Using Spirulina (Limnospira platensis) as an alternative feedstuff for poultry: Effects on ammonia and greenhouse gas emissions from excreta during storage.

Dairy production systems represent a significant source of air pollutants such as greenhouse gases (GHG), that increase global warming, and ammonia (NH3), that leads to eutrophication and acidification of natural ecosystems. Greenhouse gases and ammonia are emitted both by conventional and organic dairy systems. Several studies have already been conducted to design practices that reduce greenhouse gas and ammonia emissions from dairy systems. However, those studies did not consider options specifically applied to organic farming, as well as the multiple trade-offs occurring between these air pollutants. This article reviews agricultural practices that mitigate greenhouse gas and ammonia emissions. Those practices can be applied to the most common organic dairy systems in northern Europe such as organic mixed crop-dairy systems. The following major points of mitigation options for animal production, crop production and grasslands are discussed. Animal production: the most promising options for reducing greenhouse gas emissions at the livestock management level involve either the improvement of animal production through dietary changes and genetic improvement or the reduction of the replacement rate. The control of the protein intake of animals is an effective means to reduce gaseous emissions of nitrogen, but it is difficult to implement in organic dairy farming systems. Considering the manure handling chain, mitigation options involve housing, storage and application. For housing, an increase in the amounts of straw used for bedding reduces NH3 emissions, while the limitation of CH4 emissions from deep litter is achieved by avoiding anaerobic conditions. During the storage of solid manure, composting could be an efficient mitigation option, depending on its management. Addition of straw to solid manure was shown to reduce CH4 and N2O emissions from the manure heaps. During the storage of liquid manure, emptying the slurry store before late spring is an efficient mitigation option to limit both CH4 and NH3 emissions. Addition of a wooden cover also reduces these emissions more efficiently than a natural surface crust alone, but may increase N2O emissions. Anaerobic digestion is the most promising way to reduce the overall greenhouse gas emissions from storage and land spreading, without increasing NH3 emissions. At the application stage, NH3 emissions may be reduced by spreading manure during the coolest part of the day, incorporating it quickly and in narrow bands. Crop production: the mitigation options for crop production focus on limiting CO2 and N2O emissions. The introduction of perennial crops or temporary leys of longer duration are promising options to limit CO2 emissions by storing carbon in plants or soils. Reduced tillage or no tillage as well as the incorporation of crop residues also favour carbon sequestration in soils, but these practices may enhance N2O emissions. Besides, the improvement of crop N-use efficiency through effective management of manure and slurry, by growing catch crops or by delaying the ploughing of leys, is of prime importance to reduce N2O emissions. Grassland: concerning grassland and grazing management, permanent conversion from arable to grassland provides high soil carbon sequestration while increasing or decreasing the livestock density seems not to be an appropriate mitigation option. From the study of the multiple interrelations between gases and between farm compartments, the following mitigation options are advised for organic mixed crop-dairy systems: (1) actions for increasing energy efficiency or fuel savings because they are beneficial in any case, (2) techniques improving efficiency of N management at field and farm levels because they affect not only N2O and NH3 emissions, but also nitrate leaching, and (3) biogas production through anaerobic digestion of manure because it is a promising efficient method to mitigate greenhouse gas emissions, even if the profitability of this expensive investment needs to be carefully studied. Finally, the way the farmer implements the mitigation options, i.e. his practices, will be a determining factor in the reduction of greenhouse gas and NH3 emissions.

