References of "Dufrasne, Isabelle"
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See detailUtilisation de la prairie permanente dans le contexte d’extensification: application en productions de viande et de lait
Cameroni, F. J. D.; Hornick, Jean-Luc ULg; Istasse, Louis ULg et al

in Annales de Médecine Vétérinaire (2008), 152(3), 138-151

Les productions animales sont soumises à des restrictions qui ont pour objectif de respecter le bien être animal et la sécurité de la chaîne alimentaire ou de contrôler les volumes de production et leurs ... [more ▼]

Les productions animales sont soumises à des restrictions qui ont pour objectif de respecter le bien être animal et la sécurité de la chaîne alimentaire ou de contrôler les volumes de production et leurs impacts environnementaux. Ces dernières restrictions imposent des mesures de réduction du chargement en animaux par hectare et du niveau de fertilisation azotée et sont réglementées dans le cadre de la Directive Nitrate (91/676/EC). L’extensification des systèmes de production répond aux mesures encouragées par les politiques agricoles qui visent à réduire l’excèdent d’azote (N) dans des systèmes de production présentant intrinsèquement de faibles efficiences d’utilisation de l’azote. Le présent travail récapitule les résultats zootechniques, phytotechniques et environnementaux des systèmes de pâturage, pendant six années, pour trois catégories d’animaux (vaches allaitantes et veaux, taureaux et vaches laitières). Des protocoles semblables ont été utilisés pour les trois catégories, à savoir, un système avec fertilisation azotée et chargement conventionnel intensif (3/3 N), un traitement avec le même chargement et une fertilisation azotée réduite d’un tiers (2/3 N) et un traitement sans application de fertilisation azotée (0 N) avec un chargement adapté. Les résultats montrent qu’une réduction d’un tiers de la fertilisation azotée peut être envisagée pour réduire les excédents d’azote des systèmes de pâturage alors que les systèmes extensifs présentent des efficiences plus hautes d’utilisation de l’azote et des bilans azotés plus favorables, sans affecter le niveau ni la qualité des produits. [less ▲]

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See detailSoil-applied selenium effects on tissue selenium concentrations in cultivated and adventitious grassland and pasture plant species
Hambuckers, Alain ULg; Dotreppe, Olivier ULg; Hornick, Jean-Luc ULg et al

in Communications in Soil Science & Plant Analysis (2008), 39(5-6), 800-811

According to international nutritional standards, plant selenium (Se) concentrations in Belgium are too low. To correct this situation, adding Se in fertilizers for pastures and grasslands is suggested ... [more ▼]

According to international nutritional standards, plant selenium (Se) concentrations in Belgium are too low. To correct this situation, adding Se in fertilizers for pastures and grasslands is suggested, similar to activities in Finland. However, there is a lack of data on meadow plant species' ability to absorb Se. Therefore, a pot experiment was initiated using 24 meadow plant species cultivated on a Belgian cambisol receiving standard fertilizer treatment, with or without the addition of 9 g Se ha(-1) yr(-1) as sodium selenate. Soil Se analysis confirmed the low Se status of the native soil. Mean foliar Se concentration in the control group was 0.05 mg kg(-1). Because plant deficiency may occur at levels less than 0.10 mg Se kg(-1), data provided further evidence for Se deficiency in Belgium plant production. When grown with Se, plant species showed wide variations for Se concentration, ranging from 0.08 to 0.49 mg Se kg(-1). All values were less than 2 mg Se kg(-1), the suggested threshold toxicity level for dairy cattle. There were two different types of plants in terms of response to Se fertilization. Most of the tested plants were known as nonaccumulators. There were also two probable secondary accumulators: Sinapis arvensis and Melilotus albus. Finally, one has to question the reliability of plant Se enhancement using this method when floristic composition is poorly controlled. [less ▲]

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See detailMilk urea content: effects of environmental parameters and relationships with other milk traits
Dufrasne, Isabelle ULg; Cabaraux, Jean-François ULg; Istasse, Louis ULg et al

in Biodiversity and animal feed. Future challenges for grassland production. Proceedings of the 22nd General Meeting of the European Grassland Federation (2008)

