Abstract 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, 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 (1,340 vs. 1,388 kJ/kg body weight0.60/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 the 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.
Purpose
In agricultural life cycle assessment (LCA), the allocation method chosen to divide impacts among co-products is an important issue, since it may change conclusions about a product’s impacts. ...We developed a biophysical allocation method to assign upstream environmental burdens and the use of raw materials at farm gate to the livestock co-products at the slaughterhouse based on their metabolic energy requirements.
Methods
Biophysical allocation is designed to build a relationship between co-products of a meat-production system and their associated net metabolic energy requirements. A metabolic growth model (Gompertz function) was combined with an energy calculation model to estimate metabolic energy requirements for the growth of an animal from birth to slaughter age. Allocation factors were calculated based on the energy required to maintain and produce body tissues (excluding waste), as a function of their chemical (protein and lipid) and physiological properties. This method was applied for an average beef cow and then compared to other allocation methods (e.g., mass, dry matter, protein, and economic).
Results and discussion
At slaughter age, carcass tissues required the most energy (44 %) due to their high quantity of protein; the gastrointestinal tract and liver required about 28 and 5 %, respectively, of total metabolic energy requirements due to their roles in body metabolism. Biophysical allocation considers the energy cost of building and maintaining the tissues, regardless of their final uses. It reflects physical relationships among co-products as well as other allocation methods do. It also reveals the cause-effect relationship between tissues according to the energy required to maintain physiological functions. Once the growing time until slaughter is set, biophysical allocation factors are not influenced over time, unlike those of economic allocation, which is highly influenced by price variability.
Conclusions
This study provides a generic and robust biophysical allocation method for estimating environmental burdens of co-products, in accordance with ISO allocation rules. The method can be considered an original contribution to international debates on allocation methods applied to livestock products in LCA. In this paper, it is applied to cattle-related product, but it is generic and the principles can be adapted to any kind of livestock species. It should be considered and discussed by stakeholders in livestock production industries.
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.
Growing awareness of global challenges and increasing pressures on the farming sector, including the urgent requirement to rapidly cut greenhouse gases (GHG) emissions, emphasize the need for ...sustainable production, which is particularly relevant for dairy production systems. Comparing dairy production systems across the three sustainability dimensions is a considerable challenge, notably due to the heterogeneity of production conditions in Europe. To overcome this, we developed an ex post multicriteria assessment tool that adopts a holistic approach across the three sustainability dimensions. This tool is based on the DEXi framework, which associates a hierarchical decision model with an expert perspective and follows a tree shaped structure; thus, we called it the DEXi-Dairy tool. For each dimension of sustainability, qualitative attributes were defined and organized in themes, sub-themes, and indicators. Their choice was guided by three objectives: (i) better describe main challenges faced by European dairy production systems, (ii) point out synergies and trade-offs across sustainability dimensions, and (iii) contribute to the identification of GHG mitigation strategies at the farm level. Qualitative scales for each theme, sub-theme, and indicator were defined together with weighting factors used to aggregate each level of the tree. Based on selected indicators, a list of farm data requirements was developed to populate the sustainability tree. The model was then tested on seven case study farms distributed across Europe. DEXi-Dairy presents a qualitative method that allows for the comparison of different inputs and the evaluation of the three sustainability dimensions in an integrated manner. By assessing synergies and trade-offs across sustainability dimensions, DEXi-Dairy is able to reflect the heterogeneity of dairy production systems. Results indicate that, while trade-offs occasionally exist among respective selected sub-themes, certain farming systems tend to achieve a higher sustainability score than others and hence could serve as benchmarks for further analyses.
Aquaculture is increasingly considered a major contributor to the growing demand for worldwide seafood production. Sustainability is becoming a key issue for aquaculture systems, with the objective ...to produce seafood with lower environmental impacts and that is economically viable and socially fair. In the context of the SIMTAP project, a multi-attribute model called DEXiAqua was developed. DEXiAqua uses the DEX method to assess the sustainability of aquaculture systems via indicators from technical domains and reference methods (i.e., life cycle assessment, life cycle costing, social life cycle assessment, and emergy accounting) selected and organized by the partners in the SIMTAP project. The DEX method consists of building an attribute tree that is organized to characterize a complex problem. Qualitative or quantitative indicators are measured at the end of each branch of the tree. The value of each indicator is translated into a qualitative scale for the associated attribute via threshold values. Weighted utility functions are used to build attributes from sub-attributes until the attribute of overall sustainability is reached. DEXiAqua was applied to a case study of salmon farming in France, which illustrated its ability to assess overall sustainability and help identify ways to improve the production system by identifying environmental, social, and economic hotspots. More case studies are required to apply DEXiAqua to a variety of systems with technical and contextual differences, which could result in changing attribute weights to adapt it better to different contexts.
