David W. Miller

Dr. David W. Miller

College of Science, Health, Engineering & Education, Murdoch University, Murdoch, WA 6150, Australia
orcid

Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2002 in Animal Reproduction Science
Verified
Journal Article
Closed access
MRM.T Rae
M.T Rae
CKC.E Kyle
C.E Kyle
DMDavid W. Miller
David W. Miller
AHA.J Hammond
A.J Hammond
ABA.N Brooks
A.N Brooks
SRS.M Rhind
S.M Rhind

7 March 2011 in Animal Production Science
Verified
Journal Article
Closed access
PDF file
CSC. A. Stockman
C. A. Stockman
TCTeresa Collins
Teresa Collins
ABAnne Barnes
Anne Barnes
DMDavid W. Miller
David W. Miller
SWS. L. Wickham
S. L. Wickham
PFPatricia Fleming
Patricia Fleming
The present study examined whether observers could distinguish between cattle that are naïve to road transport and the same cattle after becoming more habituated to transport. The behavioural expression of cattle was assessed through the method of qualitative behavioural assessment (QBA), and these assessments were correlated with various physiological parameters. Fourteen Angus steers were assessed during their first road trip and then again on their ninth trip, 15 days later. Blood samples were collected immediately before and after transport, and heart rate and core body temperature were measured continuously throughout each trip. Video footage recorded during each trip was edited and clips showing each individual within the first 30 min of departure were randomly ordered and shown to observers for QBA. There was significant (P < 0.001) consensus among 40 observers in their assessment of behavioural expression of the cattle. Transport-naïve cattle were described as more ‘agitated’, while transport-habituated were described as more ‘calm’. Core body temperature (P < 0.01), plasma glucose (P < 0.05) and the neutrophil : lymphocyte ratio (P < 0.01) were higher for the first trip than for the habituated trip (P < 0.01). QBA were significantly correlated with core body temperature (P < 0.01), heart rate (P < 0.01), plasma glucose (P < 0.05) and the neutrophil : lymphocyte ratio (P < 0.01). QBA appears to be a valid and integrative method of assessing cattle welfare under the conditions tested within the present study. There was significant consensus in the ability of human observers to interpret behavioural expression of cattle during this experiment. In addition, observers could identify differences in behavioural expression between cattle that were naïve versus habituated to transport, and these differences were supported by physiological measurements.

1 December 2001 in Reproduction
Verified
Journal Article
Open access
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MRM T Rae
M T Rae
SPS Palassio
S Palassio
CKC E Kyle
C E Kyle
ABA N Brooks
A N Brooks
RLR G Lea
R G Lea
SRS M Rhind
S M Rhind
Gonad development in female sheep fetuses is thought to occur in a number of key stages. The aim of this study was to determine the effects of maternal undernutrition, applied at one or more of these critical stages, on fetal ovarian development. Groups of ewes (n = 11-19) were fed rations providing either 100% (high; H) or 50% (low; L) of energy requirements for live weight maintenance during selected 'windows' during gestation. Control ewes (HH and HHH) were fed the H ration from mating until they were killed at days 50, 65 (HH) or 110 (HHH) of gestation, whereas ewes of other groups were fed the L ration for the periods between day 0 and day 30 of gestation (LH and LHH), day 31 and day 50 or 65 of gestation (HL and HLH), day 65 and day 110 of gestation (HHL) or day 0 of gestation until the animals were killed (LL and LLL). At day 50 of gestation, there was no effect of nutritional treatment on mean fetal mass but compared with HH animals, mean fetal ovarian mass was significantly lower in HL (P < 0.05) and LL (P < 0.001) animals. At day 65 of gestation, there were significantly fewer germ cells (P < 0.05) at the resting, diplotene stage of initial meiosis in LL animals than there were in HH animals, indicating delayed germ cell maturation and onset of meiosis. Qualitative assessment of proliferative cell nuclear antigen immunostaining indicated that, at day 50 of gestation, staining was located predominantly in the germ cells, whereas by day 65 of gestation, staining was confined predominantly to somatic cells. Undernutrition in each one of these windows was associated with delayed ovarian follicular development (P < 0.05-0.001) as measured by development of the granulosa cell layer at day 110 of gestation. This study demonstrates that undernutrition before and during folliculogenesis can delay fetal follicular development.

