References of "Bastin, Catherine"
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See detailAssociations among BCS, milk production and days-open in Walloon primiparous dairy cows
Massart, Xavier; Laloux, Laurent; Bastin, Catherine ULg et al

Conference (2009, August 27)

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See detailAssociations among BCS, milk production and days-open in Walloon primiparous dairy cows
Laloux, Laurent; Bastin, Catherine ULg; Gillon, Alain ULg et al

in Book of abstracts of the 60th annual meeting of the European Association for Animal Production (2009, August)

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See detailEstimates of genetic parameters among body condition score and calving traits in first parity Canadian Ayrshire cows
Bastin, Catherine ULg; Loker, Sarah; Gengler, Nicolas ULg et al

in Book of Abstracts of the 60th Annual Meeting of the European Association for Animal Production (2009, August)

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See detailExpressing female fertility in the Walloon region of Belgium: how to do?
Vanderick, Sylvie ULg; Bastin, Catherine ULg; Gengler, Nicolas ULg

Conference (2009, August)

Since September 2007, the Walloon Region of Belgium has used a genetic evaluation system for pregnancy rate in Holsteins and has participated in 3 of the 5 MACE trait INTERBULL runs for female fertility ... [more ▼]

Since September 2007, the Walloon Region of Belgium has used a genetic evaluation system for pregnancy rate in Holsteins and has participated in 3 of the 5 MACE trait INTERBULL runs for female fertility. In order to define general way of female fertility expression, a principal component analysis was carried out on six published foreign female fertility indexes. Results of were used to compute a direct female fertility index with the INTERBULL international female fertility proofs available on the Walloon scale. An indirect female fertility index was also developed in order to increase reliability of young bulls. Approximate procedure based on selection index was used to combine both indexes in an overall index called combined female fertility index. This index was highly correlated with the direct female fertility index (.96) and the first principal component (.85), therefore it was considered as good expression of female fertility. Moreover, this allowed recovering 4,019 INTERBULL bulls with a publishable female fertility index. [less ▲]

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See detailLe BCS, une méthode simple à la source de conseils variés : ration, repro et santé
Laloux, Laurent; Bastin, Catherine ULg; Gillon, Alain ULg et al

Poster (2009, February 11)

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See detailModeling milk urea of Walloon dairy cows in management perspectives.
Bastin, Catherine ULg; Laloux, Laurent; Gillon, Alain ULg et al

in Journal of Dairy Science (2009), 92(7), 3529-40

The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management ... [more ▼]

The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management purposes. Data included 607,416 MU test-day records of first-lactation cows from 632 dairy herds in the Walloon Region of Belgium. Several advanced features were used. First, to detect the herd influence, the classical herd x test-day effect was split into 3 new effects: a fixed herd x year effect, a fixed herd x month-period effect, and a random herd test-day effect. A fixed time period regression was added in the model to take into account the yearly oscillations of MU on a population scale. Moreover, first autoregressive processes were introduced and allowed us to consider the link between successive test-day records. The variance component estimation indicated that large variance was associated with the random herd x test-day effect (48% of the total variance), suggesting the strong influence of herd management on the MU level. The heritability estimate was 0.13. By comparing observed and predicted MU levels at both the individual and herd levels, target ranges for MU concentrations were defined to take into account features of each cow and each herd. At the cow level, an MU record was considered as deviant if it was <200 or >400 mg/L (target range used in the field) and if the prediction error was >50 mg/L (indicating a significant deviation from the expected level). Approximately 7.5% of the MU records collected between June 2007 and May 2008 were beyond these thresholds. This combination allowed for the detection of potentially suspicious cows. At the herd level, the expected MU level was considered as the sum of the solutions for specific herd effects. A herd was considered as deviant from its target range when the prediction error was greater than the standard deviation of MU averaged by herd test day. Results showed that 6.7% of the herd test-day MU levels between June 2007 and May 2008 were considered deviant. These deviations seemed to occur more often during the grazing period. Although theoretical considerations developed in this study should be validated in the field, this research showed the potential use of a test-day model for analyzing functional traits to advise dairy farmers. [less ▲]

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See detailEnvironmental sensitivity for milk yield in Luxembourg and Tunisian Holsteins by herd management level.
Hammami, Hedi ULg; Rekik, Boulbaba; Bastin, Catherine ULg et al

in Journal of Dairy Science (2009), 92(9), 4604-12

Milk production data of Luxembourg and Tunisian Holstein cows were analyzed using herd management (HM) level. Herds in each country were clustered into high, medium, and low HM levels based on solutions ... [more ▼]

