Rangeland Cattle Research Articles

Rotational grazing with cattle‐free zones supports the coexistence of cattle and wild herbivores in African rangelands

Abstract African wildlife populations are declining at an alarming rate. To stop further population declines and restore ecosystems, more areas for wildlife are needed. Community‐based conservation with wildlife‐livestock coexistence in the vast rangelands of Africa presents a major opportunity. However, the efficacy of wildlife conservation in mixed land‐use areas remains an outstanding question. To assess the ecological outcomes of land‐sharing between regulated livestock herds and wildlife populations in African savannas, we test how rotational cattle grazing affects spatiotemporal dynamics of 15 large herbivore species in the Maasai Mara, Kenya. First, we tested how wild herbivore distributions across the Greater Mara Ecosystem (the Mara, ~2600 km2) are related to cattle density and environmental variables using 584,561 observations of wild herbivores (ecosystem scale). In a second analysis, we tested how rotational cattle grazing affects wild herbivore distributions in a 300 km2 subsection of the Mara using 30,583 observations (landscape scale). Finally, we tested how functional traits of wild herbivores affect species‐level spatiotemporal responses to cattle grazing. At the ecosystem scale, the presence of five wild herbivore species was positively correlated with cattle density, while cattle effects on wild herbivore abundances were species‐dependent with both increases and decreases. At the landscape scale, rotational cattle grazing strongly impacted the spatiotemporal habitat selection of wild herbivores, resulting in distinct lag periods with which different species are attracted to areas previously grazed by cattle. These lag periods were linked to functional traits, with body mass and herd size explaining 35% of the interspecific differences. Small to medium‐sized herbivores with large herds select areas recently grazed by cattle, whereas large species with large herd sizes and small species with small herd sizes avoid recently grazed areas. Synthesis and applications: Our results revealed that the effect of cattle on wild herbivores varies considerably among species, suggesting that cattle‐wildlife interactions range from facilitation to competition. To maintain species that strongly avoid cattle, designated livestock‐free zones remain essential, also in rotational grazing systems. Rotational grazing systems with regulated livestock densities present an important opportunity to better manage wildlife‐livestock coexistence and thus improve wildlife conservation in African rangelands.

PSII-11 Using GPS Data and Daily Weights to Estimate Net Energy for Activity in Yearling Steers

Abstract Past research has provided the groundwork into determining the impact of daily activity, elevation, and slope on energetic requirements for rangeland cattle. However, there is not a consensus on how to accurately account for this dynamic. Thus, the objectives of this study were to 1) calculate rolling and roughness index and distance traveled respective of elevation change and 2) create a regression analysis from objective 1 and determine differences in precision between the two methods for determining changes in NEmract. This analysis compared two methods to estimate the energetic costs of travel on elevation and slope on net energy for activity (NEmract). The analysis was conducted from a dataset consisting of six herds of yearling steers (n = 127) that grazed native summer pastures from May to August in 2021 at the Cottonwood Field Station (Philip, SD). Pastures were composed primarily of native C3 grasses, Nassella viridula and Pascopyrum smithii, and C4 grasses, Bouteloua gracilis and Buchloe dactyloides. VenceTM collars were set to record GPS fixes at 5-minute intervals. GPS data was coupled with real time weight data collected from Smart Scales (C-Lock Inc, Rapid City, SD) located at the stock tanks within six pastures at three different stocking rates treatments (n = 3, 2 reps per trt). The combination of weight and GPS data allowed for the quantification of how elevation, slope, and daily distance traveled impacted NEmract. The first method to account for daily travel is a quantification of terrain use. This method has two indexes, a roughness index and rolling index, to determine the impact of terrain on grazing distribution. Roughness index is a measure of slope and elevation of an individual animal in comparison to the herd. The rolling index quantifies animal distribution by accounting for distance from water. The second method calculated the distance and elevation changes between successive GPS fixes for individual animals over the course of the summer grazing period. The linear regression was conducted in Program R (P < 0.05) which regressed NEmr plus NEmract calculated using the two methods against back-calculated to NEmr using daily body weight and forage nutrient composition (TDN). The result of this analysis provides levels of precision for different methods when quantifying the daily distance traveled, of steers relative to horizontal and ascending locomotion helping to evaluate trade-offs based on available GPS data (e.g., 5 minutes versus 1 hour recording intervals). Technological advances have allowed unprecedented data collection on individual animals. Results from this study will help refine energetic equations on extensive rangeland systems which is important due to the inherently large travels distances on these production settings.

