Livestock Mortality Research Articles

Time to monitor livestock carcasses for biodiversity conservation and public health

Abstract Law enforcement and integration of environmental issues into other policies able to affect species and ecosystems are cornerstones for the effective protection of biodiversity. We illustrate the necessity of monitoring and improving such enforcement and integration through the example of the European sanitary policies for managing livestock carcasses after the “mad cow disease” outbreak while supporting scavengers’ conservation. Continuous updates of EU sanitary regulations for reconciling scavenger conservation and public health have led to actions whose implementation and monitoring rely on delineating scavenger feeding zones and estimating livestock mortality and scavenger feeding requirements (SFRs). However, the lack of clear and homogeneous criteria to calculate SFRs results in remarkable variations (e.g. of up to >450% in some regions). Although we offer a prospective approach to improve SFR calculations, we show here the high levels of uncertainty in these estimates based on the imperfect information available regarding scavengers’ ecology. Synthesis and applications. The multiple socioeconomic and ecological impacts of sanitary crises such as “mad cow disease” underpin the need for high‐level political commitments to guarantee public health, food security and biodiversity conservation. To effectively integrate scavenger conservation into sanitary policies, the shortfalls here detected when estimating scavenger feeding requirements should be addressed. We recommend policymakers establish systematic on‐ground carcass monitoring for detecting implementation gaps (e.g. food shortages compromising scavenger conservation, potential risks of disease transmission), and to modify EU sanitary regulations accordingly. This monitoring would increase knowledge on scavenging ecology and epidemiological surveillance while enhancing cross‐compliance. Lessons learned in Europe may help to integrate conservation issues into other sectorial policies worldwide.

Event-based probabilistic risk assessment of livestock snow disasters in the Qinghai–Tibetan Plateau

Abstract. Understanding risk using quantitative risk assessment offers critical information for risk-informed reduction actions, investing in building resilience, and planning for adaptation. This study develops an event-based probabilistic risk assessment (PRA) model for livestock snow disasters in the Qinghai–Tibetan Plateau (QTP) region and derives risk assessment results based on historical climate conditions (1980–2015) and present-day prevention capacity. In the model, a hazard module was developed to identify and simulate individual snow disaster events based on boosted regression trees. By combining a fitted quantitative vulnerability function and exposure derived from vegetation type and grassland carrying capacity, we estimated risk metrics based on livestock mortality and mortality rate. In our results, high-risk regions include the Nyainqêntanglha Range, Tanggula Range, Bayankhar Mountains and the region between the Kailas Range and the neighbouring Himalayas. In these regions, annual livestock mortality rates were estimated as >2 % and mortality was estimated as >2 sheep unit km−1 at a return period of 20 years. Prefectures identified with extremely high risk include Guoluo in Qinghai Province and Naqu, and Shigatse in the Tibet Autonomous Region. In these prefectures, a snow disaster event with a return period of 20 years or higher can easily claim total losses of more than 500 000 sheep units. Our event-based PRA results provide a quantitative reference for preparedness and insurance solutions in reducing mortality risk. The methodology developed here can be further adapted to future climate change risk analyses and provide important information for planning climate change adaption in the QTP region.

Local Ecological Knowledge on Climate Change and Ecosystem-Based Adaptation Strategies Promote Resilience in the Middle Zambezi Biosphere Reserve, Zimbabwe.

Understanding local community perceptions on impacts, causes, and responses to climate change is vital for promotion of community resilience towards climate change. This study explored local ecological knowledge (LEK) held by local communities on climate change trends and impacts in the Middle Zambezi Biosphere Reserve (MZBR), Zimbabwe. The objectives of the study were to (i) investigate local community perceptions on trends and causes of climate change, (ii) identify biophysical impacts of climate change at the local level, and (iii) explore the ecosystem-based adaptation strategies towards climate change. The study used a mixed methods approach where a household questionnaire survey (n=320), key informant interviews (n=12), and focus group discussions (n=8) were used to collect data between April 2015 and October 2016. Results from the study show that local communities have observed decreasing rainfall and increasing temperatures as key indicators of climate change. Local communities observed water scarcity, changes in vegetation phenology, livestock and wildlife mortalities, and food shortages due to drought as the major impacts on their livelihoods. LEK can contribute to adaptive management strategies that enhance resilience of socioecological systems (SES) in the face of climate change by providing information on the status and use of biophysical components of the environment and by highlighting potential local adaptation strategies that can sustain key livelihood practices.

