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 

    Current refinement(s):

    Records 1 - 20 / 183

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    Seasonal morphotypes of Drosophila suzukii differ in key life-history traits during and after a prolonged period of cold exposure
    Panel, Aurore D.C. ; Pen, Ido ; Pannebakker, Bart A. ; Helsen, Herman H.M. ; Wertheim, Bregje - \ 2020
    Ecology and Evolution (2020). - ISSN 2045-7758
    Drosophila suzukii - fertility - life history - overwintering - reproduction - seasonal polyphenism - spotted-wing drosophila - survival

    Seasonal polyphenism in Drosophila suzukii manifests itself in two discrete adult morphotypes, the “winter morph” (WM) and the “summer morph” (SM). These morphotypes are known to differ in thermal stress tolerance, and they co-occur during parts of the year. In this study, we aimed to estimate morph-specific survival and fecundity in laboratory settings simulating field conditions. We specifically analyzed how WM and SM D. suzukii differed in mortality and reproduction during and after a period of cold exposure resembling winter and spring conditions in temperate climates. The median lifespan of D. suzukii varied around 5 months for the WM flies and around 7 months for the SM flies. WM flies showed higher survival during the cold-exposure period compared with SM flies, and especially SM males suffered high mortality under these conditions. In contrast, SM flies had lower mortality rates than WM flies under spring-like conditions. Intriguingly, reproductive status (virgin or mated) did not impact the fly survival, either during the cold exposure or during spring-like conditions. Even though the reproductive potential of WM flies was greatly reduced compared with SM flies, both WM and SM females that had mated before the cold exposure were able to continuously produce viable offspring for 5 months under spring-like conditions. Finally, the fertility of the overwintered WM males was almost zero, while the surviving SM males did not suffer reduced fertility. Combined with other studies on D. suzukii monitoring and overwintering behavior, these results suggest that overwintered flies of both morphotypes could live long enough to infest the first commercial crops of the season. The high mortality of SM males and the low fertility of WM males after prolonged cold exposure also highlight the necessity for females to store sperm over winter to be able to start reproducing early in the following spring.

    Genetic parameters for atypical reproductive patterns in dairy cows estimated from in-line milk progesterone profiles
    Binsbergen, R. van; Bouwman, A.C. ; Veerkamp, R.F. - \ 2019
    Journal of Dairy Science 102 (2019)12. - ISSN 0022-0302 - p. 11104 - 11115.
    endocrine - fertility - genetic correlation - heritability

    Our aim was to estimate genetic parameters of atypical reproductive patterns and estimate their genetic correlation with milk production and classical fertility traits for commercial dairy cows. In contrast with classical fertility traits, atypical reproductive patterns based on in-line milk progesterone profiles might have higher heritability and lower genetic correlation with milk production. We had in-line milk progesterone profiles available for 12,046 cycles in 4,170 lactations of 2,589 primiparous and multiparous cows (mainly Holstein Friesian) from 14 herds. Based on progesterone profiles, 5 types of atypical reproductive patterns in a lactation were defined: delayed ovulation types I and II, persistent corpus luteum types I and II, and late embryo mortality. These atypical patterns were detected in 14% (persistent corpus luteum type II) to 21% (persistent corpus luteum type I) of lactations. In 47% of lactations, at least 1 atypical pattern was detected. Threshold model heritabilities for atypical reproduction patterns ranged between 0.03 and 0.14 and for most traits were slightly higher compared with classical fertility traits. The genetic correlation between milk yield and calving interval was 0.56, whereas genetic correlations between milk yield and atypical reproductive patterns ranged between −0.02 and 0.33. Although most of these correlations between milk yield and atypical reproductive patterns are still unfavorable, they are lower compared with the correlations between classical fertility traits and milk yield. Therefore selection against atypical reproductive patterns may relax some constraints in current dairy breeding programs, to enhance genetic progress in both fertility and milk yield at a steady pace. However, as long as the target trait for fertility is calving interval, atypical reproductive patterns will not add additional value to the breeding goal in the near future due to the low number of available records.

