Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Milk progesterone measures to improve genomic selection for fertility in dairy cows
Tenghe, Amabel Manyu Mefru - \ 2017
Wageningen University. Promotor(en): Roel Veerkamp; B. Berglund, co-promotor(en): D. J. de Koning; Aniek 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 - 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 - detection - 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.
Heritable and non-heritable genetic effects on retained placenta in Meuse-Rhine-Yssel cattle
Benedictus, L. ; Koets, A.P. ; Kuijpers, F.H.J. ; Joosten, I. ; Eldik, P. van; Heuven, H.C.M. - \ 2013
Animal Reproduction Science 137 (2013)1-2. - ISSN 0378-4320 - p. 1 - 7.
norwegian red cows - major histocompatibility complex - class-i compatibility - dairy-cattle - milk-yield - inbreeding depression - brown swiss - fertility - parameters - disorders
Failure of the timely expulsion of the fetal membranes, called retained placenta, leads to reduced fertility, increased veterinary costs and reduced milk yields. The objectives of this study were to concurrently look at the heritable and non-heritable genetic effects on retained placenta and test the hypothesis that a greater coefficient of relationship between dam and calf increases the risk of retained placenta in the dam. The average incidence of retained placenta in 43,661 calvings of Meuse-Rhine-Yssel cattle was 4.5%, ranging from 0% to 29.6% among half-sib groups. The average pedigree based relationship between the sire and the maternal grandsire was 0.05 and ranged from 0 to 1.04. Using a sire-maternal grandsire model the heritability was estimated at 0.22 (SEM = 0.07) which is comparable with estimates for other dual purpose breeds. The coefficient of relationship between the sire and the maternal grandsire had an effect on retained placenta. The coefficient of relationship between the sire and the maternal grandsire was used as a proxy for the coefficient of relationship between dam and calf, which is correlated with the probability of major histocompatibility complex (MHC) class I compatibility between dam and calf. MHC class I compatibility is an important risk factor for retained placenta. Although the MHC class I haplotype is genetically determined, MHC class I compatibility is not heritable. This study shows that selection against retained placenta is possible and indicates that preventing the mating of related parents may play a role in the prevention of retained placenta.
Interpreting experimental data on egg production - applications of dynamic differential equations
France, J. ; Lopez, S. ; Kebreab, E. ; Dijkstra, J. - \ 2013
Poultry Science 92 (2013)9. - ISSN 0032-5791 - p. 2498 - 2508.
drosophila-melanogaster - gastrointestinal-tract - quantitative genetics - mathematical-models - phosphorus - calcium - absorption - fertility - algorithm
This contribution focuses on applying mathematical models based on systems of ordinary first-order differential equations to synthesize and interpret data from egg production experiments. Models based on linear systems of differential equations are contrasted with those based on nonlinear systems. Regression equations arising from analytical solutions to linear compartmental schemes are considered as candidate functions for describing egg production curves, together with aspects of parameter estimation. Extant candidate functions are reviewed, a role for growth functions such as the Gompertz equation suggested, and a function based on a simple new model outlined. Structurally, the new model comprises a single pool with an inflow and an outflow. Compartmental simulation models based on nonlinear systems of differential equations, and thus requiring numerical solution, are next discussed, and aspects of parameter estimation considered. This type of model is illustrated in relation to development and evaluation of a dynamic model of calcium and phosphorus flows in layers. The model consists of 8 state variables representing calcium and phosphorus pools in the crop, stomachs, plasma, and bone. The flow equations are described by Michaelis-Menten or mass action forms. Experiments that measure Ca and P uptake in layers fed different calcium concentrations during shell-forming days are used to evaluate the model. In addition to providing a useful management tool, such a simulation model also provides a means to evaluate feeding strategies aimed at reducing excretion of potential pollutants in poultry manure to the environment.
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