Suchergebnisse

International audience ; The Crau Plain grasshopper, Prionotropis rhodanica Uvarov, 1923 (Orthoptera: Pamphagidae: Thrinchinae), is a rare grasshopper species endemic to the Crau Plain, a steppic habitat in France with unique floristic and faunistic communities. During recent decades, the area covered by these steppic grasslands has been highly reduced and fragmented due to the development of irrigation-based agriculture, roads, as well as industrial and military complexes. The restricted distribution, low population density and poor dispersal ability of P. rhodanica , combined with the destruction of its habitat, has led to the classification of this species as critically endangered in the IUCN Red List of Threatened Species. Decreases in habitat quality due to intensive grazing in the remnant grassland patches constitute an additional threat for P. rhodanica that can impact population dynamics at a relatively small-scale. In this work, we focused on a small area of about 3 km2 occupied by one of the largest subpopulations observed in 2000–2001. We conducted a single-time snapshot intensive survey of grasshopper density and genetic variation at 11 microsatellite markers. We used a recent method, MAPI, to visualize the spatial genetic structure as a continuous surface and to determine, with the simultaneous use of spatial cross-correlograms, whether the normalized difference vegetation index, which informs on the balance between vegetation productivity and grazing intensity, can explain grasshopper population structure at such a fine scale. We found that both population density and gene flow were strongly and positively correlated to habitat quality (higher productivity of grasslands and/or lower sheep grazing). The spatial scales of interaction between these variables were estimated to be highly similar, in the range of 812–880 meters. This result suggests that P. rhodanica is very sensitive to the quality of the grasslands it inhabits.

International audience ; The Crau Plain grasshopper, Prionotropis rhodanica Uvarov, 1923 (Orthoptera: Pamphagidae: Thrinchinae), is a rare grasshopper species endemic to the Crau Plain, a steppic habitat in France with unique floristic and faunistic communities. During recent decades, the area covered by these steppic grasslands has been highly reduced and fragmented due to the development of irrigation-based agriculture, roads, as well as industrial and military complexes. The restricted distribution, low population density and poor dispersal ability of P. rhodanica , combined with the destruction of its habitat, has led to the classification of this species as critically endangered in the IUCN Red List of Threatened Species. Decreases in habitat quality due to intensive grazing in the remnant grassland patches constitute an additional threat for P. rhodanica that can impact population dynamics at a relatively small-scale. In this work, we focused on a small area of about 3 km2 occupied by one of the largest subpopulations observed in 2000–2001. We conducted a single-time snapshot intensive survey of grasshopper density and genetic variation at 11 microsatellite markers. We used a recent method, MAPI, to visualize the spatial genetic structure as a continuous surface and to determine, with the simultaneous use of spatial cross-correlograms, whether the normalized difference vegetation index, which informs on the balance between vegetation productivity and grazing intensity, can explain grasshopper population structure at such a fine scale. We found that both population density and gene flow were strongly and positively correlated to habitat quality (higher productivity of grasslands and/or lower sheep grazing). The spatial scales of interaction between these variables were estimated to be highly similar, in the range of 812–880 meters. This result suggests that P. rhodanica is very sensitive to the quality of the grasslands it inhabits.

To understand the diversity of the European grazing livestock holdings and to evaluate the differential impacts of agricultural policy reforms, a typology has been built on the basis of the data available in the European Farm Accounting Data Network (FADN). This typology, called GLS "Grazing Livestock Systems", is a product that could be used by the General Direction for agriculture of the European Commission. It proposes to divide grazing livestock holdings into several typological classes, having regard to the composition of the breeding herd and the categories of animals. The grazing livestock holdings are broken down homogeneously at the European level into four types of production, nine livestock systems and eighteen technical systems. This typology, which is complementary to the approach by types of farming, makes it possible to undertake a comparative study of the structures and economic results of holdings which have comparable systems in different countries or different regions of the European Union. In the context of rapid adjustment of the common agricultural policy to market, the GLS typology can contribute to a more in-depth analysis of the various effects of new agricultural policy measures on the livestock fanning systems. The analysis of the main characteristics of the European farms according to the GLS typology enables to show the complexity of productive systems, the heterogeneous of farms structure (in terms of economical dimension, specialisation, intensification), the high contribution of dairy farms to meat supply and the important role played by direct support in the breeders' income. ; Pour mieux appréhender la diversité des exploitations européennes d'élevage herbivore (lait, viande bovine et ovine), une méthode de classification complémentaire à celle privilégiant les orientations technico-économiques (OTEX) est proposée à partir des données du Réseau d'information comptable agricole (RICA) européen. Cette typologie intitulée GLS (Grazing Livestock System) conduit à répartir, de façon ...

The Crau Plain grasshopper, Prionotropis rhodanica Uvarov, 1923 (Orthoptera: Pamphagidae: Thrinchinae), is a rare grasshopper species endemic to the Crau Plain, a steppic habitat in France with unique floristic and faunistic communities. During recent decades, the area covered by these steppic grasslands has been highly reduced and fragmented due to the development of irrigation-based agriculture, roads, as well as industrial and military complexes. The restricted distribution, low population density and poor dispersal ability of P. rhodanica, combined with the destruction of its habitat, has led to the classification of this species as critically endangered in the IUCN Red List of Threatened Species. Decreases in habitat quality due to intensive grazing in the remnant grassland patches constitute an additional threat for P. rhodanica that can impact population dynamics at a relatively small-scale. In this work, we focused on a small area of about 3 km2 occupied by one of the largest subpopulations observed in 2000–2001. We conducted a single-time snapshot intensive survey of grasshopper density and genetic variation at 11 microsatellite markers. We used a recent method, MAPI, to visualize the spatial genetic structure as a continuous surface and to determine, with the simultaneous use of spatial cross-correlograms, whether the normalized difference vegetation index, which informs on the balance between vegetation productivity and grazing intensity, can explain grasshopper population structure at such a fine scale. We found that both population density and gene flow were strongly and positively correlated to habitat quality (higher productivity of grasslands and/or lower sheep grazing). The spatial scales of interaction between these variables were estimated to be highly similar, in the range of 812–880 meters. This result suggests that P. rhodanica is very sensitive to the quality of the grasslands it inhabits.

The Crau Plain grasshopper, Prionotropis rhodanica Uvarov, 1923 (Orthoptera: Pamphagidae: Thrinchinae), is a rare grasshopper species endemic to the Crau Plain, a steppic habitat in France with unique floristic and faunistic communities. During recent decades, the area covered by these steppic grasslands has been highly reduced and fragmented due to the development of irrigation-based agriculture, roads, as well as industrial and military complexes. The restricted distribution, low population density and poor dispersal ability of P. rhodanica, combined with the destruction of its habitat, has led to the classification of this species as critically endangered in the IUCN Red List of Threatened Species. Decreases in habitat quality due to intensive grazing in the remnant grassland patches constitute an additional threat for P. rhodanica that can impact population dynamics at a relatively small-scale. In this work, we focused on a small area of about 3 km2 occupied by one of the largest subpopulations observed in 2000–2001. We conducted a single-time snapshot intensive survey of grasshopper density and genetic variation at 11 microsatellite markers. We used a recent method, MAPI, to visualize the spatial genetic structure as a continuous surface and to determine, with the simultaneous use of spatial cross-correlograms, whether the normalized difference vegetation index, which informs on the balance between vegetation productivity and grazing intensity, can explain grasshopper population structure at such a fine scale. We found that both population density and gene flow were strongly and positively correlated to habitat quality (higher productivity of grasslands and/or lower sheep grazing). The spatial scales of interaction between these variables were estimated to be highly similar, in the range of 812–880 meters. This result suggests that P. rhodanica is very sensitive to the quality of the grasslands it inhabits.

