Water body type and land cover shape the dragonfly communities (Odonata) in the Pampa biome,Rio Grande do Sul,Brazil

The biogeographical region known as the Pampa biome in southern Brazil, was originally mainly covered with open fields or grassland, with areas of riparian forest surrounding the water bodies. Today this landscape appears highly fragmented due to agricultural activities such as rice cultivation, extensive cattle farming, and forest plantations. Studies have shown that the Pampa biome has high levels of biodiversity and endemism, but with regard to invertebrates, this biome is still one of the least known in Brazil. We therefore designed a study comparing the dragonfly (Odonata) communities to environmental and landscape features in this area, measuring diversity by species richness, relative abundance and Shannon index. Our results showed that the Pampa is a biome very rich in odonates, and that the species communities are highly dependent on the environmental conditions of the area. Habitats such as Rivers/Streams, bordered by native grasslands and riparian forests, were shown to harbour communities that were ecologically more complex and sensitive than other habitat types. Man-made lakes and agricultural areas displayed lower levels of biodiversity and odonate communities dominated by generalist species. By combining data on the communities of Odonata and other taxa, our analyses may be instrumental in determining priority areas for future conservation measures within the area.     

System expansion and allocation in life cycle assessment of milk and beef production

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.     

Mixed crop-livestock systems: an economic and environmental-friendly way of farming?

Intensification and specialisation of agriculture in developed countries enabled productivity to be improved but had detrimental impacts on the environment and threatened the economic viability of a huge number of farms. The combination of livestock and crops, which was very common in the past, is assumed to be a viable alternative to specialised livestock or cropping systems. Mixed crop-livestock systems can improve nutrient cycling while reducing chemical inputs and generate economies of scope at farm level. Most assumptions underlying these views are based on theoretical and experimental evidence. Very few assessments of their environmental and economic advantages have nevertheless been undertaken in real-world farming conditions. In this paper, we present a comparative assessment of the environmental and economic performances of mixed crop-livestock farms v. specialised farms among the farm population of the French ‘Coteaux de Gascogne’. In this hilly region, half of the farms currently use a mixed crop-livestock system including beef cattle and cash crops, the remaining farms being specialised in either crops or cattle. Data were collected through an exhaustive survey of farms located in our study area. The economic performances of farming systems were assessed on 48 farms on the basis of (i) overall gross margin, (ii) production costs and (iii) analysis of the sensitivity of gross margins to fluctuations in the price of inputs and outputs. The environmental dimension was analysed through (i) characterisation of farmers’ crop management practices, (ii) analysis of farm land use diversity and (iii) nitrogen farm-gate balance. Local mixed crop-livestock farms did not have significantly higher overall gross margins than specialised farms but were less sensitive than dairy and crop farms to fluctuations in the price of inputs and outputs considered. Mixed crop-livestock farms had lower costs than crop farms, while beef farms had the lowest costs as they are grass-based systems. Concerning crop management practices, our results revealed an intensification gradient from low to high input farming systems. Beyond some general trends, a wide range of management practices and levels of intensification were observed among farms with a similar production system. Mixed crop-livestock farms were very heterogeneous with respect to the use of inputs. Nevertheless, our study revealed a lower potential for nitrogen pollution in mixed crop-livestock and beef production systems than in dairy and crop farming systems. Even if a wide variability exists within system, mixed crop-livestock systems appear to be a way for an environmental and economical sustainable agriculture.     

Animal husbandry: the period 1973-1995

In the last decade the intensification of the pig and poultry industries has continued with increases in production unit size and in efficiency. This has come about as a response to rising costs, competition and reasonable end-product prices. The dairy industry has also expanded output through increasing milk yield per cow, encouraged by favourable market support. However, efficiency of feed conversion to milk production is still not directly selected for in dairy cattle. Developments in beef cattle have been away from intensive systems of production in an effort to reduce capital expenditure and increases in sheep productivity have been largely through increased stocking rates, greater fertilizer use and better grazing systems. In the next decade there are many feasible technological advances awaiting application. The use of computer simulation is likely to assist in predicting quantitative and qualitative body compositional responses to nutrition and in increasing the efficiency of grass utilization, while microprocessor technology will be developed into artificial aids to the stockman. Studies of reproductive physiology will continue to help increase output, especially with pigs and sheep. The building of sophisticated housing is likely to be justified for pigs, poultry, dairy cattle and calves, but not for suckler beef and sheep. There is likely to be greater use of centralized breeding schemes for dairy cattle, beef cattle and sheep. The future application of technology will be limited by a number of socio-economic factors. For example, the use of milk quotas to control surplus production will act as a powerful economic constraint to increased milk production and the growing public concern over animal welfare, pollution and health aspects of animal produce will exert increasing pressure on certain systems of production.     