Strategies to increase adoption of animal vaccines by smallholder farmers with focus on neglected diseases and marginalized populations.

BackgroundMost smallholder farmers (SHFs) and marginalized populations (MPs) in Africa, Asia, and Latin America depend on livestock for their livelihoods. However, significant numbers of these animals do not achieve their potential, die due to disease, or transmit zoonotic diseases. Existing vaccines could prevent and control some of these diseases, but frequently the vaccines do not reach SHFs, especially MPs, making it necessary for specific vaccine adoption strategies.Principal findingsSeveral strategies that have the potential to increase the adoption of animal vaccines by SHFs and MPs have been identified depending on the type of vaccines involved. The strategies differed depending on whether the vaccines were aimed at diseases that cause economic losses, government-controlled diseases, or neglected diseases. The adoption of vaccines for neglected diseases presents a major challenge, because they are mostly for zoonotic diseases that produce few or no clinical signs in the animals, making it more difficult for the farmers to appreciate the value of the vaccines.Strategies can be aimed at increasing the availability of quality vaccines, so that they are produced in sufficient quantity, or aimed at increasing access and demand by SHFs and/or MPs. Some of the strategies to increase vaccine adoption might not provide a definite solution but might facilitate vaccine uptake by decreasing barriers. These strategies are varied and include technical considerations, policy components, involvement by the private sector (local and international), and innovation.ConclusionsSeveral strategies with the potential to reduce livestock morbidity and mortality, or prevent zoonoses in SHFs communities and MPs through vaccination, require the involvement of donors and international organisations to stimulate and facilitate sustainable adoption. This is especially the case for neglected zoonotic diseases. Support for national and regional vaccine manufacturers is also required, especially for vaccines against diseases of interest only in the developing world and public goods.

In Vitro Cytotoxicity Induced by the Bufadienolides 1α,2α-Epoxyscillirosidine and Lanceotoxin B on Rat Myocardial and Mouse Neuroblastoma Cell Lines.

Consumption of bufadienolide-containing plants are responsible for many livestock mortalities annually. Bufadienolides are divided into two groups; non-cumulative bufadienolides and cumulative bufadienolides. Cumulative bufadienolides are referred to as neurotoxic, as the chronic intoxication with this type of bufadienolide results in a paretic/paralytic syndrome known as ‘krimpsiekte’. The in vitro cytotoxicity of a non-cumulative bufadienolide, 1α,2α-epoxyscillirosidine, and a cumulative bufadienolide, lanceotoxin B, were compared using the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction) assay after exposing rat myocardial (H9c2) and mouse neuroblastoma (Neuro-2a) cell lines. The effect of these two bufadienolides on cell ultrastructure was also investigated using transmission electron microscopy (TEM). H9c2 cells exhibited greater cytotoxicity when exposed to 1α,2α-epoxyscillirosidine, compared to lanceotoxin B. In contrast, Neuro-2a cells were more susceptible to lanceotoxin B. The EC50 (half maximal effective concentration) of lanceotoxin B exposure of Neuro-2a cells for 24–72 h ranged from 4.4–5.5 µM compared to EC50s of 35.7–37.6 µM for 1α,2α-epoxyscillirosidine exposure of Neuro-2a cells over the same period. 1α,2α-Epoxyscillirosidine induced extensive vacuolization in both cell types, with swollen RER (rough endoplasmic reticulum) and perinuclear spaces. Lanceotoxin B caused swelling of the mitochondria and sequestration of cytoplasmic material within autophagic vesicles. These results corroborate the notion that cumulative bufadienolides are neurotoxic.

