References of "Gengler, Nicolas"
     in
Bookmark and Share    
Full Text
See detailEstimation of fatty acid profile in cow milk by mid-infrared spectrometry
Soyeurt, Hélène ULg; Dardenne, Pierre; Lognay, Georges ULg et al

Poster (2006, April 03)

Detailed reference viewed: 16 (5 ULg)
Full Text
See detailDifférences intra- et inter-races du profil en acides gras du lait
Soyeurt, Hélène ULg; Dardenne, Pierre; Lognay, Georges ULg et al

in 11ème Carrefour des Productions Animales (2006, January 25)

Detailed reference viewed: 29 (4 ULg)
Full Text
See detailUse of Interbull traits as indicators for only locally evaluated traits as milk quality traits
Gengler, Nicolas ULg; Vanderick, Sylvie ULg; Croquet, Coraline et al

in Interbull Bulletin (2006), 35

Detailed reference viewed: 6 (1 ULg)
Full Text
See detailPotential of mid-infrared spectrometry for prediction of fatty acid contents in cow milk
Soyeurt, Hélène ULg; Dehareng, Frédéric; Dardenne, Pierre et al

Poster (2006)

Detailed reference viewed: 33 (2 ULg)
Full Text
Peer Reviewed
See detailAccounting for heterogeneous variances in multitrait evaluation of Jersey type traits
Gengler, Nicolas ULg; Wiggans, G. R.; Thornton, L. L. M. et al

in Journal of Dairy Science (2006), 89(8), 3143-3151

The multitrait genetic evaluation system for type traits was modified to estimate adjustments for heterogeneous variance (HV) simultaneously with estimated breeding values (EBV) for final score and 14 ... [more ▼]

The multitrait genetic evaluation system for type traits was modified to estimate adjustments for heterogeneous variance (HV) simultaneously with estimated breeding values (EBV) for final score and 14 linear traits. Each variance within herd, year, and parity was regressed toward a predicted variance, which was determined by fitting a model with fixed effects of the mean final score for herd, size of the contemporary group, appraisal month, and year-season and a random effect for herd-appraisal date. Herd-appraisal date was included as a random effect to regress the observed heterogeneity for a given herd-appraisal date toward the fixed effects. Method R was used to estimate variances for the heterogeneity model in each EBV iteration. To evaluate the effect of the adjustment, parent averages were calculated from evaluations with recent appraisals removed. The adjustment slightly improved correlations within birth year between those parent averages and EBV from current data on bulls for most traits, but did not improve correlations for final score, strength, dairy form, teat length, or foot angle. Annual trends for EBV were lower with HV adjustment than for unadjusted EBV for all traits except final score and rump angle for cows and rump width for bulls, which were essentially unchanged. Standard deviations of Mendelian sampling (evaluation minus mean of parent evaluations) declined less over time for HV-adjusted than for unadjusted evaluations. The slope at year 2000 of Mendelian-sampling standard deviations from HV-adjusted evaluations ranged from 10.0% for udder depth to 42.7% for teat length compared with the slope for unadjusted evaluations. This HV adjustment, which was implemented for USDA evaluations in May 2001 for Jerseys and in 2002 for other breeds, improves the accuracy of evaluations, particularly comparisons over time, by accounting for the change in variation. [less ▲]

Detailed reference viewed: 28 (4 ULg)
Full Text
Peer Reviewed
See detailGenetic parameters and evaluation of rear legs (rear view) for Brown Swiss and Guernseys
Wiggans, G. R.; Thornton, L. L. M.; Neitzel, R. R. et al

in Journal of Dairy Science (2006), 89(12), 4895-4900

Genetic parameters were estimated for rear legs (rear view; RLRV) and 15 current linear type traits of Brown Swiss and Guernsey dairy cattle. The Brown Swiss Cattle Breeders' Association of the USA and ... [more ▼]

Genetic parameters were estimated for rear legs (rear view; RLRV) and 15 current linear type traits of Brown Swiss and Guernsey dairy cattle. The Brown Swiss Cattle Breeders' Association of the USA and the American Guernsey Association began scoring RLRV in 2004. For Brown Swiss, 8,502 records were available for 7,676 cows in 417 herds; Guernsey data included 5,437 records for 4,749 cows in 229 herds. Nine unknown-parent groups were defined for each breed, each with 2 birth years. The model included fixed effects for the interaction of herd, appraisal date, and parity; appraisal age within parity; and lactation stage within parity and random effects for animal, permanent environment, and residual error. The multitrait analysis for RLRV and the 15 linear type traits used canonical transformation, multiple diagonalization, and a decelerated expectation-maximization REML algorithm. For Brown Swiss, heritability was 0.102 for RLRV and ranged from 0.099 for rear legs (side view) to 0.453 for stature. For Guernseys, heritability ranged from 0.078 for RLRV to 0.428 for stature. For Brown Swiss, the highest genetic correlation with RLRV was 0.71 for rear udder width; the most negative correlation was -0.19 with rump angle. For Guernseys, the highest genetic correlations with RLRV were 0.43 for rear udder width and 0.42 for body depth; the most negative correlation was -0.46 with rear legs (side view). With heritability near 0.10, RLRV should be useful in selection for improved locomotion. Release of genetic evaluations for RLRV began in May 2006 for Brown Swiss and Guernseys. [less ▲]

