Livestock Biomass Research Articles

Using priorities between human and livestock bacterial antimicrobial resistance (AMR) to identify data gaps in livestock AMR surveillance

BackgroundBacterial antimicrobial resistance (AMR) is a global threat to both humans and livestock. Despite this, there is limited global consensus on data-informed, priority areas for intervention in both sectors. We compare current livestock AMR data collection efforts with other variables pertinent to human and livestock AMR to identify critical data gaps and mutual priorities.MethodsWe globally synthesized livestock AMR data from open-source surveillance reports and point prevalence surveys stratified for six pathogens (Escherichia coli, Staphylococcus aureus, non-typhoidal Salmonella, Campylobacter spp., Enterococcus faecalis, Enterococcus faecium) and eleven antimicrobial classes important in human and veterinary use, published between 2000 and 2020. We also included all livestock species represented in the data: cattle, chickens, pigs, sheep, turkeys, ducks, horses, buffaloes, and goats. We compared this data with intended priorities calculated from: disability-adjusted life years (DALYs), livestock antimicrobial usage (AMU), livestock biomass, and a global correlation exercise between livestock and human proportion of resistant isolates.ResultsResistance to fluoroquinolones and macrolides in Staphylococcus aureus were identified as priorities in many countries but, less than 10% of these reported livestock AMR data. Resistance data for Escherichia coli specific to cattle, chickens, and pigs, which we prioritized, were also well collected. AMR data collection on non-typhoidal Salmonella and other livestock species were often not prioritized. Of 232 categories prioritized by at least one country, data were only collected for 48% (n = 112).ConclusionsThe lack of livestock AMR data globally for broad resistance in Staphylococcus aureus could underplay their zoonotic threat. Countries can bolster livestock AMR data collection, reporting, and intervention setting for Staphylococcus aureus as done for Escherichia coli. This framework can provide guidance on areas to strengthen AMR surveillance and decision-making for humans and livestock, and if done routinely, can adapt to resistance trends and priorities.

Diversity of ammonia sources in Tianjin: nitrogen isotope analyses and simulations of aerosol ammonium

Environmental context Atmospheric particulate NH4+, primarily produced from the reaction of NH3 and acids, is an important component of PM2.5. In this study, nitrogen stable isotope analyses and an atmospheric chemistry model were used to estimate the contribution of major NH3 sources to particulate NH4+ in Tianjin, a megacity in North China Plain (NCP). Our research has implications for investigations of NH3 emission sources and relevant pollution control in Tianjin and NCP. Rationale The North China Plain (NCP) has been identified as an NH3 emission hotspot. Source apportionment of NH3 is a prerequisite for controlling NH3 or NH4+ pollution. Nitrogen stable isotope (δ15N) analysis is a promising method for NH3 source apportionment but its accuracy is still in question. Methodology In this study, daytime and nighttime PM2.5 samples were collected from two sites in Tianjin, NCP, in autumn. Concentrations and δ15N of particulate NH4+ were then measured. Nitrogen stable isotope analyses and isotope mixing model (MixSIAR), and an atmospheric chemistry model (WRF-CMAQ-ISAM) were used to estimate the sources of NH3 in Tianjin. Results Results from the MixSIAR and WRF-CMAQ-ISAM models suggested that all the sources including livestock breeding, N-fertiliser application, fossil fuels, NH3 slip (especially from traffic), human waste and biomass burning (mostly from bioapplication) were non-negligible to NH3 and NH4+ in Tianjin. This high complexity is due to significant agricultural and industrial production and residential life in Tianjin and the surrounding regions. Our results indicate all NH3 sources need to be considered if we want to reduce NH4+ pollution in Tianjin in autumn.

Estimating livestock biomass across diverse populations and data ecosystems.

Estimates of livestock biomass can be used as denominators in disease burden estimates, in addition to informing assessments of resource use and environmental impacts. This article explores the challenges of accurately estimating biomass across different scales and data ecosystems, with a particular focus on the use of biomass in the Global Burden of Animal Diseases programme. The greatest of these challenges is a lack of subgroup (breed, age, sex)-specific data on populations and liveweights at national and subnational level. This can be overcome by using global datasets and generic estimates of liveweight for each species, though this approach fails to account for the diversity of livestock systems.