Index-based livestock insurance to manage climate risks in Borena zone of southern Oromia, Ethiopia

Index-based livestock insurance has been introduced in Borena zone of southern Ethiopia by the International Livestock Research Institute working in partnership with Oromia Insurance Company and humanitarian agencies since 2012 as an instrument to help protect pastoralists’ herders against drought related mortality of livestock. Despite the some positive success to the concerted efforts, the continued adoption of index-based livestock insurance by pastoralists and agro-pastoralists has been limited. The current study highlighted the status, and determinants of index-based livestock insurance to managing risks resulted from the changing climate in the study area. The study used household surveys from 359 sampled households, key informant interviews, and focus group discussions to collect the data. Descriptive statistics (i.e. frequency, percentage, mean, and standard deviation), inferential tests (Chi-square test and t-test), and binary logit model were used to analyze the collected data. The results of the current study evidenced that the adoption of indexed insurance is below expectation. The results further indicated that several factors appeared to affect demand for index-based livestock insurance. Those households in a farming system with moisture stress, those who perceived climate risks, those who aware the insurance, who are better educated, who have access to credit and off-farm activity are more likely to adopt the index-based livestock insurance. Furthermore, households who have a membership to a large number of social organizations are more likely to purchase the insurance. However, households who are far from the weather station and old aged households are less likely to purchase index-based livestock insurance. Adaptation pathways to support the uptake of index-based livestock insurance must take in to account these critical factors influencing household’s decision to adopt the insurance scheme. It is also imperative to integrate the insurance into indigenous institutions and link it with the local development process.

Effect of carbon and nitrogen mobilization from livestock mortalities on nitrogen dynamics in soil

Carcass decomposition in the soil can be an important source of nutrients such as nitrogen (N) by affecting N turnover in soils. The objective of this research was to estimate N input from decaying swine carcasses, thereby evaluating the impact of carrion decomposition on N dynamics in soil. Carcass decomposition using recently culled (<6 h) swine carcasses was carried out in a reactor filled with agricultural soil. Soil samples, collected four times (at 0, 10, 30 and 60 days after carcass placement) from the reactor were used in a tracer experiment to quantify the changes in soil nutrients and N dynamics. Tracer incubation experiments were carried out for seven days using 14C-labelled L-alanine (C3H7NO2) to investigate key N cycling processes in the soil. Mortalities were a significant source of N and carbon (C), providing an average of 42 and 236 g/kg, respectively, to the soil directly below the decomposing carcasses. There was also a significant and long-term input of amino acids (ca. 11 mg/kg) into the soil. The abundance of N increased the microbial turnover of labile N substances in the tracer experiment. Based on results from this study, it has been demonstrated that decaying carcasses provide a significant and long-lasting localized resource with the potential to contribute to soil N cycling. Therefore, it is important to develop guidelines on the management of carcass burial farmland using soil from burial pits as a nutrient supplement where biosecurity is assured.

Volcanoes, medicine, and monasticism: Investigating mercury exposure in medieval Iceland

AbstractThis study aimed to evaluate the possible use of mercury as a medical treatment at the medieval monastic hospital Skriðuklaustur (ad 1494–1554) in eastern Iceland. The individuals excavated from Skriðuklaustur exhibited a wide range of pathological conditions, including the only skeletal evidence of venereal syphilis in Iceland. Skeletal remains from the Skeljastaðir cemetery (ca. ad 1000–1104) in southern Iceland were also analysed in light of the site's proximity to the mercury emitting volcano Hekla. The eruption produced a severe toxic fallout resulting in the mass mortality of livestock and is believed to have caused the abandonment of Skeljastaðir and the other farms in the region. The skeletal analyses and sampling were conducted according to standard anthropological methods. Mercury concentrations were determined in human (n = 50), faunal (n = 23), and soil (n = 22) samples using inductively coupled plasma mass spectrometry. Individuals from both sites exhibited elevated mercury concentrations. At Skriðuklaustur, some individuals showed normal concentrations, but those with pathological conditions (e.g., hydatidosis, syphilis, tuberculosis, and other non‐specific infections) had the highest concentrations overall. On the other hand, all the individuals analysed from Skeljastaðir exhibited elevated mercury concentrations, some of which were remarkably high. A few of the individuals buried at Skeljastaðir post‐date the eruption, possibly indicating that some of them experienced heavy exposure to volcanic emissions. The less extreme concentrations at Skriðuklaustur may be a result of attention to dosage and the temporary nature of mercurial treatments. None of the faunal and soil samples presented with concentrations exceeding the normal limit, implying that diagenesis was not a concern in this research. The conclusion is that a variety of factors from medical treatment to scholarly work lead to mercury exposure at Skriðuklaustur, whereas at Skeljastaðir, volcanogenic emissions are implicated.

