References of "Lessire, Françoise"
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See detailImpact of grazing practices on farm self-sufficiency, milk and economic performances of three automatized farms
Lessire, Françoise ULiege; Scohier, Catherine ULiege; Dufrasne, Isabelle ULiege

in Porqueddu, Claudio; Franca, Antonello; Lombardi, Giampiero (Eds.) et al Grassland resources for extensive farming systems in marginal lands: major drivers and future scenarios (2017, May 07)

The dairy sector is facing serious economic difficulties linked to low milk price and volatility of feedstuff price. In this context, reducing farm inputs is necessary. Optimization of use of grazed ... [more ▼]

The dairy sector is facing serious economic difficulties linked to low milk price and volatility of feedstuff price. In this context, reducing farm inputs is necessary. Optimization of use of grazed, ensiled or dried grass could be a key strategy to improve self-sufficiency and thus to decrease feeding costs. Yet, practice of grazing is disappearing due to several factors, including increased size of dairy herds and development of automation. However combining grazing and automatic milking systems (AMS) is possible. Three Walloon dairy farms equipped with an AMS were monitored to assess their grazing practices, grass proportion in the cows’ diet both at barn and on pasture and the economic advantages linked to grass use in 2015. These farms practiced various grazing strategies including full-grass system (FG), day and night grass allocation (DNG), and rotational grazing (RG) completed with a partial mixed ration. The effects of grazing on milk yield (MY) were also evaluated. Grazing reduced the daily feeding costs per cow in all systems with variable impact due to grazing management. The most pronounced decline was observed in FG with a severe drop in MY. Conversely, the decrease in MY was less marked in the other farms. [less ▲]

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See detailThe effect of concentrate allocation on traffic and milk production of pasture based cows milked by an automatic milking system
Lessire, Françoise ULiege; Froidmont, Eric; Shortall, John et al

in Animal (2017), 11(4), 1-9

Increased economic, societal and environmental challenges facing agriculture are leading to a greater focus on effective way to combine grazing and automatic milking systems (AMS). One of the fundamental ... [more ▼]

Increased economic, societal and environmental challenges facing agriculture are leading to a greater focus on effective way to combine grazing and automatic milking systems (AMS). One of the fundamental aspects of robotic milking is cows’ traffic to the AMS. Numerous studies have identified feed provided, either as fresh grass or concentrate supplement, as the main incentive for cows to return to the robot. The aim of this study was to determine the effect of concentrate allocation on voluntary cow traffic from pasture to the robot during the grazing period, to highlight the interactions between grazed pasture and concentrate allocation in terms of substitution rate and the subsequent effect on average milk yield and composition. Thus, 29 grazing cows, milked by a mobile robot, were monitored for the grazing period (4 months). They were assigned to 2 groups: a low concentrate (LC) group (15 cows) and a high concentrate (HC) group (14 cows) receiving 2 kg and 4 kg concentrate per cow per day respectively. Two allocations per day of fresh pasture were provided at 0700h and 1600h. The cows had to go through the AMS to receive the fresh pasture allocation. The effect of concentrate level on robot visitation was calculated by summing milkings, refusals and failed milkings/cow per day. The impact on average daily milk yield and composition was also determined. The interaction between lactation number and month was used as an indicator of pasture availability. Concentrate allocation increased significantly robot visitations in HC (3.60 ± 0.07 visitations/cow per day in HC - 3.10 ± 0.07 visitations/cow per day in LC; P<0.001) while milkings/cow per day were similar in both groups (LC: 2.37 ± 0.02/day - HC: 2.39 ± 0.02/day; ns). The average daily milk yield over the grazing period was enhanced in HC (22.39 ± 0.22 kg/cow per day in HC- 21.33 ± 0.22 kg/cow per day in LC; P<0.001). However the gain in milk due to higher concentrate supply was limited with regards to the amount of provided concentrates. Milking frequency in HC primiparous compared with LC was increased. In the context of this study, considering high concentrate levels as an incentive for robot visitation might be questioned, as it had no impact on milking frequency and limited impact on average milk yield and composition. By contrast, increased concentrate supply could be targeted specifically to primiparous cows. [less ▲]

