| The research reported in this dissertation studied the effects of Solenopsis invicta Buren; Hymenoptera: Formicidae, the red imported fire ant (RIFA) on Texas livestock. This research was multidisciplinary. The fast part of this research evaluated RIFA recruitment to various livestock feeds including a commercial cat food, a calf starter feed, a horse and mule feed, a cow range cube, cottonseed meal, and extruded whole cottonseed. Differences were observed for feed (P < 0.001), pasture ( P < 0.001), and feed x pasture (P < 0.05) for ant count after 15 and 30 min. The second part of this research evaluated the grazing behavior of beef cattle in pastures infested with RIFA, using a cattle-tracking GPS collar. The research was conducted in two pastures (P5 and P6) and in two phases. Phase I used 11 resident commercial Angus cow-calf pairs. Phase II used 16 non-resident crossbred yearling steers that were naïve to RIFA. The Phase I GPS collars measured cow head movement with horizontal (HOR) and vertical (VER) motion, which were also summed for a total activity (ACT) variable. Additionally both distance (m; DIS) and velocity (m/min;VEL) were calculated for both phases. Differences (P < 0.0001) were observed for cattle utilization in different areas of the pastures (AREA) for both phases and were related to the primary species of forage on offer in those areas. In Phase I and P5, differences were observed for HOP, VER, and ACT due to time-of-day (TOD; P < 0.05) and AREA ( P < 0.001) effects, and for DIS and VEL due to TOD effect ( P < 0.001). In Phase I and P6 differences were observed for VER, ACT, DIS, and VEL due to TOD (P < 0.001) and AREA ( P < 0.001) effects and for HOR due to TOD effect (P < 0.001). In Phase II, differences were observed for DIS due to TOD ( P < 0.05) and AREA (P < 0.001) effects in both pastures, and for VEL due to TOD (P < 0.001) and AREA (P < 0.001) effects in P6 only. |
