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1.
The implementation of measures to increase productivity and resource efficiency in food and bioenergy chains as well as to more sustainably manage land use can significantly increase the biofuel production potential while limiting the risk of causing indirect land use change (ILUC). However, the application of these measures may influence the greenhouse gas (GHG) balance and other environmental impacts of agricultural and biofuel production. This study applies a novel, integrated approach to assess the environmental impacts of agricultural and biofuel production for three ILUC mitigation scenarios, representing a low, medium and high miscanthus‐based ethanol production potential, and for three agricultural intensification pathways in terms of sustainability in Lublin province in 2020. Generally, the ILUC mitigation scenarios attain lower net annual emissions compared to a baseline scenario that excludes ILUC mitigation and bioethanol production. However, the reduction potential significantly depends on the intensification pathway considered. For example, in the moderate ILUC mitigation scenario, the net annual GHG emissions in the case study are 2.3 MtCO2‐eq yr?1 (1.8 tCO2‐eq ha?1 yr?1) for conventional intensification and ?0.8 MtCO2‐eq yr?1 (?0.6 tCO2‐eq ha?1 yr?1) for sustainable intensification, compared to 3.0 MtCO2‐eq yr?1 (2.3 tCO2‐eq ha?1 yr?1) in the baseline scenario. In addition, the intensification pathway is found to be more influential for the GHG balance than the ILUC mitigation scenario, indicating the importance of how agricultural intensification is implemented in practice. Furthermore, when the net emissions are included in the assessment of GHG emissions from bioenergy, the ILUC mitigation scenarios often abate GHG emissions compared to gasoline. But sustainable intensification is required to attain GHG abatement potentials of 90% or higher. A qualitative assessment of the impacts on biodiversity, water quantity and quality, soil quality and air quality also emphasizes the importance of sustainable intensification.  相似文献   

2.
To ensure a sustainable food supply for the growing population, the challenge is to find agricultural systems that can meet production requirements within environmental constraints and demands. This study compares the impacts of winter wheat production on energy use, land use and 100 years Global Warming Potential (GWP100) under different arable farming systems and farming practices. Life cycle assessment was used to simulate the impacts of organic, conventional and integrated farming (IF) systems along the production chain from input production up to the farm gate. The IF system models were designed to combine the best practices from organic and conventional systems to reduce negative environmental impacts without significant yield reductions. An integrated system that used food waste digestate as a fertiliser, and utilised pesticides and no‐tillage had the lowest energy use and GWP per functional unit of 1000 kg wheat output. When the impacts of some specific practices for reducing energy use and GWP were compared, the highest energy use reductions were achieved by replacing synthetic nitrogen fertilisers with anaerobically treated food waste or nitrogen fixing crops, increasing yields through crop breeding and using no‐tillage instead of ploughing. The highest GWP reductions were achieved by using nitrification inhibitors, replacing synthetic nitrogen fertilisers and increasing yields. The major contributors to the uncertainty range of energy use were associated with machinery fuel use and the assumed crop yields. For GWP results, the main source of uncertainty related to the N2O emissions. In conclusion, farming systems that combine the best practices from organic and conventional systems have potential to reduce negative environmental impacts while maintaining yield levels.  相似文献   

3.
Feed production is a significant source of greenhouse gas (GHG) emissions from dairy production and demands large arable and pasture acreage. This study analysed how regional conditions influence GHG emissions of dairy feed rations in a life cycle perspective, that is the carbon footprint (CF) and the land area required. Factors assessed included regional climate variations, grass/clover silage nutrient quality, feedstuff availability, crop yield and feed losses. Using the Nordic feed evaluation model NorFor, rations were optimised for different phases of lactation, dry and growing periods for older cows, first calvers and heifers by regional feed advisors and combined to annual herd rations. Feed production data at farm level were based on national statistics and studies. CF estimates followed standards for life cycle assessment and used emissions factors provided by IPCC. The functional unit was ‘feed consumption to produce 1 kg energy corrected milk (ECM) from a cow with annual milk yield of 9 900 kg ECM including replacement animals and feed losses’. Feed ration CF varied from 417 to 531 g CO2 e/kg ECM. Grass/clover silage contributed more than 50% of total GHG emissions. Use of higher quality silage increased ration CF by up to 5% as a result of an additional cut and increased rates of synthetic N-fertiliser. Domestically produced horse bean (Vicia faba), by-products from the sugar industry and maize silage were included in the rations with the lowest CF, but horse bean significantly increased ration land requirement. Rations required between 1.4 to 2 m2 cropland and 0.1 to 0.2 m2/kg semi-natural grassland per kg ECM and year. Higher yield levels reduced ration total CF. Inclusion of GHG emissions from land use change associated with Brazilian soya feed significantly increased ration CF. Ration CF and land use depended on ration composition, which was highly influenced by the regional availability and production of feedstuffs. The impact of individual feedstuffs on ration CF varies due to, for example, cultivation practices and climate conditions and feedstuffs should therefore be assessed in a ration and regional perspective before being used to decrease milk CF. Land use efficiency should be considered together with ration CF, as these can generate goal conflicts.  相似文献   

