Output list
Journal article
Published 2025
PloS one, 20, 9, e0333526
Pulmonary hypertension (PH) in dogs, characterized by abnormally high blood pressure in the pulmonary arteries, presents a management challenge, and adjunctive therapies for the standard treatment of sildenafil are needed. This study aimed to determine whether the nutraceutical Perna canaliculus oil (PCSO-524), a marine lipid extract with anti-inflammatory properties, provides additional clinical benefits to dogs with PH. In a prospective, randomized, placebo-controlled trial, seventeen client-owned dogs diagnosed with PH were assigned to receive either PCSO-524 or a placebo as an add-on to their sildenafil-based therapy for 70 days. Key outcomes were evaluated using owner-assessed clinical scores for exercise tolerance and coughing, alongside echocardiographic measurements. The PCSO-524 group demonstrated a statistically significant improvement in exercise tolerance scores by day 70 (P = 0.009). This group also showed a greater reduction in coughing scores compared to the placebo group between day 35 and day 70 (P = 0.03). While the tricuspid regurgitation pressure gradient (TRPG), an estimate of pulmonary pressure, decreased significantly over time in all dogs (P = 0.001), no significant difference was found between the groups for this specific measure. These results indicate that PCSO-524 can serve as a beneficial adjunctive therapy for improving important clinical signs, such as exercise tolerance and coughing, in dogs with PH. This suggests it may be a valuable addition to standard management for enhancing quality of life.
Journal article
Published 2023
Animal production science, 63, 18, 1949 - 1957
The pet-food industry is a significant and rapidly growing market, with global sales estimated at over US$100 billion in 2020. The market size for pet food was estimated at 22.9 million tonnes in 2020. The number of cats and dogs being fed commercial pet food is also on the rise, with an estimated 62% of cats and 68% of dogs being fed commercial pet food in the United States alone with an estimated value of A$2.3 billion in 2020. This represents a growth of 3.3% from the previous year, and the market is expected to continue growing with a forecast compound annual growth rate (CAGR) of 3.4% from 2021 to 2025. The demand for high-quality, specialised pet-food products has led to consistent year-on-year growth in the industry. With this, the increasing demand for commercial pet food on a global scale comes with growing sustainability challenges that must be addressed. In this paper, we will examine some of the opportunities for the use of black soldier fly larvae (BSFL) meal and oil in pet-food formulations to reduce the environmental impact of pet food and pet ownership and deliver nutritional and functional benefits to our pets.
Journal article
Published 2013
New Zealand Veterinary Journal, 61, 6, 323 - 329
AIMS: To investigate associations between ruminal acidosis and body condition score (BCS), prevalence of poor rumen fill, diarrhoea and lameness in dairy cows in New South Wales and Victoria, Australia. METHODS: This was a cross-sectional study conducted in 100 dairy herds in five regions of Australia. Feeding practices, diets and management practices of herds were assessed. Lactating cows within herds were sampled for rumen biochemistry (n = 8 per herd) and scored for body condition, rumen fill and locomotion (n = 15 per herd). The consistency of faecal pats (n = 20 per herd) from the lactating herd was also scored. A perineal faecal staining score was given to each herd. Herds were classified as subclinically acidotic (ACID), suboptimal (SO) and non-acidotic (Normal) when ≥3/8 cows per herd were allocated to previously defined categories based on rumen biochemical measures. Multivariate logistic regression models were used to examine associations between the prevalence of conditions within a herd and explanatory variables. RESULTS: Median BCS and perineal staining score were not associated with herd category (p >0.05). In the multivariate models, herds with a high prevalence of low rumen fill scores (≤2/5) were more likely to be categorised Normal than SO with an associated increased risk of 69% (p = 0.05). Herds that had a greater prevalence of lame cows (locomotion scores ≥3/5), had 103% higher risk of being categorised as ACID than SO (p = 0.034). In a multivariate logistic regression model, with herd modelled as a random effect, an increase of 1% of pasture in the diet was associated with a 5.5% increase in risk of high faecal scores (≥4/5) indicating diarrhoea (p = 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: This study confirmed that herd categories based on rumen function are associated with biological outcomes consistent with acidosis. Herds that had a higher risk of lameness also had a much higher risk of being categorised ACID than SO. Herds with a high prevalence of low rumen scores were more likely to be categorised Normal than SO. The findings indicate that differences in rumen metabolism identified for herd categories ACID, SO and Normal were associated with differences in disease risk and physiology. The study also identified an association between pasture feeding and higher faecal scores. This study suggests that there is a challenge for farmers seeking to increase milk production of cows on pasture to maintain the health of cattle.
