References of "Gengler, Nicolas"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailAn integration of external information for foreign stallions into the Belgian genetic evaluation for jumping horses
Vandenplas, Jérémie ULg; Janssens, Steven; Buys, Nadine et al

in Journal of Animal Breeding & Genetics (2013), 130(3), 209-217

The aim of this study was to test the integration of external information, i.e. foreign estimated breeding values (EBV) and the associated reliabilities (REL), for stallions into the Belgian genetic ... [more ▼]

The aim of this study was to test the integration of external information, i.e. foreign estimated breeding values (EBV) and the associated reliabilities (REL), for stallions into the Belgian genetic evaluation for jumping horses. The Belgian model is a bivariate repeatability Best Linear Unbiased Prediction animal model only based on Belgian performances while Belgian breeders import horses from neighbouring countries. Thereby, use of external information is needed as prior to achieve more accurate EBV. Pedigree and performance data contained 101,382 horses and 712,212 performances, respectively. After conversion to the Belgian trait, external information of 98 French and 67 Dutch stallions were integrated into the Belgian evaluation. Resulting Belgian rankings of the foreign stallions were more similar to foreign rankings according to the increase of the rank correlations of at least 12%. REL of their EBV were improved of at least 2% on average. External information was partially to totally equivalent to 4 years of contemporary horses’ performances or to all the stallions’ own performances. All these results showed the interest to integrate external information into the Belgian evaluation. [less ▲]

Detailed reference viewed: 61 (27 ULg)
Full Text
See detailLa mortalité de l'abeille domestique : entre communication médiatique et scientifique
Leclercq, Gil ULg; Francis, Frédéric ULg; Haubruge, Eric ULg et al

Conference given outside the academic context (2013)

A l’heure actuelle, plus personne n’ignore que nos populations d’abeilles domestiques subissent de lourdes pertes, chez nous comme dans de nombreux autres pays. Les médias ont axés leur communication sur ... [more ▼]

A l’heure actuelle, plus personne n’ignore que nos populations d’abeilles domestiques subissent de lourdes pertes, chez nous comme dans de nombreux autres pays. Les médias ont axés leur communication sur des messages très simples. On en retient surtout que les pesticides tuent nos abeilles. La conclusion au problème est dès lors évidente : il faut interdire les pesticides. Mais cette problématique est-elle si simple ? Ce message est-il le même que celui communiqué par les scientifiques ? Cette conférence permettra de faire le point sur les pertes en colonies d’abeilles domestiques. On s’intéressera plus particulièrement aux pertes de ces dernières années en Belgique, cartes et chiffres à l’appui. On y verra aussi comment chacun, qu’il soit citoyen, apiculteur, agriculteur,… peut aider à enrayer cette mortalité effrayante. [less ▲]

Detailed reference viewed: 74 (9 ULg)
Full Text
See detailGenetic parameters for methane emissions predicted from milk mid-infrared spectra in dairy cows
Kandel, Purna Bhadra ULg; Vanrobays, Marie-Laure ULg; vanlierde, Amélie et al

Scientific conference (2013, March 25)

Detailed reference viewed: 32 (21 ULg)
Full Text
See detailNeuartige Management Tools für Milchviehbetrieb mittels Spektralanalytik
Arnould, Valérie ULg; Reding, Romain; Bormann, Jeanne et al

Article for general public (2013)

In den letzten Jahrzenten wurde die Milch- und Fleischproduktion mehr und mehr mit generellen Nachhaltigkeitsfragen in Verbindung gebracht. Sehr oft wird eine bessere Produktionsnachhaltigkeit auch mit ... [more ▼]