    Milk progesterone measures to improve genomic selection for fertility in dairy cows
    Tenghe, Amabel Manyu Mefru - \ 2017
    Wageningen University. Promotor(en): R.F. Veerkamp; B. Berglund, co-promotor(en): D. J. de Koning; A.C. Bouwman. - Wageningen : Wageningen University - ISBN 9789463431330 - 179
    dairy cows - fertility - progesterone - milk - genomics - genetic improvement - heritability - genetic parameters - dairy performance - reproductive traits - animal genetics - animal breeding - dairy farming - melkkoeien - vruchtbaarheid - progesteron - melk - genomica - genetische verbetering - heritability - genetische parameters - melkresultaten - voortplantingskenmerken - diergenetica - dierveredeling - melkveehouderij

    Improved reproductive performance has a substantial benefit for the overall profitability of dairy cattle farming by decreasing insemination and veterinary treatment costs, shortening calving intervals, and lowering the rate of involuntary culling. Unfortunately, the low heritability of classical fertility traits derived from calving and insemination data makes genetic improvement by traditional animal breeding slow. Therefore, there is an interest in finding novel measures of fertility that have a higher heritability or using genomic information to aid genetic selection for fertility. The overall objective of this thesis was to explore the use of milk progesterone (P4) records and genomic information to improve selection for fertility in dairy cows. In a first step, the use of in-line milk progesterone records to define endocrine fertility traits was investigated, and genetic parameters estimated. Several defined endocrine fertility traits were heritable, and showed a reasonable repeatability. Also, the genetic correlation of milk production traits with endocrine fertility traits were considerably lower than the correlations of milk production with classical fertility traits. In the next step 17 quantitative trait loci (QTL) associated with endocrine fertility traits, were identified on Bos taurus autosomes (BTA) 2, 3, 8, 12, 15, 17, 23, and 25 in a genome-wide association study with single nucleotide polymorphisms. Further, fine-mapping of target regions on BTA 2 and 3, identified several associated variants and potential candidate genes underlying endocrine fertility traits. Subsequently, the optimal use of endocrine fertility traits in genomic evaluations was investigated; using empirical and theoretical predictions for single-trait models, I showed that endocrine fertility traits have more predictive ability than classical fertility traits. The accuracy of genomic prediction was also substantially improved when endocrine and classical fertility traits were combined in multi-trait genomic prediction. Finally, using deterministic predictions, the potential accuracy of multi-trait genomic selection when combining a cow training population measured for the endocrine trait commencement of luteal activity (C-LA), with a training population of bulls with daughter observations for a classical fertility trait was investigated. Results showed that for prediction of fertility, there is no benefit of investing in a cow training population when the breeding goal is based on classical fertility traits. However, when considering a more biological breeding goal for fertility like C-LA, accuracy is substantially improved when endocrine traits are available from a limited number of farms.

    Mineral nutrition of cocoa : a review
    Vliet, J.A. van; Slingerland, M.A. ; Giller, K.E. - \ 2015
    Wageningen : Wageningen UR - ISBN 9789462577053 - 57
    cacao - mineralenvoeding - bevruchting - kunstmeststoffen - mestbehoeftebepaling - vruchtbaarheid - voedingsstoffenbehoeften - voedingsstoffenbeschikbaarheid - grondanalyse - voedingsstoffentekorten - kaliummeststoffen - stikstofmeststoffen - fosformeststoffen - agrarische productiesystemen - overzichten - cocoa - mineral nutrition - fertilization - fertilizers - fertilizer requirement determination - fertility - nutrient requirements - nutrient availability - soil analysis - nutrient deficiencies - potassium fertilizers - nitrogen fertilizers - phosphorus fertilizers - agricultural production systems - reviews
    This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?
    Deriving estimates of individual variability in genetic potentials of performance traits for 3 dairy breeds, using a model of lifetime nutrient partitioning
    Phuong, H.N. ; Boer, I.J.M. de; Schmidely, P. ; Friggens, N.C. ; Martin, O. - \ 2015
    Journal of Dairy Science 98 (2015)1. - ISSN 0022-0302 - p. 618 - 632.
    repeated reproductive-cycles - milk-yield - lactating cow - holstein cows - body-size - cattle - parameters - efficiency - fertility - genotype
    This study explored the ability of an existing lifetime nutrient partitioning model for simulating individual variability in genetic potentials of dairy cows. Generally, the model assumes a universal trajectory of dynamic partitioning of priority between life functions and genetic scaling parameters are then incorporated to simulate individual difference in performance. Data of 102 cows including 180 lactations of 3 breeds: Danish Red, Danish Holstein, and Jersey, which were completely independent from those used previously for model development, were used. Individual cow performance records through sequential lactations were used to derive genetic scaling parameters for each animal by calibrating the model to achieve best fit, cow by cow. The model was able to fit individual curves of body weight, and milk fat, milk protein, and milk lactose concentrations with a high degree of accuracy. Daily milk yield and dry matter intake were satisfactorily predicted in early and mid lactation, but underpredictions were found in late lactation. Breeds and parities did not significantly affect the prediction accuracy. The means of genetic scaling parameters between Danish Red and Danish Holstein were similar but significantly different from those of Jersey. The extent of correlations between the genetic scaling parameters was consistent with that reported in the literature. In conclusion, this model is of value as a tool to derive estimates of genetic potentials of milk yield, milk composition, body reserve usage, and growth for different genotypes of cow. Moreover, it can be used to separate genetic variability in performance between individual cows from environmental noise.
