Search

We explore and develop an integrated model to enhance understanding and evaluation of the economic and environmental sustainability performance of alternative agricultural cropping production systems. More specifically, our developed Environmentally Sustainable Residual Income Decomposition Modelling (ESRIDM) integrates accounting decomposition analysis, Water and Economic Sustainability Performance Measurement (WESM), system thinking, modular thinking, Environmentally Sustainable Residual Income (ESRI) theory, into a holistic modelling system influenced by Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) approaches. The ESRIDM is theorised and applied in the context of nitrogen management in Australian Cotton production through a detailed case study and comparative analysis of three nitrogen fertiliser options. We find the ESRIDM is able to: (i) provide an overall assessment of the economic and environmental sustainability performance of each scenario modelled; (ii) increase the transparency of the production system to enable the identification of key issues which influence the likely suitability of each scenario; (iii) enable an analysis of probable outcomes under various alternatives; (iv) evaluate the feasibility of regulatory option modelled. While this paper offers a novel perspective to a specific context, ESRIDM is designed to be adapted to a variety of contexts with a view to contributing to the evolution of more sustainable systems of production more generally. [Display omitted] [ABSTRACT FROM AUTHOR]

• Thymol-based emulsions (Thy-Es) were studied to select the best preparation condition. • Thy-E with 9 % surfactant, and 2.5/3.0 min vortex/ultrasound times was selected (9 %S1). • Thy-E9 %S1 was macroscopic/microscopic stable during 28 days. • Fusarium oxysporum f. sp. lycopersici growth mycelial was controlled using Thy-E9 %S1. • No phytotoxic effects on tomato seeds were observed after treatment with Thy-E9 %S1. Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (Fol) is one of the major production constraints of tomato yield. The use of seed treatment is an alternative strategy to mitigate the occurrence of Fusarium wilt, induced by the Fol. Thus, the present study aimed to select the best condition for obtaining a thymol-based emulsion (Thy-E), considering surfactant concentration, vortex homogenization time (HVtx) and high-intensity ultrasound (HUS) time, using both the visual/macroscopic and the microscopic approaches to evaluate Thy-Es. Thy-E prepared with 9.0 % (w −1) surfactant, 2.5 min of HVtx and 3.0 min of HUS (Thy-E9 %S1) was achieved as the best condition to obtain a Thy-based emulsion, and was studied over time to evaluate the mean droplet diameter, hydrogen potential (pH) and electrical conductivity (EC) values. In addition, the effectiveness of Thy-E9 %S1 on Fol in terms of spores/conidial germination and mycelial growth, and its impact on vigor (germination, germination energy, germination index, hypocotyl, primary root growth, pH and EC tests) of tomato seed were assessed. Thy-E9 %S1 showed no evidence of considerable droplet destabilization or phase separation during 28 days of storage at 25 °C. The effective concentration values for 50 % (EC 50) and 90 % (EC 90) inhibition of Thy-E9 %S1 against Fol were 0.05 and 0.27 mg mL−1 thymol (Thy), respectively. No signs of phytotoxicity were observed in tomato seeds exposed to Thy-E9 %S1 at concentrations ranging from 2.5 to 10.0 mg mL−1 Thy, without affecting the vigor of tomato seeds for the concentrations used to control Fol. Thy-E9 %S1 showed stability over the time, fungicidal activity against Fol and did not affect the vigor of tomato seeds, enabling an alternative for the integrated plant disease management. These findings pointing out the Thy-E9 %S1 as an innovative delivery system to act as an antifungal for the seed industry. [Display omitted] [ABSTRACT FROM AUTHOR]

Diets based on large proportions of grassland-based feed are uncommon in forage-based intensive beef production, thus contradicting governmental or commercial strategies to promote the use of grassland-based feed in ruminant production systems. Compared with typical maize silage/concentrate diets, grassland-based diets are associated with impaired nitrogen (N) and energy utilisation because of the comparably lower energy and higher CP content of these feeds. However, quantitative studies concerning the effects of increased dietary proportions of grassland-derived feeds on N and energy losses and utilisation and on methane emissions are missing and the compensation potential of using a limited proportion of an energy-rich forage is unknown. Therefore, we tested five diets with varying types and proportions of forage and concentrate. Three diets consisted of grass silage, maize silage, and concentrate in ratios of, g/kg DM, 100:600:300 (G100; control), 300:500:200 (G300), and 500:300:200 (G500), respectively. Two diets were composed of grass silage, corn-cob mix (CCM), and concentrate in ratios of, g/kg DM, 500:300:200 (G500CCM), and 750:150:100 (G750CCM), respectively. A high-protein concentrate (270 g CP/kg DM) was fed to G100, whereas a low-protein concentrate (140 g CP/kg DM) was used in the remaining diets. Diets were fed throughout the entire fattening period to groups of six Limousin-crossbred bulls each. When weighing 246 ± 18 kg, each animal underwent a 7-day total daily faeces and urine collection, which was followed by measuring methane emissions in respiration chambers for 48 h. Total DM intake was similar across all diets, whereas the N intake varied (P