National audience ; The purpose of this study is to propose technical recommendations in order to graze ewes during winter on mountain rangelands in the Pre-Alps area and to analyse the economic advantage of winter grazing for sheep farming. If land access to well exposed rangelands is possible, winter grazing can be considered for open ewes, before spring mating, and pregnant ewes, with the same zootechnical results than those for ewes fed indoors with stored forages. Hay needs for winter are reduced from 40 to 60 % and rangelands areas needed are from 0,35 to 0,58 ha per ewe. Thus, the Gross Operating Surplus of the sheep farm increased from 13 to 20 % : winter grazing is of a real economic interest. At the local level, winter grazing could contribute to the renewal of rangelands use and, thus, help sheep farming to satisfy environmental functions, regarding the second pillar of the Common Agricultural Policy. ; Les objectifs de l'étude sont, d'une part, de proposer des recommandations techniques pour faire pâturer des brebis en hiver sur des parcours des Préalpes du sud, et d'autre part, de faire une analyse technico-économique de deux scénarios d'intégration du pâturage hivernal dans le fonctionnement d'une exploitation ovine. Lorsque l'accès foncier à des parcours de proximité bien exposés est possible, le pâturage hivernal peut être envisagé pour des brebis à l'entretien, avant la lutte de printemps, ou pour des brebis gravides. Les mêmes performances zootechniques que celles obtenues par une alimentation intégrale en bergerie peuvent être espérées. Le pâturage hivernal, qui substitue un stock d'herbe séchée sur pied à des fourrages conservés, permet une réduction des charges d'alimentation : les besoins en foin pour l'hiver sont diminués de 40 à 60 %. Les surfaces de parcours nécessaires sont importantes, 35 à 58 ares par brebis, avec une valorisation possible de 200 journées x brebis par hectare. Les simulations économiques prévoient ainsi une augmentation de l'excédent brut d'exploitation de 13 à 20 % : ...

National audience ; The purpose of this study is to propose technical recommendations in order to graze ewes during winter on mountain rangelands in the Pre-Alps area and to analyse the economic advantage of winter grazing for sheep farming. If land access to well exposed rangelands is possible, winter grazing can be considered for open ewes, before spring mating, and pregnant ewes, with the same zootechnical results than those for ewes fed indoors with stored forages. Hay needs for winter are reduced from 40 to 60 % and rangelands areas needed are from 0,35 to 0,58 ha per ewe. Thus, the Gross Operating Surplus of the sheep farm increased from 13 to 20 % : winter grazing is of a real economic interest. At the local level, winter grazing could contribute to the renewal of rangelands use and, thus, help sheep farming to satisfy environmental functions, regarding the second pillar of the Common Agricultural Policy. ; Les objectifs de l'étude sont, d'une part, de proposer des recommandations techniques pour faire pâturer des brebis en hiver sur des parcours des Préalpes du sud, et d'autre part, de faire une analyse technico-économique de deux scénarios d'intégration du pâturage hivernal dans le fonctionnement d'une exploitation ovine. Lorsque l'accès foncier à des parcours de proximité bien exposés est possible, le pâturage hivernal peut être envisagé pour des brebis à l'entretien, avant la lutte de printemps, ou pour des brebis gravides. Les mêmes performances zootechniques que celles obtenues par une alimentation intégrale en bergerie peuvent être espérées. Le pâturage hivernal, qui substitue un stock d'herbe séchée sur pied à des fourrages conservés, permet une réduction des charges d'alimentation : les besoins en foin pour l'hiver sont diminués de 40 à 60 %. Les surfaces de parcours nécessaires sont importantes, 35 à 58 ares par brebis, avec une valorisation possible de 200 journées x brebis par hectare. Les simulations économiques prévoient ainsi une augmentation de l'excédent brut d'exploitation de 13 à 20 % : le pâturage hivernal sur parcours présente un réel intérêt économique pour les exploitations ovines. A l'échelle d'un territoire, il peut ainsi contribuer au redéploiement de l'élevage ovin sur les surfaces pastorales, permettant à celui-ci de remplir les fonctions environnementales attendues dans le cadre du second pilier de la politique agricole commune.

A Drifter ultralight aircraft was used as a platform for line-transect aerial
surveys of three species of kangaroo in the sheep rangelands south-east of
Blackall and north of Longreach in central-western Queensland in winter 1993
and 1994. Favourable comparisons between the results of ultralight surveys and
those made from a helicopter flying the same transects and foot surveys along
another set of transects, all within a few days of the ultralight survey,
confirmed the expectation we had that an ultralight would be a satisfactory
and much cheaper vehicle for conducting aerial surveys of kangaroos. The
comparisons are even more favourable when data for the three species surveyed
are combined, pointing to a problem in species identification and underlining
the importance of using only experienced observers for aerial survey of
kangaroos, whatever the platform. The use of an ultralight aircraft could have
particular value where a comparatively small area, such as an individual sheep
or cattle property, is under consideration. In this paper, we present the
numerical comparisons, along with an evaluation of the practicability of using
this type of aircraft. We also describe a possible future scenario in which an
accreditation process could see approved kangaroo surveyors undertaking
property assessments by ultralight, under contract to graziers or other
interested parties.