    Biochar: An emerging policy arrangement in Brazil?
    Francischinelli Rittl, T. ; Arts, B.J.M. ; Kuyper, T.W. - \ 2015
    Environmental Science & Policy 51 (2015). - ISSN 1462-9011 - p. 45 - 55.
    network analysis - amazon region - soil - carbon - charcoal - availability - centrality - fertility - ferralsol - manure
    Biochar, the solid product of pyrolysis, has emerged as a new technology and policy tool to address various environmental challenges (climate change, food production and Agricultural waste management). The concept of biochar drew its inspiration from Amazonian practices that had led to the creation of Amazonian Dark Earth (ADE): fertile soils rich in (bio)char and human artefacts. In this article, we conceptualize biochar as an emerging policy arrangement, and examine it along the four dimensions of the Policy Arrangement Approach (PAA), which are actors, discourse, power and rules. We focus on Brazil as an important player in the international biochar debate. Our analysis shows that science experts are the predominant players in the network, while policy-makers, businessmen and farmers are marginally positioned. Experts from Embrapa occupy central positions and thus exercise most power in the network. Moreover, experts linked to ADE have lost prominence in the network. The reason for this is to be found in the shift from the ADE/ biochar to the biochar/technology discourse. The latter discourse includes different coalitions such as ‘climate change mitigation’, the ‘improvement of soil fertility’ and ‘improving crop residue management’. Although the biochar/climate coalition is dominant at the international level, it is far less prominent in Brazil. Nationally, it is particularly the discourses of ‘improvement of soil fertility’ and ‘improving crop residue management’ which have prompted actors’ relationships and practices. However, the biochar/technology discourse has not (yet) been formally institutionalized in Brazil. As a consequence, the country lacks an established biochar policy field.
    The optimal number of heifer calves to be reared as dairy replacements
    Mohd Nor, N. ; Steeneveld, W. ; Mourits, M.C.M. ; Hogeveen, H. - \ 2015
    Journal of Dairy Science 98 (2015)2. - ISSN 0022-0302 - p. 861 - 871.
    holstein-friesian heifers - genomic selection - simulation-model - rearing period - netherlands - costs - mortality - cattle - performance - fertility
    Dairy farmers often keep almost all their newborn heifer calves despite the high cost of rearing. By rearing all heifer calves, farmers have more security and retain flexibility to cope with the uncertainty in the availability of replacement heifers in time. This uncertainty is due to mortality or infertility during the rearing period and the variation in culling rate of lactating cows. The objective of this study is to provide insight in the economically optimal number of heifer calves to be reared as replacements. A herd-level stochastic simulation model was developed specific for this purpose with a herd of 100 dairy cows; the biological part of the model consisted of a dairy herd unit and rearing unit for replacement heifers. The dairy herd unit included variation in the number of culled dairy cows. The rearing unit incorporated variation in the number of heifers present in the herd by including uncertainty in mortality and variation in fertility. The dairy herd unit and rearing unit were linked by the number of replacement heifers and culled dairy cows. When not enough replacement heifers were available to replace culled dairy cows, the herd size was temporarily reduced, resulting in an additional cost for the empty slots. When the herd size reached 100 dairy cows, the available replacement heifers that were not needed were sold. It was assumed that no purchase of cows and calves occurred. The optimal percentage of 2-wk-old heifer calves to be retained was defined as the percentage of heifer calves that minimized the average net costs of rearing replacement heifers. In the default scenario, the optimal retention was 73% and the total net cost of rearing was estimated at €40,939 per herd per year. This total net cost was 6.5% lower than when all heifer calves were kept. An earlier first-calving age resulted in an optimal retention of 75%, and the net costs of rearing were €581 per herd per year lower than in the default scenario. For herds with a lower or higher culling rate of dairy cows (10 or 40% instead of 25% in the default scenario), it was optimal to retain 35 or 100% of the heifer calves per year. Herds that had a lower or higher cost of empty slots (€50 or 120 per month instead of €82 in the default scenario) had an optimal retention of 49 or 83% per year; the optimal retention percentage was dependent on farm and herd characteristics. For Dutch dairy farming conditions, it was not optimal to keep all heifer calves.