Climate change mitigation, the goal of reducing CO2 emissions, more stringent regulations and the increment in energy costs have pushed researchers to study energy efficiency and renewable energy sources. Manufacturing systems are large energy consumers and are thus responsible for huge greenhouse gas emissions; for these reasons, many studies have focused on this topic recently. This review aims to summarize the most important papers on energy efficiency and renewable energy sources in manufacturing systems published in the last fifteen years. The works are grouped together, considering the system typology, i.e., manufacturing system subclasses (single machine, flow shop, job shop, etc.) or the assembly line, the developed energy-saving policies and the implementation of the renewable energy sources in the studied contexts. A description of the main approaches used in the analyzed papers was discussed. The conclusion reports the main findings of the review and suggests future directions for the researchers in the integration of renewable energy in the manufacturing systems consumption models. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rise in the productivity of sweet orange in Brazil has been related to the use of superior rootstocks and higher tree density, among other factors. In order to investigate whether the cropping system and the land use efficiency would benefit from more intensive cultivation, the performance of Valencia sweet orange was evaluated over nine years on four rootstocks, which induced contrasting vigor, at 513, 696 and 1000 trees·ha−1. Agronomic Institute of Campinas (IAC) 1697 and IAC 1710 citrandarins, and diploid and allotetraploid (4×) Swingle citrumelos were classified as semi-dwarfing, super-standard, standard, and dwarfing rootstocks, respectively. The fruit yield per tree was decreased at higher tree densities, notably for more vigorous rootstocks. Conversely, the cumulative productivity was increased over the evaluation period by 27% at 1000 trees·ha−1, irrespective of the rootstock, and the most vigorous rootstock resulted in 2.5 times higher production than the dwarfing one on average. Most fruit quality parameters were seldom influenced by the tree density, while the rootstock was a decisive factor in improving the quality and the soluble solids content. Dwarfing rootstocks allowed for harvesting 17% more fruit per minute by manual pickers. Because the tree row volume per area is lower with such rootstocks, even at higher tree density, spray volume can be reduced, although appropriate equipment should be developed for better spray coverage on smaller trees. Nine years after planting under strict vector control, the cumulative incidence of huanglongbing-symptomatic trees on IAC 1710 was double that on Swingle 4×. Taken together, the results suggested that the land use efficiency in the citrus industry can be further improved by planting vigorous rootstocks at moderate to high tree densities. Nevertheless, obtaining highly productive semi-dwarfing and dwarfing rootstocks is the sine qua non for making high-density pedestrian sweet orange orchards more profitable.

Climate change mitigation, the goal of reducing CO2 emissions, more stringent regulations and the increment in energy costs have pushed researchers to study energy efficiency and renewable energy sources. Manufacturing systems are large energy consumers and are thus responsible for huge greenhouse gas emissions; for these reasons, many studies have focused on this topic recently. This review aims to summarize the most important papers on energy efficiency and renewable energy sources in manufacturing systems published in the last fifteen years. The works are grouped together, considering the system typology, i.e., manufacturing system subclasses (single machine, flow shop, job shop, etc.) or the assembly line, the developed energy-saving policies and the implementation of the renewable energy sources in the studied contexts. A description of the main approaches used in the analyzed papers was discussed. The conclusion reports the main findings of the review and suggests future directions for the researchers in the integration of renewable energy in the manufacturing systems consumption models.

