References of "Soyeurt, Hélène"
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See detailGenetic Parameters of Butter Hardness Estimated by Test-Day Model
Soyeurt, Hélène ULg; Dehareng, Frédéric; Bertozzi, Carlo et al

in Interbull Bulletin (2007), 37

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See detailPrinicpal components approach for estimating heritability of mid-infrared (MIR) spectrum in bovine milk
Soyeurt, Hélène ULg; Tsuruta, Shogo; Misztal, Ignacy et al

in Book of Abstracts of the 58th Annual Meeting of the European Association for Animal Production (2007)

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See detailGenetic variability of lactoferrin content estimated by mid-infrared spectrometry in bovine milk
Soyeurt, Hélène ULg; Colinet, Frédéric ULg; Arnould, Valérie ULg et al

in Journal of Dairy Science (2007), 90(9), 4443-4450

The effects of lactoferrin (LF) on the immune system have already been shown by many studies. Unfortunately, the current methods used to measure LF levels in milk do not permit the study of the genetic ... [more ▼]

The effects of lactoferrin (LF) on the immune system have already been shown by many studies. Unfortunately, the current methods used to measure LF levels in milk do not permit the study of the genetic variability of lactoferrin or the performance of routine genetic evaluations. The first aim of this research was to derive a calibration equation permitting the prediction of LF in milk by mid-infrared spectrometry (MIR). The calibration with partial least squares on 69 samples showed a ratio of standard error of cross-validation to standard deviation equal to 1.98. Based on this value, the calibration equation was used to establish an LF indicator trait (predicted LF; pLF) on a large number of milk samples (n = 7,690). A subsequent study of its variability was conducted, which confirmed that stage of lactation and lactation number influence the overall pLF level. Small differences in mean pLF among 7 dairy breeds were also observed. The pLF content of Jersey milk was significantly higher than that in Holstein milk. Therefore, the choice of breed could change the expected LF level. Heritability estimated for pLF was 19.7%. The genetic and phenotypic correlations between somatic cell score and pLF were 0.04 and 0.26, respectively. As somatic cell score increases in presence of mastitis, this observation seems to indicate that pLF, or a function of observed pLF, compared with expected LF might have potential as an indicator of mastitis. The negative genetic correlation (−0.36) between milk yield and pLF could indicate an undesirable effect of selection for high milk production on the overall LF level. [less ▲]

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See detailEstimation of heritability and genetic correlations for the major fatty acids in bovine milk
Soyeurt, Hélène ULg; Gillon, Alain ULg; Vanderick, Sylvie ULg et al

in Journal of Dairy Science (2007), 90(9), 4435-4442

The current cattle selection program for dairy cattle in the Walloon region of Belgium does not consider the relative content of the different fatty acids (FA) in milk. However, interest by the local ... [more ▼]

The current cattle selection program for dairy cattle in the Walloon region of Belgium does not consider the relative content of the different fatty acids (FA) in milk. However, interest by the local dairy industry in differentiated milk products is increasing. Therefore, farmers may be interested in selecting their animals based on the fat composition. The aim of this study was to evaluate the feasibility of genetic selection to improve the nutritional quality of bovine milk fat. The heritabilities and correlations among milk yield, fat, protein, and major FA contents in milk were estimated. Heritabilities for FA in milk and fat ranged from 5 to 38%. The genetic correlations estimated among FA reflected the common origin of several groups of FA. Given these results, an index including FA contents with the similar metabolic process of production in the mammary gland could be used, for example, to increase the monounsaturated and conjugated fatty acids in milk. Moreover, the genetic correlations between the percentage of fat and the content of C14:0, C12:0, C16:0, and C18:0 in fat were −0.06, 0.55, 0.60, and 0.84, respectively. This result demonstrates that an increase in fat content is not directly correlated with undesirable changes in FA profile in milk for human health. Based on the obtained genetic parameters, a future selection program to improve the FA composition of milk fat could be initiated. [less ▲]

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See detailLinear and curvilinear effects of inbreeding on production traits for walloon Holstein cows
Croquet, Coraline; Mayeres, Patrick; Gillon, Alain ULg et al

in Journal of Dairy Science (2007), 90(1), 465-471

The nonlinear effects of inbreeding were studied by comparing linear and curvilinear regression models of phenotypic performances on inbreeding coefficients for production traits (milk, fat, and protein ... [more ▼]