Ambient alkaline hydrolysis and anaerobic digestion as a mortality management strategy for whole poultry carcasses

Livestock mortality management is a critical factor for ensuring biosecurity, minimizing environmental impact, and maintaining public trust in livestock production agriculture. The number of technologies currently used for livestock mortality management is small, including composting, burial, incineration, landfilling, and rendering. Each technology has advantages and disadvantages which make their suitability situational. In this study, ambient alkaline hydrolysis (AAH) using 2, 4, or 8 M potassium hydroxide at ambient temperature and pressure was explored as a disposal method for whole broiler chicken carcasses. Alkaline hydrolysate (pH > 14) resulting from the process was neutralized by mixing with acidic corn silage, and then utilized as a substrate for anaerobic digestion in bench top continuously stirred tank reactors. All AAH treatments solubilized broiler carcasses within 20 days. Corn silage neutralized 2 M hydrolysate using a 2:1 (w/w) mixing ratio, while 4 M hydrolysate required a 4:1 mixing ratio. Anaerobic digestion of neutralized hydrolysate reduced volatile solids by >96% for all treatments. Highest methane yields were observed from the 2 M hydrolysate (607.2 ± 47.9 g mL−1 VS), while biogas production from the 8 M hydrolysate was totally inhibited over a total of 42 days. Ambient alkaline hydrolysis followed by silage neutralization and anaerobic digestion provides a feasible, straightforward technology to manage routine and emergency animal mortalities.

Cold-season disasters on the Eurasian steppes: Climate-driven or man-made

Socio-ecological damage from climate-related disasters has increased worldwide, including a type of cold-season disaster (dzud) that is unique to the Eurasian steppes, notably Mongolia. During 2000–2014, dzuds killed approximately 30 million livestock and impacted the Mongolian socio-economy. The contributions of both natural and social processes to livestock mortality were not previously considered across Mongolia. Here, we consider the contribution of both multiple climate hazards (drought, cold temperatures and snow), and socioeconomic vulnerability (herders’ livestock and coping-capacity) to mortality risk. We performed multi-regression analyses for each province using meteorological, livestock and socioeconomic datasets. Our results show that 93.5% of mortality within Mongolia was caused by a combination of multi-hazards (47.3%) and vulnerability (46.2%), suggesting dzuds were both climate- and man-made. However, in high-mortality hotspots, mortality was primarily caused by multi-hazards (drought-induced pasture deficiency and deep-snow). Livestock overpopulation and a lack of coping capacities that caused inadequate preparedness (e.g., hay/forage) were the main vulnerability factors. Frequent and severe multi-hazards greatly increased the mortality risk, while increased vulnerability caused by socioeconomic changes in Mongolia since the 1990s tended to amplify the effects of multi-hazards. Thus, reductions in herder vulnerability within high-mortality hotspots would likely be an effective means of mitigating the risk of future dzuds.

Lack of medical resources and public health vulnerability in Mongolia's winter disasters.

Many countries face the need to address medical resource shortages following various disasters. The dzud is a winter disaster that occurs in Mongolia following drought in dryland areas, and it leads to high livestock mortality. Affected provinces suffer increased mortality rates for children aged under 5 years. Using various factors, including medical resources, the present study aimed to evaluate the health risks for children during the dzud. Data from all of Mongolia's 21 provinces and the capital of Ulaanbaatar were analyzed. The change in child mortality (CCM) was defined as the difference in the under-five mortality rate from 2009 to 2010. To determine the correlations, the CCM was compared with the urbanization rate (proportion of urban population), number of physicians and nurses (per 1000 residents), average temperature, total precipitation (October 2009 to February 2010), and declining rate in livestock numbers for 2009-10 (percentage livestock loss) in each province. The correlation coefficients between the CCM and each factor were as follows: number of physicians (r=&minus;0.506, p=0.016), urbanization rate (r=&minus;0.467, p=0.029), and percentage livestock loss (r=0.469, p=0.028). In the multiple regression analysis, the number of physicians was significantly negatively related to the CCM (standardizing coefficient &minus;0.492, p=0.020). These results suggest that increased medical resources and infrastructure development have positive effects on child health - even in the setting where the dzud causes considerable damage to livestock.

