A comparison of catecholamine and cortisol responses of young lambs and calves to painful husbandry procedures.
OBJECTIVE
To compare the changes in plasma concentrations of noradrenaline, adrenaline and cortisol in lambs after ring castration plus tailing and in calves after dehorning with or without prior local anaesthesia.


METHODS
Male lambs were castrated and tailed with rings and calves were dehorned by amputation using a scoop with or without prior local anaesthesia. Blood samples were taken before and after treatment and plasma concentrations of noradrenaline, adrenaline and cortisol were determined.


RESULTS
Castration plus tailing of lambs resulted in a rapid increase in noradrenaline concentrations, a lack of an adrenaline response and a marked increase in cortisol concentration. There were similar changes in catecholamine concentrations in calves that were dehorned both with and without local anaesthetic, with adrenaline being elevated within 5 min of treatment and noradrenaline exhibiting a more protracted response. Dehorning caused a marked cortisol increase which was reduced to control concentrations by local anaesthesia for as long as the associated nerve blockade lasted.


CONCLUSIONS
The very short-lived adrenaline responses in calves were attributed to dehorning-induced nociceptor input leading to sympathetic stimulation of the adrenal medulla. The longer lasting noradrenaline responses in lambs and calves were thought be due to 'wash-out' of noradrenaline from damaged tissue associated with rings and amputation wounds, respectively.
Mellor
D J
DJ
Animal Welfare Science and Bioethics Centre, College of Sciences, Massey University, Palmerston North, New Zealand.
Stafford
K J
KJ
Todd
S E
SE
Lowe
T E
TE
Gregory
N G
NG
Bruce
R A
RA
Ward
R N
RN
D000818:Animals; D000831:Animals, Newborn; D002395:Catecholamines / Q000097:blood*; D002417:Cattle / Q000502:physiology* / Q000601:surgery; D004837:Epinephrine / Q000097:blood; D006733:Horns / Q000601:surgery; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D009919:Orchiectomy / Q000662:veterinary; D010146:Pain / Q000517:prevention & control / Q000662:veterinary*; D010147:Pain Measurement / Q000662:veterinary; D012756:Sheep / Q000502:physiology* / Q000601:surgery; D013623:Tail / Q000601:surgery; D013997:Time Factors
D002395:Catecholamines; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine