Hay production from lowland semi‐natural grasslands: a review of implications for ruminant livestock systems

摘要: Data on total, seasonal and between-year variability in the productivity nutritional quality of cut forages obtained from a range lowland semi-natural grasslands are reviewed. Dry-matter production, as hay, unfertilized species-rich ranged less than 20% to about 80% production that might be expected agriculturally improved intensively managed grasslands. Unfertilized had lower growth rates, reflecting low nutrient availability spring early summer. Low soil phosphorus appears key factor allowing high species-richness maintained. The vitro digestibilities herbage for hay were 20%, or more, below values conserved grassland. When losses incurred during hay-making process taken into account, then nitrogen content hays many appear sub-optimal productive livestock. Metabolizable energy 10–40% grass. Phosphorus most was either metabolic requirement livestock inadequate sustain individual animal performance. Potential problems associated with supplementation diet phosphorus, calcium-to-phosphorus ratios, discussed. Although potassium adequate ruminant livestock, exceptions arise after July. The magnesium some an level Most appeared contain amounts sodium. Inadequacy mineral will exacerbated by particularly so when hay- making is prolonged wet weather. Few feeding studies using nature conservation interest have been conducted. Lack such data makes it difficult plan any integrated use these feed budgets systems.