    A genome-wide association study reveals a novel candidate gene for sperm motility in pigs
    Diniz, D.B. ; Lopes, M.S. ; Broekhuijse, M.L.W.J. ; Lopes, P.S. ; Harlizius, B. ; Guimaraes, S.E.F. ; Duijvesteijn, N. ; Knol, E.F. ; Silva, F.F. - \ 2014
    Animal Reproduction Science 151 (2014)3-4. - ISSN 0378-4320 - p. 201 - 207.
    assisted semen analysis - linkage disequilibrium - reproductive traits - fertility - boar - quality - casa - expression - parameters - selection
    Sperm motility is one of the most widely used parameters in order to evaluate boar semen quality. However, this trait can only be measured after puberty. Thus, the use of genomic information appears as an appealing alternative to evaluate and improve selection for boar fertility traits earlier in life. With this study we aimed to identify SNPs with significant association with sperm motility in two different commercial pig populations and to identify possible candidate genes within the identified QTL regions. We performed a single-SNP genome-wide association study using genotyped animals from a Landrace-based (L1) and a Large White-based (L2) pig populations. For L1, a total of 602 animals genotyped for 42,551 SNPs were used in the association analysis. For L2, a total of 525 animals genotyped for 40,890 SNPs were available. After the association analysis, a false discovery rate q-value
    Asian low-androstenone haplotype on pig chromosome 6 does not unfavorably affect production and reproduction traits.
    Hidalgo, A.M. ; Bastiaansen, J.W.M. ; Harlizius, B. ; Knol, E.F. ; Lopes, M.S. ; Koning, D.J. De; Groenen, M. - \ 2014
    Animal Genetics 45 (2014)6. - ISSN 0268-9146 - p. 874 - 877.
    genome-wide association - boar taint - level - fertility - skatole - loci
    European pigs that carry Asian haplotypes of a 1.94-Mbp region on pig chromosome 6 have lower levels of androstenone, one of the two main compounds causing boar taint. The objective of our study was to examine potential pleiotropic effects of the Asian low-androstenone haplotypes. A single nucleotide polymorphism marker, rs81308021, distinguishes the Asian from European haplotypes and was used to investigate possible associations of androstenone with production and reproduction traits. Eight traits were available from three European commercial breeds. For the two sow lines studied, a favorable effect on number of teats was detected for the low-androstenone haplotype. In one of these sow lines, a favorable effect on number of spermatozoa per ejaculation was detected for the low-androstenone haplotype. No unfavorable pleiotropic effects were found, which suggests that selection for low-androstenone haplotypes within the 1.94 Mbp would not unfavorably affect the other eight relevant traits.
    Biochar increases plant-available water in a sandy loam soil under an aerobic rice crop system
    Melo Carvalho, M.T. de; Holanda Nunes Maia, A. de; Madari, B.E. ; Bastiaans, L. ; Oort, P.A.J. van; Heinemann, A.B. ; Soler da Silva, M.A. ; Petter, F.A. ; Marimon-Junior, B.H. ; Meinke, H.B. - \ 2014
    Solid Earth 5 (2014). - ISSN 1869-9510 - p. 939 - 952.
    upland rice - hydraulic conductivity - management - productivity - temperatures - fertility - retention - tropics - model
    The main objective of this study was to assess the impact of biochar rate (0, 8, 16 and 32 Mg ha-1) on the water retention capacity (WRC) of a sandy loam Dystric Plinthosol. The applied biochar was a by-product of slow pyrolysis (~450 °C) of eucalyptus wood, milled to pass through a 2000 µm sieve that resulted in a material with an intrinsic porosity =10 µm and a specific surface area of ~3.2 m2 g-1. The biochar was incorporated into the top 15 cm of the soil under an aerobic rice system. Our study focused on both the effects on WRC and rice yields 2 and 3 years after its application. Undisturbed soil samples were collected from 16 plots in two soil layers (5–10 and 15–20 cm). Soil water retention curves were modelled using a nonlinear mixed model which appropriately accounts for uncertainties inherent of spatial variability and repeated measurements taken within a specific soil sample. We found an increase in plant-available water in the upper soil layer proportional to the rate of biochar, with about 0.8% for each Mg ha-1 biochar amendment 2 and 3 years after its application. The impact of biochar on soil WRC was most likely related to an effect in overall porosity of the sandy loam soil, which was evident from an increase in saturated soil moisture and macro porosity with 0.5 and 1.6% for each Mg ha-1 of biochar applied, respectively. The increment in soil WRC did not translate into an increase in rice yield, essentially because in both seasons the amount of rainfall during the critical period for rice production exceeded 650 mm. The use of biochar as a soil amendment can be a worthy strategy to guarantee yield stability under short-term water-limited conditions. Our findings raise the importance of assessing the feasibility of very high application rates of biochar and the inclusion of a detailed analysis of its physical and chemical properties as part of future investigations.
    Strong and weak family ties revisited: reconsidering European family structures from a network perspective.