AbstractShooting ranges contain copper (Cu) and lead (Pb) contamination, which can be a risk for grazing ruminants. This study examines the accumulation of lead and copper in blood of lambs and calves, as well as in the liver of lambs. It compares these results with those of a previous study, which calculated the ingested dose of copper and lead based on soil ingestion and concentration in soil and plants. Blood samples were collected both before and after the grazing period that lasted from late May to mid-September. Liver samples were obtained during the slaughter of the lambs in the fall. Out of 61 liver samples, only one (3.7 mg Pb/kg dw) exceeding the presumed normal level in lamb liver of 3 mg/kg (dw). Copper concentrations exceeding the normal (300 mg/kg dw) concentration was found in 14 of the liver samples (341–1877 mg Cu/kg dw). Among these, two liver samples (1069 and 1877 mg Cu/kg dw) exceeded the level at which sheep are poisoned (1000 mg/kg dw). There was no statistically significant difference in the copper and lead concentration in liver of lambs that did and did not have the shooting range as part of their pasture. The average concentration of copper (lamb: 1.1 ± 0.37 µg Cu/g, calves: 0.6 ± 0.16 µg Cu/g) and lead (lamb: 0.010 ± 0.008 µg Pb/g calves: 0.01 ± 0.014 µg Pb/g) in the blood samples collected from the lambs and calves did not exceed the upper limit of what is considered normal (sheep: 1.35 mg Cu/kg and 0.3 mg Pb/kg, cattle: 1.7 mg Cu/kg and 0.35 mg Pb/kg). Copper concentration in the blood was notably higher in samples collected from the sheep before (1.3 ± 0.35 µg Cu/g) compared to after (0.8 ± 0.22 µg Cu/g) the grazing period. No statistically significant difference was found in lead and copper concentrations in the blood of lambs and calves grazing inside (lamb: 0.7 ± 0.21 µg Cu/g and 0.01 ± 0.008 µg Pb/g, calves: 0.6 ± 0.16 µg Cu/g and 0.02 ± 0.020 µg Pb/g) and outside (lamb: 0.9 ± 0.21 µg Cu/g and 0.13 ± 0.008 µg Pb/g, calves: 0.6 ± 0.17 µg Cu/g and 0.009 µg Pb/g) the shooting range. Grazing on areas contaminated by shooting activity did not appear to have any major implications for the accumulation of copper and lead in blood of cattle and sheep, as well as in the liver of sheep. The findings from this study indicate that employing site specific risk assessments for ruminants incorporating soil ingestion represents a viable approach.

In Languedoc, sheep can be raised only if they are brought to summer pastures: this is a climatic necessity. And sheep are as indispensable in the plains as in the highlands. Transhumance has thus shaped the landscape, the paths, and human relations. In this context, the shepherd's knowledge has proved to be effective and pertinent. Today, questions are raised concerning the transmission of this knowledge in a global economy that does not necessarily need sheep, but is preoccupied by the biodiversity resulting from and saved by the traffic and the grazing of the flocks.

In Languedoc, sheep can be raised only if they are brought to summer pastures: this is a climatic necessity. And sheep are as indispensable in the plains as in the highlands. Transhumance has thus shaped the landscape, the paths, and human relations. In this context, the shepherd's knowledge has proved to be effective and pertinent. Today, questions are raised concerning the transmission of this knowledge in a global economy that does not necessarily need sheep, but is preoccupied by the biodiversity resulting from and saved by the traffic and the grazing of the flocks. Adapted from the source document.