Milk production data of Luxembourg and Tunisian Holstein cows were analyzed using herd management (HM) level. Herds in each country were clustered into high, medium, and low HM levels based on solutions of herd-test-date and herd-year of calving effects from national evaluations. Data from both populations included 730,810 test-day (TD) milk yield records from 87,734 first-lactation cows. A multi-trait, random regression TD model was used to estimate (co)variance components for milk yield within and across country HM levels. Additive genetic and permanent environmental variances of TD milk yields varied with management level in Tunisia and Luxembourg. Additive variances were smaller across HM levels in Tunisia than in Luxembourg, whereas permanent environmental variances were larger in Tunisian HM levels. Highest heritability estimates of 305-d milk yield (0.41 and 0.21) were found in high HM levels, whereas lowest estimates (0.31 and 0.12, respectively) were associated with low HM levels in both countries. Genetic correlations among Luxembourg HM levels were >0.96, whereas those among Tunisian HM levels were below 0.80. Respective rank orders of sires ranged from 0.73 to 0.83 across Luxembourg environments and from 0.33 to 0.42 across Tunisian HM levels indicating high re-ranking of sires in Tunisia and only a scaling effect in Luxembourg. Across-country environment analysis showed that estimates of genetic variance in the high, medium, and low classes of Tunisian environments were 45, 69, and 81% lower, respectively, than the estimate found in the high Luxembourg HM level. Genetic correlations among 305-d milk yields in Tunisian and Luxembourg HM environments ranged from 0.39 to 0.79. The largest estimated genetic correlation was found between the medium Luxembourg and high Tunisian HM levels. Rank correlations for common sires' estimated breeding values among HM environments were low and ranged from 0.19 to 0.39, implying the existence of genotype by environment interaction. These results indicate that daughters of superior sires in Luxembourg have their genetic expression for milk production limited under Tunisian environments. Milk production of cows in the medium and low Luxembourg environments were good predictors of that of their paternal half-sisters in the high Tunisian HM level. Breeding decisions in low-input Tunisian environment should utilize semen from sires with daughters in similar production environments rather than semen of bulls proven in higher management levels. [less ▲]

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See detailAccessing genotype by environment interaction using within- and across-country test-day random regression sire models
Hammami, Hedi ULg; Rekik, Boulbaba; Soyeurt, Hélène ULg et al

in Journal of Animal Breeding & Genetics (2009), 126(5), 366-377

First-lactation test-day (TD) milk records of Luxembourg and Tunisian Holsteins were analysed for evidence of genotype by environment interaction (G · E). The joint data included 730 810 TD records of 87 ... [more ▼]

First-lactation test-day (TD) milk records of Luxembourg and Tunisian Holsteins were analysed for evidence of genotype by environment interaction (G · E). The joint data included 730 810 TD records of 87 734 cows and 231 common sires. Random regression TD sire models with fourth-order Legendre polynomials were used to estimate genetic parameters via within- and across-country analyses. Daily heritability estimates of milk yield from within-country analysis were between 0.11 and 0.32, and 0.03 and 0.13 in Luxembourg and Tunisia, respectively. Heritability estimates for 305-day milk yield and persistency (defined as the breeding value for milk yield on DIM 280 minus the breeding value on DIM 80) were lower for Tunisian Holsteins compared with the Luxembourg population. Specifically, heritability for 305-day milk yield was 0.16 for within- and 0.11 for across-country analyses for Tunisian Holsteins and 0.38 for within- and 0.40 for across-country analyses for Luxembourg Holsteins. Heritability for apparent persistency was 0.02 for both within and across-country analyses for Tunisian Holsteins and 0.08 for within and 0.09 for across-country analyses for Luxembourg Holsteins. Genetic correlations between the two countries were 0.50 for 305-day milk yield and 0.43 for apparent persistency. Moreover, rank correlations between the estimated breeding values of common sires for 305-day milk yield and persistency, estimated separately in each country, were low. Low genetic correlations are evidence for G · E for milk yield production while low rank correlations suggest different rankings of sires in both environments. Results from this study indicate that milk production of daughters of the same sires depends greatly on the production environment and that importing high merit semen for limited input systems might not be an effective strategy to improve milk production. [less ▲]

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See detailUn intervalle vêlage court: un objectif intéressant pour les hautes productrices?
Laloux, Laurent; Bastin, Catherine ULg; Devroede, Lucie