Rangeland cattle production in Uruguay: Single-output versus multi-output efficiency measures

Rangeland cattle production is the largest agricultural sector of Uruguay. Ranches produce up to three products (beef, sheep-meat, and wool) usually combined into an equivalent meat (EM) index. The objective is to compare the empirical results from the estimation of a single output stochastic production frontier (SPF) and a multi-output stochastic ray frontier (SRF) to provide insights on the useof the EM index to evaluate ranches performance. Results show similar efficiency scores. The average level of TE is 0.769 for the SPF and 0.779 for the SRF. We cannot discard EM index as a simple measure of combined production.

Community-based rangeland management in Namibia improves resource governance but not environmental and economic outcomes

Classic theories suggest that common pool resources are subject to overexploitation. Community-based resource management approaches may ameliorate tragedy of the commons effects. Here we use a randomized evaluation in Namibia’s communal rangelands to study a comprehensive four-year program to support community-based rangeland and cattle management. We find that the program led to persistent and large improvements for eight of thirteen indices of social and behavioral outcomes. Effects on rangeland health, cattle productivity and household economics, however, were either negative or nil. Positive impacts on community resource management may have been offset by communities’ inability to control grazing by non-participating herds and inhibited by an unresponsive rangeland sub-system. This juxtaposition, in which measurable improvements in community resource management did not translate into better outcomes for households or rangeland health, demonstrates the fragility of the causal pathway from program implementation to intended socioeconomic and environmental outcomes. It also points to challenges for improving climate change–adaptation strategies.

Virtual Fencing Effectively Excludes Cattle from Burned Sagebrush Steppe

On public lands grazing allotments in the western US sagebrush steppe, cattle are generally excluded from burned pastures for 2 yr post fire. If only a portion of a pasture burns, the burned area may be fenced, allowing for cattle grazing to resume in the unburned portion. However, traditional wire-based fencing is often not an option due to expense, conflicts with wildlife management objectives, and extensive procedural logistics. We evaluated the use of a “virtual fence” (VF) for excluding cattle from burned areas within small pastures in the sagebrush steppe of southeast Oregon. VF technology (Vence Corporation, San Francisco, CA) uses satellite-controlled collars that direct animal movement within user-defined polygons using auditory and electrical cues. We fall-burned a 0.6-ha area in each of six adjacent 2.1-ha pastures in a Wyoming big sagebrush plant community in 2019. In June 2020, each pasture was stocked with 3 mature dry cows for 14 d. All cows were fitted with VF collars; collars were programed to create a virtual fence around the burned area within three of the pastures (VF treatment), and remaining pastures had electrical and auditory cues turned off (control treatment). Collars recorded animal location every 5 min. Cows in the control treatment initially spent up to 40% of their time within the burned area, and forage utilization of the burned area was nearly 70%. Cows in the VF treatment spent approximately 4% of their time in the burned area on day 1 and were recorded in the burn only incidentally thereafter; forage utilization in the burn was < 3%. Our trial suggests VF technology is effective in controlling rangeland cattle movements and can severely curtail use of burned areas. Additional work is needed to evaluate VF technology in larger rangeland settings.

Hematocrit estimates comparing centrifugation to a point-of-care method in beef cattle living at high altitude.

The hematocrit (Hct) or packed cell volume (PCV) reflects the blood volume occupied by red blood cells. The development of point-of-care (PoC) instruments can accelerate the ease of measuring Hct/PCV compared with traditional capillary centrifugation (TCC) methods. However, no studies have compared Hct/PCV levels in cattle at high elevation with other measurement methods. In this study, we aimed to compare methods to estimate Hcts/PCVs of rangeland cattle at high elevation. We specifically wanted to determine if Hct/PCV levels measured with a commercial PoC instrument (i-Stat with CHEM8+ cartridges [PoCi ]) were comparable to Hct/PCV levels measured with traditional laboratory methods. We assessed the Hct/PCV of 94 mature beef cattle (black Angus; Bos taurus) at ~2195m above sea level using paired analyses of the PoCi and TCC methods from each animal. We used paired samples t-tests to compare mean Hct/PCVs. Correlation analyses relative to the line of identity and Passing-Bablok regression were used to assess systematic and proportional differences, respectively, and Bland-Altman plots were used to assess agreement between the two methods. The PoCi estimated a Hct of 28.2% ± 0.7% (SE), which was lower than the TCC estimated PCV of 39.2% ± 0.5%. The Bland-Altman plot revealed poor agreement between the two methods in addition to a -11% bias for the PoCi . The Passing-Bablok regression revealed both systematic and proportional bias between the two methods. Point-of-care blood instruments were not comparable to TCC methods for quantifying Hct/PCVs of cattle living at high elevations.