The aim of the study was to investigate the complete substitution of imported soybean meal in beef cattle diets and the consequences on performance, meat, and adipose tissue quality. Thirty growing crossbred Limousin bulls, with an initial bodyweight of 164 ± 13 kg and 4.3 ± 0.3 months of age, were fed a grass/maize-silage based diet with little additional concentrate (0.5:0.3:0.2). Concentrates contained either soybean meal (positive control), faba beans, pumpkin seed cake, or spirulina (Arthrospira platensis), resulting in about 226 g crude protein (CP)/kg concentrate dry matter (DM) and 158 g CP/kg total diet DM. A grain-based concentrate providing just 135 g CP/kg concentrate DM and 139 g CP/total diet DM served as a negative control. Bulls of all groups had comparable average daily gains (1.43 ± 0.1 kg) and feed intakes (6.92 ± 0.37 kg). Carcass and meat quality did not differ among groups. The fatty acid profile of meat lipids was hardly affected. These results indicate that soybean meal can be replaced by any of the tested protein sources without impairing performance or meat quality. Importantly, bulls fed the negative control achieved a fattening and slaughter performance comparable to that of the protein-supplemented groups without affecting meat and adipose tissue quality. Thus, the present findings suggest that feeding crossbred bulls a grass/maize-silage based diet does not require additional protein supplementation.

The current trend in internal value stream structures shows a clear development towards a combination of the specific advantages of the operation-oriented and the process-oriented production systems. All scientific approaches have in common that flexible intralogistics production networks require an autonomous and intelligent transportation systems that is not designed for a specific task, but can take on different transport roles due to their versatility. However, a comprehensive analysis of current designs and research projects in the field of AGVs and intralogistics transport robots show that there is neither the necessary interoperability of different systems nor a system architecture that addresses a flexible material flow independent of the physical design of the transportation system. AGVs mainly have a central control system, which manages the generation of transport orders and their disposition on the vehicles. In addition, the routes are specified centrally for the vehicles, even if they have free navigation. The individual transport unit is therefore only an executing machine that processes the assigned transport orders without any influence on order dispatching or route planning. Therefore, these AGV approaches do not have the flexibility and autonomy required for an intralogistics production network. The research project addresses the necessary interoperability of logistics systems and the abandonment of proprietary standalone solutions. For this purpose, methods for digitizing the workspace, route planning and path execution using a service-oriented architecture (SOA) were developed. A central component of this architecture is the approach described in the paper to enable decentralized path planning on the vehicles. Therefore, the path planning must be applicable to different target platforms without implementation effort and the vehicle software must be designed independently of the application. This approach allows intralogistics systems to be flexible and adaptable, resulting in a more sustained use of these systems. [ABSTRACT FROM AUTHOR]

Winter cover crops (WCCs) provide agronomic and environmental benefits, although their impacts on subsequent crop yields have been reported to vary across regions, soils, or under different farm practices. To address the variability in response, previous qualitative and quantitative reviews have summarized the overall yield effects of WCCs. However, the results from such reviews need constant revision as new research is published and interest in the conservation benefits of WCCs increases. Here, we update a previous meta-analysis of WCC effects on corn (Zea mays) yields, which summarized peer-reviewed research from the United Sates and Canada that was published between 1965 and 2004. Our updated data set (1965 to 2015) comprises 268 observations from 65 studies conducted in different regions of the United States and Canada, and includes information about the management practices utilized (i.e., WCC species, nitrogen [N] fertilization, termination date, tillage, etc.). The effect-size was the response ratio (RR), defined as corn yield following WCCs relative to yield after no cover crop (NC). As in the previous meta-analysis, our results showed a neutral to positive contribution of WCCs to corn yields. On average, grass WCCs neither increased nor decreased corn yields, although corn grown for grain yielded relatively higher than silage corn after grass WCCs. Legume WCCs resulted in subsequent higher corn yields by 30% to 33% when N fertilizer rates were low or the tillage system shifted from conventional tillage (CT) to no-tillage (NT). Mixture WCCs increased corn yields by 30% when the cover crop was late terminated (zero to six days before subsequent corn). Evidence of 65 years of research showed that uncertainty around the RR has decreased and corn yield response to WCCs has stabilized over time. Our results suggest that benefits of WCCs do not result in reduced corn productivity if properly managed. [ABSTRACT FROM AUTHOR]

