30%. Genetic correlations between IgM and IgA ranged from 0.74 to 0.94. The GWAS revealed one QTL on BTA1 for MDP-IgG, comprised of 3 SNPs (-log10(p) = 5.9), one significant and two suggestive, ranging from 1-8 Mbp and another QTL on BTA3 for IgM (KLH and MDP) consisting of 2 suggestive SNPs (-log10(p) = 5.02), from 13-25 Mbp. Our results suggest that natural antibodies can potentially provide an effective tool to reduce FPT using genetic selection.
    Different models for estimation of litter size variability phenotypes
    Dobrzanski, J. ; Mulder, H.A. ; Knol, Egbert ; Szwaczkowski, T. ; Sell-Kubiak, E.B. - \ 2019
    - p. 186 - 186.
    Selection to increase litter size in pigs has simultaneously increased its variability. In Large White differences in litter size between sows can be larger than 20 piglets, which causes additional labour and affects welfare of animals.
    Thus there is a need to dene phenotypes describing variability of litter size in order to reduce it. The main objective of this study was to obtain and compare new phenotypes of phenotypic variability of total number born (TNB) by
    using the residual variance of TNB. The dataset contained 246,799 litter observations from 53,803 sows from Topigs
    Norsvin multiplication farms. Three models were used to obtain estimates of residual variance for TNB in ASReml 4.1: basic (BM), basic with parity as fixed effect (BMP), and random regression (RRM). The within individual’s variance of the residuals was calculated and log-transformed, to obtain three new variability traits: LnVarBM, LnVarBMP and LnVarRRM. Then, variance components, heritability (h2), genetic coefficient of variation (GCV) and genetic correlations (r
    g) between LnVar’s and between LnVar’s and mean TNB were estimated with multi-variate models. Results for additive genetic component (0.026-0.028), residuals (1.23-1.29), h2 (0.02) and GCV (0.081-0.083) indicated that LnVar’s as variability phenotype were robust and not affected by model applied for
    their estimation. Furthermore, rg between additive genetic components of LnVar’s (~0.98) proved that genetically LnVar’s are the same trait. The positive r
    g between LnVar’s and mean TNB (~0.60) conrmed that selection for
    increased TNB increases its variability. Whereas GCV for LnVar’s indicated that TNB variability can be reduced by 1.1 piglet within four generations. These results indicate that phenotypic variability of litter size is under genetic
    control and could be reduced by selection. The project was nanced by Polish National Center for Science (grant no. 2016/23/D/NZ9/00029).

    The age difference between spouses and reproduction in 19th century Sweden
    Rotering, P.P.P. ; Bras, H.A.J. - \ 2019
    Demographic Research 41 (2019). - ISSN 1435-9871 - p. 1059 - 1090.
    Background: The influence of spousal relations on reproductive outcomes has received considerable attention in the demographic literature. Previous studies have shown the complex interplay between age difference, female autonomy, and reproductive outcomes, but only a few have focused on historical high-fertility populations.

    Objective: This study investigates the associations between spousal age difference and the timing of first and higher order births, as well as the total number of children born.

    Methods: Data from the Demographic Data Base (married women, born between 1840 and 1889, first marriages only) are used to construct individual life courses in central and northern Sweden. The relative risk of age-homogamous and age-heterogamous couples having a child is examined using event history analysis. Poisson regression is applied to identify the effects of age difference on the total number of children born.

    Results: After controlling for the age of the wife, women in wife-older marriages show higher hazard rates for the transition to first and later order births compared to women in age-homogamous marriages. By contrast, women in husband-older marriages show lower hazard rates for the transition between births, with the exception of first childbirth. However, the net effect of spousal age difference on the total number of children ever born is small.

