Publication Date
1997
Description
Grazing efficiency and livestock performance were compared on swards rotationally grazed down to either 50 or 100 mm for three years. With a fixed entry height of 200-250 mm, standing swards of mixed grasses and white clover (Trifolium repens L.) were stratified into 50 mm vertical layers both pre- and post-grazing. Through four or five cycles of grazing each year for three years, a fixed entry height range stabilized total standing herbage at 3250 to 3690 kg OM ha-1. Organic matter on-offer above 100 mm was 36, 45, and 43% of total standing herbage in the three years, compared with 60, 66, and 62% above 50 mm. Lowering residual height from 100 to 50 mm increased percentage disappearance of total standing herbage from 44, 44, and 48% at 100 mm to 60, 61, and 62% at the 50 mm residual. Grazing to the lower residual increased utilization efficiency by about 35%, but did so at the expense of individual animal intake. Daily OM intake was 2.8, 2.7, and 2.9% of bodyweight in the 100 mm residual, but declined to 2.2, 1.9, and 2.1% when stock were obliged to graze down to a 50 mm residual. The homogeneity of IVOMD above 50 mm suggests that reduced rate of intake in the 50- 100 mm layer resulted from factors other than quality, such as difficulty of prehension or avoidance of soiled herbage.
Citation
Singh, A; Johnston, J E.; and Clark, E A., "Applications of Height-Based Grazing Management in Mixed Swards" (2024). IGC Proceedings (1989-2023). 68.
https://uknowledge.uky.edu/igc/1997/session29/68
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Applications of Height-Based Grazing Management in Mixed Swards
Grazing efficiency and livestock performance were compared on swards rotationally grazed down to either 50 or 100 mm for three years. With a fixed entry height of 200-250 mm, standing swards of mixed grasses and white clover (Trifolium repens L.) were stratified into 50 mm vertical layers both pre- and post-grazing. Through four or five cycles of grazing each year for three years, a fixed entry height range stabilized total standing herbage at 3250 to 3690 kg OM ha-1. Organic matter on-offer above 100 mm was 36, 45, and 43% of total standing herbage in the three years, compared with 60, 66, and 62% above 50 mm. Lowering residual height from 100 to 50 mm increased percentage disappearance of total standing herbage from 44, 44, and 48% at 100 mm to 60, 61, and 62% at the 50 mm residual. Grazing to the lower residual increased utilization efficiency by about 35%, but did so at the expense of individual animal intake. Daily OM intake was 2.8, 2.7, and 2.9% of bodyweight in the 100 mm residual, but declined to 2.2, 1.9, and 2.1% when stock were obliged to graze down to a 50 mm residual. The homogeneity of IVOMD above 50 mm suggests that reduced rate of intake in the 50- 100 mm layer resulted from factors other than quality, such as difficulty of prehension or avoidance of soiled herbage.