Automatic Supplement Weighing Units for Monitoring the Time of Accessing Mineral Block Supplements by Rangeland Cattle in Northern Queensland, Australia

Time spent feeding by grazing cattle is an important predictor of intake and feed efficiency. This study examined the use of automatic supplement weighing (ASW) units for monitoring voluntary access of breeding cows (n = 430) to mineral block supplements in an extensive rangeland of northern Australia. The ASW units (n = 10) were located within each of experimental sites (5 units per site; Bore and Eldons). Over the 62 days of data collection, 85%, 13%, and 2% of cows spent &lt;600, 600–1200, &gt;1200 min accessing supplements, respectively, with between-animal variation (CV) of 107%. A total of 133 cows visited both sites while 142 and 155 cows visited only Bore and Eldons, respectively. Most visits (80–90%) were recorded during the day (800–1700 h), 7–17% during the night (1800–2300 h), and 3% during the dawn (0–700 h). Time spent accessing supplements differed between ASW units across the two sites (p &lt; 0.001) and varied according to the day of visits (p &lt; 0.001). There was a significant relationship between time spent at the ASW units and supplement intake on a herd basis (p &lt; 0.001; R2adj = 0.70). The results showed that the ASW units were capable of monitoring access to mineral block supplements that may reflect the supplement intake of rangeland cattle.

Rangeland Ecosystem Service Markets: Panacea or Wicked Problem?

Rangelands support nearly one-third of Earth's population and provide a multitude of ecosystem services. Land managers and society face increasing pressures to sustainably intensify rangeland food systems; therefore, the time is ripe for thoughtful approaches to simultaneously produce more food, provide economic opportunities for livestock-dependent communities, and enhance environmental benefits from rangeland ecosystems. Payments for ecosystem services (PES) programs have been put forth as potential mechanisms to maintain the quality and quantity of ecosystem services while enhancing economic viability of livestock operations. Free markets have long been proposed as solutions for mitigating trade-offs from ecosystem services that are not co-produced with livestock production; such markets have failed to emerge at the scale required to address global threats to sustainability. We highlight fundamental obstacles on demand and supply sides that challenge the concept of a market as a panacea; we do so through an interdisciplinary lens of fundamental economic underpinnings overlaid with a social survey of cattle producers' perspectives. Relevant to the demand side, we discuss the most significant impediments to development and function of non-bundled ecosystem service markets; on the supply side, we provide unique perspectives, using novel interview data from California rangeland cattle producers. Producer interviews highlighted substantial financial challenges threatening the economic sustainability of their operations. Among interviewed producers, 85% identified government regulations as the central threat to their livelihoods. Producers identified opportunities for enhancing enterprise sustainability via improved value and marketing of livestock goods co-produced with ecosystem services, participation in conservation easements, and improved connections with society. Only 11% of producers identified PES programs as future opportunities. When asked about willingness to participate in PES markets, 13% of interviewees indicated they would not, 45% were neutral, and 42% indicated they would consider participating. Interviewees stated trust in the market broker is key and they would be less willing to participate if there was government involvement. Ecosystem service markets—whether voluntary or non-voluntary—are likely not sustainable solutions to the complex social-economic-ecological dilemma ranchers and society face. Sustainability on working rangelands will require partnerships to co-develop strategies to build more equitable food systems and sustain these ecosystems.

Researching Human-Cattle Interaction on Rangelands: Challenges and Potential Solutions.

