CHEMICAL-COMPOSITION AND ENERGY VALUE OF MAIZE SILAGE MADE ON FARMS IN ENGLAND AND WALES 1984-92

The chemical composition of 960 samples of maize silage, made on commercial farms in England and Wales between 1984-1992, is described. The average composition was 302 g/kg dry matter (d.m.), pH 3.78, ammonia-N 60 g/kg N, 87 g/kg d.m. crude protein (CP), 292 g/kg d.m modified acid detergent fibre (MADF), 678 g/kg d.m neutral-detergent cellulase digestible organic matter (NCDG) and 301 g/kg d.m. starch. The predicted mean metabolizable energy content was 10.5 MJ/kg d.m. There was significant year-to-year variation for each variable. Ammonia-N and ash contents were negatively correlated and starch and metabolizable energy content were positively correlated with silage d.m. content. The results indicated that in recent years maize silage has consistently been made with d.m. contents above 300 g/kg, which should produce little or no effluent, and will lead to high silage intakes by animals.