4.
Over the past 23 years (1990 to 2012), French beef cattle farms have expanded in size and increased labour productivity by over 60%, chiefly, though not exclusively, through capital intensification (labour–capital substitution) and simplifying herd feeding practices (more concentrates used). The technical efficiency of beef sector production systems, as measured by the ratio of the volume value (in constant euros) of farm output excluding aids to volume of intermediate consumption, has fallen by nearly 20% while income per worker has held stable thanks to subsidies and the labour productivity gains made. This aggregate technical efficiency of beef cattle systems is positively correlated to feed self-sufficiency, which is in turn negatively correlated to farm and herd size. While volume of farm output per hectare of agricultural area has not changed, forage feed self-sufficiency decreased by 6 percentage points. The continual increase in farm size and labour productivity has come at a cost of lower production-system efficiency – a loss of technical efficiency that 20 years of genetic, technical, technological and knowledge-driven progress has barely managed to offset.  相似文献   

5.
Environmental impacts of 15 European pig farming systems were evaluated in the European Union Q-PorkChains project using life cycle assessment. One conventional and two non-conventional systems were evaluated from each of the five countries: Denmark, The Netherlands, Spain, France and Germany. The data needed for calculations were obtained from surveys of 5 to 10 farms from each system. The systems studied were categorised into conventional (C), adapted conventional (AC), traditional (T) and organic (O). Compared with C systems, AC systems differed little, with only minor changes to improve meat quality, animal welfare or environmental impacts, depending on the system. The difference was much larger for T systems, using very fat, slow-growing traditional breeds and generally outdoor raising of fattening pigs. Environmental impacts were calculated at the farm gate and expressed per kg of pig live weight and per ha of land used. For C systems, impacts per kg LW for climate change, acidification, eutrophication, energy use and land occupation were 2.3 kg CO2-eq, 44.0 g SO2-eq, 18.5 g PO4-eq, 16.2 MJ and 4.1 m2, respectively. Compared with C, differences in corresponding mean values were +13%, +5%, 0%, +2% and +16% higher for AC; +54%, +79%, +23%, +50% and +156% for T, and +4%, −16%, +29%, +11% and +121% for O. Conversely, when expressed per ha of land use, mean impacts were 10% to 60% lower for T and O systems, depending on the impact category. This was mainly because of higher land occupation per kg of pig produced, owing to feed production and the outdoor raising of sows and/or fattening pigs. The use of straw bedding tended to increase climate change impact per kg LW. The use of traditional local breeds, with reduced productivity and feed efficiency, resulted in higher impacts per kg LW for all impact categories. T systems with extensive outdoor raising of pigs resulted in markedly lower impact per ha of land used. Eutrophication potential per ha was substantially lower for O systems. Conventional systems had lower global impacts (global warming, energy use, land use), expressed per kg LW, whereas differentiated systems had lower local impacts (eutrophication, acidification), expressed per ha of land use.  相似文献   

6.
Livestock farmers in Sweden usually grow feed grains for livestock but import protein feed from outside Sweden. Aside from the economic implications, some environmental issues are associated with this practice. We used life cycle assessment to evaluate the impact of local protein feed production on land use and greenhouse gas emissions, compared with the use of imported protein feed, for pig meat and dairy milk produced in Sweden. Our results showed that local production reduced greenhouse gas emissions by 4.5% and 12%, respectively, for pigs and dairy cows. Land use for feed production in Sweden increased by 11% for pigs and 25% for dairy cows, but total land use decreased for pig production and increased for dairy milk production. Increased protein feed cultivation in Sweden decreased inputs needed for animal production and improved some ecological processes (e.g. nutrient recycling) of the farm systems. However, the differences in results between scenarios are relatively small and influenced to an extent by methodological choices such as co-product allocation. Moreover, it was difficult to assess the contribution of greenhouse emissions from land use change. The available accounting methods we applied did not adequately account for the potential land use changes and in some cases provided conflicting results. We conclude that local protein feed production presents an opportunity to reduce greenhouse gas emissions but at a cost of increasing land occupation in Sweden for feed production.  相似文献   