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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Nitrogen (N) flows in organic agriculture (OA) in France in 2021 were modelled.•The organic manure available could not meet the N requirements of organic crops.•9 % of the total human diet in France ...was organic.•N in the food produced in OA was mainly in crops (70 %) (only 30 % in animals).•N-use efficiency variables in OA had the most influence in the model.
Organic agriculture (OA) is the promoted sustainable agriculture model in the European Union (EU), yet its expansion is hindered by limited nutrient availability, particularly nitrogen (N). OA's main sources of N include biological N fixation by legume crops and manure from both conventional and organic livestock. However, potential stricter EU regulations on allowed external N resources for OA and pressure to reduce livestock numbers could impact N availability in OA. Understanding national-scale N flows is essential. Here, we analysed N flows in organic agri-food systems in France, the largest OA area in Europe. We show that approximately 20 % of the manure used to fertilise organic cropland came from conventional agriculture and 15 % from the dietary N nutritional requirements of organic livestock imported from outside France. N surplus is half that of the conventional agriculture at national scale. This first national assessment highlights biophysical and regulatory constraints providing insights into the possibilities of achieving the EU's target of having 25 % of agricultural land under OA.
This study assesses the environmental performance of mealworm (Tenebrio molitor) larvae meal via life cycle assessment (LCA) from cradle to mill gate. No LCA studies have yet assessed mealworm meal ...at the mill gate. Uncertainty and global sensitivity analyses were performed on the environmental performance of the system using four parameters that experts identify as critical to this performance: feed intake, electricity consumption at the farm stage, electricity consumption at the processing stage, and meal and oil yield at the processing stage. Results for the five impact categories assessed for one kg of mealworm meal are 141.3 MJ for cumulative energy demand, 3.8 kg CO2 eq for climate change, 25.6 g SO2 eq for acidification potential, 15.0 g PO4 eq for eutrophication potential, and 4.1 m2a for land use. Per kg of protein, these impacts are higher than those of soybean or fish meal. At the farm gate, our results for environmental impacts of mealworm larvae are similar to those provided by one study of the literature. The uncertainty analysis indicates coefficients of variation of approximately 20%. The global sensitivity analysis highlights that meal and oil yields are critical parameters that greatly influence variation in the environmental performance of the product. Feed intake and electricity consumption also have considerable influence on variation in the output. Several recent studies indicate that great improvements in zootechnical parameters of mealworms are expected, which should improve the latter's environmental performance. However, several macro-scale issues suggest that prospective and consequential LCAs are required to completely study the sector from an environmental perspective.
•The first environmental impact assessment of mealworm meal for animal feed.•Larvae meal protein had a poor environmental performance compared to soybean or fish meal proteins.•Innovative use of the Sobol' method to identify key factors of variability in environmental impacts.•Two main sources of variability in impacts identified: feed intake and meal-extraction yield.
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.
•Extreme Value Theory identified farms producing extreme amounts of forages in a region.•Most farms that fed more grass or less maize silage had a variety of cow breeds.•Most farms that fed less grass or more maize silage had Holstein cows.•Milk-production objectives varied as a function of region.
The production of dehydrated alfalfa for animal feed requires substantial energy-consuming processes, which raises questions about the environmental sustainability of this sector; less ...energy-intensive processes and a transition to renewable energy are needed. In this study, we quantified the environmental footprint of dehydrated alfalfa production in France and its evolution over time using data collected over two periods (2006–2009 and 2016 to 2019). This study was based on twelve production units spread throughout the main alfalfa production areas in France, which represent more than 50% of the national production of dehydrated alfalfa. A life cycle assessment was performed for the three steps of this production: production in the field, transportation from the field to the factory and the dehydration process. The results showed that the adaptation and renewal of the production tools between the two time periods allowed a reduction in the consumption of nonrenewable energy per ton of dehydrated alfalfa: lignite and coal decreased from an average of 352.3 kg t−1 dehydrated alfalfa in 2006–2007 to an average of 100.6 kg t−1 dehydrated alfalfa in 2018–2019. At the same time, the introduction of biomass as an energy source represented 127.4 kg biomass t−1 dehydrated alfalfa in 2018–2019. The decrease in the moisture content of fodder due to climate change and a longer time in the field before plant transport also significantly decreased the energy needed for dehydration at the factory level. Consequently, the French production sector reduced its impact on the “climate change” impact category from 1.150 kg CO2-eq. kg−1 dry matter of dehydrated alfalfa (first period) to 0.494 kg CO2-eq. kg−1 dry matter of dehydrated alfalfa (second period). Among the eight environmental impact categories studied, only the “land competition” criterion increased from 0.840 to 1.222 m2.y between the two periods due to the substitution of fossil energies with renewable energies from wood and energy crops.
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