Sustainable biomass system design for microenterprise-based use of bioenergy

Clean cooking systems and the incorporation of biomass and bioenergy are critical in the context of Sustainable Development Goal (SDG) 7.1.2. This article considers the biomass potential of livestock-based rural micro-enterprises and the scope for standardisation and system efficiency improvement in traditional cow-dung-based bioenergy consumption. The article also highlights the challenges that the current design of cow-dung-based traditional cookstoves poses for rural households, especially for women users. A case of rural household bioenergy system design is proposed with appropriate system specific recommendations for the stages of livestock biomass collection, drying, and preparation of fuel pellets of standard dimensions as per the requirements of the ICS (Improved cookstove). A concept design featuring multiple interventions is endeavoured with the overall objective of designing a bioenergy based sustainable energy system. The suggested design interventions are focused on rural household micro-enterprises traditionally excluded from the improved cookstove development ecosystems. Through a customised approach, multiple opportunities for improvement of fuel efficiency, operational parameters, and innovations in system design are explored.

Population, distribution, biomass, and economic value of Equids in Ethiopia.

Equids play a crucial role in the Ethiopian economy, transporting agricultural inputs and outputs in the dominant subsistence agricultural systems and the critical link for value chains throughout the country. However, these species are often neglected in policies and interventions, which reflects the data and information gaps, particularly the contribution of working equids to Ethiopia. To assess population dynamics, distribution, biomass, and economic value of equids in Ethiopia. Equine population data were obtained from the Ethiopian Central Statistics Agency (CSA) annual national agriculture surveys published yearbooks from 2004 to 2020. Parameters such as the number of effective service days and daily rental value were obtained from interviews and literature to estimate the stock monetary and service value of equids. Descriptive statistics were used to assess population dynamics and the geographical distribution was mapped. The estimated total Ethiopian equid population increased by more than doubled (by 131%) between 2004 and 2020 from 5.7 (4.9-6.6) million to 13.3 (11.6-15) million with 2.1 million horses, 10.7 million donkeys, and 380 thousand mules. Similarly, the number of households owning a working equid has increased. Equine populations are unevenly distributed across Ethiopia, although data were lacking in some districts of the country. The per human-capita equine population ranged from 0-0.52, 0-0.13, and 0-0.02 for donkeys, horses, and mules, respectively. The equid biomass was 7.4 (6.3-8.4) million Tropical livestock unit (TLU) (250 kg liveweight), 10% of total livestock biomass of the country. The stock monetary value of equids was USD 1,229 (651-1,908) million, accounting for 3.1% of total livestock monetary value and the services value of equids was USD 1,198 (825-1,516) million, which is 1.2% of Ethiopian 2021 expected GDP. The Ethiopian equine population has grown steadily over the last two decades. Equids play a central role in transportation and subsistence agriculture in Ethiopia and contribute significantly to the national economy. This pivotal role is insufficiently recognized in national livestock investments.

Calculation of livestock biomass and value by province in Indonesia: Key information to support policymaking

Accurate estimations of the biomass and value of livestock in Indonesia are of great use in supporting investment decisions by the public and private sector and as a basis for estimating the losses due to animal disease.Biomass and the partial direct use value for key livestock species (cattle, buffalo, sheep, goats, pigs, chickens) for all provinces of Indonesia were derived from secondary data using a novel spreadsheet-based model. Using beef cattle as an example, we also explored the use of a herd dynamics model to validate base data on populations and productivity used to generate biomass values, and these were found to be generally robust.Total partial direct use value of livestock is estimated to be almost USD54 billion in 2021, comprising almost USD33 billion of population value and almost USD21 billion of production value. Beef cattle account for 44% of total value and chicken (broiler, layer and native chickens) account for a further 36% of the total.Breaking the data down by province reveals the regional importance of some livestock types that are of relatively minor importance nationally (pigs in East Nusa Tenggara and sheep in West Java). It also reveals the importance of livestock in the poorest provinces of Indonesia, where livestock acts as a store of wealth and serves socio-cultural purposes.

