The dangers for herd health posed by grass silage with a very low protein content have been highlighted by Teagasc advisers.
They confirmed some silage test results have come back with very low protein level results, and advised that this feed may need to be supplemented when farmers are feeding it to certain groups of beef animals.
Bacteria in the rumen need sufficient protein so that they have enough nitrogen (N) to properly function and digest the silage being fed. Without this, animal performance will be at least reduced, and very low protein silage may in some cases lead to more serious problems.
Work from Scotland showed that where low-protein silage was fed to suckler cows, there was rumen impaction due to poor fermentation, and this led to some cows dying.
If insufficient protein is available, the cow is forced to mobilise lean tissue rather than fat, and if the deficiency is prolonged, it can result in poor calves born from thin, weak cows.
Colostrum quality may also suffer, and it may cause long-term effects on fertility.
How much extra protein needs to be fed will depend on how low the protein is in the silage, and the type of animals it is being fed to.
Generally, younger, growing animals will require a higher level of protein in their overall diet, compared to older stock and cows.
The choice of protein supplement will be influenced by prices.
Small levels of soyabean meal can very quickly bring up the protein in a diet, whereas higher feeding levels are required of protein feeds such as beans, distillers, rape or maize gluten.
Most commercial rations on their own will not be high enough to bring up the protein where very low-protein silages are being fed.
Speak with your Teagasc adviser about doing up a complete diet for each group of stock on your farm that is balanced for both protein and energy, farmers were advised.