Effect of different grazing pressures by lambs grazing Lolium perenne and Dactylis glomerata pastures during spring on: 2. Intake and growth

This study was undertaken to determine the influence of three grazing pressures [high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the performance of lambs grazing Lolium perenne and Dactylis glomerata pastures in spring. Feed intakes and average daily live weight gains (ADG in g/day) were determined for each group. In general intakes of both L. perenne and D. glomerata pastures were higher at the end of the study than at the onset. Grazing pressure had no effect on the intake of L. perenne, but on the D. glomerata pasture, HGP resulted in a decreased intake by the lambs compared to the LGP treatment. For both pasture species the ADG of the lambs were lower on the HGP compared to the MGP treatment, though intake and ADG of the lambs were higher when grazing L. perenne compared to D. glomerata. Keywords:Cocksfoot; diet selection; pasture availability; perennial rye grass; performance South African Journal of Animal Science Vol. 36 (5) 2006: pp.50-53