Integrating novel forage management into sheep farm systems

Abstract

Sheep have a higher intake of nutrients when offered continuous free access to ryegrass and white clover growing separately than when offered the same species growing as a mixture. To determine if this greater nutrient intake would translate to higher animal performance, three experiments of 3-6 weeks duration measured liveweight gain by ewes+twin lambs in early spring, weaned lambs in mid-late spring and hoggets during late winter to identify the class of sheep most responsive to this form of forage presentation. Offering pasture comprised of ryegrass and clover growing separately resulted in higher average daily gains for weaned lambs (330 vs 185 g/ day, P<0.01) and hoggets (240 vs 190 g/day, P<0.05), compared with ryegrass-only pasture. The farm simulation model STOCKPOL and the experimental results reported above were then used to examine four scenarios for implementing this form of pasture arrangement on-farm. This analysis predicted that using pastures comprised of ryegrass and clover growing separately on 15-20% of the area of a typical sheep breeding/finishing farm is feasible and could increase lamb carcass output and net farm income. A higher proportion of area than this shifts the distribution of feed supply towards summer and would be appropriate for systems having higher feed demand in summer, such as specialist lamb-finishing or highly prolific breeding flocks. Keywords: average daily gain, forage presentation, grazing behaviour, ryegr ass, STOCKPOL, white clover