Factors influencing animal-source food consumption in Timor-Leste

Poor dietary quality is an underlying contributor to the high rates of maternal and child undernutrition in Timor-Leste. The majority of households own livestock: however, the consumption of domestic animal-source food (ASF) is low, and there are few reports of the utilisation of non-domesticated species. This mixed-methods study was conducted in three villages from mid-2015 to mid-2017. Two hundred and three households with children under 24 months were enrolled in the quantitative study of maternal and child dietary diversity. To explore factors affecting household ASF consumption, 12 key informants were recruited for in-depth interviews and 312 participants, mostly mothers and fathers of young children, for focus group discussions. Participants expressed a desire to consume more ASF. Barriers to ASF consumption include having low income or limited income streams, high levels of small livestock morbidity and mortality leading to small or unstable flock or herd sizes, reserving livestock for sale and ceremonies, and living far from forested areas or where hunting is not allowed. Factors that enable greater ASF consumption include villages being located near forested areas with wild animal populations, those that observe a large number of ceremonies of long duration, households with a greater number of small livestock, and where women are able to make autonomous decisions about livestock assets. Findings suggest that policies and programs designed to achieve sustainable improvements in household nutrition would include a focus on women and improving the health and production of small livestock species frequently utilised by households.

Analysis of pastoralists' perception on challenges and opportunities for sheep and goat production in Northern Kenya.

Small ruminants' production contributes to livelihood of pastoral communities, but this faces myriad constraints. This study aimed at identifying challenges facing producers of small ruminants, prioritizing diseases and their control measures and documenting opportunities for improvement. Sixteen focus group discussions with livestock owners and 13 key informant interviews were done in selected areas in Mandera County, Northern Kenya, and both quantitative and qualitative data collected using a questionnaire guide. Occurrences of diseases (27.4%) and drought (25%) were consistently ranked high in all groups. Other production challenges included increased predation of livestock, inadequate delivery of veterinary services, and increased livestock mortalities. Peste des Petit ruminants was ranked high with a median rank of 21.5%, while contagious caprine pleuropneumonia and sheep and goat pox were ranked second and third, respectively. Other diseases included tick-borne diseases, helminthosis, and pneumonia. Vaccination was ranked as the most effective control strategy for infectious diseases. Other control measures included recitation of Quran and cauterization. However, several opportunities exist for support of small ruminants' production: increased budgetary allocation for disease control by government, initiation of projects that enhance livestock production in the region by government and its development partners. These findings are useful for policy makers for disease control and organizations that are working on projects that focuses on enhancement of pastoralists' resilience, while future research could also identify appropriate technologies that reduces these impacts.

Speciation and Geochemical Implications of Carcass Burial Leachate

Abstract. In the event of a mass livestock mortality situation, disposal routes such as burial are commonly chosen. The impact of burial on the environment could be substantial, but the composition of the leachate arising from a burial site has not been well documented. This study was performed to determine the chemical composition of leachate arising from animal mortalities in a burial setting. Three species of livestock were used: bovine, swine, and poultry. Leachate collected from lined burial pits over two years of decomposition was analyzed for major and minor ions. Analysis indicated that livestock mortality leachate contains, on average, concentrations of 46,000 mg L-1 of alkalinity (as bicarbonate), 12,600 mg L-1 of ammonium-N, 2600 mg L-1 of chloride, 3600 mg L-1 of sulfate, 2300 mg L-1 of potassium, 1800 mg L-1 of sodium, and 1500 mg L-1 of phosphorus, along with lesser amounts of iron, calcium, and magnesium. Select samples had maximum concentrations of ammonium-N and bicarbonate up to 50% higher than these average values. In comparison to earthen swine manure storages and landfills, the ionic strength of the leachate was 2 to 4 times higher, and therefore its impact on water resources could be greater. Following the study of the chemical composition of livestock mortality leachate, the potential impacts of this leachate on the soil/water systems below a burial site were investigated. The ionic strength of the leachate presents its own set of challenges. Basic modeling of ion activity using the five most common activity coefficient equations (Debye-Hückel, extended Debye-Hückel, Truesdell-Jones, Davies, and Pitzer) were considered to assess the sensitivity of these methods for calculated ion activity as impacted by the ionic strength of the leachate. This was completed to further enhance the modeling and speciation efforts. Based on the results and the applicability of the Truesdell-Jones equation, PHREEQC was used to assess the chemical speciation of the leachate. The speciation of this leachate provides evidence of phosphate and sulfate compounds available for potential unattenuated transport. Understanding the geochemical implications of livestock mortality burial will give scientists and regulators more information for performing future risk analyses when considering mortality burial as a management option, either routinely or during a mass mortality event. Keywords: Ion activity coefficient, Ionic strength, Leachate chemical composition, Livestock burial leachate, Speciation.

