Effect of neck injection and handler visibility on behavioral reactivity of beef steers.

The use of the neck region as an injection site in cattle is becoming routine. Use of a blind may reduce aversive behavior caused by the presence of the person administering the injection. To evaluate whether cattle react to the proximity of the stockperson or to the actual injection, one hundred twenty 10-mo-old Angus steers (298 +/- 28 kg of BW; mean +/- SD) were assigned to 1 of 4 treatment groups using a partial crossover design (neck/sham injection x blind/no blind) replicated over 2 d (3 d apart). Steers were restrained for a total of 60 s in a squeeze chute, with treatment being administered 20 s after entry. Animal reactivity was rated using 2 scoring methods, including a visual and an electronic score, for three 20-s intervals (pre-treatment, treatment, and posttreatment intervals). Flight speed (m/s) was used as a measure of aversion to the treatments and was taken upon release from the chute. No interactions (P > 0.10) were observed between the blind and injection treatments for any of the measurements taken. No treatment or day effect on flight speed (2.7 vs. 2.6 m/s; P > 0.03) was observed; however, the correlation between days (r = 0.74; P < 0.001) was significant. Visual scores indicated that injected steers were more agitated during the treatment interval than were the sham injected steers (1.9 vs. 1.6, respectively; P = 0.01). However, no differences (P > 0.10) were found between injection and sham injection treatments for any of the electronic scores. Steers exposed to the blind had lower electronic reactivity scores (P < 0.05) than those not exposed to the blind, which was in contrast to the results obtained for the visual scores (P < 0.05). Discrepancies between reactivity scores may be due to the difficulty of accurately assessing minor animal responses using the visual method. The presence of a handler during an injection procedure could be a contributor to the aversion response observed in cattle undergoing routine neck injections, and use of a blind helped to reduce the reactivity of the steers.