In some parts of Belgium, growing maize for silage does not guarantee a constant yield. One alternative widely practised in Northern Europe is growing other cereals that are less demanding than maize in terms of temperature sum and moisture deficit. These are harvested and ensiled before maturity. Such silage is energy-rich due to the starch present in the seeds and could therefore offer a good supplement to grass silage. In contrast to hay meadows, sowing cereals in this way qualifies for the cereal subsidy and, unlike maize, provides ground cover from autumn through to summer, thus reducing the risks of nitrate leaching. Moreover, these cereals can withstand summer drought far better than maize.
Objectives
The aim of this study is to determine whether immature wheat silage can entirely replace maize silage for dairy cows in mid-lactation. The benefit for the farmer lies in the possibility of cutting down on energy concentrate and thus reducing the cost of feeding the herd while at the same time utilising more forage produced on the farm.
Results obtained
Wheat harvested before maturity produced a lower yield than maize silage (11 compared to 19 T/ha DM). It was also slightly lower in energy (850 as against 900 VEM/kg DM), but had a higher protein content (11 compared to 7%). The test involved four dairy cows which were fed the rations shown in Table 1 according to a 2×2 factorial design. There was no variation in fat corrected milk production between the diets (Table 2). The milk fat content was higher with the wheat ration, whereas the protein level and milk urea showed little variation between the diets, even if the differences noted reached a significant threshold. These results suggest that the efficiency of use of protein intake does not vary much according to the type of silage fed and that immature wheat silage can substitute for maize silage for dairy cows in mid-lactation.
