Intensive Cattle Production Research Articles

Characterization of diarrheagenic Escherichia coli from different cattle production systems in Brazil

Diarrheagenic E. coli (DEC) can cause severe diarrhea and is a public health concern worldwide. Cattle are an important reservoir for this group of pathogens, and once introduced into the abattoir environment, these microorganisms can contaminate consumer products. This study aimed to characterize the distribution of DEC [Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC)] from extensive and intensive cattle production systems in Brazil. Samples (n = 919) were collected from animal feces (n = 200), carcasses (n = 600), meat cuts (n = 90), employee feces (n = 9), and slaughterhouse water (n = 20). Virulence genes were detected by PCR in 10% of animal samples (94/919), with STEC (n = 81) as the higher prevalence, followed by EIEC (n = 8), and lastly EPEC (n = 5). Animals raised in an extensive system had a higher prevalence of STEC (average 48%, sd = 2.04) when compared to animals raised in an intensive system (23%, sd = 1.95) (Chi-square test, P < 0.001). From these animals, most STEC isolates only harbored stx2 (58%), and 7% were STEC LEE-positive isolates that were further identified as O157:H7. This study provides further evidence that cattle are potential sources of DEC, especially STEC, and that potentially pathogenic E. coli isolates are widely distributed in feces and carcasses during the slaughter process.

30 Microbiome Manipulation to Reduce Methane Emission in Beef Cattle

Abstract Among the major sources of methane production, ruminants account for a considerable fraction of the anthropogenic methane produced. Thus, minimizing methane emission in intensive and extensive cattle production systems while maintaining/increasing performance of animals will have a significant impact on the environment and will help develop a sustainable carbon-based market system. We believe that developing science-based dietary intervention strategies using feed additives to manipulate rumen microbial communities is a viable strategy to reduce greenhouse gas emissions. Here we show the potential impact of using an essential oil formulation to reduce methane emissions in cattle. In this study, we used in-vitro fermentation experiments to evaluate the impact of the essential oil mix in reducing methane emissions. Additionally, we evaluated microbial community changes in the presence and absence of the essential oil mix to understand microbial changes that lead to reduced methane emissions. The in-vitro fermentation experiments demonstrated a significant decrease in methane emission in the essential oil mix compared with the control with no essential oil (P &amp;lt; 0.05). This decrease in methane was greater than 50%. Following in-vitro fermentation for 48 hours, the resulting inoculum was evaluated for microbial community changes using 16S rDNA sequencing. Compared with the control, the essential oil mix containing bottles were greater in Anaerovibrio and Succinivibrio and had a reduced abundance of Anaeroplasma and Prevotellaceae at the genus level. Furthermore, the essential oil mix tubes were plated to isolate members that were enriched in this treatment. The isolates obtained include Lysinibacillus halotolerans and Lysinibacillus boronitolerans. Such isolates may have the potential to be effective direct-fed microbial to reduce methane emission. Here we show the potential of the essential oil mix identified to reduce methane invitro and we have an animal study planned for the near future.

Does the mycotoxin ingestion by beef heifers on feedlot change the productive parameters?

In intensive beef cattle production systems, silage, corn, soy bean, and their coproducts are commonly used as feed. However, these ingredients are highly susceptible to contamination by fungi and mycotoxins, which may lead to immunological challenges and reduce animal production. The aim of the present study was to evaluate the effects of mycotoxin contamination of diet on intake, digestibility, and performance of heifers. Twenty non-pregnant (Nellore) heifers (age, &gt;18 months; initial body weight, 348±30 kg) were used and randomly distributed in two treatments: (1) control (non-contaminated diet) and (2) zearalenone-contaminated diet (300 ppb). The diet comprised 70% corn silage and 30% concentrate. Individual dry matter intake and digestibility were estimated using external and internal markers. Heifer body weight was evaluated every week without fasting to calculate performance. The experimental design was completely randomized. Each animal was considered one experimental unit. Assumptions were tested for variance analyses (error normality, independence of errors, and homogeneity of variances) (p&lt;0.05). There were no differences in dry matter intake (p=0.96) and digestibility (p=0.62). Performance (kg/day) did not vary as a function of zearalenone ingestion (p=0.68). Therefore, contamination of diet with 300 ppb zearalenone did not affect the intake, digestibility, and performance of feedlot-finished heifers.

