ORCID Profile
0000-0002-9696-2356
Current Organisations
Central Queensland University
,
Charles Sturt University
,
Charles Sturt University - Wagga Wagga Campus
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Physical Society (APS)
Date: 04-02-2021
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.PREVETMED.2019.104806
Abstract: A retrospective study was conducted on 1,178,329 cattle slaughtered at an eastern Australian abattoir between 2010 and 2018. The data were searched for records in which a diagnosis of hydatid disease was made by routine meat inspection and apparent prevalence was calculated. True prevalence of hydatid disease in any organ was then estimated using previously reported sensitivity and specificity for diagnosis of hepatic hydatid disease by routine meat inspection. Mixed effects logistic regression was conducted to assess putative associations between dentition (age), sex, and feed-type (grass- or grain-fed), and hydatid disease reported at slaughter, with origin (Property Identification Code [PIC] region) included as a random effect. Regression was also conducted on subsets stratified by dentition and feed-type to account for measurement bias resulting from differences in sensitivity and specificity between groups of cattle. Discrete-Poisson models (SaTScan, v.9.5) were used to detect spatio-temporal clustering of hydatid-positive cattle within PIC regions. The apparent prevalence of hydatid disease reported in any organ was 8.8% (n = 104,038 95% confidence interval [CI] 8.8-8.9%). The liver, lungs, heart, spleen, and kidneys were reported infected with hydatid cysts. Of cattle reported infected with hydatid cysts, 75.6% had both the liver and lungs reported infected. True prevalence was estimated to be 33.0% (95% CI 24.4-44.4%). Significant interaction between dentition and feed-type was identified. Risk of reported hydatid disease was highest in both eight-tooth grass- and eight-tooth grain-fed cattle (OR 17.5, 95% CI 17.0-18.1, reference level [ref] zero-tooth OR 4.8, 95% CI 4.4-5.2, ref zero-tooth, respectively). Sex was also significantly associated with reported cases of hydatid disease at slaughter, with the highest odds in females (two-tooth group, OR 1.2, 95% CI 1.1-1.2, ref male). Three spatio-temporal clusters of hydatid-positive regions were identified. The most likely cluster was located in north eastern New South Wales from June 2012 to September 2015 (log likelihood ratio 4774, P < 0.001). This study indicates a higher prevalence of hydatid disease than previously recognised and demonstrates that an effect of sex cannot be ruled out. The identification of clusters could indicate periods when hosts of Echinococcus were more abundant, or localised climatic events that facilitated transmission to cattle. Given the high prevalence, the financial impact of hydatid disease on the Australian beef industry and risk factors associated with variation in spatial distribution should be determined to target interventions.
Publisher: CSIRO Publishing
Date: 22-02-2022
DOI: 10.1071/AN21515
Abstract: The rise of sequencing technology brought about a surge of new methodologies that offered a new and deeper level of understanding of the role of the microbiome in the health and performance of livestock. This started a chain reaction in technology evolution, and a decade later, we have developed a new appreciation of a healthy gut and the role of early colonisation and nutrition in developing the microbiome, and its subsequent impact on animal productivity. An abundance of new products flooded the livestock supplement market with the promise of improving the health of intestinal microbiota. However, the impact of these products and any potential gains they might provide have not always been quantified or validated. Further to this, the potential interactions with the microbial community naturally occurring in the feed-base have not commonly been considered. We have recently shown that animal feed carries a complex microbial community that can have various impacts, including negating farm biosecurity measures. The ruminant animal provides an even greater level of complexity where physiological drivers act to maintain ruminal homeostasis. Despite many advances, numerous knowledge gaps remain, and the methodologies are not without their challenges with almost constant evolution in analysing and interpreting data. In this paper, we will discuss the benefits, challenges and shortfalls of microbiome science, its interfaces with multi-omics research and the strategies of its contribution to animal production science.