Dairy production systems represent a significant source of air pollutants such as greenhouse gases (GHG), that increase global warming, and ammonia (NH3), that leads to eutrophication and acidification of natural ecosystems. Greenhouse gases and ammonia are emitted both by conventional and organic dairy systems. Several studies have already been conducted to design practices that reduce greenhouse gas and ammonia emissions from dairy systems. However, those studies did not consider options specifically applied to organic farming, as well as the multiple trade-offs occurring between these air pollutants. This article reviews agricultural practices that mitigate greenhouse gas and ammonia emissions. Those practices can be applied to the most common organic dairy systems in northern Europe such as organic mixed crop-dairy systems. The following major points of mitigation options for animal production, crop production and grasslands are discussed. Animal production: the most promising options for reducing greenhouse gas emissions at the livestock management level involve either the improvement of animal production through dietary changes and genetic improvement or the reduction of the replacement rate. The control of the protein intake of animals is an effective means to reduce gaseous emissions of nitrogen, but it is difficult to implement in organic dairy farming systems. Considering the manure handling chain, mitigation options involve housing, storage and application. For housing, an increase in the amounts of straw used for bedding reduces NH3 emissions, while the limitation of CH4 emissions from deep litter is achieved by avoiding anaerobic conditions. During the storage of solid manure, composting could be an efficient mitigation option, depending on its management. Addition of straw to solid manure was shown to reduce CH4 and N2O emissions from the manure heaps. During the storage of liquid manure, emptying the slurry store before late spring is an efficient mitigation option to limit both CH4 and NH3 emissions. Addition of a wooden cover also reduces these emissions more efficiently than a natural surface crust alone, but may increase N2O emissions. Anaerobic digestion is the most promising way to reduce the overall greenhouse gas emissions from storage and land spreading, without increasing NH3 emissions. At the application stage, NH3 emissions may be reduced by spreading manure during the coolest part of the day, incorporating it quickly and in narrow bands. Crop production: the mitigation options for crop production focus on limiting CO2 and N2O emissions. The introduction of perennial crops or temporary leys of longer duration are promising options to limit CO2 emissions by storing carbon in plants or soils. Reduced tillage or no tillage as well as the incorporation of crop residues also favour carbon sequestration in soils, but these practices may enhance N2O emissions. Besides, the improvement of crop N-use efficiency through effective management of manure and slurry, by growing catch crops or by delaying the ploughing of leys, is of prime importance to reduce N2O emissions. Grassland: concerning grassland and grazing management, permanent conversion from arable to grassland provides high soil carbon sequestration while increasing or decreasing the livestock density seems not to be an appropriate mitigation option. From the study of the multiple interrelations between gases and between farm compartments, the following mitigation options are advised for organic mixed crop-dairy systems: (1) actions for increasing energy efficiency or fuel savings because they are beneficial in any case, (2) techniques improving efficiency of N management at field and farm levels because they affect not only N2O and NH3 emissions, but also nitrate leaching, and (3) biogas production through anaerobic digestion of manure because it is a promising efficient method to mitigate greenhouse gas emissions, even if the profitability of this expensive investment needs to be carefully studied. Finally, the way the farmer implements the mitigation options, i.e. his practices, will be a determining factor in the reduction of greenhouse gas and NH3 emissions.KeywordsAgricultureGreenhouse gasAmmoniaAbatementMixed crop-dairy systemsOrganicLivestockManureGrasslandCarbon storageSoil carbon sequestration

The decline in production of milk and its components has been extensively studied as an indicator of heat tolerance for genetic evaluations. However, the antagonistic relationship between high production and functionality raises questions about the suitability of using productive traits as indicators of heat tolerance. This study aimed to estimate changes in the relationship between production and fertility under thermoneutral (TN) and heat stress (HS) conditions, to define breeding strategies that enhance adaptation to high heat loads while maintaining both productivity and functionality. The analyzed dataset included records on 100,467 Holstein cows of first-lactation milk, fat, and protein yields (703,574 records for each yield) and conception rate (CR) at first insemination in first lactation of 247,378 cows in Spain. Temperature-humidity indices averaged over the day of milk recording or day of artificial insemination and the 2 previous days for milk traits, or the subsequent 7 d for fertility, were used to measure the heat load associated with each record. Bicharacter sire models were employed, incorporating one of the yield traits and the fertility trait. Models included random regressions with Legendre polynomials for production traits and a broken-line function for fertility to describe the trait responses to increasing heat loads. This approach allowed for the estimation of trait levels under TN and HS conditions, the slope of response under HS as heat tolerance indicators, and the correlations among these variables. The 3 yield traits exhibited estimated negative genetic correlations between their level under TN conditions and their slopes of response under HS, ranging from -0.38 for fat yield to -0.59 for milk yield. For CR, this correlation was close to zero. Estimated genetic correlations between yield traits under TN conditions and the decline in CR under HS were nearly null, ranging from -0.06 for fat yield to 0.07 for protein yield. This suggests that cows with higher production potential under TN conditions are not necessarily more susceptible to fertility decline under HS. Conversely, the correlations between fertility potential under TN conditions and the slopes of production decline under HS were positive, ranging from 0.34 for protein yield to 0.51 for fat yield. This indicates that cows with lower production losses under HS tend to have better fertility performance under TN conditions. Furthermore, the correlations between heat tolerance based on production and fertility declines under HS were positive, ranging from 0.22 for fat yield to 0.65 for milk yield. This suggests that a significant proportion of animals have the potential to maintain both productive and fertility levels under HS. Finally, the genetic correlation between fertility and production traits improved as heat load increased. For milk yield, this correlation shifted from -0.30 under TN to nearly null under extreme heat conditions. Reaction to heat load in functional traits such as fertility should help in selecting animals that show high levels of production under HS due to a better adaptation to hot conditions driven by functional reasons.

