Adapting the feed, the animal and the feeding techniques to improve the efficiency and sustainability of monogastric livestock production systems
Adapting the feed, the animal and the feeding techniques to improve the efficiency and sustainability of monogastric livestock production systems

Deliverable D6.2 Life Cycle Analyses of proposed approaches within a sample of production systems

Publication date: 
29 June 2019
Full title: 
Deliverable D6.2 Life Cycle Analyses of proposed approaches within a sample of production systems
Publishing information: 
Feed-a-Gene, June 2019


Farming systems are controversial for their impacts on the environment. Changing animal feed systems is a relevant way to reduce these impacts because the inefficient use of nutrients contributes to ecological damage. This work aims to use Life Cycle Analysis to estimate the environmental impact of two feed innovations in pig and poultry farms: (1) the use of European protein sources to replace Brazilian soybean meal, and (2) precision feeding systems to reduce the impacts associated with feed production and nutrient excretions by the animal.


The innovations were applied by simulation to the fattening period of conventional pig production and poultry production. The environmental impacts were assessed by Life Cycle Assessment (LCA) with the SimaPro software for one kilogram of animal product at the farm gate. Five impacts were considered: non-renewable energy consumption, climate change, acidification, eutrophication, and land occupation.

Innovative feedstuffs

Four innovative feedstuffs were selected from the results of WP1: a fine fraction of rapeseed meal obtained after sieving of classical rapeseed meal (IF1); two European soybean meals with a cooking-pressing process, one of which involved a preceding dehulling of the soybean (IF2), the other was done without dehulling (IF3); and Danish protein paste extracted from a bio-refining process of green biomass (IF4). Data concerning the production processes of these ingredients and their nutritional characteristics were provided by partners of the Feed-a-Gene project (WP1). Data concerning other classical feedstuffs came from the Feed tables of INRA-AFZ-CIRAD (nutritional characteristics) and from the French database AGRIBALYSE (life cycle inventories).

For pig production, two environmental benefits associated with the innovative feedstuffs were assessed:

  • Current benefit: this corresponds to the environmental results that are currently attainable. It compares the environmental impacts of animals fed with feed including innovative feedstuffs (one innovative strategy for each innovative feedstuff) to that of animals fed with classical feedstuffs (baseline). The rate of incorporation of Brazilian soybean meal in the feeds of the baseline depends on the economic context and the relative prices of protein sources. To define the incorporation rate of the innovative feedstuffs in feeds, the lowest prices during the last ten years for a reference feedstuff were applied. The simulations were applied to four economically contrasting years of the last ten years for four European countries (France, Germany, Spain, and the Netherlands).
  • Potential benefit: this is the difference in environmental impacts between innovative feeding strategies, with a maximum incorporation of innovative feedstuffs, and baseline strategies with maximum incorporation of Brazilian soybean meal. To maximize the incorporation rate of innovative feedstuffs and Brazilian soybean meal in the feeds, prices of 0€ were considered for these feedstuffs. The prices of the other ingredients are based on the four previous economic contexts in France.

For poultry production, only the potential benefit was assessed. The baseline (or "control") feeds already have a relatively high proportion of Brazilian soybean meal, meaning that the incorporation of innovative feedstuffs could already potentially replace the Brazilian soybean meal. Moreover, to maximize the incorporation rate of innovative feedstuffs, a price of 0€ was used.

Precision feeding

For pig production, two innovative precision feeding strategies were assessed: for ad libitum feeding and for restricted feeding. These strategies were applied to the fattening period and adjusted daily to supply nutrients to pigs according to their individual nutrient requirements. The first strategy gives the opportunity to let the pigs express their potential and to obtain data concerning their behaviour. The restricted feeding strategy represents the classical condition of pig production in France during fattening period. The restriction is used to control the growth of the pigs and their fat deposition. The environmental benefit of the innovative feeding strategies was assessed using two different approaches.

  • Experimental approach. Simulations considered data obtained from experiments performed by the Feed-a-Gene partners (WP4) including feed formula, feed intake, animal performance and direct energy consumption. The LCA is performed using these data by comparing the precision feeding strategies to the baseline (biphase feeding strategies with diets with a low protein content). The environmental benefit obtained represents what could be achieved currently in commercial farms by applying a precision feeding strategy.
  • Modelled approach. For both the ad libitum and restricted strategies, four steps of improvement were simulated using MOGADOR (Cadero et al., 2018): biphase feeding, biphase feeding using low-protein diets, multiphase feeding in groups, and individual multiphase feeding. In this approach precision feeding is modelled as if the individual animal profiles were known beforehand. The environmental benefits obtained are the maximum future benefits.

For broiler production, one precision feeding strategy was assessed. The control system used a maximum of four feeds in a multiphase feeding strategy, although the fourth feed was not actually used in our simulation as broilers were assumed to be slaughtered at day 32. The precision feeding system used the same feed as the control system during the first ten days (starter feed), then a mix of two pre-feeds was used that depended on the age of the animal, using a total of four pre-feeds during the batch. In our simulation, only three pre-feeds were actually used given the slaughter age of the broilers. Trial results were used to determine animal performance and they were considered equal for the control system and the precision feeding system. Results of the LCAs show the potential difference between a multiphase feeding strategy and a precision feeding strategy. These results should be considered with caution, as animal performance in our models is better than in commercial farms as they were based on trial results obtained in experimental facilities.


