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Dive into the research topics where R. D. Bush is active.

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Featured researches published by R. D. Bush.


Asian-australasian Journal of Animal Sciences | 2015

A Review of Recent Developments in Buffalo Reproduction — A Review

Hassan Warriach; David McGill; R. D. Bush; Peter Wynn; K. R. Chohan

The buffalo is an important livestock resource in several countries of South Asia and the Mediterranean regions. However, reproductive efficiency is compromised due to known problems of biological and management origins, such as lack of animal selection and poor nutrition. Under optimal conditions puberty is attained at 15 to 18 months in river buffalo, 21 to 24 months in swamp buffalo and is influenced by genotype, nutrition, management and climate. However, under field conditions these values deteriorate up to a significant extant. To improve reproductive efficiency, several protocols of oestrus and ovulation synchronization have been adopted from their use in commercial cattle production. These protocols yield encouraging pregnancy rates of (30% to 50%), which are comparable to those achieved in buffaloes bred at natural oestrus. The use of sexed semen in buffalo heifers also showed promising pregnancy rates (50%) when compared with conventional non-sexed semen. Assisted reproductive technologies have been transferred and adapted to buffalo but the efficiency of these technologies are low. However, these latest technologies offer the opportunity to accelerate the genetic gain in the buffalo industry after improving the technology and reducing its cost. Most buffaloes are kept under the small holder farming system in developing countries. Hence, future research should focus on simple, adoptable and impact- oriented approaches which identify the factors determining low fertility and oestrus behaviour in this species. Furthermore, role of kisspeptin needs to be explored in buffalo.


Animal Production Science | 2011

Improving sheep production and welfare in extensive systems through precision sheep management

Jessica E. Morris; G. M. Cronin; R. D. Bush

This overview discusses how precision sheep management could be utilised in the Australian sheep industry to improve production efficiency and reduce animal welfare concerns due to low monitoring frequency by stockpeople. The concept of precision sheep management is described. This is a system in which sheep are managed as individuals or small groups rather than as a (whole) flock. Precision sheep management utilises the application of radio frequency identification technology, enabling producers to better monitor sheep in extensive situations, and contribute to improved efficiency of management and sheep welfare. Examples of combining radio frequency identification with other technologies such as walk-over-weighing and Pedigree Matchmaker are discussed. These technologies provide producers with tools to improve the cost effectiveness of, and labour efficiency associated with, collecting data on individual animals. The combined technologies should also improve consistency and reliability of information, enhancing decision-making by producers, for example, from regular monitoring of biometric variables such as liveweight, or calculating breeding values to enable superior genetic comparisons over time.


Transboundary and Emerging Diseases | 2015

Financial Impact of Foot and Mouth Disease on Large Ruminant Smallholder Farmers in the Greater Mekong Subregion

S. Nampanya; Syseng Khounsy; A. Phonvisay; J. R. Young; R. D. Bush; P. A. Windsor

A retrospective investigation of financial losses incurred by large ruminant smallholder farmers due to outbreaks of foot and mouth disease (FMD) in 2010-12 in northern Laos was conducted in 2012. The aim was to support recommendations on sustainable transboundary animal disease control strategies in the Greater Mekong Subregion (GMS). Large ruminant smallholders in the three northern provinces of Luang Prabang (LPB), Xiengkhoung (XK) and Xayyabouli (XYL) were interviewed (n = 310). Financial losses were determined, including direct losses due to mortality (100% of pre-FMD sale value) and morbidity (difference between the expected sale price pre-FMD and 1 month following onset of FMD), and indirect losses due to costs of treatments. The losses due to FMD per household varied between provinces (P < 0.001) and were USD 1124, USD 862 and USD 381 in LPB, XK and XYL, respectively, being 60, 40 and 16% of annual household income. Comparison of the costs of FMD with annual household income from sales of large ruminants indicated losses of 213, 181 and 60% of the income in LPB, XK and XYL, respectively. The variation in losses between provinces was due to differences in levels of morbidity with highest in LPB, treatment methods with antibiotic use common in LPB, age of animals sold and sale prices with higher prices in XK. Partial budget analysis of biannual FMD vaccination indicated an average net benefit of USD 22 and USD 33 for cattle and buffalo, respectively. However, vaccination alone is unlikely to control FMD in the region. Promotion of multiple large ruminant health and production intervention programmes to stimulate interest in biosecurity in addition to vaccination is recommended, providing a more sustainable pathway for poverty reduction through the current expansion of livestock investments in the GMS.


Journal of Animal Science | 2013

Effects of crude glycerin supplementation on wool production, feeding behavior, and body condition of Merino ewes.