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See detailEnquête sur les pratiques de pâturage en Wallonie: Résultats et conclusions
Lessire, Françoise ULiege; Dufrasne, Isabelle ULiege

Conference given outside the academic context (2017)

The role of grasslands as a C sink is generally accepted. It is considered that permanent grasslands allow annual C storage rates between 22 and 44 g C/m2/y (Soussana et al., 2010) thereby contributing to ... [more ▼]

The role of grasslands as a C sink is generally accepted. It is considered that permanent grasslands allow annual C storage rates between 22 and 44 g C/m2/y (Soussana et al., 2010) thereby contributing to the mitigation of greenhouse gas (GHG) emissions. Grassland preservation has several other advantages including a decrease in feeding costs (Dillon et al., 2005), a positive effect on cows’ health (e.g.a decrease in lameness) (Burow et al., 2011) and the provision of a positive image to consumers. Despite these arguments, grazing is decreasing in Europe and grasslands are disappearing. A better understanding of grazing practices and of farmers’ expectations could suggest ways of improving these practices and limiting grassland disappearance. As a result, Walloon dairy farmers were surveyed in December 2015 and the preliminary results are presented below. [less ▲]

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See detailTraite robotisée, grands troupeaux et pâturage: retour d'expérience de 2 exploitations en Belgique
Lessire, Françoise ULiege; Knoden, David; Dufrasne, Isabelle ULiege

in Fourrages (2017), 229

La technique de traite robotisée entraîne dans bon nombre de cas l’abandon du pâturage ou, du moins, une forte diminution de la part d’herbe pâturée dans la ration des vaches laitières. Cet article montre ... [more ▼]

La technique de traite robotisée entraîne dans bon nombre de cas l’abandon du pâturage ou, du moins, une forte diminution de la part d’herbe pâturée dans la ration des vaches laitières. Cet article montre qu’il est possible de concilier traite robotisée, pâturage et grands troupeaux tout en gardant de bonnes performances économiques. [less ▲]

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See detailEvaluation of the ruminal function of Belgian dairy cows suspected of subacute ruminal acidosis.
Lessire, Françoise ULiege; Knapp, Emilie; Theron, Léonard et al

in Vlaams Diergeneeskundig tijdschrift (2017), 86(1), 16-23

Subacute ruminal acidosis (SARA) has been considered a major pathology in high producing dairy herds for years. These findings were corroborated by several studies in Europe. However, different feeding ... [more ▼]

Subacute ruminal acidosis (SARA) has been considered a major pathology in high producing dairy herds for years. These findings were corroborated by several studies in Europe. However, different feeding practices and herds’ production levels are found in Southern Belgium. This study aimed to ascertain whether dairy cows of several herds from the south of Belgium (Wallonia) with a suspicion of SARA really did present too low ruminal pH values. Twenty-four herds were visited and 172 cows were sampled using an oropharyngeal device to collect ruminal fluid, i.e. Geishauser probe. On the samples, three tests were performed: pH measurement, methylene blue reduction test and microscopic evaluation of protozoa vitality. Based on these analyses, no cows demonstrated pH values lower than 5.5 and, only ten cows could be considered at risk for SARA. By contrast, in eightteen cows, pH values higher than 7.0 were measured and ruminal inactivity was suspected. In this study, ruminal alkalosis appeared to be more frequently observed than SARA. [less ▲]

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See detailLife-Dairyclim, European project aiming to mitigate methane emissions and carbon footprint of dairy cows
Lessire, Françoise ULiege; Bernard, Maxime; Reding, Romain et al

in Höglind, Mats; Bakken, Anne Kjersti; Hovstad, Knut Anders (Eds.) et al The multiple roles of grassland in the European bioeconomy (2016, September 04)

