Kieren McCosker

Dr. Kieren McCosker

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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1 January 2013 in Journal of Animal Science
Verified
Journal Article
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JPJ. C. Petherick
J. C. Petherick
KMKieren McCosker
Kieren McCosker
DMDavid Mayer
David Mayer
PLP. Letchford
P. Letchford
MMM. McGowan
M. McGowan
The welfare outcomes for Bos indicus cattle (100 heifers and 50 cows) spayed by either the dropped ovary technique (DOT) or ovariectomy via flank laparotomy (FL) were compared with cattle subjected to physical restraint (PR), restraint by electroimmobilization in conjunction with PR (EIM), and PR and mock AI (MAI). Welfare assessment used measures of morbidity, mortality, BW change, and behavior and physiology indicative of pain and stress. One FL heifer died at d 5 from peritonitis. In the 8-h period postprocedures, plasma bound cortisol concentrations of FL, DOT, and EIM cows were not different and were greater (P < 0.05) than PR and MAI. Similarly, FL and DOT heifers had greater (P < 0.05) concentrations than PR and MAI, with EIM intermediate. Creatine kinase and aspartate aminotransferase concentrations were greater (P < 0.05) in FL and EIM heifers compared with the other treatments, with a similar pattern seen in the cows. Haptoglobin concentrations were significantly (P < 0.05) increased in the FL heifers compared with other treatments in the 8- to 24-h and 24- to 96-h periods postprocedures, and in cows were significantly (P < 0.05) increased in the FL and DOT compared with PR in the 24- to 96-h period. Behavioral responses complemented the physiological responses; standing head down was shown by more (P < 0.05) FL cows and heifers to 3 d postprocedures compared with other treatments, although there was no difference between FL and DOT heifers at the end of the day of procedures. At this same time, fewer (P < 0.05) FL and DOT heifers and cows were observed feeding compared with other treatments, although in cows there was no difference between FL, DOT, and EIM. There were no significant differences (P > 0.05) between treatments in BW changes. For both heifers and cows, FL and DOT spaying caused similar levels of acute pain, but FL had longer-lasting adverse impacts on welfare. Electroimmobilization during FL contributed to the pain and stress of the procedure. We conclude that: i) FL and DOT spaying should not be conducted without measures to manage the associated pain and stress; ii) DOT spaying is preferable to FL spaying; iii) spaying heifers is preferable to spaying cows; and iv) electroimmobilization causes pain and stress and should not be routinely used as a method of restraint. Copyright © 2013. American Society of Animal Science .

26 June 2017 in BMC Genetics
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Journal Article
Open access
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KSKanokwan Srirattana
Kanokwan Srirattana
KMKieren McCosker
Kieren McCosker
TSTim Schatz
Tim Schatz
JJJustin St. John
Justin St. John
Cattle are bred for, amongst other factors, specific traits, including parasite resistance and adaptation to climate. However, the influence and inheritance of mitochondrial DNA (mtDNA) are not usually considered in breeding programmes. In this study, we analysed the mtDNA profiles of cattle from Victoria (VIC), southern Australia, which is a temperate climate, and the Northern Territory (NT), the northern part of Australia, which has a tropical climate, to determine if the mtDNA profiles of these cattle are indicative of breed and phenotype, and whether these profiles are appropriate for their environments. A phylogenetic tree of the full mtDNA sequences of different breeds of cattle, which were obtained from the NCBI database, showed that the mtDNA profiles of cattle do not always reflect their phenotype as some cattle with Bos taurus phenotypes had Bos indicus mtDNA, whilst some cattle with Bos indicus phenotypes had Bos taurus mtDNA. Using D-loop sequencing, we were able to contrast the phenotypes and mtDNA profiles from different species of cattle from the 2 distinct cattle breeding regions of Australia. We found that 67 of the 121 cattle with Bos indicus phenotypes from NT (55.4%) had Bos taurus mtDNA. In VIC, 92 of the 225 cattle with Bos taurus phenotypes (40.9%) possessed Bos indicus mtDNA. When focusing on oocytes from cattle with the Bos taurus phenotype in VIC, their respective oocytes with Bos indicus mtDNA had significantly lower levels of mtDNA copy number compared with oocytes possessing Bos taurus mtDNA (P < 0.01). However, embryos derived from oocytes with Bos indicus mtDNA had the same ability to develop to the blastocyst stage and the levels of mtDNA copy number in their blastocysts were similar to blastocysts derived from oocytes harbouring Bos taurus mtDNA. Nevertheless, oocytes originating from the Bos indicus phenotype exhibited lower developmental potential due to low mtDNA copy number when compared with oocytes from cattle with a Bos taurus phenotype. The phenotype of cattle is not always related to their mtDNA profiles. MtDNA profiles should be considered for breeding programmes as they also influence phenotypic traits and reproductive capacity in terms of oocyte quality.

