Tall Fescue Forage Mass and Canopy Characteristics on Steer Ingestive Behavior and Performance

• Published in: Crop science Vol. 51; no. 4; pp. 1850 - 1864
• Main Authors: Burns, J. C., Fisher, D. S., Pond, K. R.
• Format: Journal Article
• Language: English
• Published: Madison, WI The Crop Science Society of America, Inc 01.07.2011; Crop Science Society of America; American Society of Agronomy
• Subjects: Agronomy. Soil science and plant productions; Animals; Biological and medical sciences; Canopies; Cattle; Diet; Experiments; Forage; Fundamental and applied biological sciences. Psychology; Grasses; Leaves; Organic matter; Pasture; Pastures; Production management; Productivity; Transition zone; Monocotyledones; Farming animal; Gramineae; Steers; Angiospermae; Spermatophyta; Fodder crop; Festuca arundinacea; Canopy(vegetation); Ingestion
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci2010.10.0578

ABSTRACT Tall fescue (Festuca arundinacea Schreb.) is a well‐adapted perennial pasture species utilized across the north–south transition zone of the United States. This 3‐yr trial evaluated the influence of three forage masses (FM) on steer and pasture responses for spring (April to July) and fall (October) growths. Spring FM averaged 1450 kg ha−1 (Short), 3032 kg ha−1 (Medium), and 3812 kg ha−1 (Tall) for the three treatments. Canopy in vitro true organic matter disappearance (ITOD) decreased linearly from Short (797 g kg−1) to Tall (771 g kg−1). Steer daily gains (0.88 kg) and gains per hectare (392 kg ha−1 yr−1) were not altered by FM, but the mean number of steers per hectare decreased linearly from Short (8.2 steers ha−1) to Tall (6.1 steers ha−1) as did effective feed units per hectare (2256 to 1712 kg ha−1 yr−1). Canopies were predominately leaf (53%) and averaged 847 g kg−1 ITOD with estimates similar among FM treatments. Diet ITOD declined linearly from Short (870 g kg−1) to Tall (839 g kg−1) as did crude protein (CP) (from 235 to 192 g kg−1). In the fall, FM averaged 1556, 3228, and 3494 kg ha−1 for the three FM treatments. Canopy ITOD averaged 774 g kg−1 and was not altered by FM. Canopy leaves averaged 60% with an ITOD of 864 g kg−1 and were similar among FM treatments. Diets selected averaged 834 g kg−1 ITOD and 233 g kg−1 CP and were not altered by FM. Tall fescue pasture free of toxic endophyte needs to be effectively utilized to enhance production and can be managed flexibly in grazing systems.