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See detailEvaluation de la Teneur Sanguine en Sélénium dans le Sang des Vaches en Wallonie (Belgique)
Mehdi, Youcef ULg; Cabaraux, Jean-François ULg; Hornick, Jean-Luc ULg et al

in 20ième Rencontre Recherches Ruminants (2013, December 04)

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See detailAssessment of the selenium status in cattle herds in Wallonia
Mehdi, Youcef ULg; Dotreppe, Olivier ULg; Robaye, Vincent ULg et al

in 64th Annual Meeting of the European Federation of Animal Science (2013, August 26)

The selenium content is low in the soil of Wallonia, the southern part of Belgium. It is therefore logical that the selenium content in feedstuffs grown in these fields-grass, conserved forages, cereals ... [more ▼]

The selenium content is low in the soil of Wallonia, the southern part of Belgium. It is therefore logical that the selenium content in feedstuffs grown in these fields-grass, conserved forages, cereals and by-products- is also low. A survey was carried on 166 farms in Wallonia. The farms were located in 4 specific agronomy areas- Pays de Herve with mainly pastures (4farms)- Ardennes (a sub-mountainous area and pastures, 24 farms), Hesbays with mainly arable lands (55 farms) and Condroz with both pastures and arable (83 farms) There were herds with dairy cow, herds with beef cow and herds with both types of animals. The average age was 44±15 months for the cows and 18±6 months for the heifers. The blood samples were taken on five healthy animals of each herd, on the end of the winter just before the animals went to pastures. The selenium status was assessed by the activity of the Glutathion peroydase. The selenium status was extremely variable for the different farms of the 4 areas with variation coefficient of 56%. It was in Pays de Herve and in Hesbaye that the average selenium status was the highest at 53 and 56 µg Se/l. By contrast, it was in Ardenne and in Condroz that the status was the lowest, at 39 and 43 µg Se/l. The selenium status was, on the whole, higher in the dairy herds than in the beef herds owing to the higher selenium provision by the mineral mixtures and the compound feedstuffs added to the diet. Assuming that the normal selenium concentration in plasma being 70µg/l, it appeared also that 81% of the individual animals tested were below the normal Se concentration. It can thus be concluded from the present survey that the cattle herds in Wallonia are deficient in selenium. [less ▲]

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See detailAmélioration des bilans d'excrétion d'azote dans deux exploitations laitières de la région wallonne par un suivi raisonné des rations
Knapp, Emilie ULg; Istasse, Louis ULg; Hornick, Jean-Luc ULg et al

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

Deux exploitations laitières situées l'une en Pays de Herve et l'autre en Ardenne ont fait l'objet de suivis réalisés en vue de déterminer les bilans d'excrétion azotée. Dans la première exploitation, les ... [more ▼]

Deux exploitations laitières situées l'une en Pays de Herve et l'autre en Ardenne ont fait l'objet de suivis réalisés en vue de déterminer les bilans d'excrétion azotée. Dans la première exploitation, les vaches étaient divisées en deux groupes, à savoir le groupes de hautes productrices (HP) et le groupe des basses productrices (BP), chaque groupe recevant une ration spécifique. Dans la seconde exploitation, les animaux constituaient un seul groupe. [less ▲]

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See detailSelenium in the environment, metabolism and involvement in the body functions
Mehdi, Youcef; Hornick, Jean-Luc ULg; Istasse, Louis ULg et al

in Molecules (2013), 13

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See detailInfluence de facteurs environnementaux influençant la teneur en urée dans le lait de vache en Wallonie et estimation des rejets azotés
Dufrasne, Isabelle ULg; Knapp, Emilie ULg; Istasse, Louis ULg et al

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

En Wallonie, les teneurs en urée du lait de tank sont déterminées dans toutes les fermes lors de chaque livraison à la laiterie par le Comité du lait. Un total de 8 295 337 données récoltées pendant ... [more ▼]