Simple SummaryResearch investigating the influence of human-animal interactions on beef cattle production and welfare often occurs during stress-inducing contexts, such as restraint and transport. Given that beef cattle which graze on expansive rangelands do not frequently interact with humans, assessment of animal response to humans may be inaccurate if they are only recorded during such stressful context. Future research aimed at identifying the causes and impacts of individual human–cattle relationships may consider conducting experiments while the cattle are in a low stress context, such as while ruminating, resting, or, grazing. By adapting methods used to research wildlife response to humans, researchers may be able to better understand how animal personality and previous experience can influence cattle production and welfare.Human-animal interaction (HAI) research spans across many scientific fields and animal taxa. For livestock species, HAI research tends to focus on animals that are managed in close proximity with humans such as poultry, dairy cattle, and swine. Given the nature of rangeland cattle production, HAI research with beef cattle often occurs in and around the processing environment. This high arousal context may skew behavioral and physiological responses by the animals due to the potentially negative interaction. The aim of this review is to describe cattle production on rangelands, examine the considerations and limitations of current HAI research used to evaluate interaction quality or traits of rangeland cattle, identify contexts in which rangeland cattle interact with humans, and provide recommendations for improving future HAI research with rangeland cattle. Current research delineating individual differences in response to humans by beef cattle occur during routine husbandry and management on rangelands (pragmatic) and in a research context (experimental). Human-cattle interactions can be distinguished based on the quality and goal of the interaction into four broad categories: human presence, human approach, human contact, and restraint. Limitations of HAI research with rangeland cattle are identified and reconciled by recommendations for HAI research that can take place outside of the processing environment (i.e., while cattle are ruminating, resting or grazing on rangelands).

Do pastoralist cattle fear African lions?

Fear of predators fundamentally shapes the ecology of prey species and drives both inter‐ and intra‐specific interactions. Extensive research has examined the consequences of predation risk from large carnivores on the behavior of wild ungulate prey species. However, many large carnivores not only hunt wild prey but also depredate domestic livestock, especially in pastoralist systems where livestock share land and resources with large carnivores. Northern Tanzania is a hotspot for human–carnivore conflict driven by livestock depredation and interactions are particularly severe between African lions Panthera leo and pastoralist cattle Bos taurus. In this ecosystem, we explored the degree to which pastoralist cattle exhibited anti‐predator behaviors during their daily grazing routines. Using focal animal sampling, we compared two typical anti‐predator behaviors, vigilance and grouping, among cattle in village rangelands with high and low background depredation rates. We found that cattle in high risk village rangelands formed 21.2% larger groups than cattle in low risk village rangelands. Interestingly, cattle in low risk village rangelands spent 68.4% more time vigilant than cattle in high risk village rangelands. These patterns were influenced significantly by the time of day: as sunset approached, cattle in low risk village rangelands spent more time vigilant and cattle in high risk village rangelands formed larger groups. These results suggest that pastoralist cattle exhibit anti‐predator strategies that vary both spatially and temporally, and that such strategies might help livestock optimally tradeoff the costs and benefits of anti‐predator behavior across timescales (i.e. the risk allocation hypothesis). We discuss the implications of our results for husbandry techniques that might reduce behavioral costs associated with cattle anti‐predator behaviors and help increase tolerance for lions and other large carnivores. These improvements are critical to human–carnivore coexistence given the prevalence of pastoralism globally and the rising potential for conflict with large carnivores such as lions.

Seasonal and Nutrient Supplement Responses in Rumen Microbiota Structure and Metabolites of Tropical Rangeland Cattle.

This study aimed to characterize the rumen microbiota structure of cattle grazing in tropical rangelands throughout seasons and their responses in rumen ecology and productivity to a N-based supplement during the dry season. Twenty pregnant heifers grazing during the dry season of northern Australia were allocated to either N-supplemented or un-supplemented diets and monitored through the seasons. Rumen fluid, blood, and feces were analyzed before supplementation (mid-dry season), after two months supplementation (late-dry season), and post supplementation (wet season). Supplementation increased average daily weight gain (ADWG), rumen NH3–N, branched fatty acids, butyrate and acetic:propionic ratio, and decreased plasma δ15N. The supplement promoted bacterial populations involved in hemicellulose and pectin degradation and ammonia assimilation: Bacteroidales BS11, Cyanobacteria, and Prevotella spp. During the dry season, fibrolytic populations were promoted: the bacteria Fibrobacter, Cyanobacteria and Kiritimatiellaeota groups; the fungi Cyllamyces; and the protozoa Ostracodinium. The wet season increased the abundances of rumen protozoa and fungi populations, with increases of bacterial families Lachnospiraceae, Ruminococcaceae, and Muribaculaceae; the protozoa Entodinium and Eudiplodinium; the fungi Pecoramyces; and the archaea Methanosphera. In conclusion, the rumen microbiota of cattle grazing in a tropical grassland is distinctive from published studies that mainly describe ruminants consuming better quality diets.