Farmers’ willingness to adopt silvopastoral systems: investigating cattle producers’ compensation claims and attitudes using a contingent valuation approach

Intensive cattle production systems are currently a major contributor to CO2 emissions and biodiversity loss. Silvopastoral systems that combine foraging pastures and trees into an integrated system for raising livestock have been suggested a promising avenue to store carbon and preserve farmland biodiversity. However, investments and maintenance costs for these improvements are paid by producers, who reap few of the environmental benefits. The objective of the present study was to assess farmers’ willingness to adopt silvopastoral systems by reforesting treeless pastures, their compensation claims related to adoption, and how both are affected by their attitudes towards silvopastoral systems. This study was based on a contingent valuation approach coupled with exploratory factor analysis to obtain measures of attitudinal constructs derived from the Theory of Planned Behavior. Results indicate that 52% of respondents were willing to adopt silvopastoral systems and the mean compensation claim per year per hectare is estimated at SEK 3107.17 (308€). Adoption decision is positively correlated with attitudes towards silvopastoral systems, suggesting that decision-making is not solely driven by profit maximization through concerns related to pecuniary factors.

Production of forest seedlings using sewage sludge and automated irrigation with ozonated cattle wastewater.

The large volume of effluents generated by intensive cattle production can become an environmental problem, requiring solutions that combine treatment and disposal of reuse water. The quality of cattle wastewater (CWW) treated by ozonation, the water requirement and its effect on the growth of seedlings of Dalbergia nigra cultivated with sewage sludge were determined under different light conditions. The study was carried out in a split plot scheme with 2 shading levels (0%-C1, and 49.4% attenuation-C2) and 3 types of irrigation water (control-T1, 1 h ozonation-T2, and 2 h-T3), with 4 repetitions. Direct sowing was realized into 280 cm3 tubes which were irrigated by drip irrigation with automatic management. The height and collar diameter were measured every 21 days, and at the end of the nursery phase, and the Dickson quality index (DQI) and irrigation water productivity (WPir) were determined. In addition, seedlings were transplanted in a forest restauration area (FRA) of Atlantic Forest, with height and diameter monitoring for 200 days. With ozonation, there was an increase in pH and a reduction in electrical conductivity, total solids and turbidity in the CWW, allowing its use for irrigation of forest seedlings. The maximum volumes of water applied were 2.096 and 1.921 L plant-1, with water supply T2 and T1, respectively, and coverages C1 and C2. In these conditions, the seedlings reached DQI of 0.47 and 0.17, and WPir of 2.35 and 1.48 g L-1, respectively. The initial vegetative growth of the seedlings planted in the FRA was benefited by the nutrients provided by the CWW treated. Therefore, the use of sewage sludge and CWW treated has the potential to produce forest seedlings, reducing the release of waste and effluents into the environment.

Spatial risk modeling of cattle depredation by black vultures in the midwestern United States

AbstractNegative economic impacts resulting from wildlife disrupting livestock operations through depredation of stock are a cause of human‐wildlife conflict. Management of such conflict requires identifying environmental and non‐environmental factors specific to a wildlife species' biology and ecology that influence the potential for livestock depredation to occur. Identification of such factors can improve understanding of the conditions placing livestock at risk. Black vultures (Coragyps atratus) have expanded their historical range northward into the midwestern United States. Concomitantly, an increase in concern among agricultural producers regarding potential black vulture attacks on livestock has occurred. We estimated area with greater or lesser potential for depredation of domestic cattle by black vultures across a 6‐state region in the midwestern United States using an ensemble of small models (ESM). Specifically, we identified landscape‐scale spatial factors, at a zip code resolution, associated with reported black vulture depredation on cattle in midwestern landscapes to predict future potential livestock depredation. We hypothesized that livestock depredation would be greatest in areas with intensive beef cattle production close to preferred black vulture habitat (e.g., areas with fewer old fields and early successional vegetation paired with more direct edge between older forest and agricultural lands). We predicted that the density of cattle within the county, habitat structure, and proximity to anthropogenic landscape features would be the strongest predictors of black vulture livestock‐depredation risk. Our ESM estimated the relative risk of black vulture‐cattle depredation to be between 0.154–0.631 across our entire study area. Consistent with our hypothesis, areas of greatest predicted risk of depredation correspond with locations that are favorable to vulture life‐history requirements and increased potential to encounter livestock. Our results allow wildlife managers the ability to predict where black vulture depredation of cattle is more likely to occur in the future. It is in these areas where extension and outreach efforts aimed at mitigating this conflict should be focused. Researchers and wildlife managers interested in developing or employing tools aimed at mitigating livestock‐vulture conflicts can also leverage our results to select areas where depredation is most likely to occur.

