An organic suckler cattle farming system in the Massif Central: analysis of technical and economic results.

in the Massif Central. An organic suckler cattle farm network was set up in order to establish technical and economic references. In 2004, 22 farms were monitored (13 of which had been monitored since 2001). All of these farms are located in economically-depressed areas. One hundred percent of the fodder area is under grassland. Annual crops (cereals and a cereal/pulse mix) take up 13% of the farm area and are used as livestock feed. The stocking rate (1 Livestock Unit/ha of fodder area) is 20% lower on organic farms than on conventional farms. Organic farms use 33% less concentrates per LU, and the meat production/LU is 16% lower than for conventional farms. The poorly structured organic beef market forces organic farmers to sell most of their animals (mainly store animals, since fattened animals represent only 43% of the animals sold) on the conventional market without getting premium prices. Since only fattened animals are sold on the organic market at a premium price, the average selling price (€/kg live-weight) of all the animals sold is only 12% higher for organically-bred than for conventionally-bred animals. However, because of lower operational costs (-35% for herd and fodder area costs), the bovine gross margin/LU is 3% higher for OF than for conventionally-bred animals. The lower stocking rate leads to a lower gross product per hectare of farm area. Since this result is balanced by a very low level of operational costs (no chemical inputs), the economic efficiency of the OF system is higher than that of the conventional system. The farm income per worker is the same in both systems. The search for feed self-sufficiency at the farm scale is a crucial element in farm economics, but it is only possible on mixed-crop livestock farms where cropping is possible with adapted crop rotation. The grassland farms, which are the least self-sufficient and have to purchase all the concentrates needed, must sell all their animals on the organic market to get the premium price that will then enable them to buy the inputs not produced on the farm

Single-bubble and multi-bubble cavitation in water triggered by laser-driven focusing shock waves

In this study a single laser pulse spatially shaped into a ring is focused into a thin water layer, creating an annular cavitation bubble and cylindrical shock waves: an outer shock that diverges away from the excitation laser ring and an inner shock that focuses towards the center. A few nanoseconds after the converging shock reaches the focus and diverges away from the center, a single bubble nucleates at the center. The inner diverging shock then reaches the surface of the annular laser-induced bubble and reflects at the boundary, initiating nucleation of a tertiary bubble cloud. In the present experiments, we have performed time-resolved imaging of shock propagation and bubble wall motion. Our experimental observations of single-bubble cavitation and collapse and appearance of ring-shaped bubble clouds are consistent with our numerical simulations that solve a one dimensional Euler equation in cylindrical coordinates. The numerical results agree qualitatively with the experimental observations of the appearance and growth of bubble clouds at the smallest laser excitation rings. Our technique of shock-driven bubble cavitation opens novel perspectives for the investigation of shock-induced single-bubble or multi-bubble cavitation phenomena in thin liquids

Direct Visualization of Laser-Driven Focusing Shock Waves

Cylindrically or spherically focusing shock waves have been of keen interest for the past several decades. In addition to fundamental study of materials under extreme conditions, cavitation, and sonoluminescence, focusing shock waves enable myriad applications including hypervelocity launchers, synthesis of new materials, production of high-temperature and high-density plasma fields, and a variety of medical therapies. Applications in controlled thermonuclear fusion and in the study of the conditions reached in laser fusion are also of current interest. Here we report on a method for direct real-time visualization and measurement of laser-driven shock generation, propagation, and 2D focusing in a sample. The 2D focusing of the shock front is the consequence of spatial shaping of the laser shock generation pulse into a ring pattern. A substantial increase of the pressure at the convergence of the acoustic shock front is observed experimentally and simulated numerically. Single-shot acquisitions using a streak camera reveal that at the convergence of the shock wave in liquid water the supersonic speed reaches Mach 6, corresponding to the multiple gigapascal pressure range 30 GPa

The Freedoms and Capabilities of Farm Animals: How Can Organic Husbandry Fulfill Them?

Organic farming promotes animal husbandry practices that consider the welfare of the animals on the farm. The concept of animal welfare and the standards that should encompass this concept have in many cases been largely generalised in practice, which leaves relevant aspects of animal freedom or capabilities insufficiently addressed. This chapter puts forth the prospect that the capabilities approach offers an appropriate practical platform by which to improve welfare in farm animals by meeting a wider range of their natural needs and abilities. The capabilities approach coupled with effective health planning could foster organic husbandry towards a more acceptable production system for farmers and consumers alike

Productivity and technical efficiency of suckler beef production systems: trends for the period 1990 to 2012

International audienc

Variability in greenhouse gas emissions, fossil energy consumption and farm economics in suckler beef production in 59 French farms

International audienceEfforts to assess the environmental performances of beef production systems often culminate in mitigation strategies without factoring in farm economics. The objective of this study was to co-assess the environmental impacts and economic performances of French suckler-beef production systems based on commercial farm data. We coordinated a technical–economic survey on 59 Charolais suckler-cattle farms in order to calculate GHG emissions and non-renewable energy (NRE) consumption over the years 2010 and 2011. Using real-world data from a farm network instead of modeled or experimental data enabled us to analyze the variability of the results and its determinants. The main variables impacting GHG emissions and NRE consumption per kg of beef (live weight) produced are (i) animal productivity (kg of live weight produced per LU), (ii) farm size (area and herd), and (iii) degree of specialization in beef production (share of cattle revenue in total farm revenue). The large, diversified farms (mixed crop–livestock farming systems) have a more negative environmental impact than the moderate-sized, specialized (beef production) farms. Animal productivity performances decrease with increasing herd size, and inputs use is below-optimal in the most strongly diversified farms. A comparison of the group of farms with the lowest and highest GHG emissions per kg beef (50% difference on GHG emissions per kg of live weight) confirmed these correlations. Through better animal productivity performances and lower use of inputs, the less-GHG-emitting farms also generate higher income per worker (+30%) while consuming less NRE. Our findings argue against the idea that size and diversification bring economic and environmental economies of scale and scope in suckler-beef production systems