Animal board invited review: Specialising and intensifying cattle production for better efficiency and less global warming: contrasting results for milk and meat co-production at different scales

Cattle are the world’s largest consumers of plant biomass. Digestion of this biomass by ruminants generates high methane emissions that affect global warming. In the last decades, the specialisation of cattle breeds and livestock systems towards either milk or meat has increased the milk production of dairy cows and the carcass weight of slaughtered cattle. At the animal level and farm level, improved animal performance decreases feed use and greenhouse gas emissions per kg of milk or carcass weight, mainly through a dilution of maintenance requirements per unit of product. However, increasing milk production per dairy cow reduces meat production from the dairy sector, as there are fewer dairy cows. More beef cows are then required if one wants to maintain the same meat production level at country scale. Meat produced from the dairy herd has a better feed efficiency (less feed required per kg of carcass weight) and emits less methane than the meat produced by the cow-calf systems, because the intake of lactating cows is largely for milk production and marginally for meat, whereas the intake of beef cows is entirely for meat. Consequently, the benefits of breed specialisation assessed at the animal level and farm level may not hold when milk and meat productions are considered together. Any change in the milk-to-meat production ratio at the country level affects the numbers of beef cows required to produce meat. At the world scale, a broad diversity in feed efficiencies of cattle products is observed. Where both productions of milk per dairy cow and meat per head of cattle are low, the relationship between milk and meat efficiencies is positive. Improved management practices (feed, reproduction, health) increase the feed efficiency of both products. Where milk and meat productivities are high, a trade-off between feed efficiencies of milk and meat can be observed in relation to the share of meat produced in either the dairy sector or the beef sector. As a result, in developing countries, increasing productivities of both dairy and beef cattle herds will increase milk and meat efficiencies, reduce land use and decrease methane emissions. In other regions of the world, increasing meat production from young animals produced by dairy cows is probably a better option to reduce feed use for an unchanged milk-to-meat production ratio.     

Applications of sexed semen in cattle production

Sexed semen will contribute to increased profitability of dairy and beef cattle production in a variety of ways. It could be used to produce offspring of the desired sex from a particular mating to take advantage of differences in value of males and females for specific marketing purposes. Commercial dairy farmers, those who produce and market milk, could use sexed semen to produce replacement daughters from genetically superior cows and beef crossbred sons from the remainder of their cow population. To increase the rate of response to selection, seedstock dairy cattle breeders could produce bulls for progeny testing from a smaller number of elite dams by using sexed semen to ensure that all of them produced a son. Using sexed semen could then reduce the cost of progeny testing those bulls, because fewer matings would be necessary to produce any required number of daughters. Commercial beef cattle farmers, producing animals for eventual slaughter, could use sexed semen to capitalize on the higher value of male than female offspring for meat production. They could also use sexed semen to produce specialized, genetically superior replacement heifers from as small a proportion of the herd as possible. This would allow the remainder of the herd to produce male calves from bulls or breeds with superior genetic merit for growth, feed conversion efficiency, and carcass merit. Single-sex, bred-heifer systems, in which each female is sold for slaughter soon after weaning her replacement daughter, would be possible with the use of X-chromosome-sorted semen. Use of sexed semen would make terminal crossbreeding systems more efficient and sustainable in beef cattle. Fewer females would be required to produce specialized maternal crossbred daughters, and more could be devoted to producing highly efficient, terminal crossbred sons.     