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See detailOrganic selenium providing by selenized fertilisation in grazed grass, grass and maize silage for beef and dairy cows.
Cabaraux, Jean-François ULg; Hornick, Jean-Luc ULg; Dotreppe, Olivier ULg et al

in Biodiversity and animal feed. Future challenges for grassland production. Proceedings of the 22nd General Meeting of the European Grassland Federation (2008)

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See detailMilk urea content: effects of environmental parameters and relationships with other milk traits
Dufrasne, Isabelle ULg; Cabaraux, Jean-François ULg; Istasse, Louis ULg et al

in Biodiversity and animal feed. Future challenges for grassland production. Book of abstracts. 22nd General Meeting of the European Grassland Federation (2008)

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See detailOrganic selenium providing by selenized fertilisation in grazed grass, grass and maize silage for beef and dairy cows
Cabaraux, Jean-François ULg; Hornick, Jean-Luc ULg; Dotreppe, Olivier ULg et al

in Biodiversity and animal feed. Future challenges for grassland production. Book of abstracts. 22nd General Meeting of the European Grassland Federation (2008)

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See detailEssential fatty acids content in beef meat as influenced by crushed, flaked or extruded linseeds
Robaye, Vincent ULg; Dotreppe, Olivier ULg; Cabaraux, Jean-François ULg et al

in book of abstract of the 59th Annual meeting of the European Association for Animal Production (2008)

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See detailCarcasses of Belgian Blue double muscle culled cows or growing fattening bulls: essential fatty acids content in 17 meat pieces
Robaye, Vincent ULg; Dotreppe, Olivier ULg; Cabaraux, Jean-François ULg et al

in book of abstract of the 59th Annual meeting of the European Association for Animal Production (2008)

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See detailDevelopment of a radioimmunoassay for bovine chymosin B
Idrissa-Sidikou, Djibo; Remy, Benoit; Dufrasne, Isabelle ULg et al

in Tropicultura (2007), 25(3), 134-139

The present study was conducted to develop and validate a specific radioimmunoassay system for measurement of bovine chymosin B (bChyB) concentrations in plasma samples. Bovine ChyB was used for ... [more ▼]

The present study was conducted to develop and validate a specific radioimmunoassay system for measurement of bovine chymosin B (bChyB) concentrations in plasma samples. Bovine ChyB was used for immunization of rabbits and as standard and tracer. Chymosin B concentrations were measured in plasma samples from two groups of calves (Group 1: calves sampled from birth to 24 hours; Group 2: calves sampled from Day 1 to 21 after birth) and from one cow during the peri-partum period. Detection limit of the assay was 9.0 ng/mL. Recovery was higher than 89.3%. Repeatability and reproducibility ranged from 1.52% to 5.23% and from 1.52% to 12.57% respectively. No cross-reaction was found with pepsinogen A from bovine, porcine or human origins. In Group 1, bChyB concentrations increased from 47.3±45.1 ng/mL (5 min after birth) to 325.5±161.2 ng/mL (12 hours after birth), then it decreased till 293.0±161.5 ng/mL (24 hours after birth). In Group 2, concentrations decreased from Day 1 (455.3±191.1 ng/mL) to Day 21 (117.9±85.1 ng/mL). In adult cow, mean concentration was 136.0±32.3 ng/mL. In conclusion, bChyB is able to cross the stomach basal membrane and to reach the blood circulation at detectable levels in both young calves and adult cows. [less ▲]

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See detailDevelopment of indicators to quantify nitrogen rejections of grazing dairy cows according to fertilisation types
Meura, Stéphane; Lambert, Richard; Dufrasne, Isabelle ULg et al

in Permanent and temporary grassland plant, environment and economy; A. De Vliegher and L. Carlier (Eds); Proceedings of 14th symposium of the European Grassland Federation (2007)

Nitrogen (N) rejections are a problem of importance in cattle production. In pasture, the amounts of N rejected by the cattle are large since grass N content exceeds the ‘animals’ requirements. The ... [more ▼]

