Free-ranging Cattle Research Articles

A regularity-based algorithm for identifying grazing and rumination bouts from acoustic signals in grazing cattle

Continuous monitoring of cattle foraging behavior is a major requirement for precision livestock farming applications. Several strategies have been proposed for this task but monitoring of free-ranging cattle for a long period of time has not been fully achieved yet. In this study, an algorithm is proposed for long-term analysis of foraging behavior that uses the regularity of this behavior to recognize grazing and rumination bouts. Acoustic signals are analyzed offline in two main stages: segmentation and classification. In segmentation, a complete recording is analyzed to detect regular masticatory events and to define the time boundaries of foraging activity blocks. This stage also defines blocks that correspond to no foraging activity (resting bouts). The detection of event regularity is based on the autocorrelation of the sound envelope. For classification, the energy of sound signals within a block is analyzed to detect pauses and to characterize their regularity. Rumination blocks present regular pauses, whereas grazing blocks do not. The evaluation of the proposed algorithm showed very good results for the segmentation task and activity classification. Both tasks were extensively analyzed with a new set of multidimensional metrics. Frame-based F1-score was up to 0.962, 0.891 and 0.935 for segmentation, rumination classification, and grazing classification, respectively. The average time estimation error was below 0.5 min for classification of rumination and grazing on recordings of several hours in length. In addition, a comparison for rumination time estimation was done between the proposed system and a commercial one (Hi-Tag; SCR Engineers Ltd., Netanya, Israel). The proposed algorithm showed a narrower error distribution, with a median of −2.56 min compared to −13.55 min in the commercial system. These results suggest that the proposed system can be used in practical applications.Web demo available at: http://sinc.unl.edu.ar/web-demo/rafar/.

Comparing the impact of a grazing regime with European bison versus one with free-ranging cattle on coastal dune vegetation in the Netherlands

Woody plant encroachment has increased across the globe and threatens biodiversity associated with open habitats. In order to prevent or reduce woody encroachment, conservation managers across Europe introduce large mammalian herbivores. While up to recently, managers were mostly using free-ranging domestic cattle and horses for this, there is an increasing interest in the use of European bison for nature management. However, we lack studies that compare the impact of these different grazers on vegetation. We report results from a unique grazing pilot in the National Park Zuid-Kennemerland, a heterogeneous coastal dune landscape in the Netherlands, where European bison, horses, and cattle were introduced to reverse the encroachment of grass and shrub species. We present results of an 8-year study on the development of woody and grassy vegetation on fixed transects in three different grazing areas within the national park; one area with European bison and horses, one area with cattle and horses, and one area where these large grazers were excluded. In all three areas, rabbit, fallow deer, and roe deer were present. Over time, we observed strong reductions in the vitality of several woody species, such as spindle tree, and this decline was similar across all areas. Grass height and cover also declined and the proportion of herbs increased in all three grazing areas in similar ways. However, the type of herbivore use (debarking, foraging on buds, branches) of several woody species differed significantly among areas. For instance, maple tree was only debarked in the E. bison area, while hawthorn branches were eaten significantly more in the cattle than in the bison area. Due to differences in herbivore densities among areas, it was difficult to draw strong conclusions on how the different herbivore species differed in their impact, but, importantly, we found that grazing regimes with bison can lead to as strong effects on vegetation structure and composition as grazing regimes with cattle. This is an important result since certain conditions, such as legal aspects, may motivate managers to introduce a wild large grazer rather than a domesticated one.

Faecal N excretion as an approach for estimating organic matter intake by free-ranging sheep and cattle

AbstractThe current study aimed to test whether organic matter intake by free-ranging ruminants could be estimated from the amount of nitrogen (N) excreted in faeces and to compare this approach to conventional techniques. An equation describing the relationship between excreted N and nutrient intake was developed in indoor digestibility trials conducted with male sheep (n= 36) and cattle (n= 24) housed in metabolism cages and solely fed hay harvested from a local rangeland. Faecal N excretion was linearly related to organic matter (OM) intake without a significant animal species effect. To evaluate the linear equation, data from free-ranging trials conducted with sheep and cattle were used. The faecal N approach was compared with eitherin situdigestibility plus external marker (n= 123) orn-alkanes (n= 272) to estimate OM intake and digestible OM intake. Estimates obtained through the faecal N approach did not closely fit those obtained with either conventional technique for any variable. Averaging all individual values, the supply of metabolizable energy (ME) estimated through faecal N was similar to the required level, whereas both thein situandn-alkanes techniques overestimated ME supply. In conclusion, OM intake by free-ranging sheep and cattle can be estimated based on the amount of N excreted in faeces with some advantages over conventional techniques: knowledge about herbage attributes is not required and it accounts for individual variability on selectivity and digestion processes.

