Investigating the Market Value of Brumbies (Equus caballus) in the Australian Riding Horse Market.

Feral horses, also known as brumbies, are widely distributed across Australia with some populations being managed largely by human intervention. Rehoming of suitable feral horses following passive trapping has wide community acceptance as a management tool. However, there is little information about the number and relative economic value of feral horses compared with cohorts in the riding horse market. We examined 15,404 advertisements of horses for sale in 53 editions of Horse Deals, published from February 2017 to July 2022. Despite the considerable media attention and public scrutiny surrounding feral horse management, rehomed feral horses represented only a tiny fraction of the horse market in the current study. Of the 15,404 advertisements examined, only 128 (0.0083%) were for feral horses. We recorded phrases used to describe behavioural characteristics and other variables. The following variables were found to be not independent: Ridden Status, Height, Age, Sex, Colour, and Warning terms/more work. Using descriptive statistics to describe basic features of the data, the average price for feral horses ($1408) was lower than that for domestic horses ($1790) with the maximum price for a domestic horse being nearly twice the maximum for a feral horse. Univariate analysis showed feral horses were over-represented among "Unbroken" horses and underrepresented among "Ridden", "Broodmare" and "Harness" horses compared with domestic bred horses (p < 0.001). Feral horses appeared over-represented at shorter heights, among younger age groups (3 years or younger and 3.1 to 6 years) (p < 0.001) and in the dilute colour category (p = 0.008). The multivariable mixed model on price revealed that for domestic horses, the highest estimated marginal mean price averaged across the colour categories was for ridden horses aged 6.1-10-year-old at $1657.04 (95% CI $1320.56-$2074.66). In contrast, for feral horses, the multivariable mixed model demonstrated the similar highest estimated marginal mean averaged was for green broken 3-6-year-old horses that have undergone foundation training under saddle at $2526.97 (95% CI $1505.63-$4208.27). Australian feral horses were valued differently tfromsimilar domestic horses in the recreational riding horse market and further research is warranted to determine appropriate target markets and boost the sustainability of rehoming as a feral horse management tool.

Grazier perceptions and management practices for liver fluke control in north eastern NSW, Australia.

A survey of livestock producers (graziers) located in north eastern NSW Australia, collected information on perceptions and management practices for liver fluke control in livestock. The total area farmed by the 161 respondents was 195,600 ha (ranging in size from 4 to 10,522 ha) with cattle and sheep being the dominant livestock enterprises. Overall, 80% of graziers relied exclusively on anthelmintics for liver fluke control and few of these graziers (9%) integrated parasite management (IPM) strategies to reduce disease prevalence. Of those relying on anthelmintic control, triclabendazole (TCBZ) was preferentially chosen by 75% of graziers. Fifty five percent of these graziers used TCBZ in combination with oxfendazole (46%), ivermectin (5%) or abamectin (4%) whilst 45% used TCBZ as a single active ingredient. Thirty eight percent of graziers drenched livestock one or more times per year for liver fluke despite claiming they had no liver fluke or confirmed knowledge of infection. Fifty one percent of graziers based anthelmintic dose on the known weight of the heaviest animal in the herd whilst 43% visually guessed livestock bodyweight to calculate anthelmintic dose. Choice of anthelmintic was predominately based on perceived efficacy (45%) despite very few graziers (2%) having conducted post-treatment fluke egg counts. The majority of graziers (76%) were unsure if they had anthelmintic resistance, 21% claimed they had no resistance whilst 3% of graziers had confirmed resistance. Most graziers (97%) also reported farms were cohabited by kangaroos highlighting additional grazing pressures on-farm. This current survey has revealed that graziers rely on anthelmintics as their primary choice for liver fluke control. Reluctance to adopt IPM strategies and a continued heavy reliance on TCBZ, whilst basing anthelmintic decisions on perception rather than measurement and testing, pose threats for the future control of liver fluke in livestock within this endemic area.

Kangaroos and liver fluke: The role played in cross-species transmission and drug resistance.

Australian livestock are challenged by liver fluke (Fasciola hepatica) in grazing regions endemic to the intermediate snail host. Liver fluke infests a wide range of herbivores including free-roaming wildlife such as kangaroos (Macropods). The role played by Macropods in cross-species transmission and as vectors for anthelmintic resistance is largely unknown. In Phase 1 of this study, liver fluke of Eastern grey kangaroo (Macropus giganteus Shaw, 1790) origin (Kangaroo isolate) were artificially infected in sheep to confirm establishment and cross-species transmission. In Phase 2, the efficacy of triclabendazole (TCBZ) was assessed in vivo against the Kangaroo isolate to identify any drug resistance. Forty (40) merino sheep were housed in pens and allocated to one of 4 groups (Groups 1-4). Groups 1 and 2 were artificially infected with a TCBZ resistant liver fluke isolate (Oberon) originating from sheep whilst Groups 3 and 4 were infected with the Kangaroo isolate (Phase 1). At 9 weeks post infection (wpi), sheep in Groups 2 and 4 were treated with 10 mg/kg TCBZ (Phase 2). Sheep were subsequently euthanased at 11 wpi to conduct total fluke counts (TFC) in the liver. Faecal samples were collected fortnightly to measure fluke egg counts and coproantigens. Individual blood samples were collected, concurrently with faecal sampling, to monitor haematocrit and plasma proteins levels. Liver fluke of kangaroo origin established to patent infections in sheep with similar establishment and pathogenicity to the Oberon isolate. TCBZ achieved an 86 % reduction in TFC (99.8 % - adult fluke, 0 % - immature fluke) in sheep with the Kangaroo isolate and a 28 % reduction in the Oberon isolate (37 % - adult, 0 % - immature fluke). An 89 % reduction in faecal coproantigens was observed in sheep with the Kangaroo isolate and no reduction in sheep with Oberon. This study confirmed cross-species transmission of liver fluke from a kangaroo to sheep. When cohabiting the livestock grazing environment, kangaroos may act as reservoirs for liver fluke and vectors for drug resistance within liver fluke endemic areas.