• Beef bulls were fed five diets with increasing grass silage proportions. • Concentrate with soybean meal was replaced with a low-protein concentrate. • Absolute methane emissions were comparable among the diet groups. • Adding 300 g/kg corn-cob mix to 500 g/kg grass silage reduced urinary N loss. • A diet combining grass silage with corn-cob mix may alleviate environmental N load. Diets based on large proportions of grassland-based feed are uncommon in forage-based intensive beef production, thus contradicting governmental or commercial strategies to promote the use of grassland-based feed in ruminant production systems. Compared with typical maize silage/concentrate diets, grassland-based diets are associated with impaired nitrogen (N) and energy utilisation because of the comparably lower energy and higher CP content of these feeds. However, quantitative studies concerning the effects of increased dietary proportions of grassland-derived feeds on N and energy losses and utilisation and on methane emissions are missing and the compensation potential of using a limited proportion of an energy-rich forage is unknown. Therefore, we tested five diets with varying types and proportions of forage and concentrate. Three diets consisted of grass silage, maize silage, and concentrate in ratios of, g/kg DM, 100:600:300 (G100 ; control), 300:500:200 (G300), and 500:300:200 (G500), respectively. Two diets were composed of grass silage, corn-cob mix (CCM), and concentrate in ratios of, g/kg DM, 500:300:200 (G500 CCM), and 750:150:100 (G750 CCM), respectively. A high-protein concentrate (270 g CP/kg DM) was fed to G100, whereas a low-protein concentrate (140 g CP/kg DM) was used in the remaining diets. Diets were fed throughout the entire fattening period to groups of six Limousin-crossbred bulls each. When weighing 246 ± 18 kg, each animal underwent a 7-day total daily faeces and urine collection, which was followed by measuring methane emissions in respiration chambers for 48 h. Total DM intake was similar across all diets, whereas the N intake varied (P < 0.05). Urinary N loss (g/day) was the highest for G750 CCM (28.2) and G100 (26.6) and lowest for G500 CCM (15.2) and G300 (16.9) (P < 0.001). Energy utilisation was comparable among all groups. Metabolisable energy intake decreased numerically only with increasing proportions of grass silage in the diet. Substituting maize silage with CCM counteracted the loss in metabolisable energy intake. Absolute methane emissions were not different across the groups, but methane emission intensity (mg/g body protein retention) varied (P < 0.05), being numerically lower for G100 (349) and G500 CCM (401) compared with the other groups (488 on average). In conclusion, the results show that the grass silage proportion in beef cattle diets can be substantially increased when strategically combined with energy-dense forages, such as CCM. This also limits the need for concentrate and additional protein sources; in addition, the associated urinary N emissions, which are potentially noxious to the environment, are avoided. [ABSTRACT FROM AUTHOR]

Nowadays the arid Chaco in central Argentina presents gradients of woody vegetation cover with a variety of management regimes with different environmental impacts. Here, we compare the relative effects of the two most widespread management systems in the region: silvopastoral and peasant managements. Soil properties, plant species richness, composition and vegetation structure were used as ecological indicators as they are crucial for long term-sustainability of production systems. Vegetation cover and plant composition responded differently to land management systems. While plant species richness and composition remained similar in both land management types, tree cover showed a strong reduction in silvopastoral systems. We also observed differences in soil properties, with increases in nitrates, sulfates and electrical conductivity in silvopastoral systems as compared to peasant land management. Tree cover reduction and higher soil salinity may impact negatively the productive capacity of soils, which may compromise the delivery of ecosystem services in silvopastoral systems of central Argentina in the long-term. Peasant land use management showed comparable less environmental impact on soils, allowing the preservation of not only provision services but also of regulating and supporting services in these highly vulnerable areas. • Environmental effects of silvopastoral and peasant systems have never been compared. • Plant species composition remained similar between management systems. • Tree cover and soil quality decreased in silvopastoral sites while bare soil increased. • Increased soil salinity can risk sustainability of silvopastures in arid chaco. • Peasant systems had lower impact on these environmental indicators. [ABSTRACT FROM AUTHOR]

