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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    EST-derived SSR markers used as anchor loci for the construction of a consensus linkage map in ryegrass (Lolium spp.)
    Studer, B. ; Kolliker, R. ; Muylle, H. ; Asp, T. ; Frei, U. ; Roldan-Ruiz, I. ; Barre, P. ; Tomaszewski, C. ; Meally, H. ; Barth, S. ; Skot, L. ; Armstead, I.P. ; Dolstra, O. ; Lubberstedt, T. - \ 2010
    BMC Plant Biology 10 (2010). - ISSN 1471-2229 - 10 p.
    crown rust resistance - f-sp lolii - sequence repeat markers - quantitative trait loci - perennial ryegrass - multiflorum lam. - qtl analysis - microsatellite markers - mapping populations - aflp markers
    Background: Genetic markers and linkage mapping are basic prerequisites for marker-assisted selection and map-based cloning. In the case of the key grassland species Lolium spp., numerous mapping populations have been developed and characterised for various traits. Although some genetic linkage maps of these populations have been aligned with each other using publicly available DNA markers, the number of common markers among genetic maps is still low, limiting the ability to compare candidate gene and QTL locations across germplasm. Results: A set of 204 expressed sequence tag (EST)-derived simple sequence repeat (SSR) markers has been assigned to map positions using eight different ryegrass mapping populations. Marker properties of a subset of 64 EST-SSRs were assessed in six to eight individuals of each mapping population and revealed 83% of the markers to be polymorphic in at least one population and an average number of alleles of 4.88. EST-SSR markers polymorphic in multiple populations served as anchor markers and allowed the construction of the first comprehensive consensus map for ryegrass. The integrated map was complemented with 97 SSRs from previously published linkage maps and finally contained 284 EST-derived and genomic SSR markers. The total map length was 742 centiMorgan (cM), ranging for individual chromosomes from 70 cM of linkage group (LG) 6 to 171 cM of LG 2. Conclusions: The consensus linkage map for ryegrass based on eight mapping populations and constructed using a large set of publicly available Lolium EST-SSRs mapped for the first time together with previously mapped SSR markers will allow for consolidating existing mapping and QTL information in ryegrass. Map and markers presented here will prove to be an asset in the development for both molecular breeding of ryegrass as well as comparative genetics and genomics within grass species.
    The impact of cooling ponds in North Central Texas on dairy farm performance
    Tomaszewski, M.A. ; Haan, M.H.A. de; Thompson, J.A. ; Jordan, E.R. - \ 2005
    Journal of Dairy Science 88 (2005)6. - ISSN 0022-0302 - p. 2281 - 2286.
    The objective of this study was to determine whether measurable differences existed between farms with and without cooling ponds. Data from Dairy Herd Improvement records for 1999 through 2002 were obtained on 42 herds located in North Central Texas. Nineteen herds had installed cooling ponds, whereas 23 herds had not. Monthly somatic cell counts for each herd were obtained from the Federal Milk Market Administrator. Data were analyzed using the PROC MIXED regression model of SAS. Within and across herd groups, milk production from June to October was significantly lower compared with milk production for the rest of the year. Although there was numerically higher average milk production per cow per day throughout the year for herds that used cooling ponds, differences between herd groups that used or did not use cooling ponds were significant only for August production. Herds without a cooling pond had 4.8 kg/d per cow lower production in August than in the cool-season months of November to May (26.4 +/- 0.6 vs. 31.2 +/- 0.5 kg/d), whereas the difference in August production was only 2.9 kg/d per cow in herds that used cooling ponds (29.0 +/- 0.7 vs. 31.9 +/- 0.6 kg/d). Differences caused by seasonal use of a cooling pond in culling, days to first service, days open, percentage of estruses observed, and somatic cell counts were not significant. Bulk tank milk samples cultured for 10 different bacteria showed no difference between cooling pond and noncooling pond herds in 2002. Also, there was no difference in incidence of violations from the Texas Department of Health for herds that used or did not use cooling ponds. However, herds with cooling ponds did have a lower percentage of successful breedings, fewer days dry, and a higher percentage of cows in milk compared with dairy herds that used other forms of cooling. Such differences may or may not be attributed to seasonal use of a cooling pond. Therefore, cooling ponds may provide relief from heat stress without adversely affecting most important measures of herd performance.