    Mönkediek, B. ; Bras, H. - \ 2014
    The History of the Family 19 (2014)2. - ISSN 1081-602X - p. 235 - 259.
    western-europe - household - fertility - attitudes - kinship - bonds - loneliness - behavior - germany - support
    Family systems appear to be an important factor framing people's individual behavior. Thus far, family systems have been primarily addressed on a macro regional level with indirect measures. Revisiting Reher (1998) and the family ties criterion, the main question of this paper is to examine to what extent we perceive family structures differently in Europe by taking direct measures of the structures of people's broader social networks into consideration. Based on the Survey of Health, Ageing and Retirement in Europe (SHARE), we derived two indicators of family regimes based on individual-level data regarding the density of ego social networks: contact frequency and geographic proximity among network members. We aggregated these data and mapped them on the NUTS 2 level regions for various locations in Europe. The results of our analyses exhibit that, based on these two network indicators, significant differences in family structures between European regions exist. These results confirm the classification of strong family Southern and comparatively weaker family Northern European regions to a large extent, though substantial regional differences in and between countries are also revealed. Our findings demonstrate that the classification of European regions largely depends on which indicator of network density we consider. This is particularly obvious in the Eastern European regions where the classification markedly differs according to the type of network indicator. Intriguingly, social networks in Central European regions can be characterized as rather loose, often even looser than the ‘traditional’ weak ties in Scandinavia. Family regimes can, therefore, be regarded as a construct of multiple dimensions of which one dimension may be classified as weak while the other can be strong at the same time.
    Cryopreservation of turkey semen: effects of breeding line and freezing method on post-thaw sperm quality, fertilization, and hatching
    Long, J.A. ; Purdy, P.H. ; Zuidberg, C.A. ; Hiemstra, S.J. ; Velleman, S.G. ; Woelders, H. - \ 2014
    Cryobiology 68 (2014)3. - ISSN 0011-2240 - p. 371 - 378.
    increased egg-production - increased body-weight - frozen-thawed semen - long-term selection - poultry semen - chicken semen - gallus-domesticus - fowl spermatozoa - reproduction - fertility
    Cryopreservation methods for poultry semen are not reliable for germplasm preservation, especially for turkeys, where fertility rates from frozen/thawed semen are particularly low. The objective was to evaluate cryopreservation methods for effectiveness in promoting cryosurvival and post-thaw function of sperm from five turkey lines: one commercial line and four research (RBC1; E; RBC2; F) lines from Ohio State University (OSU). The model for cryopreservation was set up as a 2 × 2 × 2 × 5 design for cryoprotectant (glycerol or dimethylacetamide (DMA)), cryopreservation medium (Lake or ASG), method of dilution (fixed dilution volume versus fixed sperm concentration) and turkey line, respectively. The final cryoprotectant concentrations were 11% glycerol or 6% DMA. Thawed sperm were evaluated for plasma membrane integrity and quality, motility, acrosome integrity and, after artificial insemination, for egg fertility and hatchability. Commercial turkey hens were used for all fertility trials, regardless of semen source. Turkey sperm frozen with glycerol exhibited higher membrane integrity and membrane quality upon thawing than turkey sperm frozen with DMA although no differences in total motility, and only minimal differences in progressive motility, were detected among the eight cryopreservation treatments. Within line, fertility was affected by cryoprotectant, medium and dilution method, where the overall highest percentages of fertile, viable embryos (Day 7) occurred for the DMA/ASG/fixed sperm concentration method, while high percentages (15.8–31.5%) of fertile, non-viable embryos (Day 1–6) were observed for multiple cryopreservation methods, including two glycerol treatments. From a single insemination, the duration of true and viable fertility in all lines was 10–13 weeks and 9–10 weeks, respectively. The duration of hatchability was 4–6 weeks after insemination for four of the turkey lines. The highest percentage of viable embryos was observed for the commercial line (9.5 ± 2.4%), followed by the E line (5.3 ± 1.3%), F line (3.7 ± 2.0%) and RBC2 line (2.6 ± 0.8%). For the RBC1 line, there was 100% embryonic death by Day 6 of incubation. Overall, better fertility results were obtained with the cryoprotectant DMA, the ASG diluent and fixed sperm concentration. However, the applicability of this method for preserving semen from research populations may be line dependent.
    Bodembeheer vraagt aandacht (interview met B. Kroonen en J. Verhoeven)
    Kroonen-Backbier, B.M.A. ; Verhoeven, J.T.W. - \ 2014
    De Maïsteler 12 (2014)38. - p. 18 - 19.
    akkerbouw - maïs - vruchtbaarheid - bodemmoeheid - organische stof - bemesting - arable farming - maize - fertility - soil sickness - organic matter - fertilizer application
    Continu maïs telen is een aanslag op de vruchtbaarheid van de bodem. Een lagere organische stof aanvoer in combinatie met lagere bemestingsnormen zetten de opbrengst van maïs ernstig onder druk. Werken aan een beter vanggewas, structuurproblemen oplossen en slim bemesten zijn het advies.Lukt het ook met de nieuwe gebruiksnorm van 112 kilo stikstof? “Een hele uitdaging”, zegt Brigitte Kroonen, onderzoeker in Vredepeel bij PPO van WageningenUR. “Een al te groot opbrengstverlies is te voorkomen als de bodemvruchtbaarheid en het bodembeheer top zijn.” “Een gezonde bodem is de basis voor gezond groeiende planten”, geeft John Verhoeven, projectleider onderzoeker bodem, water en bemesting bij Wageningen UR aan.
