References of "Bertozzi, Carlo"
     in
Bookmark and Share    
Full Text
See detailBilan du projet ecopathologique de l'observatoire de la santé mammaire
Bertozzi, Carlo; Froidmont, Eric; Jadoul, Thierry et al

Conference given outside the academic context (2009)

Detailed reference viewed: 52 (11 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 91 (31 ULg)
Full Text
Peer Reviewed
See detailGenetic analysis of lactoferrin content in bovine milk
Arnould, Valérie ULg; Soyeurt, Hélène ULg; Gengler, Nicolas ULg et al

in Journal of Dairy Science (2009), 92(5), 2151-2158

Bovine lactoferrin (LF) is mainly present in milk and shows important physiological and biological functions. The aim of this study was to estimate the heritability and correlation values of LF content in ... [more ▼]

Bovine lactoferrin (LF) is mainly present in milk and shows important physiological and biological functions. The aim of this study was to estimate the heritability and correlation values of LF content in bovine milk with different economic traits as milk yield (MY), fat and protein percentages, and somatic cell score (SCS). Variance components of the studied traits were estimated by REML using a multiple-trait mixed model. The obtained heritability (0.22) for LF content predicted using mid-infrared spectrometry (pLF) suggested the possibility of animal selection based on the increase of LF content in milk. The phenotypic and genetic correlation values calculated between pLF and SCS were moderate (0.31 and 0.24, respectively). Furthermore, a preliminary study of bovine LF gene polymorphism effects was performed on the same production traits. By PCR, all exons of the LF gene were amplified and then sequenced. Three new polymorphisms were detected in exon 2, exon 11, and intron 8. We examined the effects of LF gene polymorphisms of exons 2, 4, 9, 11, and 15, and intron 8 on pLF, MY, fat and protein percentages, and SCS. The different observed effects did not reach a significant level probably because of the characteristics of the studied population. However, the results were promising, and LF may be a potential indicator of mastitis. Further studies are necessary to evaluate the effect of genetic selection based on LF content on the improvement of mastitis resistance. [less ▲]

Detailed reference viewed: 76 (18 ULg)
Full Text
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)

Detailed reference viewed: 46 (15 ULg)
Full Text
Peer Reviewed
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)

Detailed reference viewed: 24 (5 ULg)
Full Text
Peer Reviewed
See detailVariation of delta(9)-desaturase activity in dairy cattle
Soyeurt, Hélène ULg; Dehareng, Frédéric; Mayeres, Patrick et al

in Journal of Dairy Science (2008), 91(8), 3211-3224

The endogenous production of unsaturated fatty acids (FA), particularly some monounsaturated FA (%MONO) and nearly all conjugated linoleic acids, is regulated by the 9-desaturase activity. The aims of ... [more ▼]

The endogenous production of unsaturated fatty acids (FA), particularly some monounsaturated FA (%MONO) and nearly all conjugated linoleic acids, is regulated by the 9-desaturase activity. The aims of this study were to assess the variation of this enzymatic activity within lactation, across dairy breeds, and to estimate its genetic parameters. The ratios of C14:1 cis-9 to C14:0, C16:1 cis-9 to C16:0, and C18:1 cis to C18:0 were calculated from FA contents predicted by mid-infrared spectrometry. Variance components and standard errors were estimated using average information REML. The multitrait mixed model included as fixed effects herd × test date × class of lactation number, class of days in milk × class of lactation number, class of age × class of lactation number, and regressions on breed composition. Four random effects were also included: animal genetic effect, 2 permanent environments (within and across lactations), and residual effect. Under the assumption that the calculated ratios are an approximate measurement of 9-desaturase activity, this study showed different sources of variation for this enzymatic activity. A slight difference was observed within lactation. The ratios of C14:1 cis-9 to C14:0 and C16:1 cis-9 to C16:0 increased as a function of days in milk. Differences across 7 dairy breeds were observed. The values of 9-desaturase indices observed for Jersey and Brown-Swiss cows were lower compared with Holstein. The opposite was observed for dual-purpose Belgian Blue cows. Values of heritability for the ratios of C14:1 cis-9 to C14:0, C16:1 cis-9 to C16:0, and C18:1 cis to C18:0 were 20, 20, and 3%, respectively. Negative genetic correlations observed between fat or protein contents and the 3 indices suggested that an increased activity of 9-desaturase could inhibit the synthesis of fat and protein in bovine milk. Negative correlations were also observed between fat or protein contents and the contents of 3 studied unsaturated FA in milk fat (C14:1 cis-9, C16:1 cis-9, and C18:1 cis). The positive genetic correlations observed between %MONO and the ratios of C14:1 cis-9 to C14:0 (0.72), C16:1 cis-9 to C16:0 (0.62), and C18:1 cis to C18:0 (0.97) showed that %MONO is linked to the 9-desaturase activity. [less ▲]

Detailed reference viewed: 38 (9 ULg)
Full Text
See detailPredicting bovine milk urea concentration for future test-day records in a management perspective
Bastin, Catherine ULg; Laloux, Laurent; Bertozzi, Carlo et al

Conference (2008, April 02)

Detailed reference viewed: 13 (1 ULg)
Full Text
See detailOptiVal: Vers de nouveaux outils de gestion pour les éleveurs laitiers wallons, Prédire la réussite à l’insémination
Laloux, Laurent; Bastin, Catherine ULg; Glorieux, Géry et al

Poster (2008, January 23)

Detailed reference viewed: 3 (2 ULg)
Full Text
See detailVariabilité génétique des composés 'Santé' du lait prédits par la spectrométrie du moyen-infrarouge
Soyeurt, Hélène ULg; Dehareng, Frédéric; Dardenne, Pierre et al

in 13ième Carrefour des Productions Animales: L'Elevage des ruminants en question: vérités et contre-vérités (2008)

Detailed reference viewed: 28 (6 ULg)
Full Text
Peer Reviewed
See detailPredicting bovine milk urea concentration for future test-day records in a management perspective
Bastin, Catherine ULg; Laloux, Laurent; Bertozzi, Carlo et al

in Proceedings of the British Society of Animal Science (2008)

Detailed reference viewed: 30 (13 ULg)
Full Text
See detailOptiVal: Vers de nouveaux outils de gestion pour les éleveurs laitiers wallons, Prédire la réussite à l’insémination
Laloux, Laurent; Bastin, Catherine ULg; Glorieux, Géry et al

in 13ième Carrefour des Productions animales: L'Elevage des ruminants en question: vérités et contre-vérités: Gembloux, le 23 janvier 2008 (2008)

Detailed reference viewed: 23 (3 ULg)
Full Text
See detailAlternative modelling of body condition score from Walloon Holstein cows to develop management tools
Bastin, Catherine ULg; Laloux, Laurent; Gillon, Alain ULg et al

in Proceedings ICAR 36th Session (2008)

Detailed reference viewed: 28 (15 ULg)
Full Text
See detailFirst results of body condition score modeling for Walloon Holstein cows
Bastin, Catherine ULg; Laloux, Laurent; Gillon, Alain ULg et al

Conference (2007, August 25)

Detailed reference viewed: 21 (6 ULg)
Full Text
See detailFirst steps to model milk urea in a management perspective
Bastin, Catherine ULg; Gillon, Alain ULg; Laloux, Laurent et al

Conference (2007, July)

Detailed reference viewed: 2 (1 ULg)