Impacts of windbreak shelter on crop and livestock production

Agroforestry (the integration of trees into agricultural landscapes) has been promoted, in Australia and elsewhere, as a way to increase farm productivity by providing a wide range of benefits. Despite this, adoption of agroforestry in Australian agricultural systems remains low. To implement agroforestry, farmers must be convinced the benefits of including trees outweigh the costs. This review evaluates the available quantitative data on shelter benefits with emphasis on Australian conditions, identifies key research gaps and determines if there is sufficient knowledge to make accurate predictions about impacts on farm productivity. Availability of quantitative data on windbreak shelter benefits was examined in five key areas; water use and evaporation, crop/pasture production, livestock mortality, livestock productivity and the capacity to model impacts of windbreaks on crop/livestock systems. Good quantitative data exists for many areas, particularly for changes in environmental conditions following tree establishment, however there were many gaps in key areas. Importantly, the ability to predict crop growth under spatially and temporally variable environmental conditions and the impact of windbreaks on livestock productivity is not yet able to be meaningfully quantified. Thus modelling the profitability of windbreaks is difficult and existing models require additional quantitative data to validate and improve them.

Feeding Strategies During Natural Calamities

India is one of worst disaster prone countries of the world. Out of 36 states and union territories in the country, 25 of them are disaster prone. Disasters continue to occur without warning and are on an increase in their magnitude, complexity, frequency and economic impact. The natural calamities in the form of floods, tsunamis, famines, cyclones, earthquakes and avalanches are considered mainly due to global warming. The major effects are acute shortages of food, feed and fodder and drinking water which adversely affect human and livestock health and nutrition. Severe malnutrition due to natural calamities may depress growth, productive and reproductive performance. Therefore, while developing the feeding strategies during natural calamities, the first priority should be to save the animals from starvation, diverting feedstuffs from lactating animals and then to sustain productivity of the animals that survived to the extent possible. The water requirement of lactating cattle is in the range of 2.5–4.5 L/kg DM intake. During water scarcity, the watering frequencies in large ruminants should be decreased to once in 2–3 days which increase the retention time and in turn digestibility of nutrients. All affected animals should be shifted to restricted feeding which will reduce the volume and metabolic activity of the viscera and other tissues and in turn basal metabolism. Feed restriction increases the extent of negative energy balance and causes transient increases in concentrations of non-esterified fatty acids, acetate and s-hydroxybutyrate in plasma due to the mobilization of nutrients from body reserves. The restricted feeding may cause loss in body weight and milk yield in lactating animals but ensures animals survivability. The strategies such as 1) restricted feeding; 2) conserved fodders in transportable silage bags; 3) fodder produced in low-cost hydroponic systems; 4) unconventional feed resources including propagation of thornless cactus; 5) urea molasses multinutrient blocks; 6) hay bales, 7) densified complete feed blocks or pellets containing untreated or urea-treated straws/stovers, tree leaves and grasses, mushroom harvested spent straw with and without feed additives could help prevent livestock mortality and morbidity in emergency situations. Once the availability of quality feed and fodder improves, the animals should be given compensatory feeding. The animals will recoup the loss in body weight completely and partly the production performance suffered during natural calamities.

Linking livestock snow disaster mortality and environmental stressors in the Qinghai-Tibetan Plateau: Quantification based on generalized additive models

Livestock snow disaster occurs widely in Central-to-Eastern Asian temperate and alpine grasslands. The effects of snow disaster on livestock involve a complex interaction between precipitation, vegetation, livestock, and herder communities. Quantifying the relationship among livestock mortality, snow hazard intensity, and seasonal environmental stressors is of great importance for snow disaster early warning, risk assessments, and adaptation strategies. Using a wide-spatial extent, long-time series, and event-based livestock snow disaster dataset, this study quantified those relationships and established a quantitative model of livestock mortality for prediction purpose for the Qinghai-Tibet Plateau region. Estimations using generalized additive models (GAMs) were shown to accurately predict livestock mortality and mortality rate due to snow disaster, with adjusted-R2 up to 0.794 and 0.666, respectively. These results showed that a longer snow disaster duration, lower temperatures during the disaster, and a drier summer with less vegetation all contribute significantly and non-linearly to higher mortality (rate), after controlling for elevation and socioeconomic conditions. These results can be readily applied to risk assessment and risk-based adaptation actions.