21 November 2010 in Australian Veterinary Journal
Verified
Journal Article
Closed access
PDF file
KMKieren McCosker
Kieren McCosker
PLP Letchford
P Letchford
JPJc Petherick
Jc Petherick
DMD Meyer
D Meyer
MMMichael McGowan
Michael McGowan

14 January 2013 in Animal Production Science
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Journal Article
Closed access
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GFGeoffry Fordyce
Geoffry Fordyce
AAAngela Anderson
Angela Anderson
KMKieren McCosker
Kieren McCosker
PWPaul J. Williams
Paul J. Williams
RHRichard G. Holroyd
Richard G. Holroyd
MSMichael S. Sullivan
Michael S. Sullivan
Hip height, body condition, subcutaneous fat, eye muscle area, percentage Bos taurus, fetal age and diet digestibility data were collected at 17 372 assessments on 2181 Brahman and tropical composite (average 28% Brahman) female cattle aged between 0.5 and 7.5 years of age at five sites across Queensland. The study validated the subtraction of previously published estimates of gravid uterine weight to correct liveweight to the non-pregnant status. Hip height and liveweight were linearly related (Brahman: P < 0.001, R2 = 58%; tropical composite P < 0.001, R2 = 67%). Liveweight varied by 12–14% per body condition score (5-point scale) as cows differed from moderate condition (P < 0.01). Parallel effects were also found due to subcutaneous rump fat depth and eye muscle area, which were highly correlated with each other and body condition score (r = 0.7–0.8). Liveweight differed from average by 1.65–1.66% per mm of rump fat depth and 0.71–0.76% per cm2 of eye muscle area (P < 0.01). Estimated dry matter digestibility of pasture consumed had no consistent effect in predicting liveweight and was therefore excluded from final models. A method developed to estimate full liveweight of post-weaning age female beef cattle from the other measures taken predicted liveweight to within 10 and 23% of that recorded for 65 and 95% of cases, respectively. For a 95% chance of predicted group average liveweight (body condition score used) being within 5, 4, 3, 2 and 1% of actual group average liveweight required 23, 36, 62, 137 and 521 females, respectively, if precision and accuracy of measurements matches that used in the research. Non-pregnant Bos taurus female cattle were calculated to be 10–40% heavier than Brahmans at the same hip height and body condition, indicating a substantial conformational difference. The liveweight prediction method was applied to a validation population of 83 unrelated groups of cattle weighed in extensive commercial situations on 119 days over 18 months (20 917 assessments). Liveweight prediction in the validation population exceeded average recorded liveweight for weigh groups by an average of 19 kg (~6%) demonstrating the difficulty of achieving accurate and precise animal measurements under extensive commercial grazing conditions.

21 March 2011 in Australian Veterinary Journal
Verified
Journal Article
Closed access
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JPJc Petherick
Jc Petherick
KMKieren McCosker
Kieren McCosker
DMDg Mayer
Dg Mayer
PLP Letchford
P Letchford
MMM McGowan
M McGowan

5 May 2025 in Smart Agricultural Technology
Verified
Journal Article
Open access
RERegina Eckhardt
Regina Eckhardt
RAReza Arablouei
Reza Arablouei
Aaron InghamAaron Ingham
Aaron Ingham
KMKieren McCosker
Kieren McCosker
HBHeinz Bernhardt
Heinz Bernhardt