This paper proposes an approach based on a systemic design methodology and the Multi-layer Enterprise Input-Output formalisation method to engage different stakeholders in a new production network to create value from waste and by-products. The proposed methodology supports the stakeholders' cooperation in the design and development phases to establish, in a bottom-up fashion, production networks based on mutual stakeholders' trust and relevant innovation content, such as industrial symbioses. The systemic design approach focuses on the characteristics of the local communities and their know-how identifying current waste and potential alternatives to exploit them as raw materials. A novel hierarchical version of the Multi-layer Enterprise Input-Output formalisation method quantitatively supports the system design and the performance assessment. It increases data consistency, supports practitioners in system formalisation, and feeds a properly developed dashboard of KPIs to provide the stakeholders with systemic design information and system techno-economic-environmental performance. The methodology implementation is shown in a case study based on the regional project InnovaEcoFood, which analyses the technical feasibility of producing healthy products from wine press residue and rice bran. The case study shows that the methodology data structure is suitable for dynamic analyses to support decision-making, performance assessment, negotiation, and development activities. The methodology engages stakeholders in the design and development process, providing consistent techno-economic-environmental data through a shared platform. In particular, it is suitable for self-organising networks and models where stakeholders themselves engage partners to build and extend the network. • Methodology to design production networks and self-organising industrial symbioses; • Helping stakeholders cooperate by comparing production and systemic alternatives; • Improve data consistency and formalisation, and enable dynamic and scale analyses; • Process and system technical, economic, and environmental KPIs since design phase; • Comparing waste exploited by the new network with waste that it will produce. [ABSTRACT FROM AUTHOR]

Agriculture is under pressure to produce greater quantities of food, feed and biofuel on limited land resources. Current over-reliance on a handful of major staple crops has inherent agronomic, ecological, nutritional and economic risks and is probably unsustainable in the long run. Wider use of today's underutilized minor crops provides more options to build temporal and spatial heterogeneity into uniform cropping systems and will enhance resilience to both biotic and abiotic stress. Many traditional vegetables and underutilized legume crops are an essential source of vitamins, micronutrients and protein and, thus, a valuable component to attain nutritional security. Vegetables in general are of considerable commercial value and therefore an important source of household income. Significant research, breeding and development efforts are needed for a range of promising crops to convert existing local landraces into competitive varieties with wide adaptation and promising commercial potential. Access to genetic diversity of these selected crops is a pre-condition for success. Three underutilized minor crops--amaranth, drumstick tree, and mungbean--are highlighted and briefly described. All three crops are well-represented in AVRDC's genebank with substantial inter- and intra-specific genetic diversity, and already have demonstrated their potential for wider adoption and commercial exploitation. [ABSTRACT FROM AUTHOR]

Driven by wind and solar photovoltaics technology, the power industry is shifting towards a distributed generation (DG) paradigm. A key challenge in deploying a renewable DG system is the power volatility. This study proposes a visionary energy concept and further presents a mathematical model that could help the large industry consumers adopt this new energy technology. The study seeks to design a grid-connected DG system that is capable of providing the necessary electricity for wafer fabs. Simulation-based optimization algorithm was applied to determine the equipment type and capacity aiming to minimize the DG lifecycle cost. The proposed method was demonstrated on fab facilitates located in three different regions in the US. [ABSTRACT FROM AUTHOR]

The rise in the productivity of sweet orange in Brazil has been related to the use of superior rootstocks and higher tree density, among other factors. In order to investigate whether the cropping system and the land use efficiency would benefit from more intensive cultivation, the performance of Valencia sweet orange was evaluated over nine years on four rootstocks, which induced contrasting vigor, at 513, 696 and 1000 trees·ha−1. Agronomic Institute of Campinas (IAC) 1697 and IAC 1710 citrandarins, and diploid and allotetraploid (4×) Swingle citrumelos were classified as semi-dwarfing, super-standard, standard, and dwarfing rootstocks, respectively. The fruit yield per tree was decreased at higher tree densities, notably for more vigorous rootstocks. Conversely, the cumulative productivity was increased over the evaluation period by 27% at 1000 trees·ha−1, irrespective of the rootstock, and the most vigorous rootstock resulted in 2.5 times higher production than the dwarfing one on average. Most fruit quality parameters were seldom influenced by the tree density, while the rootstock was a decisive factor in improving the quality and the soluble solids content. Dwarfing rootstocks allowed for harvesting 17% more fruit per minute by manual pickers. Because the tree row volume per area is lower with such rootstocks, even at higher tree density, spray volume can be reduced, although appropriate equipment should be developed for better spray coverage on smaller trees. Nine years after planting under strict vector control, the cumulative incidence of huanglongbing-symptomatic trees on IAC 1710 was double that on Swingle 4×. Taken together, the results suggested that the land use efficiency in the citrus industry can be further improved by planting vigorous rootstocks at moderate to high tree densities. Nevertheless, obtaining highly productive semi-dwarfing and dwarfing rootstocks is the sine qua non for making high-density pedestrian sweet orange orchards more profitable. [ABSTRACT FROM AUTHOR]