Sheep adaptation management, and investigation of inherited resistance to prevent Brachiaria spp. poisoning

Brachiaria spp. is the most used forage in extensive cattle production in the Central-Western region of Brazil. However, livestock fed with these grasses can develop hepatogenous intoxication due to the presence of steroidal saponins that promote photosensitivity, inefficiency of production in the herds and death. Grass toxicity depends on factors related to animal susceptibility or resistance and intrinsic plant factors, providing significant differences in the clinical manifestation and mortality of livestock. Three experiments were conducted to investigate the adaptation management and inherited resistance to prevent Brachiaria spp. poisoning in sheep. In the first experiment, the adaptive management of lambs was performed, controlling the grazing time in Brachiaria spp. pastures. Groups of sheep grazing previously in Brachiaria decumbens paddocks for 2h daily or on alternate days for 60days presented low hepatotoxic changes and had reduced the number of intoxicated lambs when compared to the control group during the challenge. In experiment 2, ruminal transfaunation from adapted adult sheep to non-adapted lambs to grazing on the grass reduced the hepatotoxicity, which suggests that Brachiaria spp. poisoning resistance could be transferred by ruminal fluid to non-adapted animals. In the third experiment, lambs from flocks raised in Brachiaria pastures showed less susceptibility to poisoning than lambs from flocks raised in non-toxic pastures, suggesting inherited resistance to the toxicosis. These results suggest that the control of grazing time combined with transfaunation can be employed to decrease the frequency of poisoning in susceptible flocks. However, a definitive solution in the long-term would be the selection of resistant sheep herds.

Analyzing the causes of alpine meadow degradation and the efficiency of restoration strategies through a mathematical modelling exercise.

As an important ecosystem, alpine meadow in China has been degraded severely over the past few decades. In order to restore degraded alpine meadows efficiently, the underlying causes of alpine meadow degradation should be identified and the efficiency of restoration strategies should be evaluated. For this purpose, a mathematical modeling exercise is carried out in this paper. Our mathematical analysis shows that the increasing of raptor mortality and the decreasing of livestock mortality (or the increasing of the rate at which livestock increases by consuming forage grass) are the major causes of alpine meadow degradation. We find that controlling the amount of livestock according to the grass yield or ecological migration, together with protecting raptor, is an effective strategy to restore degraded alpine meadows; while meliorating vegetation and controlling rodent population with rodenticide are conducive to restoring degraded alpine meadows. Our analysis also suggests that providing supplementary food to livestock and building greenhouse shelters to protect livestock in winter may contribute to alpine meadow degradation.

Interplay of environmental and socio-political factors in the downfall of the Eastern Türk Empire in 630 CE

The collapse of the Eastern Turk Empire (ETE, ca. 584–630 CE) in 630 CE marked the rise of Tang China as the paramount power on the Silk Road. It was followed by the Tang defeat of the Western Turk Empire in 659 and opened a phase of Chinese expansion into central Asia. Climate-induced environmental changes as well as economic and political consequences are mentioned in medieval Chinese records as major factors in the ETE collapse. The role of cooler temperatures has also been discussed in current scholarship. Here, we re-evaluate this question by assessing the available historical sources in the light of a global network of 16 tree-ring chronologies for this period, which reveal distinct summer cooling in the ETE heartland between 626 and 632 CE. Reconstructed peak cooling of up to − 3.4 °C in 627 and 628 CE (relative to the 1961–90 mean climatology) coincided with heavy snowfall and severe frost events in the territory of the ETE. A strong sulfate spike in Greenland ice cores that has been dated circa 626 CE is implicated in the abrupt surface cooling. We argue that the climatic perturbation and associated reduction in vegetation growth and livestock mortality are relevant in understanding the causes of the fall of the ETE but these indirect drivers must be evaluated within a comprehensive analysis of political relations within both the Turk and the Tang leadership. Our study underscores and contextualizes the vulnerability of past nomadic societies to small and episodic climate fluctuations, particularly when coupled with concurrent socioeconomic, political, and demographic changes.