1 December 2008 in Nutrition Research Reviews
Verified
Journal Article
Closed access
JRJohn R. Roche
John R. Roche
DBDominique Blache
Dominique Blache
JKJane K. Kay
Jane K. Kay
DMDale R. Miller
Dale R. Miller
ASAngela J. Sheahan
Angela J. Sheahan
DMDavid W. Miller
David W. Miller
The central nervous system undertakes the homeostatic role of sensing nutrient intake and body reserves, integrating the information, and regulating energy intake and/or energy expenditure. Few tasks regulated by the brain hold greater survival value, particularly important in farmed ruminant species, where the demands of pregnancy, lactation and/or growth are not easily met by often bulky plant-based and sometimes nutrient-sparse diets. Information regarding metabolic state can be transmitted to the appetite control centres of the brain by a diverse array of signals, such as stimulation of the vagus nerve, or metabolic ‘feedback’ factors derived from the pituitary gland, adipose tissue, stomach/abomasum, intestine, pancreas and/or muscle. These signals act directly on the neurons located in the arcuate nucleus of the medio-basal hypothalamus, a key integration, and hunger (orexigenic) and satiety (anorexigenic) control centre of the brain. Interest in human obesity and associated disorders has fuelled considerable research effort in this area, resulting in increased understanding of chronic and acute factors influencing feed intake. In recent years, research has demonstrated that these results have relevance to animal production, with genetic selection for production found to affect orexigenic hormones, feeding found to reduce the concentration of acute controllers of orexigenic signals, and exogenous administration of orexigenic hormones (i.e. growth hormone or ghrelin) reportedly increasing DM intake in ruminant animals as well as single-stomached species. The current state of knowledge on factors influencing the hypothalamic orexigenic and anorexigenic control centres is reviewed, particularly as it relates to domesticated ruminant animals, and potential avenues for future research are identified.

23 April 2008 in Molecular Human Reproduction
Verified
Journal Article
Open access
PDF file
PFPaul A Fowler
Paul A Fowler
NDNatalie J. Dorà
Natalie J. Dorà
HMHelen McFerran
Helen McFerran
MAMaria R. Amezaga
Maria R. Amezaga
DMDavid W. Miller
David W. Miller
SRStewart M. Rhind
Stewart M. Rhind
Epidemiological studies of the impact of environmental chemicals on reproductive health demonstrate consequences of exposure but establishing causative links requires animal models using ‘real life’ in utero exposures. We aimed to determine whether prolonged, low-dose, exposure of pregnant sheep to a mixture of environmental chemicals affects fetal ovarian development. Exposure of treated ewes (n = 7) to pollutants was maximized by surface application of processed sewage sludge to pasture. Control ewes (n = 10) were reared on pasture treated with inorganic fertilizer. Ovaries and blood were collected from fetuses (n = 15 control and n = 8 treated) on Day 110 of gestation for investigation of fetal endocrinology, ovarian follicle/oocyte numbers and ovarian proteome. Treated fetuses were 14% lighter than controls but fetal ovary weights were unchanged. Prolactin (48% lower) was the only measured hormone significantly affected by treatment. Treatment reduced numbers of growth differentiation factor (GDF9) and induced myeloid leukaemia cell differentiation protein (MCL1) positive oocytes by 25–26% and increased pro-apoptotic BAX by 65% and 42% of protein spots in the treated ovarian proteome were differently expressed compared with controls. Nineteen spots were identified and included proteins involved in gene expression/transcription, protein synthesis, phosphorylation and receptor activity. Fetal exposure to environmental chemicals, via the mother, significantly perturbs fetal ovarian development. If such effects are replicated in humans, premature menopause could be an outcome.

3 May 2016 in Animal Production Science
Verified
Journal Article
Open access
PDF file
PFPatricia Fleming
Patricia Fleming
TCTaya Clarke
Taya Clarke
SWSarah L. Wickham
Sarah L. Wickham
CSCatherine A. Stockman
Catherine A. Stockman
ABAnne Barnes
Anne Barnes
DMDavid W. Miller
David W. Miller
Animal welfare is increasingly important for the Australian livestock industries, to maintain social licence to practice as well as ensuring market share overseas. Improvement of animal welfare in the livestock industries requires several important key steps. Paramount among these, objective measures are needed for welfare assessment that will enable comparison and contrast of welfare implications of husbandry procedures or housing options. Such measures need to be versatile (can be applied under a wide range of on- and off-farm situations), relevant (reveal aspects of the animal’s affective or physiological state that is relevant to their welfare), reliable (can be repeated with confidence in the results), relatively economic to apply, and they need to have broad acceptance by all stakeholders. Qualitative Behavioural Assessment (QBA) is an integrated measure that characterises behaviour as a dynamic, expressive body language. QBA is a versatile tool requiring little specialist equipment suiting application to in situ assessments that enables comparative, hypothesis-driven evaluation of various industry-relevant practices. QBA is being increasingly used as part of animal welfare assessments in Europe, and although most other welfare assessment methods record ‘problems’ (e.g. lameness, injury scores, and so on), QBA can capture positive aspects of animal welfare (e.g. positively engaged with their environment, playfulness). In this viewpoint, we review the outcomes of recent QBA studies and discuss the potential application of QBA, in combination with other methods, as a welfare assessment tool for the Australian livestock industries.