Abstract

A beef farm systems experiment was conducted for 2 years in which winter grazing management of either a fast rotation (FR) of 45 days, or a slow rotation (SR) of 120 days was applied to eight small farms containing either rising-1yr, or rising-2yr Angus steers (15/farm). All farms were managed in a fast rotation (<35 days) during spring and summer.Average farm pasture covers at the end of winter were 563 (±80) and 347 (±53) kg DM/ha higher on the SR farms than the FR farms for the first and second years respectively. The FR steers at the end of winter were on average 26 (±4.0) and 22 (±4.2) kg heavier than the SR steers in the first and second years respectively. By late summer, the FR steers were 15 (±5.3) kg heavier and 2 (±5.6) kg lighter than the SR steers. There were no significant management interactions with age class. Live weight compensation of the SR steers was rapid during the first 6 weeks of spring. The results of this experiment show that winter grazing rotation length had little effect on the final live weight achieved by summer. However, between year differences showed that systems compensation during spring is dependent on pasture supply, pasture quality and stocking rate. With the ability of a whole-farm system to show compensation, a slow winter rotation is a low risk option if climatic uncertainty is an issue.

CJ, Boom, and GW Sheath

Proceedings of the New Zealand Society of Animal Production, Volume 60, Hamilton, 139-142, 2000