How can we improve the environmental sustainability of poultry production?

The review presents results of recent life cycle assessment studies aiming to quantify and improve the environmental performance of UK poultry production systems, including broiler meat, egg and turkey meat production. Although poultry production has been found to be relatively environmentally friendly compared with the production of other livestock commodities, it still contributes to environmental impacts, such as global warming, eutrophication and acidification. Amongst different sub-processes, feed production and transport contributes about 70 % to the global warming potential of poultry systems, whereas manure management contributes about 40-60 % to their eutrophication potential and acidification potential, respectively. All these impacts can be reduced by improving the feed efficiency, either by changing the birds through genetic selection or by making the feed more digestible (e.g. by using additives such as enzymes). However, although genetic selection has the potential to reduce the resources needed for broiler production (including feed consumption), the changing need of certain feed ingredients, most notably protein sources as a result of changes in bird requirements may limit the benefits of this strategy. The use of alternative feed ingredients, such as locally grown protein crops and agricultural by-products, as a replacement of South American grown soya, can potentially also lead to improvements in several environmental impact categories, as long as such feeding strategies have no negative effect on bird performance. Other management options, such as improving poultry housing and new strategies for manure management have also the potential to further improve the environmental sustainability of the poultry industries in Europe.

Effects of dietary protease on nitrogen emissions from broiler production: a holistic comparison using Life Cycle Assessment.

BACKGROUND: The aim of the study was to quantify the effects of the use of a protease Ronozyme® ProAct in broiler feed on the environmental impacts of broiler and broiler feed production chains. This was done by using a Life Cycle Assessment (LCA) modelling approach with data from trials using both standard soya-based broiler diets and reduced-protein diets with added protease. RESULTS: The results for the feed production chain showed that there was a reduction in all environmental impact categories when protease was used in the diets. The biggest reduction occurred in the category of Global Warming Potential, mainly as a result of decreased carbon dioxide emissions from land use changes related to soya production. In the results for the broiler production chain, there were relatively bigger reductions in Eutrophication Potential and especially in Acidification Potential, mainly as a result of reduced feed protein content and subsequent nitrogen emissions from housing and manure management. CONCLUSION: The use of protease in the broiler diets reduced the environmental impacts of both feed production and broiler production. The latter is mainly through reduced ammonia emissions, which has substantial benefit per se in the poultry industry.

Multi-sensor plant imaging: Towards the development of a stress-catalogue.

Agricultural production is limited by a wide range of abiotic (e.g. drought, waterlogging) and biotic (pests, diseases and weeds) stresses. The impact of these stresses can be minimized by appropriate management actions such as irrigation or chemical pesticide application. However, further optimization requires the ability to diagnose and quantify the different stresses at an early stage. Particularly valuable information of plant stress responses is provided by plant imaging, i.e. non-contact sensing with spatial resolving power: (i) thermal imaging, detecting changes in transpiration rate and (ii) fluorescence imaging monitoring alterations in photosynthesis and other physiological processes. These can be supplemented by conventional video imagery for study of growth. An efficient early warning system would need to discriminate between different stressors. Given the wide range of sensors, and the association of specific plant physiological responses with changes at particular wavelengths, this goal seems within reach. This is based on the organization of the individual sensor results in a matrix that identifies specific signatures for multiple stress types. In this report, we first review the diagnostic effectiveness of different individual imaging techniques and then extend this to the multi-sensor stress-identification approach.

Monitoring and screening plant populations with combined thermal and chlorophyll fluorescence imaging.

Thermal and chlorophyll fluorescence imaging are powerful tools for the study of spatial and temporal heterogeneity of leaf transpiration and photosynthetic performance. The relative advantages and disadvantages of these techniques are discussed. When combined, they can highlight pre-symptomatic responses not yet apparent in visual spectrum images and provide specific signatures for diagnosis of distinct diseases and abiotic stresses. In addition, their use for diagnosis and for selection for stomatal or photosynthetic mutants, these techniques can be applied for stress tolerance screening. For example, rapid screening for stomatal responses can be achieved by thermal imaging, while, combined with fluorescence imaging to study photosynthesis, they can potentially be used to derive leaf water use efficiency as a screening parameter. A particular advantage of imaging is that it allows continuous automated monitoring of dynamic spatial variation. Examples of applications include the study of growth and development of plant lines differing in stress resistance, yield, circadian clock-controlled responses, and the possible interactions between these parameters. In the future, such dual-imaging systems could be extended with complementary techniques such as hyperspectral and blue-green fluorescence imaging. This would result in an increased number of quantified parameters which will increase the power of stress diagnosis and the potential for screening of stress-tolerant genotypes.

Combining thermal and visible imagery for estimating canopy temperature and identifying plant stress.

Thermal imaging is a potential tool for estimating plant temperature, which can be used as an indicator of stomatal closure and water deficit stress. In this study, a new method for processing and analysing thermal images was developed. By using remote sensing software, the information from thermal and visible images was combined, the images were classified to identify leaf area and sunlit and shaded parts of the canopy, and the temperature statistics for specific canopy components were calculated. The method was applied to data from a greenhouse water-stress experiment of Vicia faba L. and to field data for Vitis vinifera L. Vaseline-covered and water-sprayed plants were used as dry and wet references, respectively, and two thermal indices, based on temperature differences between the canopy and reference surfaces, were calculated for single Vicia faba plants. The thermal indices were compared with measured stomatal conductance. The temperature distributions of sunlit and shaded leaf area of Vitis vinifera canopies from natural rainfall and irrigation treatments were compared. The present method provides two major improvements compared with earlier methods for calculating thermal indices. First, it allows more accurate estimation of the indices, which are consequently more closely related to stomatal conductance. Second, it gives more accurate estimates of the temperature distribution of the shaded and sunlit parts of canopy, and, unlike the earlier methods, makes it possible to quantify the relationship between temperature variation and stomatal conductance.

The effect of soil temperature on the bud phenology, chlorophyll fluorescence, carbohydrate content and cold hardiness of Norway spruce seedlings.

The effects of soil temperature on the shoot phenology, carbohydrate dynamics, chlorophyll fluorescence and cold hardiness of 4-year-old Norway spruce seedlings (Picea abies L. Karst.) were studied. The experiment was carried out under controlled conditions in the Joensuu dasotrons. Air conditions were similar but soil temperatures differed by treatments (9, 13, 18 and 21 degrees C) during the second growing period in the dasotrons. The after-effects of the treatments were investigated during the third growing period following the treatments. Low soil temperature increased the starch content of needles and delayed the loss of starch at the end of the growing season. The photochemical efficiency (F(v)/F(m)) of the PSII of the current-year needles was reduced at the lowest soil temperature. The cold hardiness of needles correlated with the soluble sugar content. The differences in soil temperature had no effect on the timing of bud burst. No after-effects from the treatments were observed during the third growing period in the dasotrons.