Showing papers by "Roel F. Veerkamp published in 2006"
TL;DR: Ranking of breeding strategies, based on the highest average genetic gain, was relatively insensitive to heritability, number of progeny per bull, and the relative importance of both environments, but was very sensitive to selection intensity.
137 citations
TL;DR: The genetic relationship of milk yield with health and fertility depending on herd environment was explored and genetic correlations of the 3 traits with milk yield were antagonistic but varied over environments.
116 citations
TL;DR: No significant difference in height of the EB profile existed between the cows on the low and high feeding level indicating that the duration and extent of NEB was not influenced by the concentrate feeding levels adopted in this study.
93 citations
TL;DR: The findings indicate that moderate GxE was present for yield traits and heritabilities of milk, fat and protein yield, and somatic cell score (SCS) were higher under organic farming conditions than under conventional farming conditions.
82 citations
TL;DR: Correlated responses in SCS across BMSCC and DIM were, on some occasions, less than half the direct response to selection in the response environment, whereas responses to selection between environments early and late in lactation tended to be low.
34 citations
01 Jan 2006
7 citations
01 Jan 2006
TL;DR: It can be concluded that breeding values for yield traits should be adapted to organic production so that the production level of cows fits better to the organic environment resulting in healthier dairy cows.
Abstract: – Due to genotype by environment interaction (GxE), conventional bulls might not be suitable for organic production circumstances. Therefore, lactation records from Holstein cows on organic and conventional farms were used to estimate the magnitude of GxE between organic and conventional production circumstances. GxE was quantified by estimating the genetic correlations between production traits in both environments. Genetic correlations for milk and protein yield were between 0.71 and 0.80 and found to be significantly different from unity. For fat yield the correlations were close to 0.90 and not significantly different from unity. It can be concluded that breeding values for yield traits should be adapted to organic production so that the production level of cows fits better to the organic environment resulting in healthier dairy cows.
2 citations