Detailed reference viewed: 22 (0 ULg)
Full Text
Peer Reviewed
See detailVariation in fatty acid contents of milk and milk fat within and across breeds
Soyeurt, Hélène ULg; Dardenne, Pierre; Gillon, Alain ULg et al

in Journal of Dairy Science (2006), 89(12), 4858-4865

The aim of this research was to study the potential for selection of cows with a higher nutritional quality of milk fat by studying the differences in fatty acid profiles within and across the following ... [more ▼]

The aim of this research was to study the potential for selection of cows with a higher nutritional quality of milk fat by studying the differences in fatty acid profiles within and across the following breeds: Dual Purpose Belgian Blue, Holstein-Friesian, Jersey, Montbeliarde, and non-Holstein Meuse-Rhine-Yssel type Red and White. Six hundred milk samples from 275 animals were taken from 7 herds. Several types of fatty acids in milk and milk fat were quantified using midinfrared spectrometry and previously obtained calibration equations. Statistical analyses were made using a mixed linear model with a random animal effect. The variance components were estimated by using REML. Results showed breed differences for the fatty acid profile. The repeatability estimate obtained in the present study may suggest the existence of moderate additive genetic variance for the fatty acid profile within each breed. Results also indicated variation for each analyzed milk component in the whole cow population studied. Genetic improvement of the nutritional quality of milk fat based on fatty acid profiles might be possible, and further research and development are warranted. [less ▲]

Detailed reference viewed: 27 (3 ULg)
Full Text
See detailInvestigation on genotype by environment interaction for milk yield of Holstein cows in Luxembourg and Tunisia
Hammami, Hedi ULg; Croquet, Coraline; Soyeurt, Hélène ULg et al

in INTERBULL Bulletin (2006), 35

Detailed reference viewed: 30 (10 ULg)
Full Text
Peer Reviewed
See detailInbreeding depression for global and partial economic indexes, production, type, and functional traits
Croquet, Coraline; Mayeres, Patrick; Gillon, Alain ULg et al

in Journal of Dairy Science (2006), 89(6), 2257-2267

The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and ... [more ▼]

The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and its components were studied by using data from the genetic evaluations of February 2004 for production, somatic cell score (SCS), computed from somatic cell counts and type. Inbreeding coefficients for 956,516 animals were computed using a method that allows assigning an inbreeding coefficient to individuals without known parents. These coefficients were equal to the mean inbreeding coefficient of contemporary individuals with known parents. The significance of inbreeding effects on the different evaluated traits and on the different indexes were tested using a t-test comparing estimated standard errors and effects. The inbreeding effect was significantly different from zero for the vast majority of evaluated traits and for all of the indexes. Inbreeding had the greatest deleterious effects on production traits. Inbreeding decreased yield of milk, fat, and protein during a lactation by 19.68, 0.96, and 0.69 kg, respectively, per each 1% increase in inbreeding. The regression coefficient of SCS per 1% increase in inbreeding was +0.005 SCS units. The inbreeding depression was thus relatively low for SCS, but inbred animals had higher SCS than non-inbred animals, indicating that inbred animals would be slightly more sensitive to mastitis than non-inbred animals. Estimates of inbreeding effects on evaluated type traits per 1% increase were small. The most strongly affected type traits were chest width, rear leg, and overall development on a standardized scale. For several type traits, particularly traits linked to the udder, the estimates suggested a favorable effect of inbreeding. The global economic index was depressed by around 6.13 Euro of lifetime profit per 1% increase in inbreeding for the Holstein animals in the Walloon region of Belgium. [less ▲]

Detailed reference viewed: 47 (18 ULg)
Full Text
See detailQualité nutritionnelle du lait - Etude de la variabilité intra- et inter-races du profil en acides gras du lait
Soyeurt, Hélène ULg; Dardenne, Pierre; Gillon, Alain ULg et al

in Le Bulletin (2006), (2), 8-10

Detailed reference viewed: 38 (5 ULg)
Full Text
Peer Reviewed
See detailWithin and across breed differences in fatty acids profiles of milk and milk fat
Soyeurt, Hélène ULg; Dardenne, Pierre; Croquet, Coraline et al

in Proceedings of the Bristish Society of Animal Science (2006)