Ecoregions within the Brazilian Pampa biome reflected in Odonata species assemblies

Based on vegetation composition, previous studies of the Pampa biome in southern Brazil have defined seven ecoregions within the area. Here, we test this ecoregion approach studying the semi‐aquatic insect group Odonata in five of these regions, aiming at comparing the ecoregions to the more traditional environmental predictors of water quality and land cover. Based on a data set of occupancy comprising 99 species distributed between 131 localities, a one‐way Permutational Multivariate Analysis of Variance was used to compare differences in the species composition between the ecoregions, followed by a Principal Component Analysis to visualize the variation. The composition varied significantly between all groups tested, and the ordination explained 61.8% of the variance. A partial redundancy analysis of ecoregions, land cover and water quality variables explained 71% of the variance in Odonata community structure. Ecoregion was the most important predictor, followed by water quality and land cover. Within these species assemblies, we could select certain species that were representative of a given ecoregion, to which their distribution within the Pampa biome was entirely or mainly confined. Of 24 representative species 41.7% were rare, while the rest were more abundant and, hence, easier to detect. We suspect that the differences found between the Pampa ecoregions might be due to geology, as such factors may be strong determinants of biodiversity. Specific ecological requirements at the family and genus levels also seemed to act selectively on the species compositions within the ecoregions. Today, the Pampa is highly fragmented due to agricultural activities such as rice cultivation, extensive cattle farming and forest plantations. We suggest that an ecoregion‐based approach to the implementation of conservation measures may be the best way to help these distinct species assemblies survive.     

Biogas as a resource-efficient vehicle fuel

There are currently strong incentives for increased use of renewable fuels in the transport sector worldwide. However, some bioethanol and biodiesel production routes have limitations with regard to resource efficiency and reduction of greenhouse gases. More efficient biofuel systems are those based on lignocelluloses and novel conversion technologies. A complementary strategy to these is to increase the production of biogas from the digestion of organic residues and energy crops, or from byproducts of ethanol and biodiesel production. Compared with other biomass-based vehicle fuels available so far, biogas often has several advantages from an environmental and resource-efficiency perspective. This provides the motivation for further technological development aiming to reduce costs and thereby increased economic competitiveness of biogas as a vehicle fuel.     

Impact of including growth,carcass and feed efficiency traits in the breeding goal for combined milk and beef production systems

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.     

Industry benefits from recent genetic progress in sheep and beef populations

An analytical model that evaluates the benefits from 10 years of genetic improvement over a 20-year time frame was specified. Estimates of recent genetic trends in recorded traits, industry statistics and published estimates of the economic values of trait changes were used to parameterise the model for the UK sheep and beef industries. Despite rates of genetic change in the relevant performance-recorded breeding populations being substantially less than theoretical predictions, the financial benefits of genetic change were substantial. Over 20 years, the benefits from 10 years of genetic progress at recently achieved rates in recorded hill sheep, sheep crossing sire and sheep terminal sire breeding programmes was estimated to be ￡5.3, ￡1.0 and ￡11.5 million, respectively. If dissemination of genetic material is such that these rates of change are also realised across the entire ram breeding industry, the combined benefits would be ￡110.8 million. For beef cattle, genetic evaluation systems have been operating within all the major breeds for some years with quite widespread use of performance recording, and so genetic trends within the beef breeds were used as predictors of industry genetic change. Benefits from 10 years of genetic progress at recent rates of change, considering a 20-year time frame, in terminal sire beef breeds are expected to be ￡4.9 million. Benefits from genetic progress for growth and carcass characters in dual-purpose beef breeds were ￡18.2 million after subtraction of costs associated with a deterioration in calving traits. These benefits may be further offset by unfavourable associated changes in maternal traits. Additional benefits from identification and use of the best animals available from the breeding sector for commercial matings through performance recording and genetic evaluation could not be quantified. When benefits of genetic improvement were expressed on an annual present value basis and compared with lagged annual investment costs to achieve it, the internal rate of return (IRR) on the combined investment in sheep and beef cattle was 32%. Despite a much higher rate of participation in performance recording, the present value of benefits and the IRR were lower for beef cattle than for sheep. The implications of these results for future national and industry investment in genetic improvement infrastructure were discussed.     

Authentication of beef production systems using a metabolomic-based approach

There is a need for new, non-invasive, rapid and reliable analytical methodologies that can easily be implemented and used for authentication of cattle production systems and the meat derived from them. Easily quantifiable markers could strengthen the current tracing methods for beef authentication. This study investigated the use of a nuclear magnetic resonance-based metabolomic approach as a tool to authenticate beef on the basis of the pre-slaughter production system. Urine and muscle samples were collected from animals fed either pasture outdoor, a barley-based concentrate indoor, silage followed by pasture outdoor or silage followed by pasture outdoor with concentrate over 1 year. A metabolomic analysis was performed on urine (n = 68) and muscle (n = 98) samples collected from animals on the different diets. The results showed that separation according to production system was possible indicating the potential use of this approach in beef authentication. Identification of the major discriminating peaks in urine led to the identification of potential markers of production system including creatinine, glucose, hippurate, pyruvate, phenylalanine, phenylacetylglycine and three unassigned resonances.     