Stakeholder mapping in animal health surveillance: A comparative assessment of networks in intensive dairy cattle and extensive sheep production in Australia

The capacity to rapidly identify and respond to suspicion of animal disease is fundamental to protecting the integrity of the Australian livestock industry. An incursion of a nationally significant endemic, emerging or exotic animal disease could be disruptive and economically damaging for the industry, broader community and national economy. To counter this potential threat, a surveillance system that includes general and targeted activities exists at a jurisdictional and national level. Such a system requires a collaborative effort from all involved to work towards a common goal, reflecting the notion of shared responsibility. As in all systems, the animal health surveillance system can be enhanced or constrained by the relationships of the players involved. This study focusses on two livestock industries, dairy cattle and sheep, exploring the interrelationships between all stakeholders, and their role within the Australian animal health surveillance system. A stakeholder mapping exercise was undertaken, including a depiction of the perceived level of stakeholder interest and influence on producers’ animal health surveillance practices and/or the surveillance system. Results from these activities were expanded upon through interviews. The findings reveal complex networks and a system that is, at times, constrained by institutional and individual barriers such as communication between and within stakeholders, and uncertainty about the consequences of reporting a suspected emergency disease. Whilst these challenges have the potential to negatively impact the robustness of the animal disease surveillance system, the study also provides clear evidence of strong and effective relationships amongst many of the key individuals and organisations.

Fine-scale quantification of stream bank geomorphic volume loss caused by cattle access

Unrestricted cattle access to streams and rivers can be a significant source of pollution in fluvial systems, contributing to bank erosion and fine sediment inputs. Despite this pressure, observational data are scarce. This study quantified stream bank geomorphic modifications caused by cattle access at fine scale using motion-capture cameras and Terrestrial Laser Scanning (TLS) campaigns. Continuous monitoring of rainfall, discharge, conductivity and turbidity further augmented this dataset. The application of these techniques extended over a five-month grazing period in agricultural sub-catchments with intensive cattle production. At low flow, high-resolution water quality data showed that the frequency of cattle activity in and around stream margins was associated with elevated turbidity signals downstream. However, when elevated turbidity coincided with high flow events, it was not possible to distinguish between local erosion and upstream sediment transfers. TLS results indicated a loss of 0.141 m3 to 1.035 m3 stream bank material, which equates to 0.067 m3 m−2 - 0.092 m3 m−2 of stream bank area (between 27% and 41% in the <2 mm fraction) over the study period from sites with 130 to 1154 discrete cattle access hits. Multiple linear regression showed that the observed geomorphic volume loss could not be explained by natural processes alone (hydrometeorology), but was more significantly related to cattle-access frequency as the principal driver. The geomorphic volume loss had the potential to impact 29 m2 to 197 m2 of stream bed with fine sediment (<2 mm) from the three study sites. Grazing parcels adjacent to streams in the study sub-catchments were enumerated at 18.4 parcels km−2 and so the results of this investigation potentially scale to a considerable fine sediment risk. Regulations and time-limited incentives to exclude cattle access to stream channels should therefore expect to reduce sediment pressures where these measures are targeted at access points.

Variability of genetic correlations of milk yield and fertility traits in Simmental cows in different regions of Serbia

The Simmental breed of cattle is mostly reared in the central part of the Republic of Serbia, where it makes up about 80% of all breeds. In areas of more intensive cattle production, populations of cattle with pronounced milk yield are reared. In more extensive, as well as hilly and mountainous areas, somewhat less productive animals are raised. The main goal of this study was to examine the variability of genetic correlations of milk and fertility traits on the farms of individual agricultural producers using modern methods, depending on the breeding area, i.e. the region in which they are bred and reared. This study included 2589 controlled Simmental heifers, with lactations concluded during one year. All first calving heifers were housed and reared on agricultural family farms in the area of Central Serbia. The paper examines genetic correlations between the following traits of milk yield and fertility: duration of lactation, milk yield in standard lactation, milk fat content in standard lactation, milk fat yield in standard lactation, yield of 4% FCM in standard lactation, age at first calving, duration of service period. The results of the study of genetic correlations were obtained using mixed LSMLMW models (Harvey 1990). The examined genetic correlations of milk yield and fertility traits in Simmental cows showed pronounced variability depending on the breeding area where the cows are reared.

