Lynch, Eilish M. and Earley, Bernadette and McGee, Mark and Doyle, Sean
Characterisation of physiological and
immunological responses in beef cows
to abrupt weaning and subsequent housing.
BMC Veterinary Research, 6 (37).
Background: Weaning involves the permanent separation of the calf from the dam and has been shown to be
stressful for both. The objectives of this study were to characterise the effect of i) abrupt weaning and ii)
subsequent housing on the extended physiological and immunological responses of beef cows. At weaning (day
(d) 0, mean age of calf (s.d.) 212 (24.5) d), cows were abruptly separated from their calves and returned to the
grazing area. After 35 d at pasture, cows were housed in a slatted floor shed and offered grass silage ad libitum
plus a mineral-vitamin supplement daily. Rectal body temperature was recorded and blood samples were obtained
on i) d 0 (weaning), 2, 7, 14, 21, 28, 35 and subsequently on ii) d 0 (housing), 2, 7, 14 and 21 for physiological,
haematological and immunological measurements.
Results: Post-weaning, concentration of cortisol and dehydroepiandrosterone were unchanged (P > 0.05). Rectal
body temperature, neutrophil number and neutrophil: lymphocyte ratio increased (P < 0.01) on d 2 compared with
pre-weaning baseline. Lymphocyte and neutrophil number decreased (P < 0.05) on d 2 to 7 and d 7 to 21,
respectively, compared with pre-weaning baseline. Interferon-g production decreased (P < 0.05) on d 2 compared
with pre-weaning baseline. An increase (P < 0.05) in acute phase proteins, fibrinogen and haptoglobin was evident
on d 2 to 35 compared with pre-weaning baseline. Concentration of glucose increased on d 2 to 28, whereas nonesterified
fatty acid decreased on d 2 to 35 compared with pre-weaning baseline. Post-housing, concentrations of
cortisol, rectal body temperature, total leukocyte number, and glucose were unchanged (P > 0.05). On d 2 posthousing,
neutrophil number and neutrophil: lymphocyte ratio increased (P < 0.05), whereas lymphocyte number
and concentrations of dehydroepiandrosterone, fibrinogen and non-esterified fatty acid decreased (P < 0.05)
compared with pre-housing baseline. Concentration of haptoglobin increased (P < 0.05) on d 14 to 21 posthousing.
Conclusions: A transitory increase in neutrophil number and decrease in lymphocyte number, increased
neutrophil:lymphocyte ratio coupled with decreased interferon-g production, and increased concentration of acute
phase proteins indicate a stress response in cows post-weaning, whereas post-housing, changes were less marked.
||The authors acknowledge E. Mulligan for skilled technical assistance,
the farm staff at Teagasc, Grange Beef Research Centre for the care and
management of the animals, the staff of Grange laboratories for feed
analysis and J. Larkin and M. Murray (Teagasc, Animal & Grassland
Research and Innovation Centre, Grange) for blood sample analysis.
Thanks are also extended to W. Byrne, H. Cameron and M. Hill at the
CVRL, Department of Agriculture, Fisheries and Food Laboratory
Complex, Co. Kildare, Ireland for their assistance in blood sample
analysis. This work was funded by a Teagasc Walsh Fellowship and a
John Hume Scholarship to E.M. Lynch.
||physiological responses; immunological responses; beef cows; weaning; housing;
||Science & Engineering > Biology
Dr. Sean Doyle
||09 Feb 2011 15:37
|Journal or Publication Title:
||BMC Veterinary Research
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