The role of carbon dioxide in emission of ammonia from manure

Animal manure contributes considerably to ammonia (NH3) and greenhouse gas (GHG) emissions in Europe. Various treatment technologies have been implemented to reduce emissions and to facilitate its use as fertilizer, but a systematic analysis of these technologies has not yet been carried out. This study presents an integrated assessment of manure treatment effects on NH3, nitrous oxide (N2O) and methane (CH4) emissions from manure management chains in all countries of EU-27 in 2010 using the MITERRA-Europe model. Effects of implementing 12 treatment technologies on emissions and nutrient recovery were further explored through scenario analyses; the level of implementation corresponded to levels currently achieved by forerunner countries. Manure treatment decreased GHG emissions from manures in EU countries by 0-17% in 2010, with the largest contribution from anaerobic digestion; the effects on NH3 emissions were small. Scenario analyses indicate that increased use of slurry acidification, thermal drying, incineration and pyrolysis may decrease NH3 (9-11%) and GHG (11-18%) emissions; nitrification-denitrification treatment decreased NH3 emissions, but increased GHG emissions. The nitrogen recovery (% of nitrogen excreted in housings that is applied to land) would increase from a mean of 57% (in 2010) to 61% by acidification, but would decrease to 48% by incineration. Promoting optimized manure treatment technologies can greatly contribute to achieving NH3 and GHG emission targets set in EU environmental policies.

Mitigation of ammonia, nitrous oxide and methane emissions during solid waste composting with different additives: A meta-analysis

Ammonia and greenhouse gases emission from impermeable covered storage and land application of cattle slurry to bare soil

Ammonia (NH3) and greenhouse gas (GHG) emissions are substantial contributors to C and N loss in composting. Lignite can increase N retention by absorbing N H 4 + and NH3. However, the effects of co-composting on NH3 and GHG emissions in view of closing nutrient cycle are still poorly investigated. In the study, poultry litter was composted without (CK) or with lignite (T1) or dewatered lignite (T2), and their respective composts N H 4 + Com_CK, Com_T1, and Com_T2) were tested in a soil incubation to assess NH3 and GHG emission during composting and following soil utilization. The cumulative NH3 flux in T1 and T2 were reduced by 39.3% and 50.2%, while N2O emissions were increased by 7.5 and 15.6 times, relative to CK. The total GHG emission in T2 was reduced by 16.8% compared to CK. Lignite addition significantly increased nitrification and denitrification as evidenced by the increased abundances of amoA, amoB, nirK, and nirS. The increased reduction on NH3 emission by dewatered lignite could be attributed to reduced pH and enhanced cation exchangeable capacity than lignite. The increased N2O was related to enhanced nitrification and denitrification. In the soil incubation experiment, compost addition reduced NH3 emission by 72%∼83% while increased emissions of CO2 and N2O by 306%∼740% and 208%∼454%, compared with urea. Com_T2 strongly reduced NH3 and GHG emissions after soil amendment compared to Com_CK. Overall, dewatered lignite, as an effective additive, exhibits great potential to simultaneously mitigate NH3 and GHG secondary pollution during composting and subsequent utilization of manure composts.

Assessment of the crucial factors influencing the responses of ammonia and nitrous oxide emissions to controlled release nitrogen fertilizer: A meta-analysis

Methane, nitrous oxide and ammonia emissions during storage and after application of dairy cattle slurry and influence of slurry treatment

Greenhouse gas and ammonia emissions from digested and separated dairy manure during storage and after land application

Anaerobic digestion (AD) of livestock manure is better known for the economic advantage derived from biogas for energy rather than for its environmental benefits. Demonstration of relevant environmental benefits from AD of manure would thus enhance adoption of this technology on animal feeding operations (AFOs). The effect of AD of dairy manure on the emissions of ammonia (NH3) and greenhouse gases (GHG) during manure storage and also in subsequent land applications are presented in this paper. Measurements of GHG emissions from both AD and non-AD manure storages were made using a floating chamber and a photoacoustic gas analyzer (INNOVA model 1412). Emissions of GHG were determined using the standard closed chamber method from field plots applied with AD and non-AD manure. Data obtained indicate significantly higher fluxes of GHG (CO2, N2O, and CH4) from land applied with non-AD manure than from land applied with AD manure. In addition, injection of non-AD manure seemed to further increase CH4 flux from the soil. More than 50% emissions of CO2 and CH4 were observed during the first 3 days after manure was land applied. Emissions of GHG from the anaerobic lagoon holding AD manure, during all four seasons, were significantly lower than from the anaerobic lagoon with non-AD manure. In contrast, the reverse was observed with NH3 emissions. This data demonstrate some environmental benefits for AD of dairy manure prior to its storage and field application but also some potential increased emission of NH3 during storage.