7.
Milk and beef production cause 9% of global greenhouse gas (GHG) emissions. Previous life cycle assessment (LCA) studies have shown that dairy intensification reduces the carbon footprint of milk by increasing animal productivity and feed conversion efficiency. None of these studies simultaneously evaluated indirect GHG effects incurred via teleconnections with expansion of feed crop production and replacement suckler‐beef production. We applied consequential LCA to incorporate these effects into GHG mitigation calculations for intensification scenarios among grazing‐based dairy farms in an industrialized country (UK), in which milk production shifts from average to intensive farm typologies, involving higher milk yields per cow and more maize and concentrate feed in cattle diets. Attributional LCA indicated a reduction of up to 0.10 kg CO2e kg?1 milk following intensification, reflecting improved feed conversion efficiency. However, consequential LCA indicated that land use change associated with increased demand for maize and concentrate feed, plus additional suckler‐beef production to replace reduced dairy‐beef output, significantly increased GHG emissions following intensification. International displacement of replacement suckler‐beef production to the “global beef frontier” in Brazil resulted in small GHG savings for the UK GHG inventory, but contributed to a net increase in international GHG emissions equivalent to 0.63 kg CO2e kg?1 milk. Use of spared dairy grassland for intensive beef production can lead to net GHG mitigation by replacing extensive beef production, enabling afforestation on larger areas of lower quality grassland, or by avoiding expansion of international (Brazilian) beef production. We recommend that LCA boundaries are expanded when evaluating livestock intensification pathways, to avoid potentially misleading conclusions being drawn from “snapshot” carbon footprints. We conclude that dairy intensification in industrialized countries can lead to significant international carbon leakage, and only achieves GHG mitigation when spared dairy grassland is used to intensify beef production, freeing up larger areas for afforestation.  相似文献   

8.
Dairy production systems are often criticized as being major emitters of greenhouse gases (GHG). In this context, the extension of the length of the productive life of dairy cows is gaining interest as a potential GHG mitigation option. In the present study, we investigated cow and system GHG emission intensity and profitability based on data from 30 dairy cows of different productive lifetime fed either no or limited amounts of concentrate. Detailed information concerning productivity, feeding and individual enteric methane emissions of the individuals was available from a controlled experiment and herd book databases. A simplified GHG balance was calculated for each animal based on the milk produced at the time of the experiment and for their entire lifetime milk production. For the lifetime production, we also included the emissions arising from potential beef produced by fattening the offspring of the dairy cows. This accounted for the effect that changes in the length of productive life will affect the replacement rate and thus the number of calves that can be used for beef production. Profitability was assessed by calculating revenues and full economic costs for the cows in the data set. Both emission intensity and profitability were most favourable in cows with long productive life, whereas cows that had not finished their first lactation performed particularly unfavourably with regard to their emissions per unit of product and rearing costs were mostly not repaid. Including the potential beef production, GHG emissions in relation to total production of animal protein also decreased with age, but the overall variability was greater, as the individual cow history (lifetime milk yield, twin births, stillbirths, etc.) added further sources of variation. The present results show that increasing the length of productive life of dairy cows is a viable way to reduce the climate impact and to improve profitability of dairy production.  相似文献   

