Submitted to: Research Day Abstracts: Regional Universities Research Day
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2003
Publication Date: 11/14/2003
Citation: Pedro, A.F., Northup, B.K., Brown, M.A., Biles, C.A., Dawkins, D. 2003. Spatial patterns in use of Bermuda grass pasture by yearling heifers: Behaviors and reasons [abstract]. Research Day Abstracts: Regional Universities Research Day. Abstract No. S-317. p. 98.
Interpretive Summary: Abstract Only.
Technical Abstract: Available forage and nutrients of warm-season pastures are distributed in a variable fashion, and may affect how cattle use available grazing stations. This paper describes how Brahman-influenced heifers used 2.0 ha bermudagrass (Cynodon dactylon) pastures in different condition (poor, low production units; good, moderate production units) during a 40-day period in June-July 2003. The 70 x 282 m pastures were divided into 35 x 35 m grid cells with visible posts, and animal behaviors were recorded at 10-minute intervals during morning (0700-1000) grazing bouts. Observations described the most-grazed cells (weekly), and were sampled to define forage availability and quality (N content, lignin, and digestibility). One animal per pasture was fitted with a global positioning system (GPS) collar, locations were recorded at 15-minute intervals for the entire study, and the information used to develop maps of pasture use. Cattle behavior in the pastures was statistically different (P<0.05). Cattle on good condition pasture spent less time grazing and more ruminating and socializing. The cattle also had a distinct preference for the southern parts of the pastures, regardless of pasture condition, accumulated grazing pasture, or forage condition. Pasture use was neither uniform nor consistent. Some parts of the pastures were heavily preferred, compared to other less-utilized areas; utilization patterns only changed slightly over time. Results indicated pasture use was affected by a combination of factors, including some unrelated to pasture condition or forage characteristics. Wind direction (southerly) and other factors (slope, locations of neighboring cattle) were affecting behavior and serving as drivers of grazing pattern.