Prevalence and gross pathology of liver fluke in macropods cohabiting livestock farms in north eastern NSW, Australia, and diagnosis using cELISA.

Liver fluke (Fasciola hepatica) is a parasite of herbivores including wildlife. Macropods, such as Eastern grey kangaroo (Macropus giganteus) and Common wallaroo (Osphranter robustus), are frequently observed sharing grazing sites with domestic livestock. The impact of Macropods, as reservoirs of infection, on livestock production and risks to cross-species transmission are largely unknown. In Phase 1 of this study, liver and faecal samples were collected from 245 Macropods (181 Eastern grey kangaroos, 64 Common wallaroos) cohabiting livestock farms (n = 7) in the Northern Tablelands regions of New South Wales. Total fluke (TFC) and fluke eggs (FEC) were counted in the liver and faeces, respectively, to assess prevalence. Faecal antigens were also measured using the commercial Bio-X Diagnostic Monoscreen AgELISA Fasciola hepatica kit (cELISA) to assess suitability as a diagnostic tool. In Phase 2, Macropod faecal samples were collected from 60 livestock farms to conduct FEC and assess prevalence by region. Liver fluke was prevalent in 22% of Eastern grey kangaroo and 20% of Common wallaroos with prevalence as high as 45% in the Eastern grey kangaroo. Fluke burdens ranged from 1 to 122 flukes (mean = 9 flukes) with a FEC range of 0-195 eggs per gram (epg) of faeces (mean = 18 epg). Evidence of dead and live flukes trapped within fibrotic capsules confirms the ability of Macropods to resolve infections. cELISA proved highly specific (100%) and sensitive (98%) in liver fluke detection however fibrotic capsules observed in the liver may reduce the correlation of coproantigens with fluke burden. Phase 2 revealed that 27% of livestock farms had Macropods infected with liver fluke. Overall, this study confirmed Eastern grey kangaroo and Common wallaroo are susceptible hosts and potential reservoirs for liver fluke and, monitoring infections in Macropods would assist in livestock disease management.

A Pilot Study Using Accelerometers to Characterise the Licking Behaviour of Penned Cattle at a Mineral Block Supplement.

Identifying the licking behaviour in beef cattle may provide a means to measure time spent licking for estimating individual block supplement intake. This study aimed to determine the effectiveness of tri-axial accelerometers deployed in a neck-collar and an ear-tag, to characterise the licking behaviour of beef cattle in individual pens. Four, 2-year-old Angus steers weighing 368 ± 9.3 kg (mean ± SD) were used in a 14-day study. Four machine learning (ML) algorithms (decision trees [DT], random forest [RF], support vector machine [SVM] and k-nearest neighbour [kNN]) were employed to develop behaviour classification models using three different ethograms: (1) licking vs. eating vs. standing vs. lying; (2) licking vs. eating vs. inactive; and (3) licking vs. non-licking. Activities were video-recorded from 1000 to 1600 h daily when access to supplement was provided. The RF algorithm exhibited a superior performance in all ethograms across the two deployment modes with an overall accuracy ranging from 88% to 98%. The neck-collar accelerometers had a better performance than the ear-tag accelerometers across all ethograms with sensitivity and positive predictive value (PPV) ranging from 95% to 99% and 91% to 96%, respectively. Overall, the tri-axial accelerometer was capable of identifying licking behaviour of beef cattle in a controlled environment. Further research is required to test the model under actual grazing conditions.

Prevalence and pathology of liver fluke (Fasciola hepatica) in fallow deer (Dama dama).