Do haematological profiles of cows in drought prone areas differ with conformation?

Aim of study: Severe and frequent droughts have resulted in loss of thousands of rangeland cattle worldwide. The objectives of the current study were to assess the reduction in dimensionality of seven conformation traits and to determine the relationships between extracted constructs and haematological parameters associated with drought resilience in beef cows.Area of study: Muzarabani district, Zimbabwe.Material and methods: Fifty multiparous Mashona cows kept on natural rangelands were used. The collinearity of seven conformation traits of the cows was reduced using principal component analysis. The relationships between the principal components and hematological profiles of the cows were subsequently determined using regression analysis.Main results: First extracted principal component described body capacity (body depth, flank circumference, chest girth). The second component described the frame size (stature and body length) of the cows and the third component was comprised of sheath height and dewlap size. Cows characterised by deep bodies, large flanks and chest girths had low percent haematocrit (HCT), mean capsular haemoglobin concentration (MCHC) and red cell distribution (RDW) (p&lt;0.05). Small-framed cows were associated with low mean platelet volume (MPV), HCT, MCHC and RDW levels in blood (p&lt;0.05). As principal component 3 of conformation traits increased, white blood cell count, mean corpuscular volume, RDW and MPV decreased (p&lt;0.05).Research highlights: Small-framed cows with large thoracic capacities, large dewlaps and belly bottoms far away from the ground surface are able to maintain haematological normalcy under rangelands in drought prone areas.

Environmental and landscape influences on the spatial and temporal distribution of a cattle herd in a South Texas rangeland

The multiple spatial and temporal parameters affecting cattle herd distribution and activity dynamics can significantly affect resource utilization but are not fully understood. The aim of this study was to determine whether current animal tracking technology and spatio-temporal analysis tools can be used to integrate multi-scale information on herd distribution patterns as a function of seasonal forage production, periods of the day, animal activity, and landscape features. Positional and activity information of 11 free-ranging cows within a 31-member herd was obtained at 5-min intervals by using GPS collars for 1 year within a 457-ha ranch in the semi-arid rangelands of South Texas. Forage biomass was calculated with satellite imagery. Spatial analysis of cattle distribution and landscape features was conducted with GIS.Herd spread was greatest during the growing season. Throughout the year, during midday, the herd showed smaller spread and greater use of shade patches than any other time of day. Cattle also aggregated under trees in winter, particularly during the night. There was no statistically significant overall pattern of seasonal changes in the use of water and supplemental feeding areas, but a trend toward highest use during the winter. However, significantly different diurnal patterns in the use of supplemental feed and water were observed within each season.This study found a strong influence of shade patches relative to the influence of water and supplemental feeding areas on the diurnal and seasonal movement patterns of cattle in shrub-dominated rangeland. Although this study used only 11 tracked cows in a 31-member herd, the results indicated that techniques such as seasonal and diurnal GPS tracking, GIS, and remote sensing data enable evaluation of multiple spatial and temporal dynamics of cattle distribution and activity patterns. The smaller spread during the dry winter season associated with the observed aggregation of individuals in water and supplemental feeding areas, may aid in determining the most critical times for providing supplemental resources and guide the allocation of those resources to areas not frequently used by cattle, thus stimulating the animals to visit unused sites during the non-growing season.

Vulnerability of rangeland beef cattle production to climate-induced NPP fluctuations in the US Great Plains.

The vulnerability of rangeland beef cattle production to increasing climate variability in the US Great Plains has received minimal attention in spite of potentially adverse socioeconomic and ecological consequences. Vulnerability was assessed as the frequency and magnitude of years in which net primary production (NPP) deviated >±25% from mean values, to represent major forage surplus and deficit years, for a historic reference period (1981-2010), mid-century (2041-2065), and late-century (2075-2099) periods. NPP was simulated by MC2, a dynamic global vegetation model, driven by five climate projections for representative concentration pathway (RCP) 4.5 and 8.5. Historically, 4-4.7years per decade showed either NPP surpluses or deficits. The future number of extreme years increased to 5.4-6.4 and 5.9-6.9 per decade for RCP 4.5 and 8.5, respectively, which represents an increase of 33%-56% and 38%-73%, respectively. Future simulations exhibited increases in surplus years to between 3 and 5years in the Northern Plains and 3-3.5 in the Southern Plains. The number of deficit years remained near historic values of 2 in the Northern Plains, but increased in the Southern Plains from 2.5 to 3.3 per decade. Historically, NPP in extreme surplus and deficit years both deviated 40% from mean NPP in all three regions. The magnitude of deficit years increased by 6%-17% in future simulations for all three regions, while the magnitude of surplus years decreased 16% in the Northern Plains and increased 16% in the Southern Plains. The Southern Plains was the only region to exhibit an increase in the magnitude of both surplus and deficit years. Unprecedented future variability of NPP may surpass the existing adaptive capacity of beef producers and adversely impact the economic viability of rangeland cattle production and ecological sustainability of rangeland resources.