Predicting population size at large scale: The case of two large felids

Approaches that allow capitalizing on local population estimates to derive global population estimates with associated uncertainty are urgently needed, especially for naturally rare species of conservation concern. Here we used published population density estimates to predict large-scale density patterns and derive global population estimates for two species of large felids, the leopard and the tiger. We modelled population density for the leopard (n = 392) and the tiger (n = 547) as a function of environmental and anthropogenic variables, while controlling for differences in sampling method and sampling area, time of data collection, spatial autocorrelation, subspecies and political protection. We used Bayesian inference to generate a distribution of plausible population sizes. Both species showed higher densities in high productivity areas, the leopard being more abundant in high precipitation, high level of terrain roughness and agricultural areas, and the tiger in areas with low croplands and low roughness. Primary roads density showed a negative effect on both species. Secondary roads density was associated to higher densities for the leopard but lower densities for the tiger. Livestock biomass showed a humped relationship with tigers’ densities. Temporal trends in average density were negative for the tiger, experiencing an average decline of 34% (IQR: 11% − 53%). In contrast, the trend for leopards showed a marginal, yet uncertain, increase in recent years 21% (IQR: −5% − 57%). We predicted a global population estimate of 261,636 (IQR = 146,768 − 461,512) and 5201 tigers (IQR = 2596 − 10,460). Large-scale models of population density that rely on unstructured data can contribute to our understanding of species ecology, produce robust population size estimates for conservation assessment and inform large-scale conservation planning. At the same time, the uncertainty around these estimates highlights the limited knowledge available for these species which should be accounted for in conservation assessments.

Herbivory baseline estimates in Spanish protected areas, and environmental implications

ContextThere are no estimations of herbivory baselines in Spain. Due to the bioclimatic conditions, ungulates have maintained Open Ecosystems until the Holocene. Pastoral tradition later fulfilled the niche of wild grazers, but this role is not considered in environmental assessments of grazing livestock.ObjectivesWe attempted to better understand the scale of herbivory in Spain. We aimed to estimate the weight of current wild herbivory and evaluate the role of domestic herbivory in these baselines. We applied them to improve the allocation of environmental impacts and emissions from grazing livestock.MethodsWe inferred an equation relating Net Primary Productivity (NPP) with ungulate biomass and enteric CH4 with data from 11 Spanish Protected Areas. We estimated theoretical baselines in Spain using other literature sources. We applied the equations to the Spanish open ecosystems that are currently grazable. We also estimated the proportion of grazing livestock that would be part of such baseline.ResultsWe found relationships between NPP and ungulate biomass and enteric CH4 emissions. However, current abundances are several times below the estimated baselines and the carrying capacity. There are major constraints for herbivore populations to reach their baseline state, particularly the absence of migration and the extinction of grazers among wild herbivores. Structural maintenance of Open Ecosystems should therefore be complemented by domestic grazers that cannot be replaced by the extant wild, mostly browser, ungulates.ConclusionsWe concluded that Spain is widely susceptible to being populated by herbivores that generate Open Ecosystems as baseline landscapes. Current grazing livestock accounts for a significant part of them, so baselines must be included in their environmental assessments. For the case of Spain, we propose a minimum baseline equivalent to 36% of current grazing livestock biomass and 23% of their enteric CH4 emissions.

Suitable municipalities for biomass energy use in Colombia based on a multicriteria analysis from a sustainable development perspective

Using renewable energies is a global strategy to mitigate the acceleration of global warming generated by industrial processes and is a sustainable way to diversify the energy matrix in all countries. Biomass is a renewable energy source that produces biofuels and generates electricity and heat. The primary purpose of this work is to identify the municipalities in Colombia where agricultural, livestock, and urban residual biomass could be suitable for energy generation in a sustainable and renewable way. To that end, we carried out a Geostatistical Multi-Criteria Decision Methodology using Analytical Hierarchy Processes such as Rank-Sum and Weighted Linear Combination, as well as considering a set of sustainable development indicators applied to official Colombian data. Two scenarios are considered for comparison purposes. The first one is according to expert criteria, and the second one considers The Sustainable Development Goals proposed by the United Nations. Under both proposed scenarios, 127 municipalities were found to be suitable for agricultural-urban residual biomass and 162 for livestock-urban residual biomass for energy generation. One of the main limitations for the use of urban biomass is that municipalities need to have sufficient production potential to fulfill their own energy needs. An additional comparison with previous works to evaluate the performance of the Multi-Criteria Decision Methodologies MCDM is also proposed.

