Steer Performance and Pasture Productivity of Caucasian Bluestem at Three Forage Masses

• Published in: Agronomy journal Vol. 102; no. 3; pp. 834 - 842
• Main Authors: Burns, J.C, Fisher, D.S
• Format: Journal Article
• Language: English
• Published: Madison American Society of Agronomy 01.05.2010
• Subjects: Agronomy. Soil science and plant productions; Animal productions; beef cattle; Biological and medical sciences; Bothriochloa bladhii; diet; feed intake; field experimentation; forage crops; forage grasses; forage quality; Fundamental and applied biological sciences. Psychology; grazing; grazing management; height; introduced species; liveweight gain; nutritive value; Pasture; pastures; plant adaptation; plant density; steers; stocking rate; Terrestrial animal productions; Vertebrates; weeds; yields; North Carolina; Productivity; Monocotyledones; Farming animal; Herbivorous; Ruminant animal; Vertebrata; Meat animals; Mammalia; Gramineae; Pasture; Agronomy; Steers; Angiospermae; Beef cattle; Spermatophyta; Artiodactyla; Fodder crop; Performance; Ungulata
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2009.0468

The introduced perennial, warm-season grass, Caucasian bluestem [Bothriochloa caucasia (Trin.) C.E. Hubbard ‘Caucasian’], appears to be adapted to the mid-Atlantic region. This 4-yr experiment compared animal and pasture productivity of Caucasian bluestem over three canopy heights, or forage masses (FM), designated as Short (14.6 cm), Medium (32.2 cm), and Tall (39.8 cm). The relationship of canopy height to diet and canopy characteristics was also evaluated. The soil was a Cecil clay loam (fine, kaolinitic, thermic Typic Kanhapludult). Pastures were continuously stocked using variable stocking from mid-May through mid-September. Forage mass (harvested to a 2.5-cm stubble), increased linearly (P = 0.04) averaging 1.42, 2.31 and 2.75 Mg ha–1 for Short, Medium, and Tall canopy heights. Steer average daily gain (ADG) was similar among FM treatments (0.76 kg d–1) but weight gain decreased linearly (P < 0.01) from Short to Tall (from 817 to 518 kg ha–1). Increasing FM resulted in a quadratic decrease (P 0.04) in stocking rate (from 9.7 to 7.8 steers ha–1) and animal days (from 1019 to 700 d ha–1) and a linear decrease (P = 0.02) in effective feed units (from 4025 to 2806 kg ha–1). Stand counts of Caucasian bluestem increased linearly (P = 0.05) from Tall to Short FM (from 22.8–70.0%) with the Tall providing openings for potential weed invasion. Caucasian bluestem can be heavily stocked and may provide acceptable quality forage for summer grazing in the mid-Atlantic region.