Cortisol and pain-related behavior in disbudded goat kids with and without cornual nerve block.

ABSTRACT

Plasma cortisol and behavior were measured in disbudded goat kids with and without the use of cornual nerve block. A total of 45 kids were used in 5 experimental groups (n=9, males and females). Group LidoD was infiltrated with 1 mL of 2% lidocaine locally at the cornual branches of lacrimal and infratrochlear nerves, 15 min before thermal disbudding. Group Lido was similarly infiltrated and was not disbudded. In group Sim, the disbudding procedure was simulated. A control group (CD) was disbudded without lidocaine infiltration, and group SD was infiltrated with saline before disbudding. The cornual nerve block did not prevent the short-term increase in cortisol levels during and after disbudding. LidoD, CD and SD groups showed higher cortisol concentrations than Lido and Sim (p<0.05) during the first 20 min after the procedure. Frequency of vocalizations during the procedure was significantly different between groups and was higher in SD (29.6 ± 3.1; mean±SE) and CD (28.4 ± 3.1) than in Sim (16.6 ± 3.1; p<0.05). Infiltrating lidocaine did not decrease this response to disbudding (21.1 ± 3.1; p>0.05). Struggles tended to be higher in SD (16.5 ± 2.5), CD (17.8 ± 2.5) and LidoD (15.6 ± 2.5) than Sim (10.6 ± 2.5; p=0.1). The total behavioral response was different between groups (CD, 59.6 ± 6.8; LidoD, 52 ± 6.8; SD, 62.6 ± 6.8; Sim, 36.8 ± 6.8; p=0.05), and disbudded animals showed the strongest reactions (disbudded, 58.1 ± 3.9 vs non-disbudded, 36.8 ± 6.8; p=0.01). It was concluded that cornual nerve block (lacrimal and infratrochlear) using 2% lidocaine did not prevent pain during thermal disbudding of goat kids.