All-year-round grazing for sheep without the need for silage and housing
Grass and how it is used is central to the competitiveness of the Irish sheep sector. Deferred (extended) grazing was developed in New Zealand during the 1970's and is established practice. It has been practised by Teagasc previously at Belclare and Knockbeg. Deferred grazing with outdoor lambing is a new system for winter management in Ireland instead of ewes been housed and offered either silage of or hay as the sole forage. During deferred grazing herbage is block grazed on a daily allowance basis. Todate, the ewe's increased requirements for nutrients in late pregnancy have been satisfied by supplementing deferred herbage with concentrate. The main factor limiting stock carrying capacity in a year round system is the proportion of the farm that needs to be closed in autumn to reserve pasture for deferred grazing. There is a paucity of data on the effects of herbage allowance, which impacts directly on the number of grazing days, for ewes during mid and late pregnancy. The main labour requirement during extended grazing is the frequency of herbage allocation. Should herbage for deferred grazing be limited on farm at what stage of pregnancy is the most opportune time to utilise it? Furthermore there is a paucity of data on the potential concentrate sparing effects of extended grazed herbage. Finally there is a paucity of information of the effects of deferred grazing on sward composition and herbage regrowth. Therefore the current study will evaluate the effects of deferred herbage allowance and frequency of allocation on the performance of pregnant ewes and ewe replacements. Furthermore the effects of deferred grazing on herbage regrowth and sward botanical composition will be evaluated. These studies will be undertaken at Athenry and on commercial farms. The results from these studies will improve the efficiency of year round grazing systems for midseason prime lamb production.
Project Leader: Tim Keady
AGRIP – Athenry Grassland Science 4925
Start Date: 1/10/2000 End Date: 30/11/2012