How can dairy farming contribute to reduce the climate change without compromising food security and farm economy? This is the question the project Life-Dairyclim wants to answer. The project gathers ... [more ▼]

How can dairy farming contribute to reduce the climate change without compromising food security and farm economy? This is the question the project Life-Dairyclim wants to answer. The project gathers partners from research groups, association of advisory services to farmers and feed industry in collaboration with private farmers in three countries (Belgium, Luxembourg and Denmark). It focuses on production of feed, including utilisation of grassland and feeding of dairy cows in order to implement strategies that can contribute to a sustainable development of the dairy sector. Feeding experiments to decrease methane from dairy cows will be assessed at the University of Liège (Belgium) with cows milked by an automatic milking system. Methane production will be analysed individually by a device (Guardian®) inserted in the feeding bin as well as by mid infrared spectrum analysis of milk. The effect of concentrate composition on methane production during grazing in combination with optimization of grazing practices will be studied in collaboration with the industrial partner, Dumoulin (Belgium). The carbon footprint of produced milk will be determined using lifecycle assessment methods based on input from the experiments in combination with effect of feed production on especially carbon sequestration from different type of crop and utilization by Aarhus University (Denmark) and Convis, association of advisory services to farmers (Luxembourg). An important part of the project is dissemination based on pilot farms in all three countries documenting the impact of mitigation strategies adopted during the project [less ▲]

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See detailGrazing practices, perception and expectations of Walloon dairy farmers
Lessire, Françoise ULiege; Bernard, Maxime; Lioy, Rocco et al

in Högling, Mats; Bakken, Anne Kjersti; Hovstad, Knut Anders (Eds.) et al The multiple roles of grassland in the European bioeconomy (2016, September 04)

The role of grasslands as a C sink is generally accepted. It is considered that permanent grasslands allow annual C storage rates between 22 and 44 g C/m2/y (Soussana et al., 2010) thereby contributing to ... [more ▼]

The role of grasslands as a C sink is generally accepted. It is considered that permanent grasslands allow annual C storage rates between 22 and 44 g C/m2/y (Soussana et al., 2010) thereby contributing to the mitigation of greenhouse gas (GHG) emissions. Grassland preservation has several other advantages including a decrease in feeding costs (Dillon et al., 2005), a positive effect on cows’ health (e.g.a decrease in lameness) (Burow et al., 2011) and the provision of a positive image to consumers. Despite these arguments, grazing is decreasing in Europe and grasslands are disappearing. A better understanding of grazing practices and of farmers’ expectations could suggest ways of improving these practices and limiting grassland disappearance. As a result, Walloon dairy farmers were surveyed in December 2015 and the preliminary results are presented below. [less ▲]

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See detailChallenges and priorities for modelling livestock health and pathogens in the context of climate change
Özkan, Şeyda; Vitali, Andrea; Lacetera, Nicola et al

in Environmental Research (2016), 151(Supplement C), 130-144

Abstract Climate change has the potential to impair livestock health, with consequences for animal welfare, productivity, greenhouse gas emissions, and human livelihoods and health. Modelling has an ... [more ▼]

Abstract Climate change has the potential to impair livestock health, with consequences for animal welfare, productivity, greenhouse gas emissions, and human livelihoods and health. Modelling has an important role in assessing the impacts of climate change on livestock systems and the efficacy of potential adaptation strategies, to support decision making for more efficient, resilient and sustainable production. However, a coherent set of challenges and research priorities for modelling livestock health and pathogens under climate change has not previously been available. To identify such challenges and priorities, researchers from across Europe were engaged in a horizon-scanning study, involving workshop and questionnaire based exercises and focussed literature reviews. Eighteen key challenges were identified and grouped into six categories based on subject-specific and capacity building requirements. Across a number of challenges, the need for inventories relating model types to different applications (e.g. the pathogen species, region, scale of focus and purpose to which they can be applied) was identified, in order to identify gaps in capability in relation to the impacts of climate change on animal health. The need for collaboration and learning across disciplines was highlighted in several challenges, e.g. to better understand and model complex ecological interactions between pathogens, vectors, wildlife hosts and livestock in the context of climate change. Collaboration between socio-economic and biophysical disciplines was seen as important for better engagement with stakeholders and for improved modelling of the costs and benefits of poor livestock health. The need for more comprehensive validation of empirical relationships, for harmonising terminology and measurements, and for building capacity for under-researched nations, systems and health problems indicated the importance of joined up approaches across nations. The challenges and priorities identified can help focus the development of modelling capacity and future research structures in this vital field. Well-funded networks capable of managing the long-term development of shared resources are required in order to create a cohesive modelling community equipped to tackle the complex challenges of climate change. [less ▲]