Accumulation patterns and risk assessment of metals and metalloid in muscle and offal of free-range chickens, cattle and goat in Benin City, Nigeria

The use of free range animals for monitoring environmental health offers opportunities to detect exposure and assess the toxicological effects of pollutants in terrestrial ecosystems. Potential human health risk of dietary intake of metals and metalloid via consumption of offal and muscle of free range chicken, cattle and goats by the urban population in Benin City was evaluated. Muscle, gizzard, liver and kidney samples were analyzed for Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, and Pb concentrations using inductively coupled plasma mass spectrometer (ICP-MS) while Hg was determined using Hg analyzer. Mean concentrations of metals (mg/kg ww) varied significantly depending upon the tissues and animal species. Human health risk estimations for children and adults showed estimated daily intake (EDI) values of tissues below oral reference dose (RfD) threshold for non essential metals Cd, As, Pb and Hg thus strongly indicating no possible health risk via consumption of animal based food. Calculated Hazard quotient (THQ) was less than 1 (< 1) for all the metals analyzed for both adult and children. However, Cd and As had the highest value of THQ suggestive of possible health risk associated with continuous consumption of Cd and As contaminated animal based foods. Hazard Index (HI) for additive effect of metals was higher in chicken liver and gizzard for children and chicken liver for adults. Thus, HI indicated that chicken liver and gizzard may contribute significantly to adult and children dietary exposure to heavy metals. Principal component analysis (PCA) showed a clear species difference in metal accumulation between chickens and the ruminants. This study provides baseline data for future studies and also valuable evidence of anthropogenic impacts necessary to initiate national and international policies for control of heavy metal and metalloid content in food items.

Activity patterns of free-ranging beef cattle in Norway

ABSTRACTThe aims of this study were to: 1) build a model to classify cattle activities based on locomotion and neck movement data and 2) study the daily time budget of non-native beef cattle in the boreal forest of southeastern Norway. We used GPS collars programmed to take positions and activity measures every five minutes on 18 cows during the grazing seasons 2015–17, together with behavioural observations in the field. The model classified the collar data into Grazing, Low (resting behaviours) and High (other active behaviours) activity with an accuracy of 79.4%. The cows spent 8.1 ± 0.5 (mean ± SD) hours per day grazing, corresponding to 34% ± 0.5% of their daily time budget. Daily grazing time increased during summer and was longer for lactating than dry cows and at low compared to high stocking density.

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.

Selenomethionine as a Safer Substitute for Barium Selenate in Long-Acting Injectable Se Supplements for Food-Producing Animals.

Nutritional supplementation with selenium (Se) can prevent Se deficiency in food-producing animals. Injection with slow-release formulations is a preferred method for free-range grazing sheep and cattle, and barium selenate (BaSeO4) provides optimal efficacy. This chemical can become a health risk to humans if the concentrated depot of an injection site is consumed, and consequently such use is recently banned in the EU. A possible replacement is selenomethionine (SeMet), a naturally occurring form of Se supplementation hitherto only administered orally. In four animal studies we found that injection with SeMet maintained nutritionally adequate concentrations of Se in blood and tissues of lambs for at least 191 days and in blood and milk of dairy cows for at least 95 days. Stereoisomer forms L- and DL-SeMet were functionally equivalent. This is the first demonstration that injectable SeMet can deliver efficacy similar to BaSeO4 but with less risk of undesirable residues in edible tissues.

