Diversity of the feeding value of conserved forage in three Belgian regions

摘要

The variability of the feeding value of maize silage, grass silage, and pasture hay was studied by analysing nearly 4 300 samples of these forages. The largest variations in the energy value and in the supply of protein digested in the intestine occurred in grass silage and in pasture hay. We have attempted to explain heterogeneity by the following factors: geographical origin, occurrence of a rainy day during curing, rank of cut, year of harvest, storage conditions. These factors, taken together, explain at most 50% of the observed heterogeneity. Moreover the main explanatory factor is not the same for all feeding parameters. Thus the energy value of grass is apparently mainly determined by farm practices and by pedo-climatic conditions, whereas its ability to yield protein digested in the intestine seems to depend on the weather during curing. It is therefore difficult to predict the value of these forages without resorting to an analysis.