Do I need to use absorbents?
There should be little need to consider absorbents unless DM levels are less than 20-25%. Under Australian conditions, most silages should have a DM content above 25%. A rapid wilt to at least 25-30% should minimise effluent losses.
In Europe, dry fibrous products (dried sugar beet pulp, distillers’ dried grain, chopped straw) are used as absorbents. Some of these are commercially available in a pelleted form. However, apart from straw, other suitable products are not readily available in Australia, and transportation costs are likely to make straw uneconomic as an absorbent.
In any event, the addition of straw is undesirable, as it will lower the ME content of the silage.
The most promising alternative for Australian producers appears to be rolled grain, which will also raise ME content. Addition of barley was also found to reduce effluent losses and improve the silage fermentation (see Table 7.23), although the whole grain component may not be well utilised by cattle.
Table 7.23 also highlights the significant quantities of nutrients that can be lost in effluent. Oats may be an alternative to barley as research indicates that cattle are able to digest oat grain efficiently when it is fed whole.