    Gene coexpression network analysis identifies genes and biological processes shared among anterior pituitary and brain areas that affect estrous behavior in dairy cows
    Kommadath, A. ; Pas, M.F.W. te; Smits, M.A. - \ 2013
    Journal of Dairy Science 96 (2013)4. - ISSN 0022-0302 - p. 2583 - 2595.
    expression patterns - quantitative measure - mechanisms - modules - tissue - transcriptome - endometrium - metabolism - fertility - discovery
    The expression of estrous (sexually receptive) behavior (EB), a key fertility trait in dairy cows, has been declining over the past few decades both in intensity and duration. Improved knowledge of the genomic factors underlying EB, which is currently lacking, may lead to novel applications to enhance fertility. Our objective was to identify genes and biological processes shared among the bovine anterior pituitary (AP) and four brain areas that act together to regulate EB by investigating networks of coexpressed genes between these tissues. We used a systems biology approach called weighted gene coexpression network analysis for defining gene coexpression networks using gene expression data from the following tissues collected from 14 cows at estrus: AP, dorsal hypothalamus (DH), ventral hypothalamus (VH), amygdala (AM), and hippocampus (HC). Consensus modules of coexpressed genes were identified between the networks for the AM-DH, HC-DH, VH-DH, AP-DH, and AM-HC tissue pairs. The correlation between the module's eigengene (weighted average gene expression profile) and levels of EB exhibited by the experimental cows were tested. Estrous behavior-cor-related modules were found enriched for gene ontology terms like glial cell development and regulation of neural projection development as well as for Kyoto Encyclopedia of Genes and Genomes pathway terms related to brain degenerative diseases. General cellular processes like oxidative phosphorylation and ribosome and biosynthetic processes were found enriched in several correlated modules, indicating increased transcription and protein synthesis. Stimulation of ribosomal RNA synthesis is known from rodent studies to be a primary event in the activation of neuronal cells and pathways involved in female reproductive behavior and this precedes the estrogen-driven expansion of dendrites and synapses. Similar processes also operate in cows to affect EB. Hub genes within EB-correlated modules (e.g. NEFL, NDRG2, GAP43, THY1, and TCF7L2, among others) are strong candidates among genes regulating EB expression. The study improved our understanding of the genomic regulation of EB in dairy cows by providing new insights into genes and biological processes shared among the bovine AP and brain areas acting together to regulate EB. The new knowledge could lead to the development of novel management strategies to monitor and improve reproductive performance in dairy cows (for example, biomarkers for estrus detection).
    Women's autonomy and husbands' involvement in maternal health care in Nepal
    Thapa, D.K. ; Niehof, Anke - \ 2013
    Social Science and Medicine 93 (2013). - ISSN 0277-9536 - p. 1 - 10.
    reproductive health - decision-making - antenatal care - fertility - men - services - fathers - india - perspectives - household
    Both increasing women’s autonomy and increasing husbands’ involvement in maternal health care are promising strategies to enhance maternal health care utilization. However, these two may be at odds with each other insofar as autonomouswomenmay not seek their husband’s involvement, and involved husbands may limit women’s autonomy. This study assessed the relationship between women’s autonomy and husbands’ involvement in maternal health care. Field work for this study was carried out during SeptembereNovember 2011 in the Kailali district of Nepal. In-depth interviews and focus group discussions were used to investigate the extent of husbands’ involvement in maternal health care. A survey was carried out among 341 randomly selectedwomenwho delivered a live baby within one year prior to the survey. The results showthat husbandswere involved in giving advice, supporting to reduce the householdwork burden, and makingfinancial and transportation arrangements for the delivery. After adjustment for other covariates, economic autonomy was associated with lower likelihood of discussion with husband during pregnancy, while domestic decision-making autonomy was associated with both lower likelihood of discussion with husband during pregnancy and the husband’s presence at antenatal care (ANC) visits. Movement autonomy was associated with lower likelihood of the husband’s presence at ANC visits. Intra-spousal communication was associated with higher likelihood of discussing health with the husband during pregnancy, birth preparedness, and the husbands’ presence at the health facility delivery. The magnitude and direction of association varied per autonomy dimension. These findings suggest that programs to improve the women’s autonomy and at the sametimeincrease the husband’s involvement should be carefully planned. Despite the traditional cultural beliefs that go against the involvement of husbands, Nepalese husbands are increasingly entering into the area of maternal health which was traditionally considered ‘women’s business’.
    Constraints on agricultural production in the Northern Uplands of Vietnam
    Bui Tan, Y. ; Visser, S.M. ; Hoanh, C.T. ; Stroosnijder, L. - \ 2013
    Mountain Research and Development 33 (2013)4. - ISSN 0276-4741 - p. 404 - 415.
    natural-resource management - land evaluation - fertility - system - suitability - integration - simulation - options
    The Northern Uplands of Vietnam form one of the largest ecological regions in the country, characterized by complex biophysical conditions and a high diversity in ethnic minorities, cultures, and farming systems. The Doi moi (“renovation”) program has, since the early 1980s, resulted in significant changes in agriculture production and related economic trends. However, poverty, low agricultural productivity, and land degradation are still major problems. This article illustrates the factors that drive these problems by analyzing agricultural land use in Suoi Con, a small agroforestry watershed in the Northern Uplands. We first identified the current land-use systems and analyzed constraints on agricultural production. The results indicate that although low soil fertility and land degradation are considerable problems, availability of household capital, low technology levels, and land fragmentation are major constraints on agricultural development. These constraints were analyzed from different points of view to identify mismatches between the implementation of top-down government policies and specific conditions that may explain why actual land-use change in the Northern Uplands deviates from the government's development plans. Results of land-use analysis in the Suoi Con watershed suggest that participatory and bottom-up approaches are needed to better understand problems and opportunities in household agricultural production in order to develop appropriate land-use plans and policies.
    The association of ruminal pH and some metabolic parameters with conception rate at first artificial insemination in Thai dairy cows
    Inchaisri, C. ; Somchai Chantsavang, ; Noordhuizen, J.P.T.M. ; Hogeveen, H. - \ 2013
    Tropical Animal Health and Production 45 (2013)5. - ISSN 0049-4747 - p. 1183 - 1190.
    body condition score - milk-production - holstein cows - acidosis - fertility - herds - cattle - yield - ovulation - lipopolysaccharide
    The objective of this study was to determine the association of metabolic parameters and cow associated factors with the conception rate at first insemination (FCR) in Thai dairy cows. The investigation was performed with 529 lactations from 32 smallholder dairy farms. At 3–6 weeks after parturition, blood samples and ruminal fluid were collected. Body condition scores (BCS) of cows were scored 1 week before expected calving date and at blood sampling date. Ruminal pH was measured at 2–4 h after morning feeding in ruminal fluid collected by ruminocentesis. Serum betahydroxybutyrate and serum urea nitrogen were measured by kinetic enzyme method. Cows with first insemination (AI) between 41 and 114 days postpartum were identified after pregnancy diagnosis for FCR. Breed, parity, interval from calving to first AI, BCS before calving, BCS after calving, loss in BCS after calving, SBHB, SUN, ruminal pH, and postpartum problems were selected as independent variables for a model with FCR as a dependent variable. A multivariable logistic regression model was used with farm as a random effect. Overall FCR was 27.2 %. The FCR depended on interval from calving to first AI, BCS before calving, and ruminal pH. The FCR between 69 and 91 days postpartum was significantly highest (45 %). Before calving, a cow with high BCS (=3.5) had significantly greater FCR than a cow with low BCS (=3.25; P
    Tochtdetectie met sensoren rendeert
    Rutten, C.J. ; Steeneveld, W. ; Hogeveen, H. - \ 2013
    Veeteelt 30 (2013)16. - ISSN 0168-7565 - p. 26 - 27.
    melkveehouderij - melkkoeien - vruchtbaarheid - oestrus - detectie - sensors - rendement - investering - dairy farming - dairy cows - fertility - oestrus - detection - sensors - returns - investment
    Sensoren die de veehouder helpen bij het opsporen van tochtige koeien, doen meestal hun werk, blijkt uit diverse onderzoeken. Maar verdient de investering zichzelf terug? Uit onderzoek van de faculteit Diergeneeskunde blijkt dat het antwoord 'ja' is.