9.
Goal, Scope and Background The objective of this study was to assess environmental impacts of Norwegian cod fishing and salmon farming and compare these with chicken farming in order to find reference levels for environmental performance and identify problem areas and potentials for improvements. Methods A Life Cycle Screening following the production of 0.2 kg fillets as a functional unit through the respective food chains is performed for all 3 products. The analysis is partly quantitative and qualitative focusing on energy use, antifouling and land use impacts. Case studies are performed to investigate potentials for improvements within the fisheries and aquaculture industry. Results and Conclusions It can be concluded that the fishing phase for the cod and the feeding phase for both salmon and chicken dominate for all environmental impacts considered. Chicken is most energy effective followed by salmon and cod, which are almost on the same level. The area of sea floor affected by bottom trawling is around 100 times larger than the land area needed to produce the chicken feed for production of the 0.2 kg fillet. - The case studies show potentials for improvement of environmental performance, both for salmon farming and cod fishing, especially when it comes to energy use. The environmental impacts on the sea floor imposed by bottom trawling are not fully explored, but based on the precautionary principle a reasonable conclusion is that bottom trawls with less impact on the sea floor should be developed. Recommendation and Perspective LCA methods have initially been developed for land based industrial applications. More effort should be given to adapt these to fishing applications in order to obtain more accurate assessment of environmental impacts from seafood products. It is recommended to put more emphasis in finding improved indicators for impacts imposed by over-fishing, fuel emission from combustion at sea, use of antifouling and seafloor ecosystem disturbance.  相似文献   

10.
The aim of this study was to compare a fully slatted concrete floor (concrete slatted (CS)) with the same floor on which synthetic rubber slats were placed on the concrete slats (rubber slatted (RS)) as housing solution for finishing beef cattle. The present study involved five commercial beef cattle farms in which the floor of at least three pens was kept as fully slatted, and in an equal number of pens a rubber cover was placed on the floor, tightly matching the gap profile of the concrete slats to allow the drainage of manure. A total of 326 finishing beef bulls were used (153 on CS and 173 on RS), and regardless of the floor treatment animals were housed in groups of 6 to 12 bulls/pen with a space allowance of 3.1±0.2 m2/bull. Bulls had similar initial live weights (422.3 kg on CS and 425.0 kg on RS), but bulls on RS were heavier at the end of the finishing period with a higher average daily gain than bulls kept on CS (1.53 v. 1.46 kg/day; P<0.05). The proportion of bulls treated for locomotor problems was lower in RS pens compared with CS. Rubber covering prevented the occurrence of bursitis, but it increased the odds for hoof overgrowth at end of the finishing period. Hoof overgrowth detected in vivo in bulls on RS was confirmed at the slaughterhouse by the longer dorsal wall and diagonal lengths of the hoof as well as by a more acute toe angle. Compared with bulls on CS, bulls on RS showed less inactivity and resting time, increased social interactions, decreased abnormal lying down and unsuccessful attempts to lie down, as well as shortened the time for lying down. Bulls in RS pens were dirtier compared with those in CS pens, likely due to the draining gaps being reduced to 11.6±1.2% of the total pen surface compared with the 16.9±1.7% in CS pens. This study gave further evidence about the positive effects of the RS floor on growth performance and welfare of finishing beef cattle, although compromising cleanliness and hoof overgrowth.  相似文献   

11.
Field experiments were conducted in the Chernobyl-affected area to assess if short rotation coppice (SRC) for energy production is a feasible alternative for contaminated land. Four willow clones were planted on sandy and peaty soil and the radiocaesium (137Cs) and radiostrontium (90Sr) transfer factors (TF) and yield relevant parameters were recorded during four growing seasons. The 137Cs and 90Sr soil-to-willow wood TF on sandy soil (second growing season) were on average 1.40+/-1.06 x 10(-3) m2 kg(-1) and 130+/-74 x 10(-3) m2 kg(-1), respectively. The 137Cs TF recorded for the peaty soil (fourth growing season or end of the first rotation cycle) was on average 5.17+/-1.59 x 10(-3) m2 kg(-1). The 90Sr-TF was on average 2.61+/-0.44 x 10(-3) m2 kg(-1). No significant differences between clones for the 137Cs and 90Sr-TF were observed. Given the high TFs and the high deposition levels, Belarus exemption levels for fuel wood were highly exceeded. The annual average biomass production for one rotation cycle on the peaty soil ranged from 7.8 to 16.0 t ha(-1) y(-1) for one of the clones, comparable with average annual yield figures obtained for western Europe. On the sandy soils, first-year yields were 0.25 t ha(-1) y(-1). These soils are not suitable for SRC production and should better be dedicated to pine forests or drought-resistant grasses.  相似文献   

12.
In this article, we first describe aspects of the environmental impact reduction strategy that was developed in conjunction with a life cycle assessment undertaken for the operations necessary to support Australia's largest Antarctic research station, Casey Station. The article then identifies future research and operational improvement opportunities for the Australian Antarctic Division, who is responsible for Australia's presence in Antarctica. These insights are mapped against knowledge, treaties, plans, and policies framing how the Australian Antarctic Division operates on the southern continent, making operational planning from the strategy relevant and actionable. The article concludes by posing recommendations, for future environmental management practice, that cover making improvements to data quality collection, undertaking a strategic approach, utilizing a new ice breaker, and facilitating behavior change via engagement and active support of staff.  相似文献   

