Comparison of the stress of abrupt and interval weaning of farmed wapiti calves ( Cervus elaphus)

Abstract

Two approaches to pre-rut weaning, abrupt and interval weaning, were examined each in 2 years. The abrupt-wean group was weaned in the first week of September with calves simultaneously being moved first to a large pen and then to a new pasture remote from their dams (as widely practised in western Canada). The interval-wean group was weaned at the same age over a 10-day period as a few hinds were shifted each day to an adjacent pasture, and then to a remote pasture. Each year, there was no significant difference in average daily weight gain between animals in the interval-wean group and the abrupt-wean group during the subsequent 3 weeks. However, there were substantial differences in behaviour between the two groups over 14 days of observation. The major activity was lying, occupying about 70% of the time for both groups. The abrupt-wean group spent more time pacing than the interval-wean group (5.7% ± 1.4 vs. 0.2 ± 0.1; p < 0.001). Vocalizations were observed only in the abrupt-wean group. Although ultimate productivity was not affected, higher neutrophil/lymphocyte ratios (0.82 ± 0.15 in abrupt-weaned vs. 48 ± 0.08 in interval-weaned calves) and elevated heart rates (15.6 ± 3.0 vs. 8.2 ± 1.9 bpm above baseline measurements) suggest that abrupt weaning was more stressful. The clearest evidence was the marked difference in vocalizations and pacing fence lines among abrupt-weaned calves. Interval weaning is recommended on welfare grounds.