The Profiling of the Farmers with Semi-Intensive and Intensive Cattle Production Systems in South Konawe District, Southeast Sulawesi Province

The study aimed at determining the profile of the beef cattle farmers with semi-intensive and intensive production systems in South Konawe district. It was expected that the results of the study could be information source for stakeholders and policymakers in developing farming resources. It was conducted in July-August 2019 using participatory rural appraisal method and involved 105 farmers selected using purposive sampling and considering production system and minimum cattle ownership. Data were quantitatively described and analyzed using independent T-test. The mean age, the cattle farming experience, the number of family members, and the cattle ownership of the farmers were not significantly different. The cattle farming motivations as savings and insurance were higher among the farmers with semi-intensive production system (P<0.05), which were 2.98±0.13 vs. 2.72±0.45, but those as primary livelihood and manure producer were higher (P<0.05) among the farmers with intensive production system, which were 2.28±0.45 and 1.46±0.50 vs. 1.62±0.53 and 1.09±0.29. The participation of the family members of the farmers in the cattle farming activity was not significantly different. It was concluded that the cattle production system related to farming motivation. The farmers with the semi-intensive production systems used cattle more as saving and insurance, while those with the intensive production system used cattle as primary source of income and manure producer.

Leaf Litter Decomposition in Diverse Silvopastoral Systems in a Neotropical Environment

ABSTRACT The intensive cattle production on the Colombian Atlantic coast causes soil degradation and low productivity on pastures. Silvopastoral systems in Colombia are based on introduced species due to a lack of native species knowledge and a cultural trend to overestimate introduced species. It is necessary to study native species in association with the established pastures to increase productivity and to improve soil properties. This research was based on the Sinú River Valley (18 masl), under Tropical dry forest, in Colombia. The aim of this study was to determine changes in nutrient cycling when native trees are incorporated into grassland systems, according to their diversity. Leaf litter decomposition of two grass species and seven forestry native species were evaluated on four experimental blocks. The results showed that residual dry matter decreased over time and facilitated nutrient release associated with species diversity and its interaction. Nutrient liberation was specie-dependent being markedly higher on G. ulmifolia and P. quinata. The concentration of N/P, P, and Mg was significant and had the highest correlation with leaf litter decomposition. The tested decomposition models showed good performance and small significant differences between them, which confirms its reliability to use them under Colombian tropical conditions.

PSXI-29 Assessing enteric methane emissions from Nellore and Angus-Nellore crossbred cattle in a tropical, intensive beef cattle production system

Abstract Crossbreeding has been used to improve performance in beef cattle; however, the effects of breed composition on methane production, yield and intensity from cattle in a tropical intensive system remain unknown. To assess the impact of breed composition on enteric methane emissions, Nellore (NE; yr 1: BW = 171.5 ± 19.4 kg; n = 10; yr 2: BW = 215.8 ± 32.3 kg, n = 25) and Angus-Nellore crossbred (AN; yr 1: BW = 214.2 ± 26.4 kg, n = 10; yr 2: BW = 242.5 ± 32.2 kg, n = 25) were compared. At trial onset, 10 mo old steers grazed Megathyrsus maximus ‘Mombaça’ in the grazing period (GP) and then were finished in a feedlot (FL) (35:65% corn silage:concentrate diet). Steers (n = 8) from each breed composition were randomly selected in GP and FL to measure CH4 production using a sulfur hexafluoride technique and DMI using titanium dioxide. The NE produced 19% less CH4 than AN in GP (17.21 vs 21.17 kg, P &amp;lt; 0.01), and no difference was observed in FL (22.34 vs 22.67 kg, P &amp;gt; 0.10). However, in FL, NE had greater CH4 intensity (CH4/ADG) compared to AN (122.76 vs 97.49 g/kg, P &amp;lt; 0.01). Furthermore, CH4/carcass weight was greater for NE than AN (0.079 vs 0.067 g/kg CW, P &amp;lt; 0.01). Breed composition did not influence CH4 yield (CH4/DMI) in either phase. The percentage CH4/GEI (Ym) for GP was higher for AN than NE (4.5 vs 3.8%), but lower than the IPCC recommended Ym of 6.5%. In FL, Ym was similar between breed composition (5.0%) and greater than the IPCC Ym of 3%. In our study the introduction of Angus into Nellore has potential to reduce CH4 intensity in tropical climates, resulting in less methane emission per kg beef produced.