Article for general public (2009)

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See detailLe BCS, une méthode simple à la source de conseils variés : ration, repro et santé
Laloux, Laurent; Bastin, Catherine ULg; Gillon, Alain ULg et al

in 14ième Carrefour des Productions animales: Les filières bovines dans la tourmente, Produire plus et mieux avec moins: Gembloux, le 11 février 2009 (2009)

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See detailEstimates of genetic parameters among body condition score and fertility traits in first-parity Canadian cows
Bastin, Catherine ULg; Loker, Sarah; Gengler, Nicolas ULg et al

in Journal of Dairy Science (2009), 92 - E-Suppl 1

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See detailExpressing female fertility in the Walloon region of Belgium: how to do?
Vanderick, Sylvie ULg; Bastin, Catherine ULg; Gengler, Nicolas ULg

in Interbull Bulletin (2009), 40

Since September 2007, the Walloon Region of Belgium has used a genetic evaluation system for pregnancy rate in Holsteins and has participated in 3 of the 5 MACE trait INTERBULL runs for female fertility ... [more ▼]

Since September 2007, the Walloon Region of Belgium has used a genetic evaluation system for pregnancy rate in Holsteins and has participated in 3 of the 5 MACE trait INTERBULL runs for female fertility. In order to define general way of female fertility expression, a principal component analysis was carried out on six published foreign female fertility indexes. Results of were used to compute a direct female fertility index with the INTERBULL international female fertility proofs available on the Walloon scale. An indirect female fertility index was also developed in order to increase reliability of young bulls. Approximate procedure based on selection index was used to combine both indexes in an overall index called combined female fertility index. This index was highly correlated with the direct female fertility index (.96) and the first principal component (.85), therefore it was considered as good expression of female fertility. Moreover, this allowed recovering 4,019 INTERBULL bulls with a publishable female fertility index. [less ▲]

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See detailDéveloppement d’un outil de prédiction de la probabilité de réussite à l’insémination chez la vache laitière à partir des données du Contrôle Laitier
Laloux, Laurent; Bastin, Catherine ULg; Glorieux, Géry et al

in 15ème Rencontres Recherches Ruminants, Paris, les 3 et 4 décembre 2008 (2008, December)

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See detailGenetic parameters of saturated and monounsaturated fatty acid content and the ratio of saturated to unsaturated fatty acids in bovine milk.
Soyeurt, Hélène ULg; Dardenne, Pierre; Dehareng, Frédéric et al

in Journal of Dairy Science (2008), 91(9), 3611-26

Fatty acid composition influences the nutritional quality of milk and the technological properties of butter. Using a prediction of fatty acid (FA) contents by mid-infrared (MIR) spectrometry, a large ... [more ▼]

Fatty acid composition influences the nutritional quality of milk and the technological properties of butter. Using a prediction of fatty acid (FA) contents by mid-infrared (MIR) spectrometry, a large amount of data concerning the FA profile in bovine milk was collected. The large number of records permitted consideration of more complex models than those used in previous studies. The aim of the current study was to estimate the effects of season and stage of lactation as well as genetic parameters of saturated (SAT) and monounsaturated (MONO) fatty acid contents in bovine milk and milk fat, and the ratio of SAT to unsaturated fatty acids (UNSAT) that reflect the hardness of butter (SAT:UNSAT), using 7 multiple-trait, random-regression test-day models. The relationship between these FA traits with common production traits was also studied. The data set contained 100,841 test-day records of 11,626 Holstein primiparous cows. The seasonal effect was studied based on unadjusted means. These results confirmed that milk fat produced during spring and summer had greater UNSAT content compared with winter (63.13 vs. 68.94% of SAT in fat, on average). The effect of stage of lactation on FA profile was studied using the same methodology. Holstein cows in early first lactation produced a lower content of SAT in their milk fat. Variance components were estimated using a Bayesian method via Gibbs sampling. Heritability of SAT in milk (0.42) was greater than heritability of SAT in milk fat (0.24). Estimates of heritability for MONO were also different in milk and fat (0.14 vs. 0.27). Heritability of SAT:UNSAT was moderate (0.27). For all of these traits, the heritability estimates and the genetic and phenotypic correlations varied through the lactation. [less ▲]

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See detailGenetic parameters of saturated and monounsaturated fatty acids estimated by test-day model in Walloon dairy cattle
Soyeurt, Hélène ULg; Bastin, Catherine ULg; Dardenne, Pierre et al

in Journal of Dairy Science (2008, July 07)

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