Importance of adaptation and genotype × environment interactions in tropical beef breeding systems

This paper examines the relative importance of productive and adaptive traits in beef breeding systems based on Bos taurus and tropically adapted breeds across temperate and (sub)tropical environments. In the (sub)tropics, differences that exist between breeds in temperate environments are masked by the effects of environmental stressors. Hence in tropical environments, breeds are best categorised into breed types to compare their performance across environments. Because of the presence of environmental stressors, there are more sources of genetic variation in tropical breeding programmes. It is therefore necessary to examine the genetic basis of productive and adaptive traits for breeding programmes in those environments. This paper reviews the heritabilities and genetic relationships between economically important productive and adaptive traits relevant to (sub)tropical breeding programmes. It is concluded that it is possible to simultaneously genetically improve productive and adaptive traits in tropically adapted breeds of beef cattle grazed in tropical environments without serious detrimental consequences for either adaptation or production. However, breed-specific parameters are required for genetic evaluations. The paper also reviews the magnitude of genotype × environment (G × E) interactions impacting on production and adaptation of cattle, where 'genotype' is defined as breed (within a crossbreeding system), sire within breed (in a within-breed selection programme) or associations between economically important traits and single nucleotide polymorphisms (SNPs - within a marker-assisted selection programme). It is concluded that re-ranking of breeds across environments is best managed by the use of the breed type(s) best suited to the particular production environment. Re-ranking of sires across environments is apparent in poorly adapted breed types across extreme tropical and temperate environments or where breeding animals are selected in a temperate environment for use in the (sub)tropics. However, G × E interactions are unlikely to be of major importance in tropically adapted beef cattle grazed in either temperate or (sub)tropical environments, although sex × environment interactions may provide new opportunities for differentially selecting to simultaneously improve steer performance in benign environments and female performance in harsher environments. Early evidence suggests that re-ranking of SNPs occurs across temperate and tropical environments, although their magnitude is still to be confirmed in well-designed experiments. The major limitation to genetic improvement of beef cattle over the next decade is likely to be a deficiency of large numbers of accurately recorded phenotypes for most productive and adaptive traits and, in particular, for difficult-to-measure adaptive traits such as resistance to disease and environmental stressors.     

Environmental Impact assessment of a semi-intensive beef cattle production in Brazil’s Northeast

Purpose

The aim of this study is to identify and evaluate the main environmental impacts related to semi-intensive beef cattle production system in the State of Bahia, in Brazil’s Northeast.

Methods

A cradle to gate study was undertaken in a beef cattle production system comprising two stages: calves production in one farm (farm 1) and cattle production in another farm (farm 2), both located in the central-southern meso-region of Bahia. The functional unit was 1?kg live weight. Impact assessment was performed using five impact categories from the ReCiPe method.

Results and discussion

When compared to calves, the cattle production had the greatest contributions in all of the five studied impact categories. The process pasture cultivation had expressive environmental impacts in all categories, with 70.05 % for climate change (CC), 82.01 % for terrestrial acidification (TA), 76.53 % for fossil depletion (FD), 86.14 % for freshwater eutrophication (FE) and 100 % for agricultural land occupation (ALO). In CC and TA, the principal elementary flow was the direct emissions due to the use of mineral fertilizers. In FE and FD, the dominant flow was related to the use of phosphate fertilizer. In ALO, the process pasture cultivation was predominant due to the physical area of the farms, which is a characteristic of pasture-based production systems. The processes breeding-rearing and fattening were second in the contribution analysis, with 29.95 % and 17.99 %, respectively, for CC and TA, due to the enteric methane (CH₄) and the direct emissions of nitrous oxide (N₂O) volatilization from the animal excreta.