Efficacy of oral BCG vaccination in protecting free-ranging cattle from natural infection by Mycobacterium bovis

Vaccination of cattle against bovine tuberculosis could be a valuable control strategy, particularly in countries faced with intractable ongoing infection from a disease reservoir in wildlife. A field vaccination trial was undertaken in New Zealand. The trial included 1286 effectively free-ranging cattle stocked at low densities in a remote 7600ha area, with 55% of them vaccinated using Mycobacterium bovis BCG (Danish strain 1311). Vaccine was administered orally in all but 34 cases (where it was injected). After inclusion, cattle were exposed to natural sources of M. bovis infection in cattle and wildlife, most notably the brushtail possum (Trichosurus vulpecula). Cattle were slaughtered at 3–5 years of age and were inspected for tuberculous lesions, with mycobacteriological culture of key tissues from almost all animals. The prevalence of M. bovis infection was 4.8% among oral BCG vaccinates, significantly lower than the 11.9% in non-vaccinates. Vaccination appeared to both reduce the incidence of detectable infection, and to slow disease progression. Based on apparent annual incidence, the protective efficacy of oral BCG vaccine was 67.4% for preventing infection, and was higher in cattle slaughtered soon after vaccination. Skin-test reactivity to tuberculin was high in vaccinates re-tested 70days after vaccination but not in non-vaccinates, although reactor animals had minimal response in gamma-interferon blood tests. In re- tests conducted more than 12 months after vaccination, skin-test reactivity among vaccinates was much lower. These results indicate that oral BCG vaccination could be an effective tool for greatly reducing detectable infection in cattle.

Effects of free-ranging cattle and landscape complexity on bat foraging: Implications for bat conservation and livestock management

Traditional agropastoralism increases biodiversity by maintaining habitats whose existence depends on human practices as well as by providing wildlife, including bats, with key spatial and trophic resources. Bats in farmland are crucial predators of crop pests, thus offering an economically important ecosystem service. It seems possible that bats may also provide services by feeding on insects associated with livestock. We tested whether bats forage over cattle in a traditionally managed pastoral area of central Italy, i.e. setting the bases for providing pest control services. We found that small bat species (mostly Pipistrellus spp.) foraged preferentially over livestock, and that their activity increased, but then reached a plateau or slightly decreased, for progressively larger herds. Landscape complexity also led to an increase in bat activity over livestock. Since insects attracted to cattle at night typically include flies such as mosquitoes (Culicidae) and biting midges (Ceratopogonidae), which are potentially harmful to cattle and may carry serious diseases, and that bats such as Pipistrellus spp. are important predators of such flies, we argue that bats may play a valuable pest-suppression role.

Assessment of stun quality after gunshot used on cattle: a pilot study on effects of diverse ammunition on physical signs displayed after the shot, brain tissue damage and brain haemorrhages

AbstractMoving the slaughter process from the abattoir to the animals’ familiar environment has the potential to reduce pre-mortal stressors to a minimum and contribute considerably to improved animal welfare at slaughter. On-farm stunning and killing of free-range cattle via gunshot became legal in Germany in November 2011, including for commercial sale of the meat. As an effective stun is essential for maintaining animal welfare until the animal dies, the goal of this study was to assess the feasibility of delivering an instantaneous and deep stun by an accurate frontal gunshot at cattle. Thirty free-range cattle (Galloway, German Angus) were shot with five different combinations of rifles and bullets. A stun-quality protocol was developed to assess musculoskeletal, optical and respiratory signs displayed after the shot. Key signs, such as failure to collapse, corneal reflex, spontaneous blinking, eyeball rotation or eyeball movement, distinct vocalisation and rhythmic breathing were not evident in 29 of the 30 cattle. Dissections of the heads were used to detect penetration depth of the projectile as well as evaluate brain tissue damage and brain haemorrhage caused by the shot. Tissue damage was marginal and not related to the ascertained level of stun quality. Brain haemorrhages assumed to be sufficient for causing a deep stun were detected in 25 out of 30 cattle. Accurate shot placement turned out to be more important than the application of a certain calibre. However, it was considered crucial for safety reasons that the projectile should remain within the cranial cavity. As long as there are high levels of accuracy, gunshot was considered to be an effective stunning method with the potential of maintaining high standards of animal welfare until death occurs.

Bull bellows and bugles: a remarkable convergence of low and high-frequency vocalizations between male domestic cattle Bos taurus and the rutting calls of Siberian and North American wapiti

Whereas low-frequency bellows (below 200 Hz) have been investigated in detail in both male and female domestic cattle (Bos taurus), male high-frequency bugle calls (over 800 Hz) have not been described so far in any large bovid species. In this study, high-frequency bugles and low-frequency bellows were recorded from three crossbred free-ranging domestic cattle bulls and analysed spectrographically. The maximum fundamental frequency of bellows was 113.6 Hz, whereas the maximum fundamental frequency of bugles was 958.4 Hz, ranging from 801 to 1125 Hz in different males. These amazingly high fundamental frequencies of bull bugles are comparable with those reported for Siberian wapiti Cervus elaphus sibiricus, but lower than reported values for some subspecies of North American wapiti Cervus canadensis. The similarity with both Siberian and North American wapiti was also observed in the production of bull biphonic bugles with two fundamental frequencies: the low and the high one. We suggest that bugles of domestic cattle bulls provide an excellent model for comparative research with cervid bugles concerning the mechanism of vocal production and the underlying anatomical and behavioural adaptations.

So Far and yet So Close: Frontier Cattle Ranching in Western Prairie Canada and the Northern Territory of Australia by Warren M. Elofson

Reviewed by: So Far and yet So Close: Frontier Cattle Ranching in Western Prairie Canada and the Northern Territory of Australia by Warren M. Elofson Ian MacLachlan Elofson, Warren M. – So Far and yet So Close: Frontier Cattle Ranching in Western Prairie Canada and the Northern Territory of Australia. Calgary: University of Calgary Press, 2015. Pp. 329. So Far and yet So Close is an environmental history comparing the nineteenth-century cattle-ranching industry in Canada’s Prairie West with Australia’s Northern Territory. The two industries had a great deal in common: their foundation was the natural resource of tens of thousands of hectares of arid grassland supporting free-ranging cattle at low stocking densities; they relied on an equestrian labour force that was largely young and male; and both regions had to overcome the challenges of animal disease, climatic adversity, and remoteness. The narrative focuses on the impact of environmental conditions on human behaviour and observes the remarkable similarity in the ways that humans adapt to environmental constraints using similar cultural and technical practices in remote regions of the world. The story is dominated by the Texas system of beef cattle husbandry, distinctive because of its low grazing density on the open range, unregulated land tenure, and minimal animal husbandry. This system diffused contagiously from Texas to Canada in the 1870s and, in the same decade, made its way to Northern Australia, thanks largely to the nineteenth-century agricultural journals extolling its virtues. However, the Texas system was ultimately unsustainable and came to a ruinous end on the northern Great Plains as a result of uncontrolled overgrazing and due to the vulnerability of European cattle breeds to severe winter conditions, contagious diseases such as mange, and predation by both humans and wolves. All of these problems were complicated by the debilitating effects of shipping live cattle over long distances to market, a sad level of ignorance on the part of investors, and a sorry lack of accounting for cattle purchases and mortality. The book’s most significant contribution to ranching history is its examination of the contrast in the early and long-term fortunes of Australian and Canadian ranchers. Australian ranches lost massive amounts of money and failed in the largest [End Page 199] numbers soon after the birth of the pastoral industry in 1879. On the other hand, the ranches of Canada’s Prairie West were more successful in their early years, largely because the initial challenges were less severe (p. 59). In the long run, however, some semblance of large-scale cattle ranching persists in the pastoral regions of the Northern Territory, while large corporate ranchers had disappeared from the Prairie West by the early twentieth century. Explaining these contrary trends becomes the principal goal and major achievement of this comparative history. For those familiar with Elofson’s research, chapter 9 reworks a theme developed in earlier works. The great leasehold ranches on open grazing land with minimal control over the animals were a fleeting phenomenon extending from the late 1870s until the start of the First World War. The ranch industry of Alberta and Assiniboia was transformed in the first two decades of the twentieth century as the big corporate ranches were so poorly adapted to their environment that most became insolvent. Frontier open-range ranching was gradually replaced in Canada by smaller and more diversified farmer-ranchers who owned a significant amount of deeded land and closely controlled it with barbed wire. Fencing allowed ranchers to improve the quality of their animals and reduced overgrazing and predation by both animals and humans. Though Elofson has made this argument before, it bears repeating as the transformation is vastly different from experiences in Australia’s Northern Territory. While the Texas system of cattle husbandry had collapsed in North America by 1887, extensive open-range cattle ranching persists in the Northern Territory. For one thing, the top end’s torrid monsoonal climate makes the land ill-suited to any alternative economic use. Notwithstanding their inauspicious start, the great cattle stations of Australia survived as the most expansive private land-using institutions on earth, practising a form of pastoralism that is most distinctive for its profound neglect...