Detailed reference viewed: 10 (1 ULg)
Full Text
See detailEstimation of fatty acid profile in cow milk by mid-infrared spectrometry
Soyeurt, Hélène ULg; Dardenne, Pierre; Lognay, Georges ULg et al

in European seminar on infrared spectroscopy (2006)

Detailed reference viewed: 29 (5 ULg)
Full Text
Peer Reviewed
See detailWithin and across breeds differences in fatty acids profiles of milk and milk fat in dairy cows.
Soyeurt, Hélène ULg; Dardenne, Pierre; Mayeres, Patrick et al

in Proceedings of the 8th World Congress on Genetics Applied to Livestock Production (2006)

Detailed reference viewed: 32 (2 ULg)
Full Text
See detailPotential Estimation of Fatty Acid Content in Cow Milk by Mid-Infrared Spectrometry
Soyeurt, Hélène ULg; Dardenne, Pierre; Lognay, Georges ULg et al

in Prooceedings of the 35th ICAR session (2006)

Detailed reference viewed: 46 (7 ULg)
Full Text
See detailGenetic evaluation of female fertility for Walloon dairy and dual purpose cows using a parity random regression model: first results
Mayeres, Patrick; Vanderick, Sylvie ULg; Croquet, Coraline et al

in INTERBULL Bulletin (2006), 34

Detailed reference viewed: 20 (6 ULg)
Full Text
See detailIntegration of longevity into the Walloon genetic evaluation system
Vanderick, Sylvie ULg; Croquet, Coraline; Soyeurt, Hélène ULg et al

in Interbull Bulletin (2006), 35

Detailed reference viewed: 33 (14 ULg)
Full Text
Peer Reviewed
See detailCorrelations of longevity evaluation with type traits in Walloon Region.
Vanderick, Sylvie ULg; Croquet, Coraline; Mayeres, Patrick et al

in Proceedings of the 8th World Congress on Genetics Applied to LivestockProduction, Belo Horizonte, Minas Gerais, Brazil, 13-18 August, 2006 (2006)

Approximated genetic correlations between direct longevity and type traits were computed for a sire Holstein population. Data were based on results for type traits (77,965 records) and for direct ... [more ▼]

Approximated genetic correlations between direct longevity and type traits were computed for a sire Holstein population. Data were based on results for type traits (77,965 records) and for direct longevity (74,289 records) from the INTERBULL routine run of November 2005. Most of type traits presented a high relationship with direct longevity (from 0.06 up to 0.29). The strongest positive correlation with longevity was for udder depth (0.29) and the strongest negative correlation was for chest depth (-0.21). According the different results, an animal with a good direct longevity seemed to be smaller and less heavy than an animal with a shorter longevity. [less ▲]

Detailed reference viewed: 29 (9 ULg)
Full Text
Peer Reviewed
See detailCorrelations of longevity evaluation with type traits in Walloon Region.
Vanderick, Sylvie ULg; Croquet, Coraline; Mayeres, Patrick et al

Poster (2006)

Approximated genetic correlations between direct longevity and type traits were computed for a sire Holstein population. Data were based on results for type traits (77,965 records) and for direct ... [more ▼]

Approximated genetic correlations between direct longevity and type traits were computed for a sire Holstein population. Data were based on results for type traits (77,965 records) and for direct longevity (74,289 records) from the INTERBULL routine run of November 2005. Most of type traits presented a high relationship with direct longevity (from 0.06 up to 0.29). The strongest positive correlation with longevity was for udder depth (0.29) and the strongest negative correlation was for chest depth (-0.21). According the different results, an animal with a good direct longevity seemed to be smaller and less heavy than an animal with a shorter longevity. [less ▲]

Detailed reference viewed: 17 (2 ULg)
Full Text
Peer Reviewed
See detailValLait - Perspective d’évolution du contrôle laitier en Wallonie (Belgique)
Abras, Sven; Gillon, Alain ULg; Bertozzi, Carlo et al

in 12ièmes Recontres Recherches Ruminants, Paris, les 7 et 8 Décembre 2005 (2005, December)

ValLait est un projet qui vise à optimaliser les valorisations des données récoltées via le contrôle laitier. Ces valorisations reposent sur une régression multiple (“BP”, pour “Best Prediction”) qui ... [more ▼]

ValLait est un projet qui vise à optimaliser les valorisations des données récoltées via le contrôle laitier. Ces valorisations reposent sur une régression multiple (“BP”, pour “Best Prediction”) qui permet d’estimer les productions journalières de lait, de matières grasses et de protéines d’un animal en se basant sur différents effets comme le stade de lactation, la date de vêlage, les historiques de production du troupeau et de la population... En outre, le modèle BP permet également, dès le début de la lactation d’un animal, de prédire ses productions journalières futures. [less ▲]

Detailed reference viewed: 197 (9 ULg)