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See detailEstimation de la quantité de matière sèche ingérée par les vaches laitières au pâturage en traite robotisée, utilisation de l’analyse des fèces en spectrométrie dans le proche infrarouge
Lessire, Françoise ULiege; Dufrasne, Isabelle ULiege; Decruyenaere, Virginie

in Agabriel, Jacques; Boichard, Didier; Choisis, Jean-Philippe (Eds.) et al 22èmes Rencontres autour des recherches sur les ruminants. (2015, December 02)

Malgré l’intérêt nutritionnel et économique de l’herbe dans la ration des vaches laitières, le pâturage est de plus en plus délaissé en raison notamment de l’automatisation de la traite et de l’extension ... [more ▼]

Malgré l’intérêt nutritionnel et économique de l’herbe dans la ration des vaches laitières, le pâturage est de plus en plus délaissé en raison notamment de l’automatisation de la traite et de l’extension de la taille des troupeaux. Une des raisons invoquées par les éleveurs pour cet abandon est leur manque de confiance par rapport aux quantités d’herbe réellement ingérées par les animaux et la crainte que ces apports inconstants se traduisent par des fluctuations de production laitière tant qualitative que quantitative. Or Decruyenaere et al. (2009, 2012) ont développé une méthode d’estimation de la matière sèche volontairement ingérée (MSVI) par analyse des bouses par spectrométrie dans le proche infra-rouge. Cette méthode présente l’avantage d’être non invasive, facile à mettre en œuvre sur le terrain et peu onéreuse. Le but de cette étude était donc d’évaluer l’utilisation de cette méthode dans un troupeau de vaches laitières traites par un robot mobile en pâture. Le troupeau (n=53) était divisé en 2 groupes dont le niveau de complémentation journalière était différent. Lors de la traite, le groupe 1 (GR1) recevait en moyenne 2,6 kg de concentrés/vache alors que le groupe 2 (GR2) en recevait 4,2 kg/vache. L’objectif était de vérifier l’impact du niveau de complémentation sur les résultats obtenus. Des prélèvements de fèces ont été faits une fois par mois sur 10 vaches (5 vaches par groupe) pendant 4 mois. Les spectres d’absorption dans le proche infra-rouge (NIR) ont été confrontés à des étalonnages NIR permettant l’estimation de la MSVI exprimée soit par rapport au poids vif (MSVI1), soit par rapport au poids métabolique (MSVI2). Ces estimations d’ingestion ont permis le calcul de la matière sèche journalière ingérée par vache (MSI1 et MSI2). Par ailleurs, les mesures d’herbe à l’entrée et à la sortie des parcelles pâturées ont été relevées ainsi que la densité du couvert herbacé pour évaluer la quantité d’herbe disponible. A ces valeurs de biomasses disponibles ont été additionnées des quantités de concentrés distribuées lors du passage des animaux au robot. Les valeurs moyennes de matière sèche ingérée (kg/vache/jour) pour le GR1 étaient de 15,20 ± 2,60 kg MS par la MSI1 et de 16,99 ± 1,80 kg MS pour la MSI2. Pour le GR2, la MSI1moyenne était de 20,20 ± 4,95 kg MS et la MSI2 moyenne de 21,95 ± 3,36 kg MS. L’estimation de la ration disponible par vache (kg MS herbe + kg MS concentrés) était de 17,25 ± 0,73 kg MS pour le GR1 et de 18,69 ±0,83 kg MS pour le GR2. Les valeurs obtenues par l’analyse NIR sont donc compatibles avec les quantités d’herbe et de concentrés disponibles. Les valeurs estimées par les 2 méthodes étaient hautement corrélées entre elles à part en période de faible ingestion (<10 kgMS). En ce cas la MSI2 semble donner des résultats plus fiables. En conclusion, l’analyse NIR des bouses apparaît une technique intéressante pour l’estimation de la quantité d’herbe ingérée au pâturage. [less ▲]

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See detailMilk production, milking frequency and rumination time of grazing dairy cows milked by a mobile milking robot.
Lessire, Françoise ULiege; Hornick, Jean-Luc ULiege; Minet, Julien ULiege et al

in Conington, J; Klopcic, M; Lauridsen, C (Eds.) et al Book of abstracts of the 66th Annual meeting of the European Federation of animal science (2015, September 28)

In Europe, analysis of meteorological data shows that the average temperature has increased by ~1°C over the past hundred years (IPCC, 2013). Heat stress periods are thus expected to be more frequent even ... [more ▼]

In Europe, analysis of meteorological data shows that the average temperature has increased by ~1°C over the past hundred years (IPCC, 2013). Heat stress periods are thus expected to be more frequent even in temperate areas. The use of an automatic milking system (AMS) implies the need to stimulate cows’ traffic to the robot, especially with grazing cows. Describing how heat stress influenced cows’ traffic to the robot is the aim of this study. Grazing dairy cows milked by an automatic system (AMS) experienced heat stress (HS) periods, twice during the summer 2013 in July (J) and August (A). The daily temperature humidity index (THI) during these periods were higher than 75. Each HS period was compared with a “normal period”(N), presenting the same number of cows, similar lactation number, days in milk, distance to come back to the robot and an equal access to water. The first HS period of 5 days with a mean THI of 78.4 was chosen in J, and a second that lasted for 6 days in A with a THI value of 77.3. Heat stress periods were cut off with the same duration of days with no stress (N) and mean THI <70. Milk production, milkings and refusals to the robot during HS were compared with N periods. Milkings and refusals were significantly more numerous in HS periods in July (HS: 2.54 ± 0.11 vs N: 2.19 ± 0.08, 1.87 ± 0.20 vs 0.72 ± 0.16) but milk production dropped from 21.8 ±0.6 kg per cow and per day during N periods to 18.9 ± 0.8 kg in HS. In August, MY increased slightly during HS. This could be explained by less high ambient temperatures and decreased distance to walk inducing less energy expenditure. The increase in milkings and refusals to the robot during HS could be linked to water availability nearby the robot and confirmed previous findings (Lessire et al., 2014). [less ▲]

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See detailChallenging land fragmentation thanks a mobile milking robot: Statement of 2 cases of implementation: Liège and Trevarez experimental farms
Brocard, Valérie; Dufrasne, Isabelle ULiege; Lessire, Françoise ULiege et al

in Conington, J; Klopcic, M; Lauridsen, C (Eds.) et al Book of abstracts of the 66th annual meeting of the European Federation of Animal Science (2015, September)

Cette présentation fait le point de l'expérience de l'utilisation de 2 robots mobiles, développés comme prototypes à la Ferme expérimentale de Trévarez et à l'Université de Liège

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See detailIs it possible for large herds to graze while keeping a high milk yield level? The experience of two Belgian dairy farms.
Lessire, Françoise ULiege; Hornick, Jean-Luc ULiege; Dufrasne, Isabelle ULiege

in van den Pol-van Dasselaer, Agnes; Aarts, H.F.M; De Vliegher, Alex (Eds.) et al Grassland and forages in high output dairy farming systems (2015, June 15)