S. J. Meale; A. V. Chaves; S. Ding; R. D. Bush; T. A. McAllister

The increasing availability of crude glycerin from the biodiesel industry has led to an interest in its use as an energy source in ruminant diets. However, its effects on ruminal fermentation patterns and methane (CH4) production are unclear, and there are no reports on the effect of its inclusion in the diet on wool production or growth of Merino sheep. Thus, the objectives of this study were to determine the effects of increasing levels of crude glycerin on in vitro ruminal fermentation and CH4 production and DMI, BW, feeding behavior, and wool growth and quality in Merino ewes. Crude glycerin (99.2% pure, colorless, odorless, viscous liquid) replaced whole wheat grain in completely pelleted diets at levels of 0%, 6%, and 12% DM in both in vitro and in vivo studies. For in vitro studies, diets were dried and ground through a 1-mm screen and incubated on 2 different days for 24 h. Modified McDougals buffer and rumen liquor were mixed 3:1, and gas production and CH4 concentration was measured after 6, 12, and 24 h of incubation with pH and IVDMD measured at 24 h. Cumulative gas (mL/g DM) and methane (mL) production was similar (P ≥ 0.35) among dietary treatments. In vitro dry matter disappearance (%) increased (P < 0.01) with increasing concentrations of crude glycerin. For the in vivo study, 39 Merino ewes were randomly assigned to 3 treatments (n = 13 ewes/treatment). Pelleted diets were available continuously for a 10-wk period through the use of automatic feeders. Ewes were weighed every 7 d. Wool yield was determined on mid-side patches of 100 cm(2) shorn at d 0 and d 70. Dye bands were used to determine wool growth and fiber length. Intake and ADG were similar among treatments (P = 0.59). Neither wool yield, length, spinning fineness, nor fiber diameter (μm) were affected after supplementation with crude glycerin (P ≥ 0.13). This study indicates the potential for crude glycerin to be included in the diets of Merino sheep at up to 12% DM without negatively affecting wool yield and quality.


Animal Production Science | 2013

Progressing smallholder large-ruminant productivity to reduce rural poverty and address food security in upland northern Lao PDR

S. Nampanya; Syseng Khounsy; Luzia Rast; J. R. Young; R. D. Bush; P. A. Windsor

Applied participatory research on large-ruminant health and production was conducted in six villages in northern Lao PDR. Three villages were classified as ‘high intervention’ (HI) and the remaining three as ‘low intervention’ (LI) sites, with a suite of health and productivity interventions implemented in the HI sites enabling comparison of outcomes with the LI sites, where only a vaccination program was introduced. A 3-year longitudinal study to establish baseline production variables, including liveweight, average daily weight gain (ADG) and reproductive performance, was conducted. The study involved 1500 head of cattle and buffalo that were ear-tagged and weighed every 3–4 months between 2008 and 2011, producing 10 data-collection points. Significant differences in ADG of the cattle between the provinces (P < 0.001), but not between HI and LI villages (P = 0.39), was observed. Low calving rates (51–75% and 41–52%) and inter-calving intervals (13.6–15.7 and 18.6–20.6 months) for cattle and buffalo, respectively, were observed. An on-farm large ruminant-fattening trial (n = 44) was conducted over a 4-month period to examine differences in productivity between cut-and-carry stall fattening (n = 26) and free-grazing (n = 18) systems. Cattle and buffalo in fattening stalls (320 and 217 g/day) had significantly greater ADG than those free-grazing (40 and 85 g/day) (P < 0.001 and P = 0.001). The increase in sale value for fattened cattle and buffalo was US


Australian Veterinary Journal | 2008

Financial modelling of the potential cost of ovine Johne's disease and the benefit of vaccinating sheep flocks in southern New South Wales.

R. D. Bush; P. A. Windsor; J. A. Toribio; Sr Webster

78 and US


Meat Science | 2016

Effect of electrical stimulation and ageing period on alpaca (Vicugna pacos) meat and eating quality

M.A. Smith; R. D. Bush; R.J. van de Ven; D.L. Hopkins

123, respectively. The longitudinal study indicated that if risks of important diseases such as foot and mouth disease and haemorrhagic septicaemia are controlled by vaccination and biosecurity, improved productivity outcomes in northern Lao PDR can be achieved by establishing forage plantations to better manage variations in seasonal availability of feed and enabling fattening. We conclude that improved large-ruminant productivity, by improving health and nutrition practices, offers opportunities for smallholder farmers to increase livestock income, alleviate rural poverty and improve regional food security in South-east Asia.