Characterization of Smallholder Beef Cattle Production System in Central Vietnam–Revealing Performance, Trends, Constraints, and Future Development

The objective of this study is to evaluate the characteristics of smallholder beef cattle production in Central Vietnam. A total of 360 households were interviewed by using semi-structured questionnaire; a total of 606 beef cows were investigated for evaluating calving interval (CI). Thirty-two fattening cattle were monitored for the estimation of diet structure. Results showed that the cattle herd size was 4.32-4.45 cattle/household. In North Central (NC), 55% of surveyed farmers kept local cattle, 45% kept crossbreeds, and none of surveyed farmers keeping exotic breeds. In South Central (SC), 63% of surveyed farmers kept cross cattle, 32% kept local cattle, and 5% kept exotic breeds. In the breeding method, 70% of surveyed farmers used artificial insemination (AI), 20% used natural mating (NM), and only 10% used both AI and NM in SC, whereas in NC 40% of farmers used AI, 40% used NM, and 20% used both AI and NM. The variety of feedstuffs fed to cattle including roughages and concentrate. The concentrate in the diet for fattening cattle was 25%-35% and protein level was 11%-13%, and the average daily gain of cattle was 0.51-0.63 kg/day. The CI of cows was 12-13 months in SC, whereas in NC it was 13-14 months. There were numerous constraints to cattle production in surveyed households including diseases, lack of good quality feed sources, breeds, knowledge, and lack of capital. In conclusion, cattle production in Central Vietnam is small scale and still largely extensive. There are constraints that must be solved to improve livestock systems in the near future, especially when shifting towards semi-intensive and/or intensive cattle production systems.

English

The review aims to examine dairy cattle production system together with pastoral and agro- pastoral, small holder, peri urban and urban intensive dairy cattle production system, breeding practice including mating system (natural mating and Artificial Insemination), breeding objectives, reproductive and productive traits of dairy cattle in Ethiopia. In Ethiopia most farmers use natural, unplanned and uncontrolled mating system by using breeding from communal grazing and a few farmer use AI for improvement of breed and production by upgrading the genetic makeup of indigenous breed of cattle. Hence in Ethiopia, using breeding objectives in line with the effective breeding policies for both natural service and AI for sustainable and effective animal breeding practice is needed. Stakeholders, animal breeders and policy designers are to pay attention in transforming the already existing traditional breeding practices that target the productivity of dairy cattle with cautious consideration of genetic conservation of local cattle breeds. Key words: Breeding objective, breeding practice, dairy cattle, Ethiopia.

Анализ эффективности молочного скотоводства в Республике Беларусь на основе статистико-экономического метода исследований

Introduction. Dairy cattle breeding occupies a leading position among the livestock breeding sectors of Belarus, in which more than half of the fixed assets are concentrated, more than 50% of labor resources are occupied and more than 30% of feed resources are consumed, which creates conditions for its accelerated development along the intensifica-tion path. The purpose of the article is to determine the main factors and directions of increasing the efficiency of dairy cattle breeding in agricultural organizations in Belarus. Results. The redistribution of costs between supporting and productive feed in the direction of increasing the lat-ter as the most effective form of saving in animal husbandry is considered. It is proved that the further development of dairy cattle breeding should be carried out by improving breeding and tribal work to create a competitive Belarusian dairy cow. It is proved that the problem of the competitiveness of dairy products is the labor input, the main reasons for which are highlighted. An economic grouping was constructed according to the annual reporting data for 2017 for 190 agricultural organizations of the Brest region with developed dairy cattle breeding, where the profitability of milk sales was chosen as a grouping attribute. Conclusions. The analysis of the results showed that a high profitability of milk sales is achieved due to the greater density of the population, a higher average annual milk yield. The increase in the profitability of milk sales is accompanied by a decrease in feed consumption while increasing the consumption of concentrated feed per 1 centner of milk. To increase the profitability of the sold products and the productivity of cattle in the dairy sector, it is necessary to provide the animals with full and high-quality feeds of their own production, and to significantly increase the propor-tion of concentrated feeds in the diet. Efficient management of the dairy industry is only possible using intensive cattle production technology. Ways of increasing the efficiency of dairy cattle breeding are proposed. Key words: efficiency, optimization, balance, resource saving, genetic potential, newest technologies.

