The preference of red deer (Cervus elaphus) to graze with cattle or sheep: A dissertation submitted in partial fulfilment of the requirements for the Degree of Bachelor of Agricultural Science with Honours at Lincoln University

Abstract

Integrating various livestock species and classes of stock are common features of a high proportion of deer farms in New Zealand. An experiment was performed to evaluate the preference of deer to graze on pastures previously prepared by cattle or sheep to a similar pasture height, and in the presence and absence of cattle and sheep. In the first experiment cattle (2-3 yearling steers) and sheep (4-20 mixed-sex hoggets) were grazed separately on ryegrass and white clover sub-plots (0.30 ha), for a period of 6 weeks. Five days subsequent to animal and temporary fence removal, the proportion of deer (18 yearling hinds) grazing over a predetermined period (30 minutes at 5 minute intervals) on the entire area of pasture prepared by, but in the absence of, cattle and sheep was recorded. The second experiment recorded the proportion of deer grazing over a predetermined period (30 minutes at 5 minute intervals) on an area of pasture previously grazed by deer, but in the presence of cattle (3 yearling steers) or sheep ( 5 mixed-sex hoggets) retained in each corner of the treatment area (approximately 10% of total area). In Experiment 1, pasture availability for each treatment (cattle or sheep grazed area) was maintained within ±100-120 kg DM/ha during the observational period. Botanical composition, although on average 6% higher clover on cattle grazed treatments after preliminary grazing, showed no significant difference between cattle and sheep grazed treatments. Deer, during the first week of observations, showed a significant (P<0.0 1) preference to graze on areas previously grazed by cattle (77% of observations) than by sheep (23% of observations). Yet after just 14 days between observations in the first and third week, deer grazing was equally distributed between cattle and sheep grazed areas (52% and 48% respectively) showing no preference. In Experiment 2, deer also showed no preference to graze within the physical presence of cattle ( 48% of observations) or sheep (52% of observations) and grazed evenly over the entire treatment area. Results from Experiment 1 indicate a clear preference of deer for areas previously grazed by cattle, than by sheep. This cannot be explained by the effect of cattle grazing on botanical composition, because although these areas contained a higher (but not significant) clover percentage, this difference was maintained throughout the entire trial period while deer grazing preference diminished during the same time period. Based on reports in the literature it is possible that faecal odour created the aversive response by deer to sheep grazed pastures during the initial observational period. This behaviour is suggested to be a mechanism exhibited by deer to avoid the increased risk of internal parasite transmission from sheep grazed pasture. Significant rainfall (91.2 mm) between the first and third week of observations may have contributed, at least to some extent, to reductions in faecal odour, creating a homogeneous environment for grazing deer. We conclude that any preference shown by deer to graze with cattle rather than sheep is due to their respective faeces not their respective presence.