In den letzten Jahrzenten wurde die Milch- und Fleischproduktion mehr und mehr mit generellen Nachhaltigkeitsfragen in Verbindung gebracht. Sehr oft wird eine bessere Produktionsnachhaltigkeit auch mit ökonomischen Aspekten verbunden. In der Tat liegt die Kunst der modernen Milchproduktion scheinbar vor allem darin, die Produktion (egal ob tier- oder betriebsindividuell) stetig bei möglichst gleichbleibenden oder gar noch geringeren Kosten zu erhöhen. Daneben ist zu bedenken, dass Konsumenten heutzutage neben preislichen Aspekten sehr oft zusätzlich Gesundheitsaspekte ins Spiel bringen, so dass es für Milchbetriebe nicht unwesentlich ist, die Produktion in gewisser Weise diesen Ansprüchen nach zu gestalten. Glücklicherweise können entscheidende Inhaltsstoffe wie der Milchfettgehalt oder das Fettsäuremuster der Milch durch Managementfaktoren wie Zucht, Selektion, Fütterung und Haltungsbedingungen zum Positiven beeinflusst werden und den Anforderungen der Nachfrageseite besser angepasst werden. Genau bei dieser Problematik liegen die Ansatzpunkte der verschiedenen CONVIS Projekte (QuaM, ManageMILK und OptiMIR) im Bereich Spektralanalysen der Milch. [less ▲]

Detailed reference viewed: 35 (11 ULg)
Full Text
Peer Reviewed
See detailEvaluation of Heat Stress Effects on Production Traits and Somatic Cell Score of Holsteins in a Temperate Environment
Hammami, Hedi ULg; Bormann, Jeanne; M'Hamdi, Naceur et al

in Journal of Dairy Science (2013), 96(3), 1844-1855

This study was aimed to evaluate the degree of thermal stress exhibited by Holsteins under a continental temperate climate. Milk, fat, protein, and somatic cell count test-day records collected between ... [more ▼]

This study was aimed to evaluate the degree of thermal stress exhibited by Holsteins under a continental temperate climate. Milk, fat, protein, and somatic cell count test-day records collected between 2000 and 2011 from 23,963 cows in 604 herds were combined with meteorological data from 14 public weather stations in Luxembourg. Daily values of six different thermal indices (TI) weighted in term of temperature, relative humidity, solar radiation, and wind speed were calculated by averaging hourly TI over 24 hours. Heat stress thresholds were firstly identified by a broken-line regression model. Regression models were thereafter applied to quantify milk production losses due to heat stress. The tipping points at which milk and protein yields declined were effectively identified. For fat yield, no valid threshold was identified for any of the studied TI. Daily fat yields tended to decrease steadily with increasing values of TI. Daily somatic cell scores (SCS) pattern was marked by increased values at both lowest and highest TI ranges with a more pronounced reaction to cold stress for apparent temperature indices. Thresholds differed between TI and traits. For production traits, they ranged from 62 (TI1) to 80 (TI3) for temperature-humidity indices (THI) and from 16 (TI5) to 20 (TI6) for apparent temperature indices. Corresponding SCS thresholds were higher and ranged from 66 (TI1) to 82 (TI3) and from 20 (TI5) to 23 (TI6), respectively. The largest milk decline per unit of mild, moderate, and extreme heat stress levels of 0.164, 0.356, and 0.955 kg, respectively, was observed when using the conventional THI (TI1). The highest yearly milk, fat, and protein losses of 54, 5.7, and 4.2 kg respectively were detected by TI2, the THI index that is adjusted for wind speed and solar radiation. The latter index could be considered as the best indicator of heat stress to be used for forecast and herd management in a first step in temperate regions under anticipated climate changes. [less ▲]

Detailed reference viewed: 92 (24 ULg)
Full Text
See detailSur la voie de l’élevage laitier de précision en Wallonie - 2. ValLait, OptiVal et OptiVal+ : valoriser des données du contrôle des performances
Bastin, Catherine ULg; Gillon, A.; Massart, X. et al

in 18ème Carrefour des Productions agricoles: Nouvelles approches pour une optimisation de nos élevages laitiers (2013, February)

Detailed reference viewed: 19 (4 ULg)
Full Text
See detailEtude de la variabilité des aptitudes à la transformation laitière en Région wallonne basée sur l'utilisation de la spectrométrie infrarouge
Colinet, Frédéric ULg; Troch, Thibault ULg; Vanden Bossche, S. et al

in 18ième Carrefour des Productions animales : Nouvelles approches pour une optimisation de nos élevages laitiers (2013, February)

Detailed reference viewed: 28 (9 ULg)
Full Text
See detailL'intérêt des races mixtes dans les systèmes laitiers : enseignements du projet BlueSel
Muchembled, A.; Beguin, E.; Glorieux, G. et al

in 18ième Carrefour des Productions animales : Nouvelles approches pour une optimisation de nos élevages laitiers (2013, February)

La « Bleue Mixte » (BM) est une race à petit effectif localisée de part et d’autre de la frontière franco-belge. Menacée de disparition, elle bénéficie d’un projet transfrontalier BlueSel soutenu par le ... [more ▼]

La « Bleue Mixte » (BM) est une race à petit effectif localisée de part et d’autre de la frontière franco-belge. Menacée de disparition, elle bénéficie d’un projet transfrontalier BlueSel soutenu par le programme européen INTERREG IV et les autorités françaises et wallonnes. L’objectif de ce projet est d’assurer la conservation, la sélection et la promotion de la BM. L’un des volets du programme a consisté à étudier la rentabilité économique des troupeaux BM. Il s’est appuyé sur un réseau de 16 fermes de références mis en place fin 2008 jusque mi 2012. La collecte des données techniques et économiques sur les 4 années comptables de 2007 à 2010 a reposé sur la méthodologie mise en oeuvre au sein du dispositif français des Réseaux d’élevage. Les exploitations BM ont été regroupées selon deux systèmes, herbivore et polyculture-élevage, et comparées aux exploitations laitières Prim’Holstein (PH) du Réseau d’élevage de Nord-Picardie. Les résultats démontrent la capacité des éleveurs de vaches BM à obtenir de bonnes performances économiques malgré de plus faibles productivité laitière (4225 l/VL) et taux (3,70 % de MG et 3,22 % de protéines), et un moindre prix du lait, grâce notamment à une conduite de troupeaux bien maîtrisée, des surfaces fourragères très bien valorisées, et la mixité lait-viande très affirmée de la race qui atténue les fluctuations du prix du lait. En système herbivore, les exploitations BM s’avèrent économes et autonomes avec une excellente valorisation des prairies. En système de polyculture-élevage, les troupeaux sont conduits de façon à peine plus intensive qu’en système herbivore, contrairement aux troupeaux PH. [less ▲]

Detailed reference viewed: 22 (5 ULg)
Full Text
See detailSystème d'évaluations génétiques des verrats Piétrain en croisement en Wallonie
Dufrasne, Marie ULg; Gengler, Nicolas ULg

Conference given outside the academic context (2013)

Detailed reference viewed: 10 (0 ULg)
Full Text
See detailEvaluations génétiques des verrats Piétrain en croisement en Wallonie
Dufrasne, Marie ULg; Gengler, Nicolas ULg

Conference given outside the academic context (2013)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailGenetic parameters of milk production traits and fatty acid contents in milk for Holstein cows in parity 1 – 3
Bastin, Catherine ULg; Soyeurt, Hélène ULg; Gengler, Nicolas ULg

in Journal of Animal Breeding & Genetics (2013), 130(2),

The objective of this study was to estimate genetic parameters of milk, fat, and protein yields, fat and protein contents, somatic cell count, and 17 groups and individual milk fatty acid (FA) contents ... [more ▼]