Utilization of Biogas in Generators to Generate Electricity

Agricultural and livestock biomass waste is a potential source of basic materials in producing biogas because the organic content it has is quite high so it needs to be used in generators as engine fuel mixtures. The purpose of the research is to get the best treatment by looking at the time the generator operates and the highest electrical power produced. This research was conducted using an experimental method with 3 treatments with 3 replications, namely using a mixture of cow dung with rice straw (P1), cow dung with corn cobs (P2), and cow dung with water hyacinth (P3), and the use of biogas and LPG as generator fuel with biogas levels of 5, 10, and 15% and LPG 95, 90, and 85%. The results showed that the best biogas yield was obtained from a mixture of cow dung and rice straw (P1) with a level of 5%. Biogas with a level of 5% can turn on the generator for longer. The generator can operate for 10.10 minutes by producing 946 watts of electrical power.

Estimation of renewable biogas energy potential from livestock manure: A case study of India

The rationale of the case study is to estimate biomass resources potential in rural Haryana, India from animal manure and mitigate greenhouse gas emissions. The state has the potential of 52.29 million tons of livestock dung which generates a biogas of 5464.11 million m3 and electrical energy of 9835.4 GWh annually. Assessment of biogas equivalence of traditional fuels is also carried out. The state has a biofertilizer potential of 6.78 million tons/year. The biomass resource distribution, power density, and electricity per-capita potential of livestock manure are projected to be 27.41 kton/km2, 0.59 W/m2, and 387.96 kWh/capita respectively. Biomass power generation leads to an estimated saving of 1707.08 to 3583.73 million kg/year, with a baseline headline of 2560.32 million kg/year CO2equivalent emissions, from transition to local livestock biomass in place of diesel for power. These findings can assist policy planners in decentralized bioenergy generation and map emission profiles with bioenergy.

Reporting on 16 years of laboratory capacity building while exploring the future of WOAH's Laboratory Twinning Programme.

Animal health laboratories are an increasingly important part of safeguarding animal and public health due to their role in surveillance and diagnostics of animal diseases, food safety, and in the development and production of medicinal products, vaccines, and diagnostic tools. Despite their importance, the global distribution of veterinary laboratory expertise is uneven, with greater concentration of reference laboratories in wealthier countries. To address this issue, the World Organization for Animal Health (WOAH, founded as OIE) created a Laboratory Twinning Programme in 2006. The paper will briefly review this Programme in the context of an increasingly populated global health security field, based on a literature review and on a combination of public and internal WOAH data and describe the implementation of the Programme in the past 16 years, noting the drivers for project implementation, its links with the global livestock biomass distribution and with the current distribution of veterinary laboratory expertise. There has been broad uptake and diversity in the focus of the twinning projects implemented in WOAH Member Countries. The Laboratory Twinning Programme would benefit from an evaluation that looks at its outcomes and quantifiable impact in beneficiary countries. A case is made for the development of a monitoring and evaluation system tailored to the Programme's specificities.

Herbaceous production lost to tree encroachment in United States rangelands

Abstract Rangelands of the United States provide ecosystem services that benefit society and rural economies. Native tree encroachment is often overlooked as a primary threat to rangelands due to the slow pace of tree cover expansion and the positive public perception of trees. Still, tree encroachment fragments these landscapes and reduces herbaceous production, thereby threatening habitat quality for grassland wildlife and the economic sustainability of animal agriculture. Recent innovations in satellite remote sensing permit the tracking of tree encroachment and the corresponding impact on herbaceous production. We analysed tree cover change and herbaceous production across the western United States from 1990 to 2019. We show that tree encroachment is widespread in US rangelands; absolute tree cover has increased by 50% (77,323 km2) over 30 years, with more than 25% (684,852 km2) of US rangeland area experiencing tree cover expansion. Since 1990, 302 ± 30 Tg of herbaceous biomass have been lost. Accounting for variability in livestock biomass utilization and forage value reveals that this lost production is valued at between $4.1–$5.6 billion US dollars. Synthesis and applications. The magnitude of impact of tree encroachment on rangeland loss is similar to conversion to cropland, another well‐known and primary mechanism of rangeland loss in the US Prioritizing conservation efforts to prevent tree encroachment can bolster ecosystem and economic sustainability, particularly among privately‐owned lands threatened by land‐use conversion.