En Wallonie, les teneurs en urée du lait de tank sont déterminées dans toutes les fermes lors de chaque livraison à la laiterie par le Comité du lait. Un total de 8 295 337 données récoltées pendant l’année 2000 et la période 2002-2011 ont été analysées à l’aide d’un modèle linéaire. Les effets fixes de la région agricole ou de l’appartenance à la zone vulnérable, du mois, de l’année, des interactions entre ces paramètres ont été inclus dans le modèle. Les teneurs en matières grasse et protéique ont été utilisées comme covariables. La moyenne des teneurs en urée dans le lait a été de 255 mg.l-1. Les modèles ont permis d’expliquer 38 % et 35 % des variations des teneurs en urée pour la région agricole et pour la zone vulnérable respectivement. À l’intérieur de ces modèles, le mois, la région, l’année et l’interaction mois – année ont été les composantes les plus explicatives. Les teneurs en urée ont été plus élevées pendant la période d’avril à octobre et les plus faibles pendant la période de novembre à mars (287 vs 210 mg.l-1). Cette observation peut être expliquée par le changement de ration. Pendant la période estivale, l’herbe constitue une part variable dans la ration et peut apporter une quantité d’azote excédentaire par rapport aux besoins des animaux. Quatre pour cent des observations ont été supérieures à 350 mg.l-1 pendant la période de novembre à mars et 14 % à 400 mg.l-1 pendant la période d’avril à octobre. Dans les régions agricoles limoneuse et sablo-limoneuse, les teneurs en urée ont été plus faibles qu’en Haute Ardenne et en Ardenne (223 et 220 mg vs 278 et 284 mg.l-1 respectivement). Dans la zone vulnérable, les teneurs en urée ont été plus basses que dans la zone non vulnérable (236 vs 273 mg.l-1). Les rejets annuels azotés calculés à partir de différentes équations ont varié de 82 à 119 kg N par vache selon la région agricole. [less ▲]

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See detailInfluence de facteurs environnementaux influençant la teneur en urée dans le lait de vache en Wallonie et estimation des rejets azotés
Dufrasne, Isabelle ULg; Knapp, Emilie ULg; Istasse, Louis ULg et al

in Vandenberghe, Christophe; Colinet, Gilles; Destain, Jean-Pierre (Eds.) et al 2ème Atelier Nitrate-Eau, évaluation du programme de gestion durable de l'azote (2013)

En Wallonie, les teneurs en urée du lait de tank sont déterminées dans toutes les fermes lors de chaque livraison à la laiterie par le comité du lait. Un total de 8295337 données récoltées pendant l'année ... [more ▼]

En Wallonie, les teneurs en urée du lait de tank sont déterminées dans toutes les fermes lors de chaque livraison à la laiterie par le comité du lait. Un total de 8295337 données récoltées pendant l'année 2000 et la période 2002-201 ont été analysées à l'aide d'un modèle linéaire. [less ▲]

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See detailEffects of environmental factors on yield and milking number in dairy cows milked by an automatic system located in pasture
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Knapp, Emilie ULg et al

in Grassland Science (2012), 17

A herd of 45 Holstein dairy cows was milked with an automatic milking system (AMS) located on a permanent pasture. The cows grazed from 22.06.2010 until 20.10.2010 on a rotational system. They were ... [more ▼]

A herd of 45 Holstein dairy cows was milked with an automatic milking system (AMS) located on a permanent pasture. The cows grazed from 22.06.2010 until 20.10.2010 on a rotational system. They were fetched twice a day to the AMS but they could also reach it freely. The sward height was measured at the entry and exit of each paddock. Data about daily milk yield and milking number were analysed according to a GLM including the effect of animal, days in paddock, distance between AMS and paddock, rotation cycle number and complementation. [less ▲]

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See detailInfluence of dietary selenium enrichment on performance and chemical composition of meat in Belgian Blue Bulls
Mehdi, Youcef ULg; Istasse, Louis ULg; Hornick, Jean-Luc ULg et al

in Proceedings of the 2nd Scientific Meeting of the Faculty of Veterinary Medicine (Liège – Belgium) (2012)

Selenium (Se) is a major structural component of various selenoproteins which contain a selenocysteine and a Se atom in their active site (except selenoprotein-P). They play an important role in many ... [more ▼]

Selenium (Se) is a major structural component of various selenoproteins which contain a selenocysteine and a Se atom in their active site (except selenoprotein-P). They play an important role in many functions, such as antioxidant defense and the formation of thyroid hormones. [less ▲]

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See detailProduction laitière et nombre de traites de vaches laitières en prairie avec un robot: effets des facteurs environnementaux.
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Knapp, Emilie ULg et al

Poster (2012)

En Belgique, comme dans d'autres pays européens, le recours à la traite robotisée est en augmentation. La majorité des troupeaux traits avec un robot ne pratique pas le pâturage car les exploitants ... [more ▼]

En Belgique, comme dans d'autres pays européens, le recours à la traite robotisée est en augmentation. La majorité des troupeaux traits avec un robot ne pratique pas le pâturage car les exploitants considèrent que cette méthode n'est pas conciliable avec le pâturage. La fragmentation des parcelles est aussi un frein au pâturage. La mise en place d'un robot dans une structure mobile permet d'utiliser le même robot à l'étable en hiver et dans les prairies distantes de l'exploitation en été. L'objectif de cette étude est de tester l'effet de facteurs environnementaux, l'animal, la complémentation, la distance entre le robot et la parcelle, les numéros du jour dans la parcelle et de cycle de rotation sur la production laitière (PL) et le nombre de traites (NT). [less ▲]