Journal article
Feeding management and feeds on dairy farms in New South Wales and Victoria
Published 2012
Animal Production Science, 52, 1, 20 - 29
Feeding practices in Australian dairy herds were recorded in 100 dairy herds in five districts of two states. A questionnaire about the feeding practices was completed and pasture samples were also collected, where applicable, for analysis. Data and pasture samples were collected once from each farm with visits to regions occurring at different times of the year. Diets were evaluated for nutritional adequacy using the CPM Dairy program. Average milk yield on the day of sampling was 22.8 L/day. The combination of grazed pasture with grain fed during milking was the most prevalent feeding system (54%) in all areas. This was followed by combination of pelleted grain/by-products combined with pasture grazing (25%). Only one herd in the study was not feeding any form of concentrates at the time of sampling. The estimated percentage of concentrate in the diet ranged from 25% +/- 11.6 to 44% +/- 12.0. Wheat, which was fed at up to 9.8 kg/cow. day DM was the most prevalent grain in all areas, except for Gippsland. The predominant sources of protein in all areas were canola meal, cottonseed meal and lupins. By-products were prevalent, with brewers grain and wheat millrun the most commonly used, fed at 2.8 and 1.6 kg/cow. day DM, respectively. Most farms (81/100) incorporated at least one type of 'buffer' in the ration, and limestone (67%) was the most prevalent mineral additive. Monensin and virginiamycin were fed in all areas, with a varying prevalence. Feeding or dose rates used for minerals and rumen modifiers were not always appropriate to those recommended for mineral needs or control of rumen function. This paper demonstrated that a wide variety of feeding systems are used in Australian dairy herds and provides information on nutritive characteristics of pastures.
Conference paper
Published 2011
19th Conference of the Association for the Advancement of Animal Breeding and Genetics, 19/07/2011–21/07/2011, Perth, Western Australia
One hundred and fifty female Angus cattle were genotyped for the bovine leptin gene SNPs UASMS1, UASMS2, E2FB and E2JW. Net Feed Intake (NFI) Estimated Breeding Values (EBVs) and E2JW SNP data was also acquired from 169 Angus cattle that originated from Trangie Research Station, NSW, and were selected for a divergence in feed efficiency. The E2JW SNP was associated with NFI, NFI EBV and P8 fatness. The UASMS1 and UASMS2 SNPs were associated with circulating leptin concentrations. These particular associations have not been reported previously but similar associations have reported in North American studies. The inconsistent associations suggest that these SNPs are not good candidates for marker-assisted selection for NFI. Also, the investigation of associations with endocrine profiles that reflect body composition such as leptin, requires genotyping of a larger number of Australian cattle than was possible in this experiment.
Journal article
Rural veterinary services in Western Australia: Part B. Rural practice
Published 2008
Australian Veterinary Journal, 86, 3, 74 - 80
Objective To determine the current status of rural veterinary services in Western Australia. Procedure A questionnaire was sent to all eligible rural practitioners registered in 2006 and the replies were transferred to Microsoft Excel for analysis. Results Of the rural practitioners invited to participate in the survey replies were received from 67%. There were equal numbers of females and males. Their mean age was 44 years. Ninety per cent of respondents considered knowledge gained as an undergraduate was sufficient to equip them for practice, but only 60% considered their practical skills adequate. Thirteen per cent of those in rural practices in 2005 had left by 2006. Eighty-nine per cent of respondents were in mixed practice, the balance in specific species practice, such as equine, large animal and production animal consultancy. The majority of rural practitioners relied on servicing companion animals for their viability; 7% earned their income from servicing production animals only. Seventy per cent utilised merchandising and the sale of pet foods to supplement the income received from the traditional veterinary services and 34% found it necessary to earn an independent income. A quarter considered that rural practice did not have a future. Conclusion The majority of rural practitioners in Western Australia depend on companion animals, not production animals, to remain viable, with very few operating production animal services. Poor remuneration is a major reason why veterinarians leave rural practice, and many find it necessary to supplement their income or develop an independent income.
Journal article
Rural veterinary services in Western Australia: Part A. Government veterinary services
Published 01/2008
Australian Veterinary Journal, 86, 1-2, 7 - 11
Objective To determine the status of rural veterinary services in Western Australia. Procedure Two questionnaires were mailed to eligible, registered veterinary surgeons in Western Australia in 2006. The first was mailed to government veterinarians and the second to private practitioners in rural practice. Part A presents the replies from government veterinary officers and Part B the replies from rural practitioners. Replies were transferred to Microsoft Excel for analysis. Results Sixty-seven per cent of government veterinary officers responded to the questionnaire. Eighty per cent of these had been in the service for 20 years or more and their average age was 54. Work with sheep and beef cattle occupied 75% of their time, with dairy cattle receiving 10% and pigs and poultry less than 10%. The majority of respondents reported changes in the attitude of farmers to the service as a result of rural recessions and the decision to make a direct charge for government veterinary services. Although most respondents thought that the government veterinary service would continue in the future there were differences of opinion as to what form that would take. Conclusion Government veterinary services in Western Australia are undergoing major changes, with the service decreasing in size and scope. Recently the Department of Agriculture has been renamed the Department of Agriculture and Food and it is likely that the role of its veterinary officers will change accordingly.