Grazing is more and more abandoned because of increasing size of herds and automation of herd management (e.g. automatic milking system – AMS). In this context, this study aims to evaluate milk production ... [more ▼]

Grazing is more and more abandoned because of increasing size of herds and automation of herd management (e.g. automatic milking system – AMS). In this context, this study aims to evaluate milk production and composition of 2 large Belgian dairy herds equipped with AMS during winter and summer. These herds were followed over 2 years. At grazing, 30% of the offered feed was grass. Milk production in both herds was similar in summer and winter (30.2 ± 7.14 vs 29.7 ± 7.8 ± in Herd 1 and 26.9 ± 0.8 vs 26.4 ± 0.8 in Herd 2) while their milk composition differed. In conclusion, it is possible for grazing to be preserved even in large herds without impacting noticeably on the herd performance. [less ▲]

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See detailCorrelation between levels of β-hydroxybutyrate and fatty acids in blood and milk and its impact on ketosis diagnosis in dairy cows
Lessire, Françoise ULiege; Knapp, Emilie ULiege; Dotreppe, Olivier et al

Poster (2015, April 16)

SKC at herd level is difficult to diagnose. Poor production and reproduction performances are usually observed as an increased incidence of periparturient diseases in the herd (Suthar et al., 2013 ... [more ▼]

SKC at herd level is difficult to diagnose. Poor production and reproduction performances are usually observed as an increased incidence of periparturient diseases in the herd (Suthar et al., 2013). Diagnosis methods include determination of beta-hydroxybutyrate (BHB) and increased non-esterified fatty acids (NEFA) resulting from body fat mobilization. BHB and NEFA could be dosed in blood of animals in late gestation and in early lactation. Post calving, cows presenting BHB over 1. 2-1.4 mmol/L are considered SCK-cows while those presenting NEFA over 0.6 mg/L are labelled fat mobilising cows. Development of non-invasive diagnosis techniques could be interesting to sample animals at a larger scale with lesser stress. The aim of this study was to verify whether blood and milk BHB values were correlated and whether diagnostic methods by milk analysis could be developed. Seventy -five cows out of 8 selected Walloon dairy herds were followed up monthly from calving to pregnancy diagnosis regarding production and reproduction. At each visit (V), BHB and NEFA levels were determined in milk and blood. A maximum of 5 V was made. BHB was determined in blood using a cow-side test and in milk by a colorimetric test . Blood NEFA and milk fatty acids were determined by gas chromatography (GC). Statistical analysis was performed by SAS 9.1. BHB levels in blood and milk were highly correlated (r= 0.86), indicating the possibility of diagnosis of SCK by milk sampling. The earliest the samples have been taken, the better the correlation is (r=0.95 V1; r = 0.91 V2). Comparison of BHB with NEFA demonstrated a better correlation with milk BHB than with blood BHB (respectively 0.51 and 0.53 in milk vs 0.41 and 0.48 in blood for the V1 and V2 respectively). After the 2d V, the correlation dropped to 0.38 (V3) and -0.14 (V4).To conclude, dosage of milk BHB could be a good indicator for ketosis diagnosis taking into account that correlation with blood BHB and with NEFA is time-related. [less ▲]

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See detailRumination time, milk yield, milking frequency of grazing dairy cows milked by a mobile automatic system during mild heat stress
Lessire, Françoise ULiege; Hornick, Jean-Luc ULiege; Minet, Julien ULiege et al

in Advances in Animal Biosciences (2015), 6(01), 12-14

Grazing dairy cows milked by an automatic system (AS) experienced mild heat stress (HS) periods, twice during the summer. The daily temperature humidity index (THI) during these periods were higher than ... [more ▼]