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See detailEffect of water availability on milking frequency and yield of dairy cows milked in pastures by an automatic milking system.
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Knapp, Emilie ULg et al

Poster (2012)

Nowadays farmers have to manage larger herds but at the same time, want to benefit from a normal social life. The automatic milking system (AMS) can be a solution. Its use can reduce physical labour and ... [more ▼]

Nowadays farmers have to manage larger herds but at the same time, want to benefit from a normal social life. The automatic milking system (AMS) can be a solution. Its use can reduce physical labour and allow flexibility. This technology can result in a reduction in grazing even though grazing is considered as a natural practice of the cows which is appreciated by the consumers. However, the milking frequency is decreased when outdoor grazing rather than an indoor feed systems is combined with automatic milking system (AMS) are combined compared to an indoor system. On pasture, cows tend to visit the AMS by group and enter in close succession. Improved cow traffic would allow increased milking frequency and avoid long waiting before milking. In this aim, effect of water availability in the grazing paddocks on the frequencies of cow visits to was tested. [less ▲]

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See detailTotal fat content and essential fatty acids profile in 46 dry dog foods
Ricci, Rebecca; Paligot, Michele ULg; Dequenne, Marjorie ULg et al

in Castrillo, Carlos (Ed.) Congress Proceedings 15th Congress ESVCN (2011, September)

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See detailEffects of environmental factors on yield and milking number in dairy cows milked by an automatic system located in pasture
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Knapp, Emilie ULg et al

Poster (2011)

Nowadays, farmers have to manage larger herds but want, at the same time, benefit from a normal social life. The milking robot can bring solutions. Its use can reduce physical labour and allow flexibility ... [more ▼]

Nowadays, farmers have to manage larger herds but want, at the same time, benefit from a normal social life. The milking robot can bring solutions. Its use can reduce physical labour and allow flexibility. This technology results in a reduction in grazing even through grazing appears as a natural practice which is appreciated by the consumers. This project aims to develop strategies to use milking robots in pasture in order to benefit from advantages regarding feeding costs as well as animal welfare and health. It aims to study the effects of grass height, animal, days in milk, rotation cycle number and distance from grazed paddocks on daily milk yield and milking number of grazed cows. [less ▲]

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See detailNitrogen excretions in dairy cows on a rotational grazing system: effects of fertilization type, days in the paddock and time period.
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Istasse, Louis ULg et al

in Schnyder, Hans; Isselstein, J.; Taube, F. (Eds.) et al Grassland in a changing world (2010, September)

The present study aims to quantify nitrogen (N) excretions in dairy cows on a rotational grazing system with different types of fertilization (mineral N, slurry and compost) after 3 or 5 days in the ... [more ▼]

The present study aims to quantify nitrogen (N) excretions in dairy cows on a rotational grazing system with different types of fertilization (mineral N, slurry and compost) after 3 or 5 days in the paddock and during two different periods in June and September. Individual samples of faeces and urine were collected to assess N excretions from cows in the paddocks. The urea content in milk from the tank or from the individual cows was also measured. N intake was higher on day 3 compared to day 5 (465 vs 425 g d-1, P<0.001) and in September as compared to June (488 vs 425 g d-1, P<0.001) but was not influenced by the fertilization type. The amount of excreted urinary N was significantly higher in the mineral N group than in the two other groups (272 vs 226 g d-1; P<0.001). The N excretion in faeces and urines decreased with days (92 vs 84 g d-1, P<0.01; 256 vs 228 g d-1, P<0.001 respectively for days 3 and 5). Urinary N excretion was lower in June than in September (181 vs 302 g d-1, P<0.001) while the N excretion in the faeces was higher (96 vs 80 g d-1, P<0.01). [less ▲]

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See detailGrazing with a mobile milking robot
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Istasse, Louis ULg et al

in Schnyder, Hans; Isselstein, J.; Taube, F. (Eds.) et al Grassland in a changing world (2010, September)

The size of dairy cow herds in Europe is increasing. Farmers have to manage larger herds but want, at the same time, benefit from a normal social life. So, the milking robot can bring solutions. Its use ... [more ▼]