Seroprevalence of bovine brucellosis and associated risk factors in Nakasongola district, Uganda.

A cross-sectional study was carried out between November 2015 and January 2016 to determine the seroprevalence of Brucella antibodies in cattle raised under communal, fenced farms and tethering systems and the associated factors. Seven hundred twenty-eight bovine sera were collected and tested with rose Bengal test as a screening test and the indirect enzyme-linked immunosorbent assay as a confirmatory test. Animal- and herd-level data were collected and binary logistic regression was used to assess the potential risk factors. True animal- and herd-level prevalence was highest in the fenced farms (4.5% (95%CI, 2.3-6.9) and 19.5% (95%CI, 8.2-32.7) respectively). The risks for natural brucellosis infection were sharing water with wild animals (OR = 0.21, 95%CI, 0.104-0.83), herd size (medium: OR = 0.089, 95%CI 0.017-0.449; large: OR = 0.024, 95%CI 0.003-0.203), fenced farms (OR = 3.7, 95% CI, 1.7-7.9), sex (OR = 0.03, 95%CI, 0.01-0.079), and lactation (OR = 0.013, 95%CI, 0.004-0.049). Changes in rangeland tenure and the shift towards intensive cattle production have influenced brucellosis epidemiology. Future studies should aim at identifying the infecting Brucellae and examining the role of wildlife in brucellosis epidemiology.

Whole genome sequencing of the monomorphic pathogen Mycobacterium bovis reveals local differentiation of cattle clinical isolates

BackgroundBovine tuberculosis (bTB) poses serious risks to animal welfare and economy, as well as to public health as a zoonosis. Its etiological agent, Mycobacterium bovis, belongs to the Mycobacterium tuberculosis complex (MTBC), a group of genetically monomorphic organisms featured by a remarkably high overall nucleotide identity (99.9%). Indeed, this characteristic is of major concern for correct typing and determination of strain-specific traits based on sequence diversity. Due to its historical economic dependence on cattle production, Uruguay is deeply affected by the prevailing incidence of Mycobacterium bovis. With the world’s highest number of cattle per human, and its intensive cattle production, Uruguay represents a particularly suited setting to evaluate genomic variability among isolates, and the diversity traits associated to this pathogen.ResultsWe compared 186 genomes from MTBC strains isolated worldwide, and found a highly structured population in M. bovis. The analysis of 23 new M. bovis genomes, belonging to strains isolated in Uruguay evidenced three groups present in the country. Despite presenting an expected highly conserved genomic structure and sequence, these strains segregate into a clustered manner within the worldwide phylogeny. Analysis of the non-pe/ppe differential areas against a reference genome defined four main sources of variability, namely: regions of difference (RD), variable genes, duplications and novel genes. RDs and variant analysis segregated the strains into clusters that are concordant with their spoligotype identities. Due to its high homoplasy rate, spoligotyping failed to reflect the true genomic diversity among worldwide representative strains, however, it remains a good indicator for closely related populations.ConclusionsThis study introduces a comprehensive population structure analysis of worldwide M. bovis isolates. The incorporation and analysis of 23 novel Uruguayan M. bovis genomes, sheds light onto the genomic diversity of this pathogen, evidencing the existence of greater genetic variability among strains than previously contemplated.

Species conservation profile of the rare and endemic trapdoor spider Calathotarsus simoni (Araneae, Migidae) from Central Argentina.

