Urinary cortisol: An indicator of stress in dairy cattle
C.J. Morrow, E.S. Kolver, G.A. Verkerk and L.R. Matthews
AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton,
New Zealand
Proceedings of the New Zealand Society of Animal Production.
2000 60: 218-221
The measurement of immunoreactive urinary corticosteroids was
validated as a method of monitoring adrenocortical activity in lactating
dairy cows. The physiological relevance of the technique was validated
by demonstrating that (i) injection of ACTH led to a significant
increase in plasma and urinary corticosteroid concentrations, and (ii)
the translocation of cows from pasture to a barn facility resulted in a
1.1- to 2.5-fold increase in urinary cortisol concentrations. Plasma
cortisol concentrations exhibited a 15- to 33-fold increase above basal
concentrations 30 mins after ACTH administration (2.98±0.35 vs 63.7±3.9
ng/ml plasma; meanąSEM; P<0.001) and remained elevated for 4.0-4.5h.
Urinary corticosteroid concentrations paralleled plasma cortisol with a
1- to 2-h temporal lag and exhibited a 5.6- to 13-fold increase at 120
mins after ACTH injection (130±9.9 vs 1149±159 ng/mg creatinine;
meanąSEM; P<0.01). Monitoring urinary corticosteroid concentrations is a
valid tool for studying and evaluating adrenal activity and acute stress
in cattle.
Keywords: NZSAPAB;
dairy cows; urine; cortisol; ACTH; stress.
Last Updated 12-07-2000
