The Veterinary Record 162:609-614 (2008)
© 2008 British Veterinary Association
Immunophysiological responses of horses to a 12-hour rest during 24 hours of road transport
C. L. Stull, MS, PhD1,
J. Morrow, MS, PhD, (deceased)2,
B. A. Aldridge, BVSc, MS, PhD, DAVIM3,
J. L. Stott, MS, PhD1 and
J. J. McGlone, MS, PhD2
1 School of Veterinary Medicine, University of California, 1 Shields Avenue,
Davis, CA 95616, USA
2 Animal and Food Science Department, Texas Tech University, Lubbock, TX
79409, USA
3 Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9
7TA
Thirty-eight mature horses were assigned to one of two equal groups to
evaluate two treatments consisting of either 24 hours of continuous road
transport (24T) or two 12-hour periods of transport separated by off-loading,
resting and feeding the horses for 12 hours (12/12T). A subset of six horses
from each group served as controls for the other group. The horses were loaded
into a commercial straight-deck trailer and travelled loose in one of two
standard-sized compartments. After the journeys the horses were put back into
their paddocks for a 24-hour recovery period. Venous blood samples were
collected before loading, after unloading and after the 24-hour recovery
period. Transport significantly increased the horses' cortisol concentrations,
neutrophil counts and neutrophil:lymphocyte (NL) ratios, and
decreased the numbers of all the lymphocyte subpopulation cell types.
Collectively, no significant differences were observed between the two
treatments in the horses' cortisol concentrations, total leucocyte counts,
neutrophil and lymphocyte counts, NL ratios, and the
CD8A+ and CD21+ lymphocyte subpopulations, but there
were differences in the numbers of CD3+, CD4+, and
CD8B+ subpopulations. The inclusion of a 12-hour rest-stop
interrupted the transport-related decline in the lymphocyte subpopulations and
allowed them to recover towards their resting levels.
Copyright © 2008 British Veterinary Association
