Analysis of milk production and greenhouse gas emissions as a function of extreme variations in forage production among French dairy farms.

Many studies that investigate mitigation strategies of greenhouse-gas (GHG) emissions from farming systems often build farm typologies from average data from multiple farms. Results from farm typologies are useful for general purposes but fail to represent variability in farm characteristics due to management practices or climate conditions, particularly when considering consequences of extreme environmental events. This limitation raises the issue of better distinguishing, within datasets of farms, farms that have average characteristics from those that deviate from average trends, in order to improve assessment of how climate variability influences farm performance. We applied the statistical method called Extreme Value Theory (EVT) to identify dairy farms that produced "extreme" amounts of forage. Applying EVT to a dataset of dairy farms from Normandy, Lorraine and Nord-Pas-de-Calais (France) identified subsamples of 10-30% of dairy farms with the smallest or largest amounts of grass from pastures or maize silage in each region. Characteristics of farms with extreme amounts of each forage often differed among regions due to the influence of geography and climate. Farms with the largest amounts of grass or the smallest amounts of maize silage had a variety of cow breeds in Normandy and Lorraine but had only Holstein cows in Nord-Pas-de-Calais. Conversely, most farms with the smallest amounts of grass or the largest amounts of maize silage had Holstein cows, regardless of region. The region also influenced whether farms were oriented more toward producing milk with higher fat and protein contents (Normandy and Lorraine) or toward producing larger amounts of milk (Nord-Pas-de-Calais). As the amount of a given forage changed from smallest to largest, a significant increase or decrease in the amount of milk produced usually changed GHG and enteric methane (CH4) emissions per farm in the same direction as the amount of milk produced. For instance, an extreme increase in the amount of grass fed on farms (1314 vs. 5093 kg/livestock unit/year, respectively) in Normandy was associated with decreased mean milk production (8236 vs. 5834 l/cow/year, respectively) and GHG (7117 vs. 5587 kg CO2 eq./farm/year) and enteric CH4 (3870 vs. 3296 kg CO2 eq./farm/year, respectively) emissions.

Contribution of LCA to decision making: A scenario analysis in territorial agricultural production systems.

Territorial Life Cycle Assessment (TLCA) appears a promising method to support informed decision making of local actors in territorial agricultural production systems (TAPS), by assessing environmental impacts of agricultural activities and potential strategies. The objectives of this study were to i) adapt TLCA methodology to integrated environmental assessment of TAPS and ii) evaluate TLCA's contribution to supporting informed decision making by assessing scenarios of change in TAPS. A TLCA of the agricultural sector was performed for a territory in the Aube department in France, including main crops and animal production types from raw material extraction to the first stage of processing. Exchanges of agricultural products and by-products among agricultural subsectors were considered by allocating impacts, which prevented double-counting them. Two contrasting scenarios were assessed with TLCA - development of on-farm biogas production and reintroduction of sheep grazing - and compared to the current situation. Results were expressed per unit area (ha), per unit biomass produced (kg) and per percentage contribution to total impacts of the territory before and after processing (at and beyond the farm gate, respectively). The main contributors (cereal and oilseed crops) did not have the highest impact at the farm scale (per ha and per kg), which highlights that contribution to total impacts of the territory is a relevant addition to the impacts per functional unit. Consideration of exchanges showed that TLCA can be used to assess effects of material interactions (biomass flows) between sectors. Scenario results showed no significant differences in impacts, except for higher water resource depletion for the biogas scenario, because most differences between scenarios were smaller than uncertainties in the input data. Other challenges were identified, such as the need to evaluate consequences of changes beyond the territory gate when performing TLCA of scenarios or the utility of characterizing the network of biomass flows in more detail. In conclusion, the methodological framework that was developed successfully identified environmental hotspots and reflected environmental impacts of material interactions between actors. Finally, it can estimate environmental impacts of future strategies, as long as uncertainty is reduced; thus, it shows potential as a decision-support tool.

Multiobjective formulation is an effective method to reduce environmental impacts of livestock feeds.

