Comparison of flail-harvested, precision-chopped and round-bale silages for growing beef cattle

Abstract

The effects of silage conservation method on silage composition and animal performance were examined in two experiments. In Experiment 1, unwilted, flail-chopped silages made with or without an additive (sodium nitrite and hexamethylene tetramine) were compared with wilted, round-bale silage. The dry matter (DM) concentration of round bale silage (460 g/kg) was higher than that of flail silage (214 g/kg) and this restricted fermentation and N solublisation. When fed to growing cattle, intake (P<0.01), live-weight (LW) gain (P<0.001) and LW gain to feed ratio (P<0.05) were greater for round-bale silage than for flail silage. In Experiment 2, flail-harvested silage was compared with wilted, precision-chopped and round-bale silages conserved either without or with pre-slicing immediately before baling. The DM concentration of flail, precision-chopped and round-bale silages were 163, 334 and 468 g/kg, respectively. Fermentation in flail silage was more extensive than in precision-chopped and particularly round-bale silages, but insoluble-N concentration was unaffected. Round-bale silage was more digestible (P<0.05) than flail or precision-chopped silages. Voluntary intake was higher for steers fed round-bale silages compared to flail silage (P<0.05), while intake of steers fed precision-chopped silage was intermediate (P>0.05). Steers fed round-bale silages had higher LW gain (1.0 kg/day) than those fed flail (0.7 kg/day) or precision-chopped silage (0.8 kg/day; P<0.05). Efficiency of utilization of DM for LW gain was similar for all silages. Pre-slicing at baling had no effect on animal performance. It is concluded that the increased performance by cattle offered silages made by the wilted round-bale system was largely due to higher voluntary intake.