The nonlinear effects of inbreeding were studied by comparing linear and curvilinear regression models of phenotypic performances on inbreeding coefficients for production traits (milk, fat, and protein yields) of Holstein cows in their first lactation. Three different regression models (linear, quadratic, and cubic) were introduced separately into a single-trait, single-lactation, random regression test-day model. The significance of the different regression coefficients was studied based on a t-test after estimation of error variances and covariances associated with the different regression coefficients. All of the tested regression coefficients were significantly different from 0. The traditional regression coefficients of milk, fat, and protein yields on inbreeding were, respectively, -22.10, -1.10, and -0.72 kg for Holstein cows in their first lactation. However, the estimates of 305-d production losses for various classes of animals based on inbreeding coefficients showed that the effect of inbreeding was not a linear function of the percentage of inbreeding. The 305-d milk yield loss profiles attributable to inbreeding, obtained by the various regression models, were different. However, for inbreeding coefficients between 0 and 10%, these differences were small. [less ▲]

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See detailVariation of lactoferrin content predicted by mid-infrared spectrometry (MIR)
Soyeurt, Hélène ULg; Colinet, Frédéric ULg; Arnould, Valérie ULg et al

in Book of Abstracts of the 58th Annual Meeting of the European Association for Animal Production (2007)

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See detailGenetic parameters of the major fatty acid (FA) contents in cow milk
Soyeurt, Hélène ULg; Gillon, Alain ULg; Vanderick, Sylvie ULg et al

in Book of Abstracts of the 58th Annual Meeting of the European Association for Animal Production (2007)

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See detailPrincipal components approach for estimating heritability of mid-infrared spectrum in bovine milk
Soyeurt, Hélène ULg; Tsuruta, Shogo; Misztal, Ignacy et al

in Journal of Dairy Science (2007)

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See detailEstimating fatty acid content in cow milk using mid-infrared spectrometry
Soyeurt, Hélène ULg; Dardenne, Pierre; Dehareng, Frédéric et al

in Journal of Dairy Science (2006), 89(9), 3690-3695

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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

Poster (2006, August)

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See detailContribution à l'étude de la variabilité génétique de la composition en acides gras du lait d'origine bovine
Soyeurt, Hélène ULg

Master of advanced studies dissertation (2006)

Currently there is no cattle selection program in Walloon region which is considering the fatty acid profile of milk fat. However the interest of dairy industry for the differentiated products is ... [more ▼]

Currently there is no cattle selection program in Walloon region which is considering the fatty acid profile of milk fat. However the interest of dairy industry for the differentiated products is increasing. Thus it would be interesting for the farmers to have the possibility to select their animals from nutritional criteria. The objective of this study is to evaluate the feasibility of animal selection to improve the nutritional quality of bovine milk fat. In this case, the estimation of the genetic parameters like the heritabilities and the correlations between each major fatty acids of milk was done. The variability among 7 breeds (Dual Purpose Belgian Blue, Brown Swiss, Holstein-Friesian, Jersey, Montbeliarde, Normande and Red and White) was also studied. The heritabilities for each studied fatty acid ranged from 0.12 and 0.36. Moreover the heritabilities for the ratio of product on substrate which reflected the importance of delta-9 desaturase activity were estimated between 0.11 and 0.17. The obtained genetic correlations showed that the link between different fatty acids was related to their origin in the mammary gland. The differences among the studied breeds showed that each breed have a specific fatty acid profile in milk and a specific delta-9 desaturase activity. In conclusion, a further animal selection program based on the delta-9 desaturase activity could increase the concentrations of monounsaturated fatty acids and conjugated linoleic acid in milk. [less ▲]

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See detailPotential estimation of fatty acid content in cow milk by mid-infrared spectrometry
Soyeurt, Hélène ULg; Dardenne, Pierre; Lognay, Georges ULg et al

Conference (2006, June)

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See detailIntegration of longevity into the Walloon genetic evaluation system
Vanderick, Sylvie ULg; Croquet, Coraline; Soyeurt, Hélène ULg et al

Conference (2006, June)

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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)

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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)

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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

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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)

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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 ▲]

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