The interaction of typical host adapted enteric bacterial pathogens with fresh produce grown in fields is complex. These interactions can be more pronounced in co-managed or sustainable farms where animal operations are, by design, close to fresh produce, and growers frequently move between the two production environments. The primary objectives of this study were to 1) determine the transmission of STEC or enteric pathogens from small and large animal herds or operations to fresh produce on sustainable farms in TN and NC, 2) identify the possible sources that impact transmission of AMR E. coli , specifically STEC on these systems, and 3) WGS to characterize recovered E. coli from these sources. Samples were collected from raw and composted manure, environment, and produce sources. The serotype, virulence, and genotypic resistance profile were determined using the assembled genome sequences sequenced by Illumina technology. Broth microdilution was used to determine the antimicrobial susceptibility of each isolate against a panel of fourteen antimicrobials. The prevalence of E. coli increased during the summer season for all sources tested. ParSNP trees generated demonstrated that the transmission of AMR E. coli is occurring between animal feeding operations and fresh produce. Ten isolates were identified as serotype O45, a serotype that is associated with the "Big Six" group that is frequently linked with foodborne outbreaks caused by non-O157 E. coli. However, these isolates did not possess the stx gene. The highest frequency of resistance was detected against streptomycin (n = 225), ampicillin (n = 190) and sulfisoxazole FIS (n = 140). A total of 35 (13.7%) isolates from two TN farms were positive for the blaCMY (n = 5) and blaTEM (n = 32) genes. The results of this study show the potential of AMR E. coli transmission between animal feeding operations and fresh produce, and more studies are recommended to study this interaction and prevent dissemination in sustainable farming systems. • First to study E. coli transmission on commercial sustainable farms in two states • Transmission of AMR E. coli detected on sustainable farms. • Transmission was observed mainly during the summer months. • The majority (55%) of the E. coli were multidrug resistant. • WGS is a tool used to elucidate connections between isolates from multiple sources. [ABSTRACT FROM AUTHOR]

• Relationship between rural credit policy and diffusion of ICLS was investigated. • A Simultaneous Equation System was adopted to deal with reverse causality. • Access to rural credit policy increases the adoption of ICLS. • The adoption of ICLS increases the demand of rural credit. • Public policy is encouraging the diffusion of sustainable systems in Brazil. This study analyzes the effectiveness of rural credit policy to increase the adoption of ICLS. Analyzes are based on a survey with 175 farmers in the State of São Paulo, Brazil. Our estimates suggest that rural credit has positive and relevant impacts on the adoption of ICLS. In turn, the adoption of these systems may also involve investments in fixed capital and increases in operational costs, which create additional demand for rural credit. Other factors, such as access to extension policy, production scale, ex-ante perceptions, and market infrastructure also explain ICLS adoption. The access to rural credit policy is also determined by dependence on farm income, farmer's perception of transaction costs, and supply of credit in the municipality. The study finally discusses important implications for the devising of rural credit policies and the diffusion of sustainable production systems in developing countries. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the complete substitution of imported soybean meal in beef cattle diets and the consequences on performance, meat, and adipose tissue quality. Thirty growing crossbred Limousin bulls, with an initial bodyweight of 164 ± 13 kg and 4.3 ± 0.3 months of age, were fed a grass/maize-silage based diet with little additional concentrate (0.5:0.3:0.2). Concentrates contained either soybean meal (positive control), faba beans, pumpkin seed cake, or spirulina ( Arthrospira platensis ), resulting in about 226 g crude protein (CP)/kg concentrate dry matter (DM) and 158 g CP/kg total diet DM. A grain-based concentrate providing just 135 g CP/kg concentrate DM and 139 g CP/total diet DM served as a negative control. Bulls of all groups had comparable average daily gains (1.43 ± 0.1 kg) and feed intakes (6.92 ± 0.37 kg). Carcass and meat quality did not differ among groups. The fatty acid profile of meat lipids was hardly affected. These results indicate that soybean meal can be replaced by any of the tested protein sources without impairing performance or meat quality. Importantly, bulls fed the negative control achieved a fattening and slaughter performance comparable to that of the protein-supplemented groups without affecting meat and adipose tissue quality. Thus, the present findings suggest that feeding crossbred bulls a grass/maize-silage based diet does not require additional protein supplementation.