Maximising Annual Intake of Grazed Grass for Beef Production.

Abstract

Grass is by far the most important crop grown in Ireland.Well-managed grassland supports high levels of animal performance, and the production of high quality produce. Grazed grass is a relatively cheap feed source for beef production (O'Kiely, 1994). Grazed grass does not always match feed requirements in efficient beef production systems. Supply tends to exceed demand in the late spring and summer whereas deficiencies in feed supply occur in late autumn and during the winter and early spring. The objective of the present series of experiments was to examine the potential to increase the utilization of grazed grass in beef production systems.There are two aspects to this: one relates to the utilization of grass in situ; the second relates to the strategic approach to grass utilization, i.e. matching feed requirements with supply of grazed grass and silage conservation during the year. The first two experiments presented in this report examine the utilization of grass in situ. The effects of pre-grazing pasture mass and nitrogen (N) fertilization on the production and subsequently the utilization and digestibility of the grass under grazing by cattle were examined. A third experiment and examines the effect of pre-grazing pasture mass on performance of beef cattle during a grazing season. The fourth experiment investigates the role of perennial ryegrass cultivars in supplying grass for grazing during the spring, and for the production of high nutritive value first cut silage.