The Importance of Collecting and Archiving Data on Domestic and Cultivated Organisms

At least 29% of the world’s terrestrial ecosystems have been significantly modified by human activity (Ellis 2011). Total livestock biomass is 15 times greater than that of wild mammals (Bar-On et al. 2018). Crops such as maize, soybean, rice, and wheat cover 23% of available agricultural land (Ritchie and Roser 2013). Even where land is not farmed, it is often converted to highly modified habitats such as urban ecosystems. Within the matrix of anthropogenic ecosystems spread around the world are many wild species (i.e., free-living, non-domesticated or feral). Some native species persist from the original ecosystems, while others colonize anthropogenic ecosystems including alien invasive species. Thus, wild flora and fauna in many areas are part of ecosystems that are dominated by, and often characterised by, the domestic and cultivated organisms that exist in them. Examples include large herbivores raised for milk and meat production, and omnivorous and carnivorous species such as both domestic and feral dogs and cats. Moreover, crops are typically grown in monoculture plots including tree plots in commercial forestry, and an enormous array of cultivated plants are grown in gardens, parks, and along streets in urban areas. Tellingly, in many ecosystems the domestic bee is the primary pollinator and domestic cats are the main predator. Domestic and cultivated organisms are not isolated from wild organisms and indeed they interact in many ways, including predation, parasitism, and herbivory, competition for biotic and abiotic resources, and pathogen transmission. If we are to understand modern ecosystems, clearly we cannot ignore the domesticated and cultivated components of ecosystems. So where are the observational data on these species? iNaturalist reluctantly tolerates them but does not publish them to the Global Biodiversity Information Facility (GBIF), eBird actively discourages recording them, and GBIF doesn’t encourage their submission either. Some information can be gleaned from land cover maps and remote sensing, but without knowing the specific species present in the land use category it is hard to build a holistic picture of an ecosystem. Data on domesticated and cultivated organisms have many uses, including horizon scanning and risk assessment for invasive species, understanding the impacts of invasive species, predicting the spread of disease, the spillover of disease to and from wild and domestic organisms, and many others (Groom et al. 2021). Evidently there are important components of ecosystems largely missing from our public databases. As data on biodiversity becomes more intergrated, such as implementing Digital Extended Specimens (Webster et al. 2021), it will become increasingly important to access data from all aspects of an ecosystem, included those that are domestic and cultivated. In this talk we will expand on why we should be mobilising such data. They can be published without ruining the integrity of data on wild organisms, so why don’t we embrace and use these fundamentally important, but much ignored, data?

Livestock Biomass: Energy source for 26 municipalities in Hidalgo State experiencing high marginalization

The high consumption of natural non-renewable resources has caused an exponential increase in the greenhouse gases which provoke global warming and as a result, every country on the planet suffers environmental issues due to the excessive use of fossil fuels. There are several different sources of gas production, principally caused by human beings, however there is little to no interest in mitigating them. Global interest is instead currently focused on containing them via the reduction of carbon dioxide (CO2) and methane (CH4). In the Paris Agreement, participating countries have committed to keeping the rise of the mean global temperature below 2 °C and to limiting its increase to 1.5 °C. Latin America as a whole (and principally, Mexico) has committed to lowering greenhouse gases 25% by 2030 and 50% by 2050 (AZEL, 2018). To achieve this, it is necessary to contribute by applying clean energy alternatives. The current project proposes using bovine and swine organic wastes for the production of biogas and electric energy in 26 cities of high marginalization in Hidalgo, a state in Mexico which contributes to lowering environmental pollution, providing access to better services for raising the quality of life of its inhabitants, and minimizing the use of (therefore saving the money provided for) subsidies for conventional electric energy.

Comparison of different biomass methodologies to adjust sales data on veterinary antimicrobials in the USA.