Environmental and economic performances of livestock production are related largely to the production of complete feeds provided on commercial farms. Formulating feeds based on environmental and economic criteria appears a suitable approach to address the current challenges of animal production. We developed a multiobjective (MO) method of formulating feed which considers both the cost and environmental impacts (estimated via life cycle assessment) of the feed mix. In the first step, least-cost formulation provides a baseline for feed cost and potential impacts per kg of feed. In the second, the minimised MO function includes normalised values of feed cost and impacts climate change, P demand, non-renewable energy demand and land occupation. An additional factor weights the relative influence of economic and environmental objectives. The potential of the method was evaluated using two scenarios of feed formulation for pig, broiler and young bulls. Compared to baseline feeds, MO-formulated feeds had lower environmental impacts in both scenarios studied (-2 to -48 %), except for land occupation of broiler feeds, and a moderately higher cost (1-7 %). The ultimate potential for this method to mitigate environmental impacts is probably lower than this, as animal supply chains may compete for the same low-impact feed ingredients. The method developed complements other strategies, and optimising the entire animal production system should be explored in the future to substantially decrease the associated impacts.

Eco-friendly diet: nutrient digestibility, nitrogen and energy balances and growth performance of growing pigs.

The traditional approach to formulating pig diets is based only on minimizing cost while meeting nutritional requirements and thus does not consider the environmental impacts associated with producing feed ingredients. To reduce the overall environmental impact of pork production, that of feed ingredients can be considered to formulate environmentally friendly diets. However, their potential effects on pig performance could decrease environmental benefits at the farm gate. The objective of this study was to quantify the effects of such eco-friendly pig diets on nitrogen (N) and energy (E) balances, the components of heat production (HP) and the performance of growing pigs. Digestibility coefficients of dry matter (84.5% vs 88.2%, P < 0.01) and N (80.4% vs 86.3%, P < 0.01) were significantly lower for the eco-friendly diet than the Control-diet (a commercial diet used in France). N excretion in feces was significantly higher for the group of pigs fed the eco-friendly diet than for the group fed the Control-diet (9.8 vs 6.9 g/d, respectively, P = 0.01), while the N retention tended to be lower (27.8 vs 30.3 g/d, respectively; P = 0.06). The metabolizable E:digestible E ratio did not differ between diets, but total HP was significantly lower for the eco-friendly diet group than for the Control-diet group (1340 vs 1388 kJ/kg body weight (BW)0.60/d, respectively, P = 0.03). Using feed ingredients with lower environmental impacts, such as locally produced protein or co-products from wheat processing, is an effective way to decrease environmental impacts of pig production. However, the nutritional composition of these eco-friendly ingredients could be overestimated, in particular the true digestibility of amino acids. This indicates the need to better estimate and consider the true digestibility of eco-friendly diets to decrease environmental impacts of livestock production without decreasing animal performance.

LCA and emergy accounting of aquaculture systems: towards ecological intensification.

An integrated approach is required to optimise fish farming systems by maximising output while minimising their negative environmental impacts. We developed a holistic approach to assess the environmental performances by combining two methods based on energetic and physical flow analysis. Life Cycle Assessment (LCA) is a normalised method that estimates resource use and potential impacts throughout a product's life cycle. Emergy Accounting (EA) refers the amount of energy directly or indirectly required by a product or a service. The combination of these two methods was used to evaluate the environmental impacts of three contrasting fish-farming systems: a farm producing salmon in a recirculating system (RSF), a semi-extensive polyculture pond (PF1) and an extensive polyculture pond (PF2). The RSF system, with a low feed-conversion ratio (FCR = 0.95), had lower environmental impacts per tonne of live fish produced than did the two pond farms, when the effects on climate change, acidification, total cumulative energy demand, land competition and water dependence were considered. However, RSF was clearly disconnected from the surrounding environment and depended highly on external resources (e.g. nutrients, energy). Ponds adequately incorporated renewable natural resources but had higher environmental impacts due to incomplete use of external inputs. This study highlighted key factors necessary for the successful ecological intensification of fish farming, i.e., minimise external inputs, lower the FCR, and increase the use of renewable resources from the surrounding environment. The combination of LCA and EA seems to be a practical approach to address the complexity of optimising biophysical efficiency in aquaculture systems.

Emergy evaluation of contrasting dairy systems at multiple levels.

Emergy accounting (EmA) was applied to a range of dairy systems, from low-input smallholder systems in South Mali (SM), to intermediate-input systems in two regions of France, Poitou-Charentes (PC) and Bretagne (BR), to high-input systems on Reunion Island (RI). These systems were studied at three different levels: whole-farm (dairy system and cropping system), dairy-system (dairy herd and forage land), and herd (animals only). Dairy farms in SM used the lowest total emergy at all levels and was the highest user of renewable resources. Despite the low quality of resources consumed (crop residues and natural pasture), efficiency of their use was similar to that of industrialised inputs by intensive systems in RI, PC and BR. In addition, among the systems studied, SM dairy farms lay closest to environmental sustainability, contradicting the usual image of high environmental impact of cattle production in developing countries. EmA also revealed characteristics of the three intensive systems. Systems from RI and PC had lower resource transformation efficiency and higher environmental impacts than those from BR, due mainly to feeding strategies that differed due to differing socio-climatic constraints. Application of EmA at multiple levels revealed the importance of a multi-level analysis. While the whole-farm level assesses the overall contribution of the system to its environment, the dairy-system level is suitable for comparison of multi-product systems. In contrast, the herd level focuses on herd management and bypasses debates about definition of system boundaries by excluding land management. Combining all levels highlights the contribution of livestock to the global agricultural system and identifies inefficiencies and influences of system components on the environment.

Eco-Friendly Feed Formulation and On-Farm Feed Production as Ways to Reduce the Environmental Impacts of Pig Production Without Consequences on Animal Performance.

Animal feeding has a major contribution to the environmental impacts of pig production. One potential way to mitigate such effects is to incorporate an assessment of these impacts in the feed formulation process. The objective of this study was to test the ability of innovative formulation methodologies to reduce the impacts of pig production while also taking into account possible effects on growth performance. We compared three different formulation methodologies: least-cost formulation, in accordance with standard practices on commercial farms; multiobjective (MO) formulation, which considered feed cost and environmental impacts as calculated by life cycle assessment (LCA); and MO formulation, which prioritized locally produced feed ingredients to reduce the impact of transport. Ninety-six pigs were distributed between three experimental groups, with pigs individually weighted and fed using an automatic feeding system from 40 to 115 kg body weight. Based on the experimental results, six categories of impacts were evaluated: climate change (CC), demand in non-renewable energy (NRE), acidification (AC), eutrophication (EU), land occupation (LO), and phosphorus demand (PD), at both feed plant gate and farm gate, with 1 kg of feed and 1 kg of live pig as functional units, respectively. At feed level, MO formulations reduced CC, NRE, AC, and PD impacts but sometimes increased LO and EU impacts. These formulations reduced the proportion of cereals and oil meals into feeds (feed ingredients with high impacts), while the proportion of alternative protein sources, like peas, faba beans, or high-protein agricultural coproducts increased (feed ingredients with low impacts). Overall, animal performance was not affected by the dietary treatment; because of this, the general pattern of results obtained with either MO formulation at farm gate was similar to that obtained at feed level. Thus, MO diet formulation represents an efficient way to reduce the environmental impacts of pig production without compromising animal performance.

Life cycle inventory data on French organic waste treatments yielding organic amendments and fertilisers.

To inform the modelling of organic waste treatments yielding organic amendments and fertilisers in France, published as "Screening LCA of French organic amendments and fertilisers" [1], we compiled data pertaining to the chemical characteristics of both raw and treated organic residues, as well as inventory data on the most common organic waste treatments. The majority of these life cycle inventory data was obtained from reports and other literature, but primary data was also compiled, notably for commercial organic fertiliser production. The data presented here can be used by future life cycle assessment studies on organic waste treatments, as well as to inform agricultural modelling.

Allocation factors for meat coproducts: Dataset to perform life cycle assessment at slaughterhouse.