Effect of GPS sample interval and paddock size on estimates of distance travelled by grazing cattle in rangeland, Australia

The distance travelled by an animal, when determined by using global positioning system (GPS) coordinates, is usually calculated assuming linear movement between the recorded coordinates. When using long sample intervals, some movement may be overlooked if linear movement between each recorded position is assumed, because of the tendency of livestock to move in meandering paths. Conversely, overestimation of the true distance travelled could occur with short sample intervals because of the accumulation of extra distance due to GPS measurement error. Data from 10 experiments were used to explore the effect of paddock size and GPS sampling rate on the calculation of distance travelled by free-ranging cattle. Shortening the sample interval increased apparent distance travelled according to a power function. As paddock size increased from &lt;1 ha to &gt;450 ha, distance travelled increased according to a logarithmic relationship; however, other variation between experiments could have affected these results. It was concluded that selecting an optimal GPS sampling interval is critical to accurately determining the distance travelled by free-ranging cattle.

Direct and Indirect Impacts to Ranchers from Wolves and Other Predators: Building a Baseline in California

Author(s): Macon, Dan; Lile, David; Stackhouse, Jeff; Rivers, Carissa Koopmann; Schohr, Tracy; Snell, Laura; Harper, John; Ingram, Roger; Rodrigues, Kim; Baldwin, Roger A.; Saitone, Tina; Macaulay, Luke; Roche, Leslie | Abstract: While the direct economic impacts of gray wolves and other predators on rangeland livestock production are relatively easy to measure, indirect impacts (e.g., reduced livestock productivity and increased expense) may be more economically significant. We initiated a long-term (10 year), longitudinal survey of rangeland cattle, sheep and goat producers in northern California to quantify the direct and indirect impacts from gray wolves, which are increasing in numbers in the state, and other large carnivores on rangeland livestock production. During winter/spring 2017, we hosted seven producer-researcher workshops across northern California, featuring livestock-predator conflict experts. At these workshops, we collected the first round of survey data from 90 livestock operations. Our initial survey results document the adoption rates, efficacy and cost of a variety of commonly used livestock protection tools on rangeland livestock operations at a variety of scales.

Spatial occupancy patterns and activity of arid rangeland cattle grazing small riparian pastures.

The spatial occupancy patterns and activity of cattle grazing three riparian pastures was investigated in northeastern Oregon using Global Positioning System (GPS) collars logging at 1-sec intervals. Cattle consistently selected plant communities as grazing areas that had forage in sufficient volume to meet their requirements and favored communities as resting areas that were dry and open. Cattle were stationary for more than 50% of the time in each pasture and consistently rested between dark and 04:00 hours. Interaction with stream channels was found to be 1-2% of total occupancy time and occurred on less than 10% of channel length. Cattle were indifferent or avoided channel areas relative to their area and, when in this zone, they spent most of their time moving not resting. Cattle did not prefer the stream bank zone and spent only 2% of their time in that zone. When occupied, the stream bank zone was used as a travel corridor to gain access to water or cross the channel to access other pasture areas. These results are in contrast with the general belief that cattle are a primary occupant of the stream bank/channel area; additional research is needed to define factors influencing cattle occupancy.