ObjectivesThe United States (US) FDA, European Surveillance of Veterinary Antimicrobial Consumption (ESVAC), Public Health Agency of Canada (PHAC) and World Organisation for Animal Health (OIE) established methodologies that characterize antimicrobial sales for use in food animals by adjusting the sales by animal biomass. Our aim was to review and compare these methodologies on US-specific data.MethodsAnnual antimicrobial sales for cattle, swine, chickens and turkeys in the USA between 2016 and 2018 were adjusted by the FDA, ESVAC, PHAC and OIE methodologies. To better understand the advantages and disadvantages of the four methodologies, their biomass denominators were compared regarding the level of detail accounted for in the estimated US livestock biomass, their ability to observe temporal trends in animal biomass within a country and practicality in biomass estimation for comparing antimicrobial sales across countries.ResultsThe four methodologies resulted in substantially different estimates of biomass-adjusted antimicrobial sales for use in US food animals. The 2018 estimates were the highest with the ESVAC methodology (314.7 mg of active antimicrobial ingredient/kg of animal biomass), followed by PHAC (191.5 mg/kg), FDA (127.6 mg/kg) and OIE (111.5 mg/kg). The animal weight parameters used in each methodology had the most impact on the biomass-adjusted sales estimates.ConclusionsIn regard to the estimation of the animal biomass, no methodology was found to be perfect; however, the FDA methodology had the best resolution in characterizing the US livestock biomass while the OIE methodology was best for biomass estimation for global monitoring of antimicrobial sales for use in food animals.

Transforming livestock productivity through watershed interventions: A case study of Parasai-Sindh watershed in Bundelkhand region of Central India

CONTEXTGlobal experiences reveal the positive impact of watershed-based interventions in improving livelihoods and environmental security. In the drylands, increasing forage resources and improving livestock productivity is a critical challenge. OBJECTIVESThe overarching aim of this paper is to analyse the impact of watershed-based interventions on livestock population, productivity, fodder resources, and biomass availability. The paper describes the interrelationship between land, water, crop, and livestock and how the gap in forage deficit can be bridged through a range of watershed interventions. METHODSThe study was undertaken in the Parasai-Sindh watershed of Central India between 2011 and 2016. A 300-year-old defunct haveli (a traditional rainwater harvesting structure) was renovated and nine check dams along the drainage line were constructed. Nearly 25,000 running-meters of field bunds were constructed. Large fields (2-3 ha) were divided into relatively smaller plots (0.3–0.5 ha) to reduce runoff velocity. The impact of watershed interventions on water availability, livestock productivity, forage yield, and income was studied through hydrological monitoring, primary household survey and principal component analysis (PCA) biplot and hierarchical clustering. RESULTS AND CONCLUSIONSThe watershed interventions enhanced groundwater availability leading to greater fodder availability, 22% increase in livestock population (ACU) and a 120% increase in milk production over a period of five years. The bovine population recorded a surge of 193% (cattle) and 32% (buffalo) over this period. Mean dry matter (DM, fodder) availability also increased from 10 t/household/year to 16.7 t/household/year owing to improved water availability. Groundnut (rainy season) and wheat (post rainy season) contributed significantly as forage resources. There was an annual forage demand of 5560 t DM for a livestock population of 2175 ACU in 2011 and of 6770 t DM for a livestock population of 2650 ACU in 2016. Annual forage biomass availability was estimated at 4219 t DM in 2011 and 6977 t DM in 2016. There was a deficit of 1341 t DM (24%) in 2011 which turned into a 3% surplus of 210 t DM in 2016 through watershed-based interventions. With increased cropping intensity and milk production, average annual household income increased from US$ 1325 to US$ 2430 over the five-year period. SIGNIFICANCEThis case study clearly illustrates the impact of watershed-based interventions on livestock population, productivity, forage resources, and biomass availability to bridge the gap in forage deficit. Its findings serve as a guide to widely scale up watershed-based interventions for improved water and biomass availability, and livestock productivity in semi-arid and dryland regions.