13.
Across the energy sector, alternatives to fossil fuels are being developed, in response to the dual drivers of climate change and energy security. For transport, biofuels have the greatest potential to replace fossil fuels in the short‐to medium term. However, the ecological benefits of biofuels and the role that their deployment can play in mitigating climate change are being called into question. Life Cycle Assessment (LCA) is a widely used approach that enables the energy and greenhouse gas (GHG) balance of biofuel production to be calculated. Concerns have nevertheless been raised that published data show widely varying and sometimes contradictory results. This review describes a systematic review of GHG emissions and energy balance data from 44 LCA studies of first‐ and second‐generation biofuels. The information collated was used to identify the dominant sources of GHG emissions and energy requirements in biofuel production and the key sources of variability in published LCA data. Our analysis revealed three distinct sources of variation: (1) ‘real’ variability in parameters e.g. cultivation; (2) ‘methodological’ variability due to the implementation of the LCA method; and (3) ‘uncertainty’ due to parameters rarely included and poorly quantified. There is global interest in developing a sustainability assessment protocol for biofuels. Confidence in the results of such an assessment can only be assured if these areas of uncertainty and variability are addressed. A more defined methodology is necessary in order to allow effective and accurate comparison of results. It is also essential that areas of uncertainty such as impacts on soil carbon stocks and fluxes are included in LCA assessments, and that further research is conducted to enable a robust calculation of impacts under different land‐use change scenarios. Without the inclusion of these parameters, we cannot be certain that biofuels are really delivering GHG savings compared with fossil fuels.  相似文献   

14.
The objectives of the present study were: (1) to evaluate the importance of genotype×production environment interaction for the genetic evaluation of birth weight (BW) and weaning weight (WW) in a population of composite beef cattle in Brazil, and (2) to investigate the importance of sire×contemporary group interaction (S×CG) to model G×E and improve the accuracy of prediction in routine genetic evaluations of this population. Analyses were performed with one, two (favorable and unfavorable) or three (favorable, intermediate, unfavorable) different definitions of production environments. Thus, BW and WW records of animals in a favorable environment were assigned to either trait 1, in an intermediate environment to trait 2 or in an unfavorable environment to trait 3. The (co)variance components were estimated using Gibbs sampling in single-, bi- or three-trait animal models according to the definition of number of production environments. In general, the estimates of genetic parameters for BW and WW were similar between environments. The additive genetic correlations between production environments were close to unity for BW; however, when examining the highest posterior density intervals, the correlation between favorable and unfavorable environments reached a value of only 0.70, a fact that may lead to changes in the ranking of sires across environments. The posterior mean genetic correlation between direct effects was 0.63 in favorable and unfavorable environments for WW. When S×CG was included in two- or three-trait analyses, all direct genetic correlations were close to unity, suggesting that there was no evidence of a genotype×production environment interaction. Furthermore, the model including S×CG contributed to prevent overestimation of the accuracy of breeding values of sires, provided a lower error of prediction for both direct and maternal breeding values, lower squared bias, residual variance and deviance information criterion than the model omitting S×CG. Thus, the model that included S×CG can therefore be considered the best model on the basis of these criteria. The genotype×production environment interaction should not be neglected in the genetic evaluation of BW and WW in the present population of beef cattle. The inclusion of S×CG in the model is a feasible and plausible alternative to model the effects of G×E in the genetic evaluations.  相似文献   

