Skip to main content
ARS Home » Research » Publications at this Location » Publication #68289
Title: SPECTRAL ANALYSIS OF BOVINE GRAZING BEHAVIOR ON ACREMONIUM COENOPHIALUM INFESTED TALL FESCUE

Author
item SEMAN, D - UNIVERSITY OF GEORGIA
item Stuedemann, John
item ANDERSON, J - UNIVERSITY OF GEORGIA

Submitted to: Journal of Animal Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Tall fescue is a cool season perennial grass that occupies approximately 35 million acres of land in the United States, primarily in the humid pasture region of the East. Unfortunately, animal production is reduced on most of this fescue because it is infested with a fungus. Cattle grazing infested fescue characteristically consume less forage than cattle grazing fungus-free fescue. Examination of 24-hour grazing behavior revealed that cattle grazing fungus-infested pastures had repeatable cycles of grazing that were farther apart than those of cattle grazing fungus-free fescue and avoided the hottest times of the day. Steers grazing fungus-free fescue may have been sensitive to normal appetite stimult such as those associated with the digestive tract. However, these stimuli appeared to be overridden or altered in cattle grazing fungus-infested fescue causing their grazing behavior to be controlled by other stimuli.

Technical Abstract: Bovines spend less time grazing and have reduced intake when grazing endophyte-infected (E+), (Acremonium coenophialum Morgan-Jones and Gams) versus endophyte-free (E-) tall fescue (Festuca arundinacea, Shreb.). An experiment was conducted to compare behavior of steers grazing E+ and E- Kentucky-31 (KY-31) tall fescue pastures using spectral analysis. Two 0.81 ha paddocks, one containing E- KY-31 and one containing E+ KY-31 (100% tiller infection rate) were stocked with yearling Angus steers in the spring and summer of 1984 and 1985. Trained observers monitored steer behavior during two 48-h periods each year. Spectral analysis suggested that steers grazing E+ fescue tended to repeat grazing behavior in 12-h intervals versus 6-h intervals for E- steers in year 1. In year 2, E+ steers showed repeating grazing cycles every 8-h while E- steers lacked this cycle. Steers grazing E+ fescue spent less time grazing and lying(P<.05), and more time standing (P<.05), than E- steers for both years. Hourly grazing behavior was crosscorrelated with hourly solar radiation resulting in significant, negative correlations at lag = 0 for E+ steers and with correlations near zero for E- steers. We conclude steers grazing E+ fescue exhibited different grazing behavior than steers grazing E- fescue and that spectral analysis was valuable in describing grazing behavior.