Environmental performances of Sardinian dairy sheep production systems at different input levels

Comparing carbon footprints of sheep farming systems in semi-arid regions of India: A life cycle assessment study

Carbon foot prints (CFs) studies based on life cycle assessment between sheep farming systems and green house gases (GHG) emissions is one of the best indicators to quantify the amount of GHG emissions per kg of product. Therefore, a life cycle assessment (LCA) study was conducted for three different sheep farming systems i.e. intensive system (stall fed only), semi-intensive (grazing with supplementation) and extensive system (grazing only) under semiarid region of India to assess the carbon cost of sheep rearing. The total CFs were estimated to be 16.9, 15.8 and 17.1 kg CO2-eq in intensive, semi-intensive and extensive system of grazing indicating semi-intensive system to be most carbon (C) efficient. For 1kg mutton production in semi-intensive and intensive system, around 30% and 24% CFs were contributed from enteric fermentation and feed respectively, whereas, in extensive system, the contribution of enteric fermentation increased up to 50%. The carbon foot prints analysis gives an insight of carbon inputs used but the amount of CO2 sequestered in soil making LCA a holistic approach for estimating GHG emissions from livestock.

A large share of climate impacts of beef and dairy can be attributed to ecosystem services other than food production

Domesticated ruminants supply nutrient-dense foods but at a large environmental cost. However, many ruminant production systems are multi-functional, providing ecosystem services (ES) other than direct provision of food. When quantifying the climate impact of ruminant products using life cycle assessment (LCA), provisioning ES (i.e. beef and milk) are generally considered the only valuable outputs and other ES provided are ignored, which risks overlooking positive contributions associated with ruminant production. Non-provisioning ES can be included in LCA by economic allocation, using compensatory payments (through agri-environmental schemes) as a proxy for the economic value of ES. For example, farmers can receive payments for maintenance of pastures, which supports e.g. pollination. However, the association between different payment schemes, the ES provided, and livestock production is not always straightforward and it can be difficult to determine which payment schemes to include in the allocation. This study examined how accounting for ES in quantification of climate impact for beef and milk production on Swedish farms was affected by different ways of coupling ES to livestock production through payment schemes. Quantification was done using LCA, attributing the climate impact to beef, milk, and other ES by economic allocation. This resulted in <1-48% and 11-31% of climate impacts being allocated to other ES, instead of beef and milk, respectively, affecting suckler farms most. The results were influenced by which payment schemes, representing different ES, that were included; when only payments directly related to livestock rearing were included, the difference in the climate impact was still large between farm types, while the difference decreased considerably when all environmental schemes were included. While emissions do not disappear, ES-corrected climate impact can potentially be useful as part of consumer communication or in decision-making, reducing the risk of overlooking ES provided by ruminant production in a simpler way than using separate indicators.

Sustainability in the Sardinian sheep sector: A systems perspective, from good practices to policy

Three million sheep raised on 10 000 active farms operating in traditional and innovative farming systems in Sardinia, Italy, account for 13% of sheep milk production in the European Union (EU). Almost all of the milk delivered is processed to sheep cheese and is destined for world trade. The Sardinian dairy sheep sector also emits approximately 1600 kt CO₂ eq/year, approximately 60% of regional livestock greenhouse gas (GHG), prompting the need for regional mitigation plans. The SheepToShip LIFE project (EU-LIFE Climate Change Action 2014-2020) is a regional case study to test emission mitigation strategies. Based on the SheepToShip LIFE findings, this paper presents a systems perspective against the backdrop of the Sustainable Development Goals (SDGs) framework, with the aim of underlining system interlinkages between environmental, societal, and economic objectives. The project included (i) a life cycle thinking approach featuring environmental and socioeconomic traits of 18 sheep farms, (ii) on-farm implementation and demonstration of eco-innovative mitigation techniques indicating the most viable actions to reduce impact, (iii) focus groups discussing beliefs and reactions of the main stakeholders, and (iv) group model building producing a causal loop diagram from a systems thinking approach and exploring insights for regional policy-making that aligns with the SDGs. Causal links connect public interventions and stakeholder interaction (SDG 17) to boost farm eco-innovations (SDGs 9 and 8) and education and farmer training (SDG 4), and they foster efficient production (SDG 12) and high-quality food provisioning (SDG 2). These benefits contribute to climate change mitigation (SDG 13), water quality (SDG 6), and farm ecosystem services (SDG 15). Integr Environ Assess Manag 2022;18:1187-1198. © 2022 SETAC.

Sustainability Assessment of Pasture-Based Dairy Sheep Systems: A Multidisciplinary and Multiscale Approach

This article describes a novel methodological approach for the integrated sustainability assessment of pasture-based dairy sheep systems. Most studies on livestock system sustainability focus on animal production, farm profitability, and mitigation strategies of greenhouse gas emissions. However, recent research indicates that pasture-based livestock farming also contributes positively to rural areas, and the associated increase in plant diversity promotes ecosystem functioning and services in natural and managed grasslands. Likewise, little attention has focused on how pasture-based livestock systems affect soil carbon changes, biodiversity, and ecotoxicity. Furthermore, the quality and safety of food products, particularly sheep milk and cheese, and socioeconomic issues such as cultural heritage and consumer behavior are often neglected in livestock system sustainability assessments. To improve the analysis of sustainability and adaptation strategies of livestock systems, we suggest a holistic approach that integrates indicators from diverse disciplines with complementary methods and models capable of capturing the complexity of these systems at multiple scales. A multidisciplinary perspective generates new indicators to identify critical trade-offs and synergies related to the resilience of dairy sheep livestock systems. A multiscale approach provides insights on the effects of socioeconomic and environmental changes associated with current dairy sheep grazing systems across multiple scales. The combined approach will facilitate the development and progressive implementation of novel management strategies needed to adapt pasture-based dairy sheep farms to changing conditions under future socioeconomic and environmental scenarios.