BackgroundCalathotarsus simoni Schiapelli & Gerschman 1975 is the only species of Migidae in Argentina. It is a rare and endemic spider only found in relict grassland of mountain systems in the province of Buenos Aires. This species is a habitat specialist spider occupying specific areas with certain microclimatic conditions on hilly and rocky grassland areas at about 500-1500 meters above sea level.New informationThe observed extent of occurrence (EOO) is 7207 km2 and the area of occupancy (AOO) is 16 km2. Two locations are identified based on the threat event related to the invasion of the species habitat by alien woody plants. In addition, intensive cattle production and agriculture also constitute relevant threats to the species.

Greenhouse gas emissions in conversion from extensive pasture to other agricultural systems in the Andean region of Colombia

The challenge of agricultural sector is to reduce greenhouse gas (GHG) emissions while increasing food, fiber and energy production without jeopardizing environmental integrity. In the Andean zone of Colombia, there is a growing need to develop GHG mitigation techniques associated with milk production. The present study focuses on GHG emissions and potential sinks associated with milk production scenarios in the Andean zone of Colombia. The scenarios considered were as follows: conventional agriculture of Pennisetum clandestinum in rotation with potatoes (PRP), improved pastures of Lolium multiflorum (IP) and silvopastoral system of P. clandestinum in association with Acacia decurrens and Trifolium repens (SPS). Based on the IPCC (Guidelines for national greenhouse gas inventories. The intergovernmental panel on climate change, Institute for Global Environmental Strategies, Kanagawa, 2006. http://www.ipcc-nggip.iges.or.jp/support/Primer_2006GLs.pdf ) methodologies, the annual GHG emissions considering a 6-year production cycle included agricultural sources and gasoline consumption related to the most important agricultural phases in the field, and a potential for soil carbon accumulation and biomass carbon fixation in all the studied scenarios. The lowest GHG emissions were estimated in PRP scenario (3684 kg CO2-eq ha−1 year−1), which also presented additional emissions because of soil carbon losses beyond the lower milk productivity. Highest GHG emissions were observed in IP scenario (7711 kg CO2-eq ha−1 year−1), which exhibited the highest milk productivity and a considerable potential for soil carbon accumulation that could help to offset its emissions. Nevertheless, SPS scenario, which had milk productivity close to that of IP, presented the highest potential to offset the total GHG emission (4878 kg CO2-eq ha−1 year−1) because of soil carbon accumulation and biomass carbon fixation in trees. This study contributed to indicate management strategies that should be prioritized to mitigate the main sources of GHG emission in the extensive and intensive dairy cattle production in the Andean region of Colombia.

Effects of rangeland management on survival of female greater prairie‐chickens

ABSTRACTIdentifying relationships between habitat selection and population processes is important for habitat management and wildlife conservation. For prairie‐obligate species, space use and demography in extant grasslands are influenced by habitat conditions caused by rangeland management practices associated with livestock production. Greater prairie‐chickens (Tympanuchus cupido) are an indicator species for native tallgrass prairie ecosystems, but populations have declined in the Flint Hills ecoregion of eastern Kansas, USA because of intensification of rangeland management practices, including annual prescribed fire and high stocking densities. Patch‐burn grazing is a rotational system that provides heterogeneous habitats and can improve productivity of grassland birds, but the effects of grazing systems on habitat use or survival of greater prairie‐chickens are unknown. We used 3 types of survival analyses to investigate impacts of rangeland management on female greater prairie‐chickens in the central Flint Hills during 2011–2013: Kaplan–Meier models and Cox proportional hazards to examine factors affecting annual survival rates, hazard functions to assess seasonal patterns of mortality, and Andersen–Gill models to explore the links between habitat selection and cause‐specific mortality risk. Females captured at properties managed with patch‐burn grazing had annual survival rates (0.61 ± 0.07 SE) that were 35% higher than females on properties managed with annual burning and intensive early cattle stocking (0.45 ± 0.06). Moreover, females that selected habitats associated with intensive management had increased mortality risk and were particularly vulnerable to avian predators, whereas females that selected habitats created by patch‐burn grazing experienced lower overall mortality risk but were more vulnerable to mammalian predators. Overall mortality risk was significantly reduced under patch‐burn grazing management, and widespread implementation of annual spring burning and intensive early stocking is likely depressing survival of greater prairie‐chickens in the Flint Hills ecoregion. Our results join a growing body of evidence that patch‐burn grazing can provide higher quality grassland habitats for native wildlife species than current rangeland management associated with intensive cattle production. © 2017 The Wildlife Society