High fodder value and feeding likelihood favour endozoochorous plant dispersal

Questions In pasture-dominated landscapes, endozoochory by large herbivores is an important vector of plant dispersal. Conditions influencing the potential for endozoochorous dispersal of plant species by grazers are, however, still poorly known. Here, we assess the impact of feeding habits and functional traits on the likelihood of endozoochorous dispersal by cattle (ruminant) and horses (non-ruminant). Location Pasture of 27 ha in NW-Germany year-round grazed by free-ranging cattle and horses. Methods Vegetation relevees were established in 45 plots, in which dung samples of cattle and horses were collected. The number and composition of seedlings emerging from dung samples were compared with the vegetation of the study site in terms of plant functional trait composition. For the first time, feeding habits were included in the analysis. Generalized linear models were used to identify traits that increased the potential for endozoochorous dispersal. Results A total of 65 species germinated from the dung samples. These species had higher average fodder and nutrient indicator values than the species composition of the vegetation. Especially species found in horse dung were more tolerant of grazing and had more elongated seeds. The likelihood of endozoochorous dispersal was higher for common than for rare species and was influenced by feeding habits. Conclusions The likelihood of plant species being dispersed endozoochorously can be linked to different functional traits and is dependent on the type of grazer and the population size of target species in the vegetation. Differences between cattle and horses in seed dispersal may result from species-specific grazing habits and different digestion modes. This article is protected by copyright. All rights reserved.

Spatial and temporal activity of cattle grazing in Mediterranean oak woodland

We examined the temporal and spatial variation patterns of the grazing activity of free-ranging cattle in Mediterranean oak woodland in the Western Galilee, Israel, as affected by seasonal and management factors.The vegetation is dominated by scrub-oak woodland (Quercus calliprinos Webb.), interspersed with patches of semi-dwarf shrubs and herbaceous vegetation. High and moderate animal population densities of 0.55 and 0.33cowha−1, respectively, were replicated twice. Cattle behavior was monitored with activity sensors on GPS collars, and pedometers, and spatial data were processed with Geographic Information System (GIS) tools.Overall, cattle devoted 9.7±0.7h/day to grazing, mostly in woodland areas, although they are natural herbaceous grazers. Behavior was associated with seasonal changes in biotic and abiotic factors. Preference for the woody vegetation types was detectable over the annual time scale but large seasonal differences in preference canceled out to a large extent when viewed at that time scale. Cattle under high density spent more time grazing and made more use of woody vegetation and steeper slopes. Thus, relatively high population densities may be required for landscape-oriented management. The present findings should contribute to rational management of cattle grazing in Mediterranean woodlands.

Technology roadmap: Cattle farming sustainability in Germany

Cattle farming is one of the most environmentally threatening industries worldwide. Its impact has been assessed as a main driver for soil degradation, deforestation, water bed contamination, and greenhouse gas emissions. Germany is one of the largest consumers and producers of livestock products in the world. This high volume demand for livestock forces farmers and consumers to import from overseas and increase national yields. Technologies worldwide are being developed with a focus on sustainability and cleaner production; however, this may not necessarily be easily adapted and implemented by German farmers. This paper uses the technology roadmap approach to propose a plan for implementing these technologies by identifying the barriers and actions to remove them. Aquaponics, grazing management, and capturing methane are current global trends used in the effort to reduce the impact of livestock. While aquaponics are at an early stage of development and implementation in Germany, grazing management techniques and methane processing on free range cattle are mostly still unknown and not implemented by farmers producing in the country.

Remote chemical immobilisation method for free-ranging Australian cattle

Many situations are encountered in Australia where the capture and restraint of free-ranging cattle (Bos taurus/Bos indicus) is required. Chemical immobilisation via darting is a potentially useful tool for managing and researching large wild herbivores; however, there is no reliable method for its application to Australian cattle. The aim of this study was to develop an efficacious, humane, cost-effective ground darting method for free-ranging cattle. The 30 female cattle were darted and captured on a pastoral station in north-west Australia from a vehicle. Xylazine (0.59 mg/kg) and ketamine (3.59 mg/kg) were used to capture animals and yohimbine (0.10 mg/kg) was used as an antagonist to xylazine to reduce recumbent time. Cattle became recumbent at a mean time of 8 min and a mean distance of 260 m from darting. The mortality rate was zero on the day of capture and 7% at 14 days post-capture. The majority of darted cattle were successfully immobilised with one dart and recovered within 30 min, with consumables costing approximately A$30 per captured animal. The technique developed represents a rapid and humane method for capturing free-ranging cattle and, with consideration for legislation surrounding use of veterinary chemicals, could be applied in many contexts across Australia.