The objective of this study was to estimate genetic parameters of milk, fat, and protein yields, fat and protein contents, somatic cell count, and 17 groups and individual milk fatty acid (FA) contents predicted by mid-infrared spectrometry for first-, second- and third-parity Holstein cows. Edited data included records collected in the Walloon region of Belgium from 37 768 cows in parity 1, 22 566 cows in parity 2 and 8221 in parity 3. A total of 69 (23 traits for three parities) single-trait random regression animal test-day models were run. Approximate genetic correlations among traits were inferred from pairwise regressions among estimated breeding values of cow having observations. Heritability and genetic correlation estimates from this study reflected the origins of FA: de novo synthetized or originating from the diet and the body fat mobilization. Averaged daily heritabilities of FA contents in milk ranged between 0.18 and 0.47. Average daily genetic correlations (averaged across days in milk and parities) among groups and individual FA contents in milk ranged between 0.31 and 0.99. The genetic variability of FAs in combination with the moderate to high heritabilities indicated that FA contents in milk could be changed by genetic selection; however, desirable direction of change in these traits remains unclear and should be defined with respect to all issues of importance related to milk FA. [less ▲]

Detailed reference viewed: 54 (23 ULg)
Full Text
See detailPhenotyping of robustness and milk quality
Berry, D.P.; McParland, S.; Bastin, Catherine ULg et al

in Advances in Animal Biosciences (2013), 4(3), 600-605

A phenotype describes the outcome of the interacting development between the genotype of an individual and its specific environment throughout life. Animal breeding currently exploits large data sets of ... [more ▼]

A phenotype describes the outcome of the interacting development between the genotype of an individual and its specific environment throughout life. Animal breeding currently exploits large data sets of phenotypic and pedigree information to estimate the genetic merit of animals. Here we describe rapid, low-cost phenomic tools for dairy cattle. We give particular emphasis to infrared spectroscopy of milk because the necessary spectral data are already routinely available on milk samples from individual cows and herds, and therefore the operational cost of implementing such a phenotyping strategy is minimal. The accuracy of predicting milk quality traits from mid-infrared spectroscopy (MIR) analysis of milk, although dependent on the trait under investigation, is particularly promising for differentiating between good and poor-quality dairy products. Many fatty acid concentrations in milk, and in particular saturated fatty acid content, can be very accurately predicted from milk MIR. These results have been confirmed in many international populations. Albeit from only two studied populations investigated in the RobustMilk project, milk MIR analysis also appears to be a reasonable predictor of cow energy balance, a measure of animal robustness; high accuracy of prediction was not expected as the gold standard method of measuring energy balance in those populations was likely to contain error. Because phenotypes predicted from milk MIR are available routinely from milk testing, longitudinal data analyses could be useful to identify animals of superior genetic merit for milk quality and robustness, as well as for monitoring changes in milk quality and robustness because of management, while simultaneously accounting for the genetic merit of the animals. These sources of information can be very valuable input parameters in decision-support tools for both milk producers and processors. [less ▲]

Detailed reference viewed: 3 (2 ULg)
Full Text
Peer Reviewed
See detailGenetics of body condition score as an indicator of dairy cattle fertility. A review
Bastin, Catherine ULg; Gengler, Nicolas ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(1), 64-75

Body condition score (BCS) is a subjective measure of the amount of metabolizable energy stored in a live animal. Change in BCS of dairy cows is considered to be an indicator of the extent and the ... [more ▼]

Body condition score (BCS) is a subjective measure of the amount of metabolizable energy stored in a live animal. Change in BCS of dairy cows is considered to be an indicator of the extent and the duration of postpartum negative energy balance. Although change in BCS over lactation is lowly heritable, heritability estimates of level of BCS range from 0.20 to 0.50. Also, BCS tends to be more heritable in mid-lactation indicating that genetic differences are more related to how well cows recover from the negative energy balance state. BCS measurements are generally highly correlated within and between lactations. Genetic correlations with BCS are unfavorable for milk, fat, and protein yield, suggesting that genetically superior producers tend to have lower BCS, especially during the lactation. Genetic correlations are generally moderate and favorable with fertility indicating that cows with higher levels of BCS would have a greater chance to conceive after insemination and fewer number of days when not pregnant. Because direct selection to improve fertility might be complicated by several factors, selection for higher levels of BCS, especially in mid-lactation, appears to be a good option to indirectly improve fertility in dairy cows. [less ▲]