15.
Life Cycle Impact assessment of land use based on the hemeroby concept   总被引:1,自引:0,他引:1  
The impact category ‘land use’ describes in the Life Cycle Assessment (LCA) methodology the environmental impacts of occupying, reshaping and managing land for human purposes. Land use can either be the long-term use of land (e.g. for arable farming) or changing the type of land use (e.g. from natural to urban area). The impact category ‘land use’ comprises those environmental consequences, which impact the environment due to the land use itself, for instance through the reduction of landscape elements, the planting of monocultures or artificial vegetation, or the sealing of surfaces. Important environmental consequences of land use are the decreasing availability of habitats and the decreasing diversity of wildlife species. The assessment of the environmental impacts of land use within LCA studies is the objective of this paper. Land use leads to a degradation of the naturalness of the area utilised. In this respect the naturalness of any area can be defined as the sum of land actually not influenced by humans and the remaining naturalness of land under use. To determine the remaining naturalness of land under use, this study suggests applying the Hemeroby concept. “Hemeroby is a measure for the human influence on ecosystems” (Kowarik 1999). The Hemeroby level of an area describes the intensity of land use and can therefore be used to characterise different types of land use. Characterization factors are proposed, which allow calculating the degradation of the naturalness of an area due to a specific type of land use. Since the resource ‘nature/naturalness’ is on a larger geographical scale by far not homogeneous, the assessment of land use needs to be regionalised. Therefore, the impact category ‘land use’ has been subdivided into the impact sub-categories ‘land use in European biogeographic regions’. Following the general LCA framework, normalization values for the impact sub-categories are calculated in order to facilitate the evaluation of the characterization results with regard to their share in a reference value. Weighting factors, which enable an aggregation of the results of the different land use sub-categories and make them comparable to other impact categories (e.g. climate change or acidification) are suggested based on the assumption that the current land use pattern in the European biogeographic regions is acceptable.  相似文献   

16.
Perennial bioenergy crops have significant potential to reduce greenhouse gas (GHG) emissions and contribute to climate change mitigation by substituting for fossil fuels; yet delivering significant GHG savings will require substantial land‐use change, globally. Over the last decade, research has delivered improved understanding of the environmental benefits and risks of this transition to perennial bioenergy crops, addressing concerns that the impacts of land conversion to perennial bioenergy crops could result in increased rather than decreased GHG emissions. For policymakers to assess the most cost‐effective and sustainable options for deployment and climate change mitigation, synthesis of these studies is needed to support evidence‐based decision making. In 2015, a workshop was convened with researchers, policymakers and industry/business representatives from the UK, EU and internationally. Outcomes from global research on bioenergy land‐use change were compared to identify areas of consensus, key uncertainties, and research priorities. Here, we discuss the strength of evidence for and against six consensus statements summarising the effects of land‐use change to perennial bioenergy crops on the cycling of carbon, nitrogen and water, in the context of the whole life‐cycle of bioenergy production. Our analysis suggests that the direct impacts of dedicated perennial bioenergy crops on soil carbon and nitrous oxide are increasingly well understood and are often consistent with significant life cycle GHG mitigation from bioenergy relative to conventional energy sources. We conclude that the GHG balance of perennial bioenergy crop cultivation will often be favourable, with maximum GHG savings achieved where crops are grown on soils with low carbon stocks and conservative nutrient application, accruing additional environmental benefits such as improved water quality. The analysis reported here demonstrates there is a mature and increasingly comprehensive evidence base on the environmental benefits and risks of bioenergy cultivation which can support the development of a sustainable bioenergy industry.  相似文献   

17.
Background, Goal and Scope  System expansion is a method used to avoid co-product allocation. Up to this point in time it has seldom been used in LCA studies of food products, although food production systems often are characterised by closely interlinked sub-systems. One of the most important allocation problems that occurs in LCAs of agricultural products is the question of how to handle the co-product beef from milk production since almost half of the beef production in the EU is derived from co-products from the dairy sector. The purpose of this paper is to compare different methods of handling co-products when dividing the environmental burden of the milk production system between milk and the co-products meat and surplus calves. Main Features  This article presents results from an LCA of organic milk production in which different methods of handling the co-products are examined. The comparison of different methods of co-product handling is based on a Swedish LCA case study of milk production where economic allocation between milk and meat was initially used. Allocation of the co-products meat and surplus calves was avoided by expanding the milk system. LCA data were collected from another case study where the alternative way of producing meat was analysed, i.e. using a beef cow that produces one calf per annum to be raised for one and a half year. The LCA of beef production was included in the milk system. A discussion is conducted focussing on the importance of modelling and analysing milk and beef production in an integrated way when foreseeing and planning the environmental consequences of manipulating milk and beef production systems. Results  This study shows that economic allocation between milk and beef favours the product beef. When system expansion is performed, the environmental benefits of milk production due to its co-products of surplus calves and meat become obvious. This is especially connected to the impact categories that describe the potential environmental burden of biogenic emissions such as methane and ammonia and nitrogen losses due to land use and its fertilising. The reason for this is that beef production in combination with milk can be carried out with fewer animals than in sole beef production systems. Conclusion, Recommendation and Perspective  Milk and beef production systems are closely connected. Changes in milk production systems will cause alterations in beef production systems. It is concluded that in prospective LCA studies, system expansion should be performed to obtain adequate information of the environmental consequences of manipulating production systems that are interlinked to each other.  相似文献   