The effects of Alchemilla vulgaris (AV) on haematology and serum, liver, and ovarian antioxidant status of heat-stressed quail in the late laying period were observed in this study. A 2×3 factorial design was used with 0, 1 and 3% AV fed in thermoneutral (TN) and heat stress (HS) conditions. A total of 150 quails were randomly assigned to six groups. The quails were located in temperature controlled rooms. The mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and platelet distribution width (PDW) obtained in quail fed 1% AV were higher than in 3% AV under both TN and HS conditions. Comparing 3% AV to 1% AV, the concentration of MCH obtained for 1% AV was higher in HS and lower in TN conditions. Besides, quails fed for 1% AV had a lower procalcitonin (PCT) value in HS than 3% AV but this PCT value was the same in TN. The serum malondialdehyde (MDA) was lower in 1% AV than 3% AV in both HS and TN. The ovarian MDA was lower in TN than HS. In both TN and HS conditions, the ovarian MDA value was determined higher for 1% AV than for 3% AV. The liver glutathione (GSH) value was higher in 1% AV than 3% AV in both TN and HS conditions. The Total Oxidant Capacity (TOS) value was found higher for 3% AV in TN and 1% AV in HS. The serum GSH, TOS, and oxidative stress index (OSI) values were lower for 3% AV compared to 1% AV for both TN and HS conditions, whereas for MDA value this was the opposite. The ovarium MDA and TOS values were lower for 3% AV than for 1% AV in both TN and HS. Also, the liver MDA, GSH, and Total Antioxidant Capacity (TAS) values were lower for 3% AV than for 1% AV in both TN and HS conditions. Finally, dietary AV has been shown to have a partial antioxidative effect on the defense system and also has effect on red blood cell profiles and platelet counts rather than white blood cell profiles.

Several solutions are today proposed to farmers to minimize ammonia (NH3) emissions during storage. In the present study, special attention was given to slurry acidification and slurry crust enhancement and our objective was to assess the effect of slurry bio-acidification using sugar and cheese whey as an alternative to sulphuric acid, and the potential of rice bran as crust enhancer on NH3 and greenhouse gases emissions during storage. Both the cheese whey and the rice bran are materials, available in large amounts, with low commercial value in some EU regions as Portugal and its use, at farm scale, will be a win-win situation. Sugar is also a good alternative to acid attending its relatively low value. A laboratory experiment was performed for 2 months with five treatments: non-treated cattle slurry (CTRL), slurry treated with sulphuric acid (ACID), slurry treated with sugar (SUGAR), slurry treated with cheese whey (WHEY) and rice bran applied on the slurry surface (RICE). The SUGAR treatment led to a reduction of NH3 emissions by 45% relative to CTRL while WHEY and RICE resulted in a reduction of 68% and 25%, respectively. Nevertheless, this effect of SUGAR and WHEY was shorter than in ACID, since NH3 emissions started to be observed in those 2 treatments after 31 and 35 days of storage, respectively. Nitrous oxide emissions remained close to zero in ACID and SUGAR. RICE led to the highest emissions of carbon dioxide (CO2) releasing almost 5% of carbon present in the initial mixture (slurry + rice bran) and presented the highest methane emissions. The ACID and SUGAR led to a significant decrease of the total greenhouse gas (GHG) emissions. Our results indicate that bio-acidification using a source of sugar could be a good alternative to H2SO4 to reduce simultaneously NH3 and GHG emissions during storage.

We hypothesized that supplementation with rumen undegradable protein (RUP) during the rearing phase mitigates nitrous oxide (N2O), methane (CH4), and ammonia (NH3) emissions from excreta of Nellore animals in Urochloa brizantha ‘Xaraés’ pasture. The treatments applied to soil were urine and dung of animals supplemented without RUP or with RUP in the middle and end of the rearing phase. We assessed N2O and CH4 emissions using a static closed chamber and NH3 emissions using the semi‐open static chamber method. No effects were observed for supplement, excreta type, period, or interaction on N2O emissions. The mean emission factor was 0.03% of N in the excreta lost as N2O. Higher NH3 losses were observed for the urine treatments in the end period, regardless of the supplement type. The mean NH3 emission factor for urine was 2.96 and 13.8% for the middle and end periods, respectively, while the mean value for dung was 3.9%. The type of supplement did not affect CH4 emissions, and the mean dung emission factor was 0.12 kg CH4 head–1 year–1. In summary, the supplementation of beef cattle in pastures with RUP did not mitigate NH3, N2O, and CH4 emissions from excreta. The excreta emission factors for the GHGs measured, regardless of differences in the type of excreta, type of supplement, and period, were lower than the default value of Intergovernmental Panel on Climate Change revised guidelines. Further studies will be needed to fully understand the mechanisms underlying the effects of RUP on greenhouse gas emissions.