9 May 1997

Wilting when wet

WILTING wet silage grass will reduce the cost of additives, says Colin Morgan of the Scottish Agricultural College.

He advises aiming to make silage above 25% dry matter to minimise additive costs. An additive costing £3/t of fresh weight applied to 20% dry matter grass equates £15/t of silage dry matter, but on 30% dry matter grass the costs fall to £10/t DM.

Additive manufacturers recommended rates usually apply to fresh weight silage, so the wetter the product the more additive is required for each tonne of DM.

"Also beware of the cost of absorbents on wet silage," says Dr Morgan. "Beet pulp, for example, is a good feed but when 85kg of beet pulp is added to each tonne of 15% dry matter silage a third of the dry matter is sugar beet pulp. This makes it a large proportion of the diet fed and can be costly."