Air quality measurements in four sheep barns part II: pollutant gas emissions

Pollutant gas emissions from animal barns affect indoor air quality, the health and well-being of farmers, and the surrounding environment. This study was carried out in four sheep barns (SB) in Bursa, an important region for animal husbandry operations. Concentrations of NH₃, CO₂, H₂S, and CH₄ were measured in four sheep barns by monitoring throughout 24 h in 1 year. Pollutant gas emissions from barns were also calculated and modeled. The average pollutant gas emissions obtained in this study were 5 kg day^-1 barn^-1 for NH₃, and 18 kg day^-1 barn^-1 for CH₄. The average NH₃ and CH₄ emissions from each barn were 2.1 and 2.7 kg day^-1 barn^-1 for SB1; 9.4 and 12.9 kg day^-1 barn^-1 for SB2; 4.0 and 3.6 kg day^-1 barn^-1 for SB3; and 4.5 21 kg day^-1 barn^-1 for SB4, respectively. There are statistically significant differences between daytime and nighttime for pollutant gas emissions. Pollutant gas emissions in the monitored barns are generally higher in summer than in other seasons. Models for estimating NH₃, and CH₄ emissions were developed using measured temperature and relative humidity values in the barns. These models can only be used in the Bursa region. The results of this study were compared with other studies under similar conditions in the literature.

An Integrated Approach to Convert Lignocellulosic and Wool Residues into Balanced Fertilisers

Valorising biomass waste and producing renewable energy or materials is the aim of several conversion technologies. In this work, we consider two residues from different production chains: lignocellulosic residues from agriculture and wool residues from sheep husbandry. These materials are produced in large quantities, and their disposal is often costly and challenging for farmers. For their valorisation, we focus on slow pyrolysis for the former and water hydrolysis for the latter, concisely presenting the main literature related to these two processes. Pyrolysis produces the C-rich biochar, suitable for soil amending. Hydrolysis produces a N-rich fertiliser. We demonstrate how these two processes could be fruitfully integrated, as their products can be flexibly mixed to produce fertilisers. This solution would allow the achievement of balanced and tuneable ratios between C and N and the enhancement of the mechanical properties. We propose scenarios for this combined valorisation and for its coupling with other industries. As a result, biomass waste would be returned to the field, following the principles of circular economy.

The influence of fertiliser and pesticide emissions model on life cycle assessment of agricultural products: The case of Danish and Italian barley

Barley is an ancient crop and a great source of nutrients. It is the third largest agricultural commodity produced in Denmark and represents a relevant crop in Italy too. Due to the increasing customers awareness of sustainability issues, it has become essential to evaluate the environmental impact and the use of resources in food production and distribution systems. However, especially in agriculture, difficulties are encountered when emissions from fertilisers and pesticides need to be modelled, due to a variety of modelling options and their dependency on the availability of site-specific information. How to address these difficulties might affect the results reliability. Hence, this study aims to evaluate, using the life cycle assessment (LCA) methodology, the influence of different models for estimating emissions from fertilisers and pesticides on the environmental impacts of barley cultivation in Denmark and Italy. Two models for fertilisers and pesticides' emissions have been applied; these differ on the extent of data requirements and complexity of calculation algorithms, which might increase the results accuracy and robustness. The results show that the modelling options do affect the environmental impacts of barley production, in particular climate change, eutrophication categories, acidification and freshwater eco-toxicity. This study estimates that the variations for such categories range from 15% in the case of climate change to 89% in the case of marine eutrophication. These findings highlight the importance of the emission modelling options as well as the constraints of data requirements, critical aspects when a LCA study on agricultural products is carried out.

Greenhouse-gas mitigation potential of agro-industrial by-products in the diet of dairy goats in Spain: a life-cycle perspective

Goat milk production is an important agricultural resource in the Mediterranean basin. Market demands and scarcity of pastures during drought periods has led to farms becoming more intensive and based on imported concentrate feeds. The use of alternative feedstuffs from agro-industry can help decrease dependence on external concentrates, while preventing the environmental issues associated with livestock production and by-product disposal. From a life-cycle assessment perspective, we investigated the change on greenhouse-gas (GHG) emissions of replacing a conventional dairy goat diet in southern Spain with two alternative dietary strategies, including tomato waste or olive by-products silages. The effect on enteric methane emissions and milk productivity was assessed through specific feeding trials. Experimental data were integrated within a modelling framework comprising different submodels to describe the farm system and associated production chain. A new model describing carbon and nitrogen losses from solid waste was applied to estimate the emissions associated with the baseline scenarios for food by-product management. The assessment revealed that the two dietary strategies achieve GHG reductions (~12–19% per kg milk). In both cases, nitrous oxide and carbon dioxide emissions from crop production were partially reduced through the displacement of typical concentrate ingredients. An additional mitigation effect was obtained when including tomato wastes in the diet because it reduced the methane emissions from enteric fermentation. Results suggested that use of agro-industrial residues for feeding is a feasible mitigation option in this case. However, as organic by-products could have alternative uses (bioenergy, soil amendment), with different implications for land use and soil carbon stocks, a more complete overview of both scenarios is recommended. Potential trade-offs from non-GHG categories may play an important role in a decision-making process.