Grazing dairy cows milked by an automatic system (AS) experienced mild heat stress (HS) periods, twice during the summer. The daily temperature humidity index (THI) during these periods were higher than 72. Milk production, as well as milking frequency, rumination time and milk fat to protein ratio (F/P) during these periods were compared to adjacent periods with mean THI of 61. The daily milking frequency, the total number of visits to AS and the milk production were significantly higher in HS periods (2.12 vs 1.97, 2.99 vs 2.69, and 19.7 vs 18.5 kg milk per cow, respectively). There were significant interactions between times and periods for milking frequency and number of visits, while the daily rumination time was significantly lower (339 vs 419 min) and the F/P in milk tended to be decreased (1.17 vs 1.23). These results could be explained by changes in cow behaviour during HS periods. [less ▲]

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See detailEffects of concentrate level on milk production and traffic of grazing cows milked by a mobile automatic milking system on pasture
Lessire, Françoise ULiege; Hornick, Jean-Luc ULiege; Dufrasne, Isabelle ULiege

in Hopkins, Alan; Collins, Rosemary; Fraser, Marieacia (Eds.) et al EGF at 50: The future of European Grasslands (2014, September 10)

Cows milked by an automatic milking system in pastures were assigned in 2 groups receiving different amounts of concentrates (2.1 kg vs 4.1 kg). The effect of concentrates’ level on milk yield (MY) and ... [more ▼]

Cows milked by an automatic milking system in pastures were assigned in 2 groups receiving different amounts of concentrates (2.1 kg vs 4.1 kg). The effect of concentrates’ level on milk yield (MY) and returns to the robot was assessed. Concentrates’ level had a positive influence on daily milk production over the grazing period as cows of low concentrates group produced 21.43 ± 0.62 kg compared with 24.33 ± 0.62 kg in high concentrates group. However this effect was modulated subsequently to grass quality and availability. Regarding daily voluntary returns to the robot, high concentrates group showed higher frequency (3.66 ± 0.05, compared with 3.22 ± 0.04 in low concentrates group) demonstrating positive impact of complement distribution on cows’ traffic. [less ▲]

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See detailEffects of mild heat stress periods on milk production, milking frequency and rumination time of grazing cows milked by an automatic milking system
Lessire, Françoise ULiege; Hornick, Jean-Luc ULiege; Dufrasne, Isabelle ULiege

in Hopkins, A; Collins, Rosemary; Fraser, Mariecia (Eds.) et al EGF at 50: The future of European grasslands (2014, September 10)

Grazing dairy cows milked by an automatic system (AS) experienced mild heat stress (HS) periods, twice during the summer. The daily temperature humidity index (THI) during these periods were higher than ... [more ▼]

Grazing dairy cows milked by an automatic system (AS) experienced mild heat stress (HS) periods, twice during the summer. The daily temperature humidity index (THI) during these periods were higher than 72. Milk production, as well as milking frequency, rumination time and milk fat to protein ratio (F/P) during these periods were compared to adjacent periods with mean THI of 61. The daily milking frequency, the total number of visits to AS and the milk production were significantly higher in HS periods (2.12 vs 1.97, 2.99 vs 2.69, and 19.7 vs 18.5 kg milk per cow, respectively). There were significant interactions between times and periods for milking frequency and number of visits, while the daily rumination time was significantly lower (339 vs 419 min) and the F/P in milk tended to be decreased (1.17 vs 1.23). These results could be explained by changes in cow behaviour during HS periods. [less ▲]

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See detailEconomical evaluation of feeding costs in pilot farms at grazing.
Lessire, Françoise ULiege; Dufrasne, Isabelle ULiege

Conference (2014, September 07)

Cette présentation montre la méthodologie de calcul des coûts alimentaires dans des fermes laitières au pâturage.Ce calcul nécessite l'évaluation de la quantité d'herbe présente dans la ration et l ... [more ▼]

Cette présentation montre la méthodologie de calcul des coûts alimentaires dans des fermes laitières au pâturage.Ce calcul nécessite l'évaluation de la quantité d'herbe présente dans la ration et l'évaluation du coût de production de celle-ci. La quantité d'herbeest estimée par différentes méthodes explicitées dans la présentation. [less ▲]