18.
The objective of the trial was to study the effects of dietary supplementation of gallic acid (GA) on nitrogen (N) balance, N excretion pattern and urinary N constituents in beef cattle. In a 4 × 4 Latin square design, four male 30-month-old Simmental cattle (443 ± 22 kg live weight) received four levels of GA (purity ≥ 98.5%), i.e. 0, 5.3, 10.5, 21.1 g/kg DM, added to a basal ration. Each experimental period lasted 17 d, consisting of 12 d adaptation and 5 d sampling. The results showed that supplementation of GA at 5.3, 10.5 or 21.1 g/kg DM did not affect the N balance but regulated the N excretion pattern by increasing the ratio of faecal N/urinary N and decreasing the ratio of urinary urea N/total urinary N in beef cattle fed at maintenance level.  相似文献   

19.
Maize silage-based diets with three dietary crude protein (CP) supplements were offered to 96 finishing cattle of contrasting breed (Holstein Friesian (HF) v. Simmental × HF (SHF)) and gender (bull v. steer) housed in two types of feeding system (group fed v. individually fed). The three protein supplements differed either in CP or protein degradability (degradable (LUDP) v. rumen undegradable (HUDP)) and provided CP concentrations of 142 (Con), 175 (LUDP) and 179 (HUDP) g/kg dry matter (DM) respectively, with ratios of degradable to undegradable of 3.0, 1.4 and 0.9:1 for diets Con, LUDP and HUDP, respectively. DM intakes were marginally higher (P = 0.102) for LUDP when compared with Con and HUDP. Rates of daily live-weight gain (DLWG) were higher (P = 0.005) in LUDP and HUDP when compared with Con. HF had higher DM intakes than SHF although this did not result in any improvement in HF DLWG. Bulls had significantly better DM intakes, DLWG and feed conversion efficiency than steers. Conformation scores were better in SHF than HF (P < 0.001) and fat scores lower in bulls than steers (P < 0.001). There was a number of first order interactions established between dietary treatment, breed, gender and housing system with respect to rates of gain and carcass fat scores.  相似文献   

20.
Improving feed efficiency in dairy cattle could result in more profitable and environmentally sustainable dairy production through lowering feed costs and emissions from dairy farming. In addition, beef production based on dairy herds generates fewer greenhouse gas emissions per unit of meat output than beef production from suckler cow systems. Different scenarios were used to assess the profitability of adding traits, excluded from the current selection index for Finnish Ayrshire, to the breeding goal for combined dairy and beef production systems. The additional breeding goal traits were growth traits (average daily gain of animals in the fattening and rearing periods), carcass traits (fat covering, fleshiness and dressing percentage), mature live weight (LW) of cows and residual feed intake (RFI) traits. A breeding scheme was modeled for Finnish Ayrshire under the current market situation in Finland using the deterministic simulation software ZPLAN+. With the economic values derived for the current production system, the inclusion of growth and carcass traits, while preventing LW increase generated the highest improvement in the discounted profit of the breeding program (3.7%), followed by the scenario where all additional traits were included simultaneously (5.1%). The use of a selection index that included growth and carcass traits excluding LW, increased the profit (0.8%), but reduced the benefits resulted from breeding for beef traits together with LW. A moderate decrease in the profit of the breeding program was obtained when adding only LW to the breeding goal (−3.1%), whereas, adding only RFI traits to the breeding goal resulted in a minor increase in the profit (1.4%). Including beef traits with LW in the breeding goal showed to be the most potential option to improve the profitability of the combined dairy and beef production systems and would also enable a higher rate of self-sufficiency in beef. When considering feed efficiency related traits, the inclusion of LW traits in the breeding goal that includes growth and carcass traits could be more profitable than the inclusion of RFI, because the marginal costs of measuring LW can be expected to be lower than for RFI and it is readily available for selection. In addition, before RFI can be implemented as a breeding objective, the genetic correlations between RFI and other breeding goal traits estimated for the studied population as well as information on the most suitable indicator traits for RFI are needed to assess more carefully the consequences of selecting for RFI.  相似文献   

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