Wilting of grass prior to ensiling generally produces positive responses in dry matter (DM) intake of cattle, but the responses in animal performance are often small, or even negative. The primary objective of the present study was to compare energy utilization from heavily wilted and unwilted silages by growing cattle when given at equal metabolisable energy (ME) intakes. A secondary objective was to evaluate effects of silage additive type (inoculant v. formic acid) on energy utilization.
Four silages were produced from unwilted and wilted grasses (DM 193 and 450 g/kg) obtained from a perennial ryegrass sward. The wilted grass was dried in the field for 26 hours using rapid wilting techniques involving crop conditioning and spreading. At ensiling both the unwilted and wilted grasses were each treated with two additives, a bacterial inoculant (Ecosyl, Zeneca Bioproducts Limited) and a formic acid additive (ADD-F, BP Chemicals Ltd.).