    Determining farm effects attributable to the introduction and use of a dairy management information system in The Netherlands
    Tomaszewski, M.A. ; Asseldonk, M.A.P.M. van; Dijkhuizen, A.A. ; Huirne, R.B.M. - \ 2000
    Agricultural Economics 23 (2000)1. - ISSN 0169-5150 - p. 79 - 86.
    Yearly production and reproduction data on dairy farms in The Netherlands were obtained to determine whether management information systems significantly improved herd performance variables (management information systems (MIS) effects). The analysis included 357 adopters of a management information system and 357 herds were used as controls. The data comprised years 1987 through 1996, and included for the adopters both the 'before' and 'after' period. Panel data analysis enabled to estimate MIS effects both within and between farms, allowing for a separation of farm-specific effects and common (trend) effects. Adoption and use of a management information system resulted in a significant annual increase in rolling herd average milk (carrier) and protein production of 62 and 2.36 kg per cow, respectively. Calving interval was shortened by 5 days. The pay-back period was approximately 5 years of the system (including the hardware), and therefore, MIS appears to be economically profitable.
    Management information system impact on dairy production for selected herds in Texas
    Tomaszewski, M.A. ; Dijkhuizen, A.A. ; Huirne, R.B.M. ; Otten, A. - \ 2000
    Computers and Electronics in Agriculture 26 (2000)1. - ISSN 0168-1699 - p. 1 - 11.
    Yearly production and performance data were obtained for dairy herd improvement members in Texas to determine whether on-farm use of a management information system (MIS) quantitatively impacted performance. Data from 66 dairy operations for the years 1983–1996 were evaluated. Herds enrolled in an MIS program increased rolling herd average milk production by 281 kg and received a return on investment of 212%. Most of the increase in production occurred during the initial year of MIS usage. Throughout the study, larger herds and those that increased in size tended to adopt a management information system.
    The economic value of information technology on dairy farms in The Netherlands.
    Asseldonk, M.A.P.M. van; Huirne, R.B.M. ; Dijkhuizen, A.A. ; Tomaszewski, M.A. - \ 1998
    Journal of Animal Science (1998)supplement. - ISSN 0021-8812
    Economic effects of information technology on dairy farms in The Netherlands and Israel.
    Asseldonk, M.A.P.M. van; Huirne, R.B.M. ; Dijkhuizen, A.A. ; Tomaszewski, M.A. ; Gelb, E.M. - \ 1998
    In: American Agricultural Economics Association, Salt Lake City, USA 80 - p. 1179 - 1179.
    Effects of Information Technology on Dairy Farms in The Netherlands: An Empirical Analysis of Milk Production Records
    Asseldonk, M.A.P.M. van; Huirne, R.B.M. ; Dijkhuizen, A.A. ; Tomaszewski, M.A. ; Harbers, A.G.F. - \ 1998
    Journal of Dairy Science 81 (1998)10. - ISSN 0022-0302 - p. 2752 - 2759.
    This study empirically quantified the effects of the adoption of an automated concentrate feeder, on-line measurement of milk production, and activity measurement on milk production and reproduction. The data comprised annual results of Dutch farms operating in a milk quota system from 1987 to 1996; data included both adopters and nonadopters as well as farm results before and after adoption. The use of an automated concentrate feeder improved the annual carrier production of milk, milk protein, and milk fat (102, 4.95, and 5.52 kg per cow, respectively). In contrast, on-line measurement of milk production did not significantly affect milk production records. Calving interval was shortened by 5.7 d after the adoption of an activity measurement system but was not affected by the adoption of an automated concentrate feeder or by the measurement of on-line milk production.
    Determining the effect of a management information system on herd production.
    Tomaszewski, M.A. ; Sudweeks, E.M. ; Dijkhuizen, A.A. ; Huirne, R.B.M. - \ 1997
    Journal of Dairy Science 80 (1997)Suppl. 1. - ISSN 0022-0302 - p. 148 - 148.
    Determining the Profitability of Management Information Systems on Dairy Farms.
    Tomaszewski, M.A. - \ 1997
    In: Anders Ringgaard Kristensen (eds.), Proceedings of the Dutch/Danish Symposium on Animal Health and Management Economics, Copenhagen, Dina Notat 56 - p. 119 - 123.
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