The sharing of total environmental impacts between the different products of a multi-output system is crucial in Life Cycle Assessment. ISO standards recommend subdivision then substitution methods when possible. Sometimes, allocations rules are necessary. They consist of allocating the total impact to the different products in proportion to a value that characterize the products. They can be based on physical parameters (such as mass, protein, dry matter, etc.) or the economic value of coproducts can be used as a proxy. As they are based on various type of parameters, allocation rules can lead to significantly different environmental impact results. Then a consensus is difficult to reach between stakeholders as for example in meat sector. To make the debate going further, Chen et al. (2017) proposed a new allocation method based on biophysical parameters (Chen et al., 2017). Adapted from previous methods, they propose to allocate impacts in proportion to the energy needed for the growth, the maintenance and the activity of each tissue. The method has been judged as scientifically viable but also particularly difficult to apply due to the amount of necessary data and to the complexity of the calculation model. In a recent project, we developed a freeware to easily calculate biophysical allocation factors as well as mass and economic factors to allow a fair comparison: MeatPartTool. We also collected data to create a dataset of mass, economic and biophysical allocation factors for a large range of beef (132 individuals), calf (54 individuals) and lamb (14 individuals) at the slaughterhouse stage. This data paper provides both primary data and calculated allocation factors.

ECOALIM: A Dataset of Environmental Impacts of Feed Ingredients Used in French Animal Production.

Feeds contribute highly to environmental impacts of livestock products. Therefore, formulating low-impact feeds requires data on environmental impacts of feed ingredients with consistent perimeters and methodology for life cycle assessment (LCA). We created the ECOALIM dataset of life cycle inventories (LCIs) and associated impacts of feed ingredients used in animal production in France. It provides several perimeters for LCIs (field gate, storage agency gate, plant gate and harbour gate) with homogeneously collected data from French R&D institutes covering the 2005-2012 period. The dataset of environmental impacts is available as a Microsoft® Excel spreadsheet on the ECOALIM website and provides climate change, acidification, eutrophication, non-renewable and total cumulative energy demand, phosphorus demand, and land occupation. LCIs in the ECOALIM dataset are available in the AGRIBALYSE® database in SimaPro® software. The typology performed on the dataset classified the 149 average feed ingredients into categories of low impact (co-products of plant origin and minerals), high impact (feed-use amino acids, fats and vitamins) and intermediate impact (cereals, oilseeds, oil meals and protein crops). Therefore, the ECOALIM dataset can be used by feed manufacturers and LCA practitioners to investigate formulation of low-impact feeds. It also provides data for environmental evaluation of feeds and animal production systems. Included in AGRIBALYSE® database and SimaPro®, the ECOALIM dataset will benefit from their procedures for maintenance and regular updating. Future use can also include environmental labelling of commercial products from livestock production.

Digesta transit in different segments of the gastrointestinal tract of pigs as affected by insoluble fibre supplied by wheat bran.

Digestibility is the result of two competing processes: digestion and digesta transit. To develop or parameterise mechanistic models of digestion, both processes have to be quantified. The aim of this study was to determine the effect of insoluble dietary fibre on the transit in the gastrointestinal tract of pigs. Six barrows (33 kg initial body weight and fitted with two simple T-cannulas at the proximal duodenum and distal ileum) were used in a double 3 x 3 Latin square design. Pigs were offered diets differing in total dietary fibre content (170, 220 and 270 g/kg DM) at 4 h intervals. A single meal marked with YbO2 and Cr-EDTA was used to determine the kinetics of markers concentrations of the solid and liquid phases, respectively. The mean retention time (MRT), calculated by the method of the moments, averaged 1, 4 and 38 h in the stomach, small intestine and large intestine, respectively. Increasing the insoluble fibre content in the diet had no effect on MRT in the stomach and decreased the MRT of both phases in the small intestine (P < 0.05). In the large intestine, increasing the insoluble fibre content decreased the MRT of the liquid phase (P = 0.02) and tended to decrease the MRT of the solid phase (P = 0.06). Transit of the solid phase in the large intestine was 4-8 h slower than transit of the liquid phase. Analysis of marker excretion curves indicated that the small and large intestine should be represented mathematically to have both a tubular (propulsion) and compartmental (mixing) structure.