    Contribution: This study provides empirical evidence of the association between spousal age gap and fertility outcomes, using the spousal age gap as a proxy for conjugal power. It shows that women in wife-older marriages used their greater female autonomy to shorten the interval between childbirths, although the effect on the total number of children born is negligible.
    A risk based surveillance programme for Toxoplasma gondii in pigs using a combination of farm auditing and serological screening
    Wisselink, H.J. ; Swanenburg, M. ; Gonzales Rojas, Jose ; Asseldonk, M.A.P.M. van; Wagenberg, Coen van; Giessen, J. van der; Meerburg, B.G. ; Krijger, Inge ; Eppink, D.M. ; Bouwknegt, M. ; Oorburg, D. - \ 2019
    Toxoplasma gondii is recognized as one of the major foodborne pathogens with a high human disease burden. In the Netherlands, pork contributes to about 11 % of the meatborne T. gondii infections. To control T. gondii infections in pigs, EFSA has advised to perform serological testing of pigs and audits of pig farms on risk factors for T. gondii infection. In the Netherlands, a program was started to translate the EFSA advice into a practical risk based surveillance system. In first instance, a large scale serological monitoring of fattening pigs was started and seroprevalence over time was determined. Next, the association between within-herd seroprevalence and risk factors for T. gondii on fattening pig farms in the Netherlands was determined. For this, a questionnaire for auditing farms for the presence of risk factors of T. gondii was developed and used on 25 case and 50 control farms. Results show that there is a significant association between seroprevalence and risk factors as cats present on farms, use of unheated feed products and feeding wet feed. Moreover, on-farm presence of rats and mice also increases Toxoplasma transmission risks. Subsequently, a study was started on farms to quantify the effectiveness of interventions on farms. A cross-over clinical trial was set up in which case farms were their own control and the cross-over moment is the implementation of interventions on risk factors to change farm management. Farms with a high within-herd seroprevalence were followed for at least during a year and monitored periodically for seroprevalence and implementation of interventions to eventually reduce the disease burden. The break-even point was calculated for which the intervention cost at fattening pig farms equal averted human disease burden and averted cost-of-illness minus cost of the surveillance program. The results shows favourable economic perspectives for interventions to control pig meat-born transmission of T. gondii.
    Boosted trees to predict pneumonia, growth, and meat percentage of growing-finishing pigs
    Mollenhorst, Herman ; Ducro, Bart J. ; Greef, Karel H. de; Hulsegge, Ina ; Kamphuis, Claudia - \ 2019
    Journal of Animal Science 97 (2019)10. - ISSN 0021-8812 - p. 4152 - 4159.
    boosted trees - growth - machine learning - pig production - pneumonia

    In pig production, efficiency is benefiting from uniform growth in pens resulting in single deliveries from a pen of possibly all animals in the targeted weight range. Abnormalities, like pneumonia or aberrant growth, reduce production efficiency as it reduces the uniformity and might cause multiple deliveries per batch and pigs delivered with a low meat yield or outside the targeted weight range. Early identification of pigs prone to develop these abnormalities, for example, at the onset of the growing-finishing phase, would help to prevent heterogeneous pens through management interventions. Data about previous production cycles at the farm combined with data from the piglet's own history may help in identifying these abnormalities. The aim of this study, therefore, was to predict at the onset of the growing-finishing phase, that is, at 3 mo in advance, deviant pigs at slaughter with a machine-learning technique called boosted trees. The dataset used was extracted from the farm management system of a research center. It contained over 70,000 records of individual pigs born between 2004 and 2016, including information on, for example, offspring, litter size, transfer dates between production stages, their respective locations within the barns, and individual live-weights at several production stages. Results obtained on an independent test set showed that at a 90% specificity rate, the sensitivity was 16% for low meat percentage, 20% for pneumonia and 36% for low lifetime growth rate. For low lifetime growth rate, this meant an almost three times increase in positive predictive value compared to the current situation. From these results, it was concluded that routine performance information available at the onset of the growing-finishing phase combined with data about previous production cycles formed a moderate base to identify pigs prone to develop pneumonia (AUC > 0.60) and a good base to identify pigs prone to develop growth aberrations (AUC > 0.70) during the growing-finishing phase. The mentioned information, however, was not a sufficient base to identify pigs prone to develop low meat percentage (AUC < 0.60). The shown ability to identify growth aberrations and pneumonia can be considered a good first step towards the development of an early warning system for pigs in the growing-finishing phase.

    Check title to add to marked list
    << previous | next >>

    Show 20 50 100 records per page

    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.