Conclusions

The cattle production is responsible for the greater part of impacts, compared to the calves production. The direct emissions from fertilizers used in the pastures, from enteric emissions and from animal wastes in the breeding-rearing and fattening processes were identified as the critical points of the analysed cattle production system. Measures aiming at the improvement of the feed conversion of the animals and at the substitution of synthetic nitrogen fertilizers by natural nitrogen fixation can considerably contribute to the reduction of environmental impacts of these production systems. Accordingly, the respective modifications should be considered in future studies on the potential of these measures to enhance the environmental performance of semi-intensive beef cattle production. These results will complement other similar studies conducted in other regions of the country, following the tendency of growing usage of the life cycle assessment methodology in Brazilian agricultural and livestock systems.

     

Beef or grasshopper hamburgers: The ecological implications of choosing one over the other

Both the means by which we produce our food and our eating habits influence some of the most important environmental problems of our planet. The most exploited livestock for the past 50 years has been cattle, which are fed primarily on maize to increase production. However, this combination of maize and cattle is inefficient in ecological terms. Producing and consuming proteins from animals with more efficient biomass and energy conversions could help to solve certain environmental problems. For instance, insects that are considered pests in agricultural systems — including, specifically, the Orthoptera species — may be excellent candidates as protein sources. This work analyses the feed conversion ratio (FCR) of the three types of livestock that are most widely bred worldwide: cattle, pigs, and poultry. It then compares these results with those of potential minilivestock from the Orthoptera species that are more abundant in agroecosystems. Based on the calculated FCRs (cow:pork:poultry:grasshopper pests and insects grown on farms; 10:6:2:4:1.7), we project that reducing beef production by half could significantly lower greenhouse gas emissions and the maize sowing hectares destined for feed (2.1–2.9 × 10⁷ ha), while simultaneously releasing maize for human consumption. Additionally, consuming insect-based protein could reduce pollution problems by decreasing insecticide use (by at least 7 × 10⁷ l). Though a comprehensive solution to current environmental problems (e.g. global warming), will require coordinated global effort (e.g. to replace fossil fuels), there is one way that everyone can contribute: eating grasshopper burgers instead of beef burgers.     

Environmental Load from Dutch Private Consumption: How Much Damage Takes Place Abroad?

This article describes a method for determining the environmental load of Dutch private consumption. The method generates detailed information about consumption-related environmental impacts. The environmental load of households (direct) and production (indirect) was determined for 360 expenditure categories reported in the Dutch Expenditure Survey. The indirect environmental load was calculated with linked input-output tables covering worldwide production and trade. The environmental load per Euro turnover of industries was linked to consumer expenditures. With this method we can quantify several types of environmental load per expenditure category and per economic production region.
It was found that food production, room heating, and car use are the most important elements in the environmental load of Dutch private consumption. The impacts taking place abroad were—with the exception of emission of greenhouse gases and road traffic noise—found to be larger than domestic impacts. Most land use was found to take place in developing (non-OECD) countries, whereas most emissions occur in industrialized (OECD) countries.     

Livestock waste treatment systems for environmental quality,food safety,and sustainability

The intensification of livestock operations has benefited production efficiency but has introduced major environmental issues, becoming a concern in both developed and developing countries. The aim of this paper is primarily to address the impact of the livestock sector on environmental pollution (ammonia, greenhouse gases and pathogens), evaluate the related health risks and, subsequently, assess the potential role of waste treatment systems in attenuating these environmental and health issues. This paper is a collection of data pertaining to world trends in livestock production, since the mid 1990s and intensive livestock farming practices along with their impact on: water pollution by nitrates and through eutrophication; air pollution, particularly ammonia and greenhouse gases emissions, and soil pollution because of nutrient accumulation. Finally, this paper examines some of the benefits of treating livestock manures, issues related to the adoption of treatment systems by livestock operations and current as well as past technological developments.     

Localising livestock protein feed production and the impact on land use and greenhouse gas emissions

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.     