Detailed reference viewed: 7 (4 ULg)
Full Text
Peer Reviewed
See detailReview: Milk composition as management tool of sustainability
Arnould, Valérie ULg; Reding, Romain; Bormann, Jeanne et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(4), 613-621

The main objective of this paper is the use of milk composition data as a management tool. Milk composition, and in particular, milk fat content and fatty acid profiles may be significantly altered due to ... [more ▼]

The main objective of this paper is the use of milk composition data as a management tool. Milk composition, and in particular, milk fat content and fatty acid profiles may be significantly altered due to a variety of factors. These factors are reviewed in the literature; they include diet, animal (genetic) selection, management aspects and animal health. Changes in milk composition can be used as an indicator of the animal’s metabolic status or the efficiency of the feed management system. The advantages of using this kind of data as a management tool would be to allow the early detection of metabolic or management problems. The present review suggests that milk and, especially milk fat composition may be used as a sustainability management tool and as a monitoring and prevention tool for several pathologies or health disorders in dairy cattle. Further, due to the use of MIR technology, these tools may be easily implemented in practice and are relatively cheap. In the field, milk labs or milk recording agencies would be able to alert farmers whenever threshold values for disease were reached, allowing them to improve their dairy production from an economic, ecological and animal (welfare) point of view. [less ▲]

Detailed reference viewed: 40 (19 ULg)
Full Text
Peer Reviewed
See detailEstimation of genetic parameters for birth weight, preweaning mortality, and hot carcass weight of crossbred pigs
Dufrasne, Marie ULg; Misztal, Ignacy; Tsuruta, Shogo et al

in Journal of Animal Science (2013), 91

Genetic parameters for birth weight (BWT), preweaning mortality (PWM), and hot carcass weight (HCW) were estimated for a crossbred pig population to determine if BWT could be used as an early predictor ... [more ▼]

Genetic parameters for birth weight (BWT), preweaning mortality (PWM), and hot carcass weight (HCW) were estimated for a crossbred pig population to determine if BWT could be used as an early predictor for later performances. Sire genetic effects for those traits were estimated to determine if early selection of purebred sires used in crossbreeding could be improved. Data were recorded from one commercial farm between 2008 and 2010. Data were from 24,376 crossbred pigs from Duroc sires and crossbred Large White × Landrace dams and included 24,376 BWT and PWM records, and 13,029 HCW records. For the analysis, PWM was considered as a binary trait (0 for live or 1 for dead piglet at weaning). A multi-trait threshold-linear animal model was used, with animal effect divided into sire genetic and dam effects; the dam effects included both genetic and environmental variation due to the absence of pedigree information for crossbred dams. Fixed effects were sex and parity for all traits, contemporary groups for BWT and HCW, and age at slaughter as a linear covariable for HCW. Random effects were sire additive genetic, dam, litter, and residual effects for all traits, and contemporary group for PWM. Heritability estimates were 0.04 for BWT, 0.02 for PWM, and 0.12 for HCW. Ratio between sire genetic and total estimated variances was 0.01 for BWT and PWM, and 0.03 for HCW. Dam and litter variances explained respectively 14% and 15% of total variance for BWT, 2% and 10% for PWM, and 3% and 8% for HCW. Genetic correlations were −0.52 between BWT and PWM, 0.55 between BWT and HCW, and -0.13 between PWM and HCW. Selection of purebred sires for higher BWT of crossbreds may slightly improve survival until weaning and final market weight at the commercial level. [less ▲]

Detailed reference viewed: 16 (5 ULg)
Full Text
Peer Reviewed
See detailGenetic analysis of longitudinal measurements of feed intake in Piétrain sire lines
Dufrasne, Marie ULg; Jaspart, Véronique; Wavreille, José et al

in Journal of Animal Science (2013), 91(E-Suppl.2), 293

Detailed reference viewed: 27 (8 ULg)