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ARS Home » Pacific West Area » Burns, Oregon » Range and Meadow Forage Management Research » Research » Publications at this Location » Publication #139988
Title: EFFECTS OF PREVIOUS GRAZING IN PASTURES ON LIVESTOCK DISTRIBUTION AND NUTRITION

Author
item Ganskopp, David
item BOHNERT, DAVID - OREGON STATE UNIVERSITY

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 12/1/2001
Publication Date: 2/20/2002
Citation: GANSKOPP, D.C., BOHNERT, D. EFFECTS OF PREVIOUS GRAZING IN PASTURES ON LIVESTOCK DISTRIBUTION AND NUTRITION. SOCIETY FOR RANGE MANAGEMENT MEETING ABSTRACTS. 2002.

Interpretive Summary: With conservative stocking, cattle reluctantly forage upon grasses supporting cured stems from previous years. Forage conditioning with fire, heavy grazing, or mowing removes these materials and enhances palatability. Our objective was to quantify livestock distribution and nutrition in pastures supporting stands of both wolfy and uncontaminated grasses. One-half of each of 4 paddocks was conditioned by high intensity grazing in 2000. The other half was rested (unconditioned). Cattle distribution was quantified with GPS collars, and diet quality assayed with rumen cannulated steers in a 1-week May/June 2001 trial. Of total time at pasture, cattle were in conditioned sectors (supporting 201 kg of forage per ha) and unconditioned sectors (supporting 543 kg/ha) 61 and 39% of the time, respectively. When grazing, 68 and 32% of the observations were in conditioned and unconditioned sections, respectively. CP of cured grasses was 2%, current season¿s growth 11%, and standing crop 6.5% in the wolfy sectors. Cannulated steers confined to treatments, exhibited dietary CP¿s averaging 13.5% with no difference between treatments. While cattle prefer foraging among conditioned grasses, they can at least initially acquire a high plain of nutrition in unconditioned stands with selective grazing.

Technical Abstract: With conservative stocking, cattle reluctantly forage upon grasses supporting cured stems from previous years. Forage conditioning with fire, heavy grazing, or mowing removes these materials and enhances palatability. Our objective was to quantify livestock distribution and nutrition in pastures supporting stands of both wolfy and uncontaminated grasses. One-half of each of 4 paddocks was conditioned by high intensity grazing in 2000. The other half was rested (unconditioned). Cattle distribution was quantified with GPS collars, and diet quality assayed with rumen cannulated steers in a 1-week May/June 2001 trial. Of total time at pasture, cattle were in conditioned sectors (supporting 201 kg of forage per ha) and unconditioned sectors (supporting 543 kg/ha) 61 and 39% of the time, respectively. When grazing, 68 and 32% of the observations were in conditioned and unconditioned sections, respectively. CP of cured grasses was 2%, current season¿s growth 11%, and standing crop 6.5% in the wolfy sectors. Cannulated steers confined to treatments, exhibited dietary CP¿s averaging 13.5% with no difference between treatments. While cattle prefer foraging among conditioned grasses, they can at least initially acquire a high plain of nutrition in unconditioned stands with selective grazing.