Silage Quality - Do you really know what you are feeding?

Enda Maloney, Drystock Advisor, Teagasc Westport

The wet weather over the last few weeks has meant that farmers have started housing their cattle, while others won’t be far behind.  With pits of silage and bales being opened right across the country, it’s important that farmers know what quality of feed they are feeding their stock.

The winter feeding period is the most expensive stage in Irish farming systems. Consequently, it is critical that animal nutrition is tailored correctly to each animal group to optimise animal performance.

By analysing silage it will allow farmers to supplement animals with the appropriate rate of concentrates to meet the animals nutritional needs to help each animal group achieve its performance targets. The level of concentrate feeding required by animals over the winter period is determined by the quality of the silage being fed.

The table below indicates the feeding value in DMD of the silage and the meal required in kgs / head  by the animal to hit its target growth rate over the housing period. The target live weight gain for a spring-born beef weanling over its first winter is 0.6kg/day to allow for cheap weight gain off grazed grass in the second grazing season. For finishing cattle such as steers at 600kgs to achieve an average daily gain of 1.0kg/day when offered silage at varying levels of DMD, the table below clearly indicates the poorer the silage quality the more meal that is required.  At current meal prices poor quality silage will prove very costly and highlights the clear benefits of making good quality silage.

Without analysing silage it is very difficult to know if we are under or over feeding cattle the required concentrates they need to achieve their performance targets. From visiting farms regularly I can see that there is a lot of animals not been fed adequate meal and therefore the performance of these animals is often quite poor, primarily due to the fact that the silage quality is not as good as the farmer thinks it is. The most effective way to determine the quality of the silage you are feeding is to get it analysed.

A silage analysis will tell you the feeding quality of the silage such as Dry matter (DM), Dry matter digestibility (DMD), the protein content and the energy value (MJ/UFL).  It also gives the farmer an indication of how well preserved the silage was by assessing the lactic acid, ammonia and PH levels.

For farmers who have never taken a sample before it is critical to get an accurate sample from their bales or pit otherwise poor sampling technique will lead to unreliable silage analysis results. For that reason farmers should follow the steps below

• Farmers with a pit need to get a silage corer and take 3-5 well spaced cores across the pit. The core will take a sample profile through the pit given a good even representative. Dispose of the top 100mm of each core before mixing all the cores together and sending off for analysis.
• Alternatively, sample an open pit and take 8- 10 grab samples in a “W” pattern across the pit face.
• For bales, sample 2 bales per cut by grabbing random hand samples throughout the bale when freshly opened and then put the sample into a zip-lock bag, exclude the air, seal well and post immediately early in the week.

When the results are analysed and send back to the farmer it is then vitally important for the farmer to consult their nutritionist or advisor in order to formulate a diet for the stock on their farm.