Nitrogen (N) rejections are a problem of importance in cattle production. In pasture, the amounts of N rejected by the cattle are large since grass N content exceeds the ‘animals’ requirements. The present study aims to quantify, with dairy cows in a rotational system, N rejections from urine. The trial paddocks were fertilized with compost, slurry or mineral N and grazed during 7 days by 35 dairy cows in late lactation. Milk urea concentration was determined in tank milk samples every day. Urine samples were taken from each cow at the 3rd and the 5th day after the entry in the grazing plot. Urine N and creatinin were determined to quantify urine N excretion. These observed values were compared to urine N excretion data obtained from dry matter intake and grass N content. The mean observed urine N excretion of 312 g N day-1 was similar to the mean calculated urine N excretion of 330 g N day-1. The correlation between calculated urinary N excretion and observed urinary N excretion was significant (P<0.001; r2= 22.4%) and the correlation between observed urinary N excretion and milk urea content tended to be significant (P<0.10; r2 =60%). From these data, it appears that urine N excretion prediction can be more precise with tank milk urea than with urine N excretion calculated from N intake. This research has to be continued and to be repeated during other grazing periods and with cows at different lactation periods to validate the results. [less ▲]

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See detailNitrogen balance and nitrate residues in pastures grazed by dairy cows and fertilised with mineral fertiliser, pig slurry or cattle compost
Dufrasne, Isabelle ULg; Meura, Stéphane; Cabaraux, Jean-François ULg et al

in Permanent and temporary grassland plant, environment and economy; A. De Vliegher and L. Carlier (Eds); Proceedings of 14th symposium of the European Grassland Federation (2007)

A code of good practices was established by each European member state according to the nitrate directive. In Belgium, the nitrogen (N) inputs from slurry or compost are limited to 230 kg N/ha in pastures ... [more ▼]

A code of good practices was established by each European member state according to the nitrate directive. In Belgium, the nitrogen (N) inputs from slurry or compost are limited to 230 kg N/ha in pastures. Larger amounts can be applied when a program of additional measurements, including soil nitrates analysis, is followed by the farmer. This trial aims to measure nitrogen balance and soil nitrates in pastures fertilised with mineral nitrogen fertiliser (min N), pig slurry (S) or cattle compost (C). The pastures were grazed by dairy cows and the fertilisation allowed similar efficient N levels. N inputs by fertilisation were different at 169, 170 and 102 kg N/ha in C, S and min N plots respectively. The use of pig slurry and cattle compost as compared with mineral N fertiliser increased N balance and reduced apparent N efficiency. The nitrogen, potassium and phosphorus nutrition indexes, the number of grazing days and the milk yields per ha were not different. The soil nitrate contents were not increased by use of slurry or compost. The overall low nitrate contents suggested a low nitrate leaching with the three types of fertilisation. [less ▲]

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See detailMilk urea content as influenced by geographical area and season in Wallonia
Meura, Stéphane; Dufrasne, Isabelle ULg; Cabaraux, Jean-François ULg et al

in Permanent and temporary grassland plant, environment and economy; A. De Vliegher and L. Carlier (Eds); Proceedings of 14th symposium of the European Grassland Federation (2007)

Milk urea concentration is routinely determined in commercial dairy farms along with the official milk analyses carried out on milk samples for the dairies by the “Comité du lait”. The milk urea content ... [more ▼]

Milk urea concentration is routinely determined in commercial dairy farms along with the official milk analyses carried out on milk samples for the dairies by the “Comité du lait”. The milk urea content do not modify milk price but can be useful for the farmers for diet calculation, milk urea content being related to the energy-protein ratio in the diet. The aim of this paper was to study the evolution of the milk urea content according to the months and the areas. Milk urea concentration changed according to the months owing to the diet: the summer diets, mainly composed by grass in many farms, were characterized by higher nitrogen content which as result an increase in milk urea concentration. The geographic areas can also influence milk urea concentration due to dietary difference. For example, in the Hesbaye area, beet and cereals are produced while in the Ardennes, grasslands are dominant. The urea content in milk can be an useful measurement for the diet calculations in order to decrease nitrogen waste and to reduce the feed costs. [less ▲]

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See detailDifferent treatments of linseed of culled cows and young bulls
Robaye, Vincent ULg; Dotreppe, Olivier ULg; Cabaraux, Jean-François ULg et al

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

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See detailInclusion of cereals, hay and straw naturally enriched in selenium by use of fertilizers in horses diets: overtime effects on antioxidant markers
Hornick, Jean-Luc ULg; Paeffgen, S.; Cabaraux, Jean-François ULg et al

in 11th Congress of the European Society of Veterinary and Comparative Nutrition (2007)

Detailed reference viewed: 14 (1 ULg)