Ovine psoroptic mange (sheep scab) is a debilitating and damaging condition caused by a hypersensitivity reaction to the faecal material of the parasitic mite Psoroptes ovis. Farmers incur costs from the use of prophylactic acaricides and, if their sheep become infected, they incur the costs of therapeutic treatment plus the economic loss from reduced stock growth, lower reproductive rate, wool loss and hide damage. The unwillingness of farmers to use routine prophylactic treatment has been cited as a primary cause of the growing incidence of sheep scab in the United Kingdom (UK) since the disease was deregulated in 1992. However, if farmers behave rationally from an economic perspective, the optimum strategy that they should adopt will depend on the risk of infection and the relative costs of prophylactic versus therapeutic treatment, plus potential losses. This calculation is also complicated by the fact that the risk of infection is increased if neighbours have scab and reduced if neighbours treat prophylactically. Hence, for any farmer, the risk of infection and optimum approach to treatment is also contingent on the behaviour of neighbours, particularly when common grazing is used. Here, the relative economic costs of different prophylactic treatment strategies are calculated for upland and lowland farmers and a game theory model is used to evaluate the relative costs for a farmer and his/her neighbour under different risk scenarios. The analysis shows that prophylaxis with organophosphate (OP) dipping is a cost effective strategy, but only for upland farmers where the risk of infection is high. In all other circumstances prophylaxis is not cost effective relative to reliance on reactive (therapeutic) treatment. Hence, farmers adopting a reactive treatment policy only, are behaving in an economically rational manner. Prophylaxis and cooperation only become economically rational if the risk of scab infection is considerably higher than the current national average, or the cost of treatment is lower. Should policy makers wish to reduce the national prevalence of scab, economic incentives such as subsidising the cost of acaricides or rigorously applied financial penalties, would be required to make prophylactic treatment economically appealing to individual farmers. However, such options incur their own infrastructure and implementation costs for central government.

Abstract ContextHuman activity in wildlands can influence wildlife populations by decreasing or degrading habitat, decreasing survival, or through displacement. For bighorn sheep (Ovis canadensis), some human activities are detrimental and may result in physiological stress, altered activity budgets, or habitat abandonment. From 1979 to 2000, human recreation increased over 300% in areas occupied by desert bighorn sheep (O. c. nelsoni) in south-eastern Utah. Concurrently, the population of desert bighorn sheep occupying the Potash Bighorn Sheep Management Unit of south-eastern Utah was in steep decline. AimsWe investigated behavioural responses of desert bighorn sheep to different levels of human activity in this area from 2002 to 2003. MethodsWe divided the study population into two areas on the basis of the level of human use, i.e. low and high. We observed desert bighorn sheep at seven sites within these areas, including three with a high level of human use and four areas of a low level of human use. Key resultsDesert bighorn sheep spent significantly less time grazing and more time vigilant in areas of a high level of human use than in areas of a low level of human use. ConclusionsHuman recreational use of desert bighorn sheep habitat has the potential to negatively affect foraging by desert bighorn sheep. ImplicationsWe raise a cautionary flag because recreational use in bighorn sheep habitat near Moab, Utah, continues to increase and bighorn numbers continue to decline. When managers consider proposals to increase areas or trails for human recreation, they should incorporate ways to minimise impacts and reduce stressors to bighorn sheep.

National audience ; The interest of grazing grows usually on a par with the constraints dictated by the environment, as is illustrated by a simplified presentation of the main livestock farming systems in the European Union : the cattle and sheep suckling systems which predominate largely in the so-called underendowed regions, where their economic role is often determinant. ln the most intensive dairying systems, there is often a growing interest for grazing, in most European countries and even in North America. Present-day expectations of society (health security, nutritive value, quality and genuineness of the nutriments, conditions of production such as animal welfare, regard for the environment and specifically for water, etc.) reinforce this trend. To these factors should be added the beneficial impact on the maintenance of landscapes and of bio-diversity, so that the arguments in favour of maintaining or even extending grazing are becoming ever more numerous. The mastering of the grazing practice however will always require the learning of rules difficult to write down, the more so as the new expectations of society may involve quite different management techniques. The creation of tools that will be an aid to decision-making at various stages, from setting up a forage production plan to the change of paddocks, still opens large possibilities of research. ; Le pâturage est le mode d'alimentation naturel des herbivores, il se pratique dans des milieux physiques et des systèmes agraires forts différents dans les diverses régions européennes. Dans le contexte actuel d'une pression sociétale forte, la place du pâturage évolue et de nouveaux enjeux se dessinent. L'intérêt du pâturage croît souvent avec l'augmentation des contraintes du milieu comme l'illustre une présentation simplifiée des principaux systèmes d'élevage de l'Union Européenne. Cependant, même chez les systèmes laitiers intensifs, on constate un regain d'intérêt pour le pâturage. Les nouvelles attentes de la société (sécurité sanitaire, qualité ...