Managing silage making to reduce losses

Abstract

Losses of dry matter and metabolisable energy (ME) occur in silage making due to delayed harvest and also between field and feed trough due to fermentation and aerobic spoilage. Farmers should aim to exert greater control of silage making operations to improve timeliness of harvest and to minimise losses of nutrients. Concentrate input per unit of milk production is often higher than optimal which is more often a reflection of low silage quality than of wasteful overfeeding. A week's delayed harvest of grass is estimated to incur a net cost of 13 pence per cow per day of winter feeding. Mowing a dry crop and spreading it out to maximise rate of water loss during the wilting period can reduce losses in the field. Consolidation of crop in the silo to achieve a minimum fresh weight density of 700 kg/m3 and dry matter (DM) density of 210 kg/m3 will help to minimise losses during the storage period, paying particular attention to the outermost layer which should be covered with an oxygen barrier film. A feed-out progression rate of at least 1 metre per week in winter and 1.5 to 2 metres per week in summer, coupled with harvesting a clean crop with low yeast and mould counts will help to reduce losses during feed-out. Many bunker silos are too old, too small, have no safety rail and are over-filled. Safety issues should be considered at all stages of silage making. Appropriate steps should be taken wherever possible to minimise risk of injury.