    Effect of predictor traits on accuracy of genomic breeding values for feed intake based on a limited cow reference population
    Pszczola, M.J. ; Veerkamp, R.F. ; Haas, Y. de; Wall, E. ; Strabel, T. ; Calus, M.P.L. - \ 2013
    Animal 7 (2013)11. - ISSN 1751-7311 - p. 1759 - 1768.
    dairy-cattle - selection - genotype - system - information - parameters - efficiency - fertility - holsteins - animals
    The genomic breeding value accuracy of scarcely recorded traits is low because of the limited number of phenotypic observations. One solution to increase the breeding value accuracy is to use predictor traits. This study investigated the impact of recording additional phenotypic observations for predictor traits on reference and evaluated animals on the genomic breeding value accuracy for a scarcely recorded trait. The scarcely recorded trait was dry matter intake (DMI, n = 869) and the predictor traits were fat-protein-corrected milk (FPCM, n = 1520) and live weight (LW, n = 1309). All phenotyped animals were genotyped and originated from research farms in Ireland, the United Kingdom and the Netherlands. Multi-trait REML was used to simultaneously estimate variance components and breeding values for DMI using available predictors. In addition, analyses using only pedigree relationships were performed. Breeding value accuracy was assessed through cross-validation (CV) and prediction error variance (PEV). CV groups (n = 7) were defined by splitting animals across genetic lines and management groups within country. With no additional traits recorded for the evaluated animals, both CV- and PEV-based accuracies for DMI were substantially higher for genomic than for pedigree analyses (CV: max. 0.26 for pedigree and 0.33 for genomic analyses; PEV: max. 0.45 and 0.52, respectively). With additional traits available, the differences between pedigree and genomic accuracies diminished. With additional recording for FPCM, pedigree accuracies increased from 0.26 to 0.47 for CV and from 0.45 to 0.48 for PEV. Genomic accuracies increased from 0.33 to 0.50 for CV and from 0.52 to 0.53 for PEV. With additional recording for LW instead of FPCM, pedigree accuracies increased to 0.54 for CV and to 0.61 for PEV. Genomic accuracies increased to 0.57 for CV and to 0.60 for PEV. With both FPCM and LW available for evaluated animals, accuracy was highest (0.62 for CV and 0.61 for PEV in pedigree, and 0.63 for CV and 0.61 for PEV in genomic analyses). Recording predictor traits for only the reference population did not increase DMI breeding value accuracy. Recording predictor traits for both reference and evaluated animals significantly increased DMI breeding value accuracy and removed the bias observed when only reference animals had records. The benefit of using genomic instead of pedigree relationships was reduced when more predictor traits were used. Using predictor traits may be an inexpensive way to significantly increase the accuracy and remove the bias of (genomic) breeding values of scarcely recorded traits such as feed intake.
    Economic values for yield, survival, calving interval and beef daily gain for three breeds in Slovenia
    Haas, Y. de; Veerkamp, R.F. ; Shalloo, L. ; Dillon, P. ; Kuipers, A. ; Klopcic, M. - \ 2013
    Livestock Science 157 (2013)2-3. - ISSN 1871-1413 - p. 397 - 407.
    production circumstances - output limitations - production traits - selection - milk - fertility - objectives - efficiency - situations - weights
    Breeding indices need to be looked at periodically to evaluate the objective of the breeding program. In recent times the economic perspective of the breeding program has received a higher priority in deciding breeding objectives than in the past. However, prices of input and output products are becoming more difficult to predict with increased fluctuations in most prices, which adds a level of complexity to their inclusion in the selection index. With these challenges in mind, the breeding program in a new EU country (Slovenia) was evaluated. All three national Breeding Associations joined the deliberations. The aim of this study was to develop an economic selection index for three breeds (Simmental, Brown Swiss and Holstein-Friesian) in Slovenia. Because farming circumstances differ within Slovenia, differences in the production systems were also taken into account; e.g., flat land vs. hilly/mountainous areas, and for conventional vs. organic farming. Economic values (€) were calculated for milk, fat and protein yields (€/cow/year/kg), survival (€/cow/year/%survival), calving interval (€/cow/year/day), and beef daily gain (€/cow/year/kg). Economic values were calculated by changing one of these traits whilst keeping the other traits at the default level. Economic indices were calculated using a farm economic model (Moorepark Dairy Systems Model). Herd parameters (e.g., number of milking cows, replacements, young stock and calving pattern), milk production, feed requirements and ration, land use and labour requirements were re-parameterised in order to be relevant to the Slovenian circumstances. Absolute economic values were slightly negative for milk yield for all breeds (-0.02 to -0.04€ per kg milk), but positive for milk components (0.55 to 1.45€ per kg fat, and 2.89 to 3.38€ per kg protein). High absolute economic values were calculated for survival (7.37 to 9.55€ per %). Absolute economic values for calving interval were approximately -1€ per day for all breeds, while the economic value for beef daily gain was 0.14€ per kg for Brown Swiss and 0.32€ per kg for Simmental. The constructed economic indices ranked bulls in a significantly different manner than how the Slovenian Total Merit Indices ranked the bulls. The economic indices were robust towards changes in prices and farming system. Ranking was most sensitive towards variation in milk price. Assumptions concerning feed intake in relation to growth influenced the economic value for beef daily gain. Assumptions regarding the farming system (i.e., organic farming systems) only slightly affected the ranking of the bulls.
    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.