ABSTRACT
Early weaning of Iambs in a subterraneum clover-hardinggrass-annual ryegrass pasture (Cauquenes). Part II.

Julia Avendaño R.1 y Carlos Ovalle M.2
 

In the second year, of a two years study, the effects and relations of five total daily forage availabilities/animal (D.F.A.), in the subhumid Mediterranean zone, were compared. Liveweights (L.W.) and daily liveweight gains (D.G.) of early weaned lambs (41 days of age and 17.5 kg) were followed for 70 grazing days. L.W. and D.G. ranged from 31.3 to 37.3 kg and 0.184to 0.269 kg, respectively. Significant (P < 0.05) highest D.G. were obtained with the largest D.F.A. With D.F.A. of 49, 87, 118, and 163 kg D.M.I animal, D.G. values were similar, attaining also final L.W. aboye 30 kg and productions of 300 to 400 kg L.W./ha; however, the pasture with the Iowest D.F.A. was overgrazed. The rearing-fattening of early weaned lambs is feasible in these pastures without supplementing the grazing. With D.F.A. between 90 to 160 kg D.M./animal, during 70 to 56 grazing days starting from early September, it is possible to rear-fatten lambs weaned at 18 to 19 kg and 41 days of age. Lower D.F.A. values, even though they do lead to marketable weights and maximize L.W. production per hectare, promote overgrazing and can adversely affect persistance of the sown pasture species.

Keywords:
1 Subestación Experimental Cauquenes (INIA), Casilla 165, Cauquenes, Chile.
2 Estación Experimental Quilamapu (INIA), Casilla 426, Chillán, Chile.