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See detailLes herbivores, transformateurs de produits fourragers et de coproduits issus de l'agro-industrie en aliments nobles pour l'homme
Decruyenaere, Virginie; Lessire, Françoise ULiege; Beckers, Yves ULiege et al

in CRA-W (Ed.) La viande bovine remise en question: De sa production à sa consommation (2014, February 19)

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour ... [more ▼]

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour celles-ci bien souvent, les sommes de température et la durée de végétation active sont faibles et limitent considérablement le choix des cultures susceptibles d’atteindre la maturité avant récolte avec certitude. Dans d’autres régions, les prairies s’imposent davantage en raison de contraintes agronomiques : nature du sol, disposition des parcelles, relief du territoire, intérêt dans la rotation pour les prairies temporaires… Ainsi, la grande majorité des prairies de notre Région ne peut pas être remplacée par des cultures ; elles doivent dès lors être perçues comme une bonne alternative à la valorisation du territoire. Grâce à la présence du rumen en amont de l’estomac, les ruminants ont la capacité de transformer des productions non éligibles pour l’homme, tels que les fourrages et les co-produits des industries agro-alimentaires. Ces aliments, de nature essentiellement fibreuse mais pas pour autant pauvres en protéine et en énergie, sont largement fermentés par les micro-organismes du rumen qui les dégradent en composés plus simples, valorisables ensuite par l’animal. Par ce mécanisme, les ruminants contribuent à transformer ces aliments grossiers en produits nobles, tels que le lait et la viande. On comprend dès lors aisément que la présence des ruminants est étroitement liée aux superficies enherbées, elles-mêmes dépendantes des conditions pédo-climatiques d’une région. Malgré des systèmes de production intensifs et l’amélioration continue du potentiel génétique des animaux, les bovins restent peu dépendants des aliments du commerce comparativement aux autres spéculations animales. Ainsi, selon l’APFACA, de l’ordre de 16% des aliments composés produits en Belgique et importés sont utilisés pour les bovins, dont seulement 1/3 est écoulé dans la filière viande bovine. L’herbe, les produits herbagers et les aliments produits sur l’exploitation tels que le maïs restent donc majoritaires dans la ration des bovins élevés pour la production de viande. La valorisation de l’herbe et des produits herbagers dépend fortement des performances zootechniques recherchées. Les objectifs de croissance sont établis, en autre, sur base des prix offerts par la cheville variant avec les catégories d’âge et de poids d’abattage. Ces dernières années, il semble que les animaux abattus un peu plus tardivement soient moins dépréciés qu’auparavant, facilitant la formulation de rations à base de matières premières herbagères. A l’inverse, l’intensification dans le but de produire des animaux abattus plus jeunes ou à un poids supérieur, implique une croissance plus soutenue, et de ce fait la distribution de rations plus denses en énergie. Pour la formulation de telles rations, certains coproduits disposent de valeurs nutritionnelles intéressantes, permettant de satisfaire des besoins nutritionnels élevés, tout en conservant une certaine autonomie alimentaire. Leur valorisation au niveau local représente en outre un intérêt considérable pour la rentabilité des industries agro-alimentaires qui, sans la présence de l’animal, devraient trouver d’autres débouchés pour les coproduits sous peine d’être dans l’obligation de financer leur élimination. Cet exposé a pour objectif d’illustrer les potentiels, mais aussi les limites, des aliments produits localement pour les bovins viande, que ce soit selon leur type (vache de réforme- taurillon…), leur race et leurs performances zootechniques, mais aussi l’intérêt de ces aliments en termes d’efficiences alimentaire et économique. Il analyse les atouts et faiblesses de la spéculation viande bovine en ne se limitant pas à l’échelle de l’animal seul, mais en le replaçant en tant que véritable maillon de la chaîne agro-alimentaire. Ce positionnement permet non seulement de mieux cerner les enjeux de ces élevages au niveau de la production primaire, mais aussi leur importance dans les secteurs amont et aval. [less ▲]

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