Innovative feedstuffs

Per ton of ingredient, the innovative feedstuffs have an interesting impact on reducing climate change compared with Brazilian soybean meal (>50%). This is also the case for energy consumption, which is higher for Brazilian soybeans because of transport to Europe. The impact on acidification and land occupation could be higher for the innovative feedstuffs compared to Brazilian soybean meal because soybean is a legume and does not need fertilisation and there are two harvests per year in Brazil compared to only one in Europe.

For pig production, the relevance of replacing Brazilian soybean meal by innovative feedstuffs is rather limited because little Brazilian soybean meal is currently used in pig feeds (less than 5% in finish diets). This is due to the relative prices of the different protein sources, which makes rapeseed and sunflower meals more competitive than soybean meal. In a virtual context in which Brazilian soybean meal would become the main protein source (i.e., incorporation of 13% in the finishing diet), the innovative feedstuff results in a reduction in climate change impacts (by 8-9% for the European soybean meal and by 3-4% for the protein paste and the fine fraction of rapeseed meal). As indicated before, other impacts, such as acidification and land occupation, increased.

For broiler production, innovative feedstuffs were studied at their maximum incorporation rate (zero price for innovative feedstuffs) and could replace Brazilian soybean meal in broiler and laying hen feeds. For broiler feeds, the use of European soybean meal can lead to a reduction in the use of phosphorus and non-renewable energy, climate change impacts, and acidification, but it would increase eutrophication and land occupation. The use of the fine fraction of rapeseed meal slightly increases acidification and land occupation and slightly decreases all the other impacts. The use of protein paste increases almost all impacts, although only slightly for phosphorus consumption and climate change, and decreases non-renewable energy use. These last results reflect the use of soybean oil, which is incorporated in the feeds using protein paste, and of Brazilian soybean meal, which will still be incorporated despite the use of protein paste.

For laying hen feeds, the conclusions are similar. The use of European soybean meal, per kg of feed, decreases all impacts except for eutrophication (no significant change) and land occupation (+27%). The use of protein paste increases acidification, eutrophication, and land occupation (depending on the economic context). The use of the fine fraction of rapeseed meal decreases all impacts except acidification, in relatively limited proportions.

Precision feeding

For pig production, the environmental benefits of precision feeding mainly reflect reductions in acidification and eutrophication because of the associated reduction in nitrogen excretion. In the experimental approach, the nitrogen excretion was reduced by 8% and 10% for the ad libitum and restricted strategies respectively, compared to biphase feeding with a low protein content diet. The resulting reductions in acidification for one kilogram of pig at the farm gate were 5.5% and 4.3%, respectively for the two strategies. For the restricted strategy, the environmental impact of precision feeding was moderated by a slight increase in the feed conversion ratio between the biphase feeding and precision feeding strategies. This shows the importance of maintaining animal performance to preserve the environmental benefits of precision feeding. In the modelling approach, the potential environmental benefit appears higher, with a 12% reduction in acidification, compared to a biphase feeding strategy with low protein diets. This is linked to the assumption that we will be able (in the future) to estimate the nutrient requirements of individual animals in real time using appropriate genetic and individual data.
For broiler production, using a precision feeding strategy allows to reduce all impacts, although only to a limited extent. Land occupation is reduced by 0.4% between the multiphase control and the precision feeding system. Other impacts are reduced by 4 to 5%, except for phosphorus consumption, which is reduced by 8.5%. These results are linked to the composition of the pre-feeds, the amount of pre-feeds used, and the ability to match diet composition with the requirement of the animals.


The environmental benefits of the innovative feedstuffs depend on the economic context and the incorporation rate of Brazilian soybean meal. In the current context, there is little incentive to use Brazilian soybean meal for pig production. Considering a more “favourable” virtual context for Brazilian soybean meal, a reduction in climate change impacts can be achieved by using alternative sources of protein, especially with European soybean meal, but it will lead to increased land use, resulting in a trade-off question between the benefits and drawbacks. It is necessary to integrate the rebound effects in a larger perimeter of analysis, as shown by Van Zanten et al. (2017). Still, the use of innovative feedstuffs is integrated into the development plans of crop producers and feed manufacturers and there is an ambition to increase production from 150,000 ha of soybean per year in France to 250,000 ha in 2030.
For pig production, precision feeding provides a means to reduce nitrogen excretion, which impacts on acidification and eutrophication. The results of experiments assessed by LCA show that the modest benefits of reduced nitrogen excretion (<5%) can be offset by a reduction in animal performance. With the modelling approach, more interesting environmental benefits have been estimated (e.g., a reduction in acidification of 12%). Individual precision feeding allows to reduce the protein content of feeds and to reduce nitrogen excretion. The environmental benefit measured corresponds to individual multiphase feeding using two different feeds mixed every day: further improvement of performance could be obtained in the future by using three different feeds.

For broiler production, precision feeding can also reduce environmental impacts, but experimental results show only a limited potential with most reductions being between 4 and 5%, with a maximum reduction of 8.5%.

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