Location of supplementary feed and water troughs on the sward affects movement and spatial distribution of Brahman cattle (Bos indicus)

The grazing dynamics of animals differ depending on whether they are raised on rangeland or sward areas. Grazing patterns of cattle raised on rangeland can be modified by the location of supplement feed and water troughs. However, no information about the use of this strategy is available for swards. Thus, the effects of the location of supplementary feed and water troughs in small (7500 m2) irrigated swards on movement, behavior and distribution were studied in a herd of 15 Brahman cows. The herd grazed on five swards in rotation, for seven days on each sward, so that each sward then had 28 days of rest. There were four rotations, giving four replicates of each of five treatments. For each rotation, one of the following treatments was randomly assigned to each sward. Supplementary feed and water troughs were: T1 in the same corner of the sward; T2 separate, each in the middle of one of the shorter sides of the sward; T3 separate in diagonally opposite corners; T4 separate in adjacent corners; T5 together in the sward center. The behavior and location of each cow was registered on a daily basis, every 2 h from 9:00 to 15:00 h, 7 days/week, using instantaneous scan sampling during the 140 days that the experiment lasted. Total distance traveled of each cow (i.e. the sum of Euclidean distances between the four subsequent positions of each cow within each day) was longer in T2 and T3 than in T5 (159.8, 162.5 vs 119.5 m respectively; p = 0.006), with the rest of the treatments showing intermediate values. The distance to the nearest cow was longer in T1 vs. T2 and T3 (6.2 vs 4.0 and 4.7 m, respectively; p = 0.007). Similarly, the herd home range was greater in T1 vs. T2 (792.6 vs. 574.7 m2, respectively; p = 0.01). Regardless of the treatment, social disruption occurred on day 1, which gradually decline through the week of grazing. The results show that the location of supplementary feed and water troughs affects the movement and cattle distribution in small (<1 ha) irrigated swards. This might have practical applications in the design of grazing strategies and in the animal welfare of cattle maintained on small swards.