A survey conducted on fallow deer (n = 79) in northern New South Wales Australia, aimed to ascertain the prevalence and gross pathology of liver fluke. In total, three deer populations were assessed (1 farmed and 2 wild) across 2 sites (site A and B) by conducting total fluke counts in the liver and fluke egg counts in faecal samples. At site A, 16 of 19 farmed deer (84.2 %) and 9 of 20 wild deer (45 %) had active or resolved infections. At site B, 16 of 40 wild deer (40 %) had active or resolved infections. Deer with active infections had low fluke burdens (1-11 fluke) which were in the adult development stage, shedding eggs with faeces (0-121.7 eggs per gram). Liver pathology score did not exceed 3.5 out of 5 with gross pathomorphological lesions predominately confined to the peripheral regions of the left lobe. Farmed deer, confined within a fluky habitat, attained the highest group mean pathology score, with dense fibrosis and concomitant atrophy of the left lobe (site A: farmed - 1.8, wild- 0.6; site B: wild - 0.3). Well-defined fibrotic capsules captured and restricted fluke migration beyond the peripheral region of the left lobe of the liver. The presence of live and dead fluke within the fibrotic capsules confirms the inherent ability of fallow deer to resolve infections. This survey has highlighted the susceptibility of fallow deer to liver fluke within an endemic region. Recurrent exposure, as seen in the farmed deer confined within a fluky habitat, appears to strengthen tissue response in terms of gross pathology and may impede the release of fluke eggs from the liver. Low fluke burdens and limited lesions suggest fallow deer have a strong level of resistance to liver fluke. Nevertheless, within this endemic region, fallow deer are widespread and clearly facilitating the liver fluke life cycle. Further research is warranted to ascertain the impact of fallow deer on disease transmission in livestock production when cohabiting the grazing environment.

Alpaca Field Behaviour When Cohabitating with Lambing Ewes.

A common strategy to reduce predator attack on livestock is the deployment of guardian alpacas. However, little research has been conducted on the behaviour of this species while housed with other livestock. This study monitored two male alpacas cohabitating with 180 lambing ewes in order to quantify field behaviour in two phases. Phase one assessed diurnal patterns of alpacas and lambing ewes using Global Navigation Satellite System (GNSS) collars recording data over 41 days, in combination with observational recordings. Phase two developed an alpaca behavioural ethogram through continuous observations from 05:30 to 19:30 h over a 3-day period. The two alpacas shared similar behaviours with commonality of distance travelled, and both species exhibited an increase in activity level based on speed between the times of 05:00 and 17:00 h. The GNSS data indicated that the alpacas flocked with the ewes at night sharing the same resting location, however, would spend time during the day on the outskirts of the paddock. Alpacas were observed to spend the majority of the observation period in two behavioural states: grazing (57%) and resting (27%). As a result of this study we were able to catalogue a range and frequency of field behaviours which alpacas exhibit while cohabitating with lambing ewes. However, further research is needed to determine in more detail how these behaviours correspond with the effectiveness of this species as a livestock guardian.

Using Movement Sensors to Assess Lying Time in Horses With and Without Angular Limb Deformities.

Chronic musculoskeletal pathologies are common in horses, however, identifying related effects can be challenging. This study tested the hypothesis that movement sensors and analgesics could be used in combination to confirm the presence of restrictive pathologies by assessing lying time. Four horses presenting a range of angular limb deformities (ALDs) and four nonaffected controls were used. The study comprised two trials at separate paddock locations. Trial A consisted of a 3-day baseline phase and 2 × 3-day treatment phases, during which two analgesics were administered to two ALD horses and two controls in a standard crossover design. Trial B replicated trial A, except that as no difference between analgesics had been evident in trial A, only one analgesic was tested. Movement sensors were used to measure the horses' lying time and lying bouts. In trial A, ALD horses' basal mean lying time was significantly less than controls (means ± SD for ALD horses 213 ± 1.4 minutes and for controls 408 ± 46.7 minutes, P = .007); with analgesic administration, the difference became nonsignificant. In trial B, ALD horses' basal mean lying time was also significantly less than controls (ALD horses 179 ± 110.3 minutes; controls 422.5 ± 40.3 minutes, P < .001), again becoming nonsignificant with analgesic administration. Given the increases in ALD horses' lying time with analgesic administration, it is possible that their shorter basal lying time is associated with musculoskeletal discomfort. Despite the small sample size, movement sensors effectively measured this behavior change, indicating that they could be a useful tool to indirectly assess the impact of chronic musculoskeletal pathologies in horses.

Predicting Lameness in Sheep Activity Using Tri-Axial Acceleration Signals.

Lameness is a clinical symptom associated with a number of sheep diseases around the world, having adverse effects on weight gain, fertility, and lamb birth weight, and increasing the risk of secondary diseases. Current methods to identify lame animals rely on labour intensive visual inspection. The aim of this current study was to determine the ability of a collar, leg, and ear attached tri-axial accelerometer to discriminate between sound and lame gait movement in sheep. Data were separated into 10 s mutually exclusive behaviour epochs and subjected to Quadratic Discriminant Analysis (QDA). Initial analysis showed the high misclassification of lame grazing events with sound grazing and standing from all deployment modes. The final classification model, which included lame walking and all sound activity classes, yielded a prediction accuracy for lame locomotion of 82%, 35%, and 87% for the ear, collar, and leg deployments, respectively. Misclassification of sound walking with lame walking within the leg accelerometer dataset highlights the superiority of an ear mode of attachment for the classification of lame gait characteristics based on time series accelerometer data.