Journal article
The definition of acidosis in dairy herds predominantly fed on pasture and concentrates
Published 2008
Journal of Dairy Science, 91, 1, 308 - 321
This cross-sectional survey examined the prevalence of ruminal acidosis and the effects of acidosis on the production of dairy cattle. Eight fresh cows, 3 primiparous and 5 multiparous (<100 d in milk), were selected randomly from each of 100 dairy herds in 5 regions of Australia. Rumen fluid was obtained from each cow by rumenocentesis and a stomach tube, and samples were tested for pH. Stomach tube rumen fluid samples were analyzed for volatile fatty acid, ammonia, and d-lactate concentrations. On the basis of the results of all assays, cows were categorized into 3 distinct categories (categories 1, 2, and 3) by cluster analysis. The percentages of cattle in categories 1, 2, and 3 were 10.2, 29.9, and 59.9%, respectively. Mean rumen pH for categories 1, 2, and 3 were 5.74±0.47, 6.18±0.44, and 6.33±0.43, respectively. Biochemically, categories 1, 2, and 3 were characterized, respectively, as follows: mean total VFA concentration (mM), 100.74±23.22, 94.79±18.13, and 62.81±15.65; mean ammonia concentration (mM), 2.46±2.02, 7.79±3.75, and 3.64±2.03; and mean d-lactate concentration (mM), 0.34±0.86, 0.28±0.97, and 0.12±0.51. Category 1 cows had higher propionate, valerate, isovalerate, and caproate concentrations and were of lower parity than cows in other categories. Cows in category 1 had higher milk production but lower milk fat content than category 2 cows. Herds were assigned to 1 of 3 groups according to the numbers of cows assigned to each category. Herds with ≥3 of the 8 cows in category 1 were classified as acidotic. Herds with ≥3 of the 8 cows in category 2 were classified as having suboptimal rumen function, and herds with ≥3 of the 8 cows in category 3 were classified as normal. Herds that had 3 or more of the 8 cows in category 1 (acidotic herds) had diets with higher energy and nonfiber carbohydrate contents and a lower neutral detergent fiber content than herds with a high prevalence of category 2 or 3 cows. The lack of significance of a herd effect in the statistical models developed suggests that the categories were robust across production systems, in which diets varied from all pasture to total mixed rations. A point prevalence of 10% (95% credible interval, 8 to 12%) of cows with an acidotic profile indicates a high risk for acidosis in the cattle sampled. The higher nonfiber carbohydrate and lower neutral detergent fiber contents of diets for herds with a high prevalence of category 1 cows (acidotic herds) indicates that there may be opportunities to reduce the risk of acidosis by dietary manipulation.
Journal article
Clinical acidosis in a Gippsland dairy herd
Published 2005
Australian Veterinary Journal, 83, 6, 347 - 352
Objective: To report on spontaneous clinical and subclinical acidosis in a large dairy herd, to evaluate the diets and feeding strategies involved, and to report on measures of rumen function in the cows affected. Design: A Gippsland dairy herd was sampled as part of a wider randomised cross-sectional study that examined the prevalence, risk factors for, and effects of, acidosis on rumen function of dairy cattle. Three herds on the farm were involved in the study: the transition herd (cows 3 weeks prior to calving), the very fresh lactating herd (1
Journal article
Nutrition during live export of cattle
Published 2003
Recent Advances in Animal Nutrition in Australia, 14, 49 - 56
This paper reports work aimed at improving performance and welfare of cattle during live export for long periods aboard ship. Roughage quality was manipulated in pellet diets to promote better nutritional performance and reduced nitrogen excretion. The type of pellet binder us manipulated to decrease urinary pH and consequent ammonia volatilisation. Rooms were established to simulate heat and humidity loads during live export, and feed and water intake and liveweight of Bos taurus and Bos indicas cattle were monitored in these conditions. Good quality roughage decreased estimated total nitrogen excretion and still maintained cost—effective liveweight gain. Lime produced alkaline urinary pH. Use of gypsum instead of lime, or addition of acid salts such as ammonium chloride or calcium chloride to lime, acidified urinary pH. These dietary manipulations of roughage quality and acid salts reduced atmospheric ammonia under simulated export environments but lucerne diets produced high atmospheric ammonia. Nutritional performance of cattle can be improved cost-effectively by diets containing good quality roughage instead of straw. Atmospheric ammonia can be reduced by addition of acidifying salts such as calcium chloride to export diets. Under high heat and humidity loads the feed intake of B. Taurus decreased, the feed intake of B. indicus did not change, but the water intake of both species increased. B. indicas rapidly recovered any liveweight lost under high heat and humidity within six days of recovery but B. Taurus cattle did not. B. indicas cattle cope significantly better with high heat and humidity loads than B. taurus cattle.