Publisher: CSIRO Publishing
Date: 03-02-2022
DOI: 10.1071/AN21528
Abstract: Context Neonate management remains a key issue in extensive beef production systems where producers are faced with substantial environmental and management challenges that limit their ability to monitor and manage livestock in a timely manner. Parturition is a critical event and can affect the calf health and survival, particularly in the perinatal period (up to 48 h after birth). As such, monitoring parturition using precision livestock technologies may provide producers with additional tools to manage their cattle and mitigate the impacts of neonatal mortality in extensive beef systems. Aims The purpose of this study was to determine whether data from a global navigation satellite system (GNSS) collar could be used to detect parturition events in extensively grazed beef cattle. Methods Forty-eight Bos taurus cows (583.5 kg body weight ± 9.25 s.e.m.) were allocated to a 28 ha paddock between 8 January 2021 and 6 March 2021 during the calving season. Thirty of the animals were fitted with GNSS-equipped collars (Smart Paddock, Vic., Australia) that captured data at 10 min intervals. Parturition events were recorded daily by visual observation. Collected data were used to calculate key predictive features related to calving behaviour. Derived features were compared and assessed for changes in the period surrounding parturition. Key results Increases were observed in distance to nearest neighbour and to herd aggregate features, and decreases were observed in paddock utilisation and distance travelled features in the lead-up to calving (P 0.05). Furthermore, the number of animals within a 20 m radius decreased significantly (P 0.05) in the lead up to parturition, supporting known isolation behaviours. Conclusions With further development of predictive algorithms, on-animal sensors may be valuable in the prediction of calving events in extensive beef production systems. Implications Remote management and monitoring with on-animal sensor technologies, such as GNSS collars and tags, will provide producers with an additional means of monitoring their animals, while overcoming many of the management challenges associated with extensive grazing operations.
Publisher: Wiley
Date: 21-12-2022
DOI: 10.1111/AVJ.13226
Abstract: Frothy bloat, associated predominantly with grazing legume‐based pastures, is considered the second most costly disease in beef cattle in southern Australia, costing $84.4 M annually. It frequently results in the sudden death of cattle. In response to concerns from cattle producers, an online survey was conducted in southern Australia in late 2020 to determine the impact of bloat, identify risk factors and determine the efficacy of current preventive measures. For 217 responses, over two‐thirds (70%) of producers reported bloat occurring in the previous 12 months, with estimated morbidity and mortality rates of 3.7% and 5.0% respectively. Bloat was associated with clover or clover‐dominant paddocks (79%) and was not associated with grass or grass‐dominant pastures or low clover pastures (92%) nor grazing crops (27%). For bloat that occurred in the past 12 months, cattle were very commonly grazing on clover or clover‐dominant paddocks (90%) and occasionally lucerne‐dominated paddocks (7%). Two‐thirds of producers reported having preventive measures in place when losses occurred. Bayesian Network analysis confirmed that grazing clover‐based pastures for more than 7 days, yearling cattle and the months of July–September were the main risk factors for bloat occurrence, with pasture type (clover) being the most important. Conversely, no clear relationship between weather conditions and bloat occurrence was evident. This survey highlights the known risk of clover‐based pastures for causing bloat in cattle, and that losses occur in many cases despite preventive measures being used. This suggests that current methods for preventing bloat in cattle are suboptimal.
Publisher: American Physical Society (APS)
Date: 26-02-2020
Publisher: Elsevier BV
Date: 09-2020
Publisher: Hindawi Limited
Date: 07-02-2021
DOI: 10.1111/TBED.13993
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.PREVETMED.2019.03.014
Abstract: Hydatid disease, caused by Echinococcus granulosus, is a widespread, endemic disease of Australian livestock, wildlife, and occasionally, humans. In the Australian beef industry, the disease is believed to have a substantial economic impact. The reference standard test (gold standard) for detection of hepatic hydatid cysts is gross identification of cysts following cutting of livers into 5-6 mm slices with histological identification in the case of equivocal cysts. This test is not feasible in abattoirs because it takes too long, destroys inspected livers which have monetary value, and could require laboratory facilities. Therefore, routine meat inspection in abattoirs comprises visualisation of the organ surface and palpation to detect hydatid cysts. In this study, we aimed to evaluate the diagnostic sensitivity and specificity of current routine meat inspection processes in an abattoir to detect hepatic hydatid disease (the index test) in comparison to the reference standard test. Both the index and reference standard tests were performed on a systematic random s le of 636 livers from 5023 cattle slaughtered during the study period. Relative proportions of the true positives and false negatives were calculated for categories age, sex, feed-type (grass- or grain-fed), number of cysts, and size of cysts. Pearson's Chi-squared analyses were used to assess the significance of these proportions. Relative diagnostic sensitivity and specificity of the index test were determined whilst accounting for the s ling fraction. The relative proportion of true positives to false negatives in livers with one cyst (True Positives [TP] = 30.2%) was significantly lower than in livers with 2-5 cysts (TP = 59.2% P < 0.05), and livers with more than ten cysts (TP = 75% P < 0.001). The diagnostic sensitivity and specificity of the index test was 24.9% (95% Confidence Interval [CI] 18.9-32.3) and 98.9% (95% CI 97.6-99.6), respectively. The high specificity demonstrates that truly uninfected livers are generally correctly reported. However, the low sensitivity of the index test indicates that prevalence reported by the focus abattoir is underestimated. Although the intended use of routine meat inspection for hydatid disease - to remove "unwholesome" meat from the line of human consumption - is conducted, the results of this study demonstrate that the prevalence of E. granulosus might be higher than reported in abattoir data.