Transboundary and Emerging Diseases | 2015

The Socioeconomic Impacts of Clinically Diagnosed Haemorrhagic Septicaemia on Smallholder Large Ruminant Farmers in Cambodia

M. Kawasaki; J. R. Young; S. Suon; R. D. Bush; P. A. Windsor

OBJECTIVE To develop an enterprise gross margin (GM) model that predicts the on-farm financial impact of ovine Johnes disease (OJD) for various sheep enterprises in Australia. In addition, to estimate the benefits and costs of control through the use of the Gudair vaccination, including a breakeven point. DESIGN AND POPULATION Data for the model was gained from an observational study conducted over a 3-year period from 2002 to 2004 using sheep from 12 OJD-infected flocks from southern New South Wales. Flocks ranged between 3500 and 20,000 sheep, with owner estimates of 5% or greater OJD mortality at the start of the study. PROCEDURE A GM model was developed to predict the on-farm financial impact of OJD for various sheep enterprises in Australia, comparing non-infected, infected (status quo) and infected (vaccination) disease scenarios. RESULTS Vaccination breakeven points are achieved within 2 to 3 years for breeding enterprises if OJD mortalities are high, rising towards 7 years for a Merino ewe enterprise if OJD mortalities are low. CONCLUSION The GM model demonstrates the returns to investment of vaccination for Australian sheep producers with OJD-infected flocks.


Animal Production Science | 2010

Effects of feeding fresh citrus pulp to Merino wethers on wool growth and animal performance.

Y. T. E. Fung; J. Sparkes; I. van Ekris; A. V. Chaves; R. D. Bush

This study investigated the effects of using medium voltage (~300 V) electrical stimulation (ES) and ageing on alpaca meat. A total of 50 huacaya alpacas were distributed across three age groups (18, 24 and 36 months) and two genders (females and castrated males). At 24h post mortem the m. longissimus thoracis et lumborum (LL) and m. semimembranosus (SM) muscles were removed and aged for either 5 or 10 days. In comparison to non-ES samples, ES significantly reduced: LL purge values by 3.0% and LL shear force (SF) at 5 and 10 days (by 21.6N and ageing further reduced tenderness by 6.6N), and SM SF by 5.8 N with significant age effects observed in both ES and non-ES SM samples, such that SF increased by 0.53 N with each month increase in animal age. Consumers rated ES samples higher on tenderness, juiciness, flavour and overall rating. ES and ageing of alpaca carcasses are recommended.


Meat Science | 2015

Carcass traits and saleable meat yield of alpacas (Vicugna pacos) in Australia.

M.A. Smith; R. D. Bush; Peter C. Thomson; D.L. Hopkins

Haemorrhagic septicaemia (HS) is an acute fatal infectious disease of mainly cattle and buffalo and outbreaks occur commonly in Cambodia. Disease outbreak reports were examined to select five villages from three provinces for a retrospective investigation of HS epidemiology and socioeconomic impact on smallholders, with an aim of identifying potential benefits from improving disease prevention through biosecurity and vaccination. The Village Animal Health Worker (VAHW) or Chief in each village and 66 affected smallholders were surveyed. At the village level, 24% of all households were affected with an estimated mean village herd morbidity of 10.1% and mortality of 28.8%. Affected farmers reported HS disease morbidity and mortality at 42.7% and 63.6% respectively. Buffalo had a higher morbidity (OR = 2.3; P = 0.003) and mortality (OR = 6.9; P < 0.001) compared with cattle, and unvaccinated large ruminants a higher morbidity (OR = 2.9; P = 0.001). The financial impact varied depending on whether the animal survived, provision of treatment, draught replacement and lost secondary income. The mean cost per affected household was USD 952.50 based on ownership of five large ruminants. The impact per affected animal was USD 375.00, reducing the pre-disease value by 66.1%. A partial budget revealed an overwhelming incentive for farmers to practice biannual vaccination, with a net benefit of USD 951.58 per household based on an annual disease incidence rate of 1. Sensitivity analysis showed that a net benefit of USD 32.42 remained based on an outbreak every 20 years. This study indicates HS can cause a catastrophic financial shock to smallholders and remains a critical constraint to improving large ruminant productivity and profitability. Addressing HS disease control requires a focus on improving smallholder farmer knowledge of biosecurity and vaccination and should be priority to stakeholders interested in addressing regional food insecurity and poverty reduction.

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David McGill

Charles Sturt University

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S. Suon

Ministry of Agriculture

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Hassan Warriach

University of Veterinary and Animal Sciences

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