Grazing effects on plant diversity in the endemic Erica mackayana heathland community of north-west Spain

Background: Large areas of heathland landscapes in Galicia, north-west Spain, have traditionally been extensively grazed by free-ranging cattle and wild ponies. Recently, a large reduction in the number of these larger herbivores has been observed, with unknown consequences for the habitat.Aims: To evaluate the effects of grazing and herbivore density on plant diversity, community composition and vegetation structure of the endemic wet heathlands dominated by Erica mackayana in Galicia.Methods: Field sampling of vascular plants, generalised linear models (GLMs), non-metric multidimensional distance scaling (NMDS).Results: Grazed sites had significantly higher total and rare species richness and diversity than ungrazed sites. Higher densities of cattle resulted in lower numbers of rare species, while wild pony density had no effect on rare species richness. In grazed sites, vegetation was lower with greater variation in height, resulting in greater heterogeneity of the habitat. Precipitation and summer temperatures were related to plant diversity, mainly beta diversity. Soil organic matter negatively correlated with rare species.Discussion: Grazing, mostly by wild ponies, was demonstrated to be positively related to plant diversity and vegetation structure. Lack of grazing or high cattle densities resulted in a negative effect on total and rare species richness and diversity. Future climate change may negatively affect heathland plant diversity. Galician wild ponies represent a unique case of sustainable management of a wild species and an invaluable cultural heritage. Moreover, they have a significant role in maintaining the endemic E. mackayana heathlands, what would justify specific conservation actions for these large herbivores.

Sympatric guanacos and livestock share water resources in drylands of Argentina

AbstractThere is growing concern about the effect of livestock on wild ungulate populations, particularly in arid ecosystems, where waterholes are an extremely scarce resource, around which animals tend to gather, primarily in the dry season. This situation is worrying in South American deserts, where guanaco is the native species that often shares trophic and water resources with livestock from local communities, even inside protected areas. We assess through general linear modeling (GLM) the use of waterholes by guanaco and two introduced species, free-ranging cattle and feral donkeys, during the summer-wet and winter-dry seasons, in an arid, water-limited region in northwestern Argentina. Waterholes were more intensively used in the dry than the wet season by all three herbivores. However, introduced ungulates did not use all of the waterholes, whereas guanaco used them all with equal intensity, which points to an apparent absence of interference probably due to the low density of the introduced species. Nevertheless these results could mask negative effects regarding the risk of parasite transmission, the under-use of one of the waterholes, and the risk related to increasing livestock density in a near future. Therefore, it would be advisable to make long-term monitoring to prevent potentially negative effects on guanacos.

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.

Comparing grazing and resting electivity of beef cattle for BC bunchgrass communities using GPS collars

Thompson, D., Wheatley, B. J., Church, J. S., Newman, R. and Walker, J. 2015. Comparing grazing and resting electivity of beef cattle for BC bunchgrass communities using GPS collars. Can. J. Anim. Sci. 95: 499–507. Grasslands in the interior of British Columbia often contain a mosaic of plant communities that provide variable habitat for free-ranging cattle. Global positioning system (GPS) collars have been used to study natural habitat use by cattle on a coarse scale (such as riparian, grassland and forested habitats), but not on a fine scale (such as choice among grassland plant communities). Cows equipped with GPS collars were tracked during the spring grazing period for 4 yr. Six grassland pastures were used as replicates. The activity (grazing or resting) of cattle at GPS locations was classified using a distance travelled algorithm. A detailed plant community map of five plant community types was constructed, and cow relative use within the plant communities was determined. Electivity, which scales for differences in community area, was used to compare the use of plant communities. While grazing, electivity for the Kentucky bluegrass community (mean +0.3) was greater than for the bluebunch wheatgrass community (mean −0.2). While resting, these differences were more pronounced. GPS collars can be used to estimate fine-scale choices among grassland communities.