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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    We will mail you new results for this query: keywords==production circumstances
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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.
A stochastic model for the derivation of economic values and their standard deviations for production and functional traits in dairy cattle
Nielsen, H.M. ; Groen, A.F. ; Ostergaard, S. ; Berg, P. - \ 2006
Acta Agriculturae Scandinavica Section A-Animal Science 56 (2006)1. - ISSN 0906-4702 - p. 16 - 32.
feed-intake capacity - selection indexes - production circumstances - profit-functions - breeding goals - herd - bias
The objective of this paper was to present a model of a dairy cattle production system for the derivation of economic values and their standard deviations for both production and functional traits under Danish production circumstances. The stochastic model used is dynamic, and simulates production and health in a dairy herd. Because of indirect effects between traits, the phenotypic levels of (related) traits can change as a result of genetic changes. Economic values for milk production and body weight were 0.28 and -0.76 euro/kg per cow-year respectively. For incidence of milk fever, mastitis, retained placenta and laminitis economic values were -402.1, -162.5, -79.0 and -210.2 euro/incidence per cow-year. The economic values for involuntary culling rate, stillbirth and conception rate were -6.66, -1.63, and 1.98 euro/% per cow-year, respectively and the economic value for days from calving to first heat was -0.94 euro/day per cow-year. Standard deviations of economic values expressing variation in realised profit of a farm before and after a genetic change were computed using a linear Taylor series expansion. Expressed as coefficient of variation, standard deviations of economic values based on 1000 replicates ranged between 0.07 (milk production) to 16 (retained placenta)
Economic values for production and functional traits in Holstein cattle in Costa Rica
Vargas, B. ; Groen, A.F. ; Herrero, M. ; Arendonk, J.A.M. van - \ 2002
Livestock Production Science 75 (2002). - ISSN 0301-6226 - p. 101 - 116.
feed-intake capacity - dairy-cattle - production circumstances - output limitations - production systems - breeding goals - live weight - situations - selection - model
Economic values for production traits (carrier, fat, protein, and dressing percentage) and functional traits (conception rate, survival rate, body weight, and rumen capacity) were calculated for Holstein cattle of Costa Rica. Economic values were derived using a bio-economic model that combined genetic potential performance, feeding strategies and optimum culling and insemination policies to obtain actual phenotypic performance. Two evaluation bases were considered: fixed herd-size and fixed milk-output. With a fixed herd-size economic values were 0.04 (carrier), 5.25 (fat), 3.95 (protein), 0.92 (dressing percentage), 1.30 (conception rate), 2.42 (survival rate), 0.81 (body weight) and 84.53 (rumen capacity). With a milk-output limitation, economic values for all traits except survival rate were lower than for fixed herd-size. The respective values were -0.04, 3.53, 2.91, 0.88, 0.85, 3.18, 0.51 and 45.59. Sensitivity analysis indicated that economic values of fat, protein and rumen capacity increased significantly with higher prices of milk solids. Other traits were less sensitive to a change in price of milk solids. Changes in price of concentrate did not alter economic values significantly. Under a fixed feeding strategy, economic values for functional traits increased substantially, while those for production traits decreased. The results of this analysis suggest that genetic improvement of fertility, health and cow-efficiency traits will have a clear positive effect on profitability of Holstein cows in Costa Rica, especially when feeding conditions are not optimal. (C) 2002 Elsevier Science BY All rights reserved.
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