The size of dairy cow herds in Europe is increasing. Farmers have to manage larger herds but want, at the same time, benefit from a normal social life. So, the milking robot can bring solutions. Its use can reduce physical labour and allow flexibility. During the past 10 years, the number of milking robots has been increased in Europe. In farm practice, this technology has resulted in a reduction in the amount of grazing even though grazing appears as a natural practice which is appreciated by the consumers. At the experimental farm of the University of Liège, we are developing the concept of a mobile milking robot in collaboration with a private company. This prototype will allow cows to graze and could be moved to different locations on pastures during the grazing season. The prototype will be used indoors during the end of the winter season and will be moved outdoor during the 2010 grazing season. The feasibility of this prototype has to be tested in the field. Milk production and quality, the number of visits and the grazing parameters will be recorded. Different equipments in view to attract the cows to the robot as the presence of a cow brush, the location of the drinking point, will be compared. The behaviour of animals will be also assessed. [less ▲]

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See detailInfluence of the fertilization type, the day in the paddock and the month on nitrogen rejections in dairy cows
Dufrasne, Isabelle ULg; Istasse, Louis ULg; Robaye, Vincent ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14

Influence of the fertilization type, the day in the paddock and the month on nitrogen rejections in dairy cows. The present study aims to quantify nitrogen (N) rejections in dairy cows on a rotational ... [more ▼]

Influence of the fertilization type, the day in the paddock and the month on nitrogen rejections in dairy cows. The present study aims to quantify nitrogen (N) rejections in dairy cows on a rotational grazing system with different types of fertilization (compost, slurry and mineral N) at two different days in the paddock (days 3 and 5) and during two different periods (June and September). Grass yield and height were measured along with the chemical composition. The live weight was recorded when the cows moved into the paddock and milk yields was recorded at each milking. N intakes were measured on the basis of the energy requirement. When the cows were in the paddocks, individual samples of faeces and urine were collected to assess N rejections. The urea content in milk from the tank or from the individual cows was also measured. N intake was higher on day 3 than on day 5 and in September as compared with in June but was not influenced by the fertilization. The amount of N produced in milk was not influenced either by the fertilization, by the day on the paddock or by the month. The amount of urinary N was significantly higher in the N mineral group than in the two other groups. The N excretion in faeces and urines was higher on day 3 than on day 5. In June, the N excretion by the urine was lower than in September while the N excretion by the faeces was higher. Equations were calculated in order to estimate the N excretion by the urine in grazing dairy cows from the urea content in milk of a group of cows. [less ▲]

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See detailStudy on environmental factors influencing the urea content of cow milk in Wallonia (Belgium)
Dufrasne, Isabelle ULg; Istasse, Louis ULg; LAMBERT, René ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14

Study on environmental factors influencing the urea content of cow milk in Wallonia (Belgium). The urea content in tank milk is currently assessed in Wallonia (Belgium) for all milk producers by the ... [more ▼]

Study on environmental factors influencing the urea content of cow milk in Wallonia (Belgium). The urea content in tank milk is currently assessed in Wallonia (Belgium) for all milk producers by the Comite du lait. A statistical analysis was carried out on 5,675,758 data collected over the 2002-2008 period in order to study the variation in the urea content in milk from cows according to the months of the years and the agronomy areas. The data were analyzed with a linear model (proc GLM) including the fixed effects of the area, the month of sampling, the year and the interactions. The fat and proteins contents in milk were used as covariables. The average urea content in milk over the six years was 258 mg.l(-1). A proportion of 19% of the contents were over 350 mg.l(-1)and 10% over 400 mg.l(-1). The model explained 35% of the variation of the urea content. Within the model, the agronomy area was the most explicative component (44%). It was followed by the area-month interaction (18.6%), the protein content (17.8%) and the month (10.5%). The variation of the urea content in milk could be mainly explained by the differences in the diets offered to the lactating dairy cows according to the agronomy areas. The composition of the diets varies with the crops produced and therefore with the agronomy area. Higher urea contents were observed in areas with a lot of pastures (grazing areas) than in the arable areas. In the grazing areas, feedstuffs higher in protein than in energy are consumed by the cows: the excess of protein is probably the reason for the higher urea content. The feedstuffs produced in the arable areas are more various with more diversified and balanced diets. The season influenced also the urea content, a higher urea content being observed during the summer period as compared with the winter period. The changes could be explained by dietary differences between the indoor winter period and the grazing period in Summer. During the indoor period, the dairy cows are offered normally a complete diet which is more balanced than during the grazing period. [less ▲]

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See detailProblem of applying sodium selenate to increase selenium concentrations in grassland plant in Southern Belgium
Hambuckers, Alain ULg; Dotreppe, Olivier ULg; Istasse, Louis ULg

in Communications in Soil Science & Plant Analysis (2010), 41

Detailed reference viewed: 64 (24 ULg)