Publisher: Oxford University Press (OUP)
Date: 10-2021
DOI: 10.1093/AF/VFAB055
Publisher: Elsevier BV
Date: 03-2020
Publisher: Wiley
Date: 20-01-2020
DOI: 10.1111/AVJ.12916
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.PREVETMED.2019.104791
Abstract: The characteristics and risk factors associated with hepatic Echinococcus granulosus sensu stricto infection (hydatid disease) were investigated in beef cattle slaughtered at an abattoir in eastern Australia. S led cattle were sourced from all eastern states, predominantly from regions associated with the Great Dividing Range. Livers and corresponding demographic data were collected from 601 carcasses. Livers were examined for the number, size, viability, and fertility of hydatid cysts. Mixed effects logistic regression was used to evaluate associations of sex, feed-type (grass- or grain-fed), and dentition (age) on hydatid disease. Hydatid cysts were detected in all dentition groups. The most commonly s led dentition group was zero-tooth cattle (less than 18 months). Twenty-nine percent of infected livers had only one cyst, and 48% of infected livers contained viable cysts. Thirty-seven percent of infected livers had cysts that were 3-10 mm in diameter. The size and number of cysts were positively correlated with age of the animal. Regression analysis showed that the odds of hydatid disease were highest in eight-tooth cattle (>42 months OR 26.9 95% CI 11.8-61.6 reference level [ref] zero-tooth). Being grass-fed was also significantly associated with the presence of hydatid disease (total effect OR 3.0 95% CI 1.7-5.5 ref grain-fed). Although there was no evidence of a total effect of sex across the study population, males of a given dentition group and feed-type (grass- or grain-fed) were more likely to be infected than respective females. Despite changes in Australian agriculture in the last 30 years, the burden (number, size, and viability of cysts) of hydatid disease in in idual infected animals remains similar to previous Australian studies.
Publisher: Elsevier BV
Date: 03-2020
Publisher: MDPI AG
Date: 28-09-2022
DOI: 10.3390/ANI12192609
Abstract: Chitosan oligosaccharide (COS) is derived through deacetylation of chitin from crustacean shells. Previous studies reported the benefits of COS to gut microbiota, immunity and health of host species. In this study, 120 pregnant composite ewes were sub ided into treatment and control groups in duplicate. COS was supplemented via a loose lick to provide an estimated intake of COS @100–600 mg/d/ewe for five weeks pre-lambing until lamb marking. Body weight was recorded pre-treatment for ewes, and at lamb marking and weaning for both ewes and lambs. Serum immunity markers immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), secretory immunoglobulin A (sIgA), interleukin (IL)-2, IL10 and faecal sIgA were determined for ewes and lambs at lamb marking and weaning by enzyme-linked immunosorbent assay (ELISA). We found that COS can be incorporated in sheep feed without compromising palatability. Maternal COS supplementation did not influence the body weight of ewes or lambs. It did, however, significantly increase the concentrations of serum IL2 in ewes at marking and weaning (p 0.001). In lambs, COS also significantly increased the IL2 concentration at making (p = 0.018) and weaning (p = 0.029) and serum IgM at marking (p 0.001). No significant effect was observed in the concentration of any other immune marker or cytokine in either ewes or lambs. In conclusion, maternal COS supplementation significantly modulated some immunity markers in both ewes and lambs. The short duration of maternal COS supplementation and optimal seasonal conditions during the trial may explain the lack of significant body weight in ewes and lambs from the COS supplementation.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 16-08-2019
Abstract: The general theory of relativity predicts that a star passing close to a supermassive black hole should exhibit a relativistic redshift. In this study, we used observations of the Galactic Center star S0-2 to test this prediction. We combined existing spectroscopic and astrometric measurements from 1995-2017, which cover S0-2's 16-year orbit, with measurements from March to September 2018, which cover three events during S0-2's closest approach to the black hole. We detected a combination of special relativistic and gravitational redshift, quantified using the redshift parameter ϒ. Our result, ϒ = 0.88 ± 0.17, is consistent with general relativity (ϒ = 1) and excludes a Newtonian model (ϒ = 0) with a statistical significance of 5σ.
No related grants have been discovered for Cara Wilson.