Effects of Passive and Structural Stream Restoration Approaches on Transient Storage and Nitrate Uptake

Understanding nitrogen dynamics in headwater streams is important for ascertaining how they influence downstream nutrient loads and identifying strategies for reducing loading through stream restoration. We compare nitrate uptake associated with two restoration approaches in headwater streams, Sheep Creek and Nunn Creek, of northern Colorado, USA. Segments of Sheep Creek were exclosed (fenced off) from open rangeland cattle grazing in the 1950s, allowing riparian corridors of these segments to naturally revegetate (passive approach), while other segments have been continually grazed. In 2003, restoration structures including cross vanes, J‐hook vanes, rootwads, log vanes, and bank riprap (structural approach) were installed along portions of Nunn Creek for trout habitat enhancement and local bank stabilization. We performed detailed physical characterizations and multiple nutrient injections of Br⁻ and NO₃ ⁻ to estimate transient storage and nitrate uptake in four reaches along Sheep Creek (two reaches exclosed from grazing and two grazed reaches) and two reaches along Nunn Creek (one with restoration structures and one without structures). Parameters of transient storage and nitrate uptake were estimated with the one‐dimensional transport with inflow and storage model run through universal inverse modelling code for optimization. Responses of transient storage and nitrate uptake to restoration techniques depended upon the type and extent of restoration implemented, as well the context and physical setting of each study reach. For example, in the higher‐gradient pair of Sheep Creek reaches, the restored reach showed greater nitrate uptake, while in the lower‐gradient pair of reaches, the non‐restored reach had greater uptake. At Nunn Creek, the reach with instream wood but without restoration structures exhibited more transient storage and nitrate uptake when compared with the reach with extensive J‐hook vane structures. Copyright © 2016 John Wiley & Sons, Ltd.

Behavioral and Physiological Responses of Calves to Marshalling and Roping in a Simulated Rodeo Event.

Simple SummaryRodeos often include a calf roping event, where calves are first lassoed by a rider on a horse, who then dismounts, ties the calves’ legs, lifts it from the ground and releases it back to the floor. We tested whether calves that were familiar to the roping experience stress during the roping event, and found increased concentrations of stress hormones in their blood after the roping. We also found increased concentrations of stress hormones in the blood of calves that had never been roped before but were just marshelled across the arena by the horse and rider. We conclude that the roping event in rodeos is stressful for both experienced and naïve calves. Rodeos are public events at which stockpeople face tests of their ability to manage cattle and horses, some of which relate directly to rangeland cattle husbandry. One of these is calf roping, in which a calf released from a chute is pursued by a horse and rider, who lassoes, lifts and drops the calf to the ground and finally ties it around the legs. Measurements were made of behavior and stress responses of ten rodeo-naïve calves marshalled by a horse and rider, and ten rodeo-experienced calves that were roped. Naïve calves marshalled by a horse and rider traversed the arena slowly, whereas rodeo-experienced calves ran rapidly until roped. Each activity was repeated once after two hours. Blood samples taken before and after each activity demonstrated increased cortisol, epinephrine and nor-epinephrine in both groups. However, there was no evidence of a continued increase in stress hormones in either group by the start of the repeated activity, suggesting that the elevated stress hormones were not a response to a prolonged effect of the initial blood sampling. It is concluded that both the marshalling of calves naïve to the roping chute by stockpeople and the roping and dropping of experienced calves are stressful in a simulated rodeo calf roping event.

Chemical immobilisation and rangeland species: assessment of a helicopter darting method for Australian cattle

Chemical immobilisation (darting) is increasingly being used for the capture of rangeland animals. The aim of the present study was to assess a newly developed helicopter-based chemical immobilisation method for free-ranging Australian rangeland cattle (Bos taurus and Bos indicus). Eighteen cattle were darted from a helicopter in north-western Australia in September 2015 using a combination of xylazine and ketamine, partially reversed with yohimbine. Following a recently published framework for assessing helicopter darting methods, we quantified several animal welfare measures designed to quantify the severity and duration of stress imposed by the procedures. The duration of the procedures was generally short (median total duration 41 min), but for 33% of animals total duration exceeded 60 min. Although the sample size was small, mortality rate on the day of capture was 17% (three animals) and 28% (five animals) required physical restraint to achieve recumbency. We describe this newly developed method and discuss its relatively poor animal welfare outcomes compared with other validated helicopter darting methods. Legislation restricts veterinary chemicals that may be used for food-producing species in many countries, including Australia. Chemical immobilisation regimens other than the one chosen in the present study may produce superior animal welfare outcomes but would not be compliant with legislation in Australia. As a result of these restrictions, we suggest that development of an improved helicopter darting method for Australian cattle may prove difficult. Rangeland managers should carefully consider animal welfare impacts before undertaking chemical immobilisation programs, especially for food-producing species.