ChileanJAR

Thirty spring born Hereford young bulls, with an average body weight of 220 kg and 8 to 9 months of age, were used in a trial, at the Carillanca (INIA-Temuco) Exp. Sta. The animals were fed with tall fescue-subterranean clover silage, malt sprouts and minerals, plus 0 (T1), 2 (T2), 4 (T3), 6 (T4) and 8% (T5) of rapessed oil (D.M. basis). Silage, malt sprouts and minerals were included at 72.5, 23.5, and 4%; 69.65, 24.35, and 4%; 66.94, 25.06, and 4%; 64.12, 25.88, and 4%; and 61.41, 26.59, and 4%, respectively. Daily gains (kg) were 0.353a, 0.516b, 0.587bc, 0.654c, and 0.620bc (P < 0.05) for T1, T2, T3, T4 and T5, respectively. The were not differences (P > 0.05) in D.M. intake and the efficiencies of feed conversion were 11.12a, 5.5b, 6.7c, 6.1 c, and 6.3c (P < 0.05) kg D.M./ kg L.W., respectively. In vivo digestibil ity of the rations were analyzed. It was concluded that the use of a 4 and 6% of rapeseed oil in the ration improves daily gain and efficiency of feed conversion, without affecting animal performance.