TY - JOUR
T1 - Effects of continuous or rotational grazing of two perennial ryegrass varieties on the chemical composition of the herbage and the performance of finishing lambs
AU - Marley, Christina Louise
AU - Fraser, Mariecia Dawn
AU - Fisher, William J.
AU - Forbes, A. B.
AU - Jones, R.
AU - Moorby, Jonathan Martin
AU - MacRae, John C.
AU - Theodorou, Michael Kyriacos
N1 - Marley, C. L., Fraser, M. D., Fisher, W. J., Forbes, A. B., Jones, R., Moorby, J. M., MacRae, J. C.. Theodorou, M. K.. (2007). Effects of continuous or rotational grazing of two perennial ryegrass varieties on the chemical composition of the herbage and the performance of finishing lambs. Grass and Forage Science, 62 (3), 255-264
PY - 2007/9
Y1 - 2007/9
N2 - Plant breeding has developed perennial ryegrass varieties with increased concentrations of water-soluble carbohydrates (WSCs) compared with conventional varieties. Water-soluble carbohydrates are major metabolic and storage components in ryegrass. Therefore, if perennial ryegrass herbage is allowed to grow to greater heights it should contain higher water-soluble carbohydrates concentrations, for example as under rotational grazing rather than continuous grazing by livestock. This study investigated this hypothesis and measured the performance of lambs grazed rotationally and continuously. Replicated plots of the variety AberDart (bred to express high WSC concentrations) or the variety Fennema were grazed by a core group of ten male Cheviot lambs for 10 weeks. Lambs were weighed and replicate forage samples were taken every 7 d. Concentrations of WSC in AberDart herbage were significantly (P < 0·05), but not substantially, higher than those in Fennema herbage. Rotational grazing did not increase the differential in WSC concentration between the AberDart and Fennema varieties. However, there was a tendency (P = 0·07) for lambs rotationally grazing the AberDart swards to have a higher final live weight than lambs grazing the Fennema swards. Overall, lamb performance was increased when either perennial ryegrass variety was rotationally rather than continuously grazed (P < 0·001).
AB - Plant breeding has developed perennial ryegrass varieties with increased concentrations of water-soluble carbohydrates (WSCs) compared with conventional varieties. Water-soluble carbohydrates are major metabolic and storage components in ryegrass. Therefore, if perennial ryegrass herbage is allowed to grow to greater heights it should contain higher water-soluble carbohydrates concentrations, for example as under rotational grazing rather than continuous grazing by livestock. This study investigated this hypothesis and measured the performance of lambs grazed rotationally and continuously. Replicated plots of the variety AberDart (bred to express high WSC concentrations) or the variety Fennema were grazed by a core group of ten male Cheviot lambs for 10 weeks. Lambs were weighed and replicate forage samples were taken every 7 d. Concentrations of WSC in AberDart herbage were significantly (P < 0·05), but not substantially, higher than those in Fennema herbage. Rotational grazing did not increase the differential in WSC concentration between the AberDart and Fennema varieties. However, there was a tendency (P = 0·07) for lambs rotationally grazing the AberDart swards to have a higher final live weight than lambs grazing the Fennema swards. Overall, lamb performance was increased when either perennial ryegrass variety was rotationally rather than continuously grazed (P < 0·001).
KW - water-soluble carbohydrate
KW - lolium perenne
KW - grazing systems
KW - sweetgrass
UR - http://hdl.handle.net/2160/35267
U2 - 10.1111/j.1365-2494.2007.00582.x
DO - 10.1111/j.1365-2494.2007.00582.x
M3 - Article
SN - 0142-5242
VL - 62
SP - 255
EP - 264
JO - Grass and Forage Science
JF - Grass and Forage Science
IS - 3
ER -