Snow Leopard Dietary Preferences and Livestock Predation Revealed by Fecal DNA Metabarcoding: No Evidence for Apparent Competition Between Wild and Domestic Prey

Accurate assessments of the patterns and drivers of livestock depredation by wild carnivores are vital for designing effective mitigation strategies to reduce human-wildlife conflict. Snow leopard’s (Panthera uncia) range extensively overlaps pastoralist land-use and livestock predation there is widely reported, but the ecological determinants of livestock consumption by snow leopards remain obscure. We investigated snow leopard dietary habits at seven sites across the Sanjiangyuan region of the Qinghai–Tibetan Plateau (QTP), an area central to the species’ global range. Snow leopard abundance, wild prey composition, and livestock density varied among those sites, thus allowing us to test the effects of various factors on snow leopard diet and livestock predation. Using DNA metabarcoding, we obtained highly resolved dietary data from 351 genetically verified snow leopard fecal samples. We then analyzed the prey preferences of snow leopards and examined ecological factors related to their livestock consumption. Across the sites, snow leopard prey was composed mainly of wild ungulates (mean = 81.5% of dietary sequences), particularly bharal (Pseudois nayaur), and supplemented with livestock (7.62%) and smaller mammals (marmots, pikas, mice; 10.7%). Snow leopards showed a strong preference for bharal, relative to livestock, based on their densities. Interestingly, both proportional and total livestock consumption by snow leopards increased linearly with local livestock biomass, but not with livestock density. That, together with a slight negative relationship with bharal density, supports apparent facilitation between wild and domestic prey. We also found a significant positive correlation between population densities of snow leopard and bharal, yet those densities showed slight negative relationships with livestock density. Our results highlight the importance of sufficient wild ungulate abundance to the conservation of viable snow leopard populations. Additionally, livestock protection is critically needed to reduce losses to snow leopard depredation, especially where local livestock abundances are high.

Predictive risk model of livestock rabies occurrence in Peru

Livestock rabies is endemic in Peru. Hence, its persistence and annual dissemination represent an important economic impact, especially for impoverished farming communities. The disease is mostly transmitted by the hematophagous bat Desmodus rotundus. The present study aimed to adapt an existing predictive model of the occurrence of livestock rabies to Peru, in which the risk of rabies transmission from bats to livestock was estimated using decision-tree models of receptivity and vulnerability. Official rabies surveillance data between 2010 and 2015 were used along with possible risk factors, such as livestock biomass, environmental changes, and geomorphological characteristics. Several scenarios were established to evaluate the prediction of the occurrence of livestock rabies cases by determining more than one cut-off point of the receptivity variables. During the study period, the precision of the model was estimated through the sensitivity (39.46%) and specificity (98.64%) by using confusion matrices. Targeting control efforts, especially in districts with a high estimated risk, could represent the prevention of a significant proportion of livestock rabies cases, which would optimize the human and economic resources of the Peruvian surveillance service. However, the quality of data produced by the surveillance should be improved not only to obtain higher model precision but also to allow the adequate planning of control actions.

Multi-functional biochar preparation and heavy metal immobilization by co-pyrolysis of livestock feces and biomass waste

Biomass waste is a desirable additive in livestock feces biochar preparation due to its easy access, better moisture adjustment, and abundant organic content. In the present study, co-pyrolysis of livestock feces (PM: pig manure, CM: chicken manure) and biomass wastes (WC: wood chips, BS: bamboo sawdust, RH: rice husk, and CH: chaff) with different blending ratios was conducted at 600 °C to investigate the biochar characteristic and Cu/Zn immobilization performances. The results showed that WC and BS have more significant effect on the increase in fixed carbon content and heating value and the decrease in ash content of biochar. The biochar with lower pH and electrical conductivity is obtained from co-pyrolysis of manure with RH and CH. Compared with CM-based biochar, PM-based biochar presented better potential as fuel and soil remediation considering the higher heating value and lower aromatic H/C ratio. Specially, the residual fractions of Cu and Zn in PM biochar increased from 73.09% and 65.54% to 90.68% and 72.31% after 10 wt% BS addition and those in CM biochar increased from 81.07% and 73.57% to 88.87% and 84.11% after 10 wt% WC addition, which induced the lowest environmental risk of biochar. This work provided a strategy and direction for targeted enhancement in biochar characteristics with selective biomass addition during manure pyrolysis, which is beneficial to the local treatment and utilization of farm wastes.