Invited review: Improving feed efficiency of beef cattle – the current state of the art and future challenges

Improvements in feed efficiency of beef cattle have the potential to increase producer profitability and simultaneously lower the environmental footprint of beef production. Although there are many different approaches to measuring feed efficiency, residual feed intake (RFI) has increasingly become the measure of choice. Defined as the difference between an animal’s actual and predicted feed intake (based on weight and growth), RFI is conceptually independent of growth and body size. In addition, other measurable traits related to energy expenditure such as estimates of body composition can be included in the calculation of RFI to also force independence from these traits. Feed efficiency is a multifactorial and complex trait in beef cattle and inter-animal variation stems from the interaction of many biological processes influenced, in turn, by physiological status and management regimen. Thus, the purpose of this review was to summarise and interpret current published knowledge and provide insight into research areas worthy of further investigation. Indeed, where sufficient suitable reports exist, meta-analyses were conducted in order to mitigate ambiguity between studies in particular. We have identified a paucity of information on the contribution of key biological processes, including appetite regulation, post-ruminal nutrient absorption, and cellular energetics and metabolism to the efficiency of feed utilisation in cattle. In addition, insufficient information exists on the relationship between RFI status and productivity-related traits at pasture, a concept critical to the overall lifecycle of beef production systems. Overall, published data on the effect of RFI status on both terminal and maternal traits, coupled with the moderate repeatability and heritability of the trait, suggest that breeding for improved RFI, as part of a multi-trait selection index, is both possible and cumulative, with benefits evident throughout the production cycle. Although the advent of genomic selection, with associated improved prediction accuracy, will expedite the introgression of elite genetics for feed efficiency within beef cattle populations, there are challenges associated with this approach which may, in the long-term, be overcome by increased international collaborative effort but, in the short term, will not obviate the on-going requirement for accurate measurement of the primary phenotype.     

Trade-off assessments between environmental and economic indicators in cropping systems of Pampa region (Argentina)

An overall sustainability assessment should include changes in the economic return, the social benefits and the human intervention on the biophysical resources in order to highlight potential trade-off or synergies among them. In this work, we studied the performance of 36 cropping systems (CS) of the Pampa region, Argentina, which include three different crops, three increasing levels of technology adoption in four contrasting site conditions. For each CS, we simultaneously assessed 1) the ecosystem energy flow using the emergy synthesis; 2) the pesticide ecotoxicity using a simple dose-response model; and 3) the economic profit, in order to evaluate the influence of crop identity, technological level, and site location on the indicators values as well as to detect potential trade-offs between indicators. Results revealed that maize crop entailed the most sustainable indicator profile by exhibiting relative high emergy return, low non-renewable emergy use, low pesticide ecotoxicity, and high gross income. In addition, results showed a significant trade-off between economic profit and ecotoxicological risk in the CS studied. Further studies should be conducted for including more contrasting indicators in order to explore the potential trade-off among other ecosystem components as a promising way to identify sustainable crop management regimes for different production zones.     

Upgrading plant amino acids through cattle to improve the nutritional value for humans: effects of different production systems

Efficiency in animal protein production can be defined in different ways, for example the amount of human-digestible essential amino acids (HDEAA) in the feed ration relative to the amount of HDEAA in the animal products. Cattle production systems are characterised by great diversity and a wide variety of feeds and feed ration compositions, due to ruminants’ ability to digest fibrous materials inedible to humans such as roughage and by-products from the food and biofuel industries. This study examined the upgrading of protein quality through cattle by determining the quantity of HDEAA in feeds and animal products and comparing different milk and beef production systems. Four different systems for milk and beef production were designed, a reference production system for milk and beef representing typical Swedish production systems today and three alternative improved systems: (i) intensive cattle production based on maize silage, (ii) intensive systems based on food industry by-products for dairy cows and high-quality forage for beef cattle, and (iii) extensive systems based on forage with only small amounts of concentrate. In all four production systems, the quantity of HDEAA in the products (milk and meat) generally exceeded the quantity of HDEAA in the feeds. The intensive production models for beef calves generally resulted in output of the same magnitude as input for most HDEAA. However, in beef production based on calves from dairy cows, the intensive rearing systems resulted in lower output than input of HDEAA. For the extensive models, the amounts of HDEAA in meat were of the same magnitude as the amounts in the feeds. The extensive models with beef calves from suckler cows resulted in higher output in meat than input in feeds for all HDEAA. It was concluded that feeding cattle plants for production of milk and meat, instead of using the plants directly as human food, generally results in an upgrading of both the quantity and quality of protein, especially when extensive, forage-based production models are used. The results imply that the key to efficiency is the utilisation of human-inedible protein by cattle and justifies their contribution to food production, especially in regions where grasslands and/or forage production has comparative benefits over plant food production. By fine-tuning estimation of the efficiency of conversion from human-edible protein to HDEAA, comparisons of different sources of protein production may be more complete and the magnitude of amino acid upgrading in plants through cattle more obvious.