Despite excellent stocks and reports of encouraging feed quality, many farmers are reporting that grass silages are not milking as well as expected.

How well are your silages delivering this winter?

Despite excellent stocks and reports of encouraging feed quality, many farmers are reporting that grass silages are not milking as well as expected. UFAC-UKs Mark Townsend considers the reasons why and what can be done to improve performance for the rest of the winter.

To produce the optimum yield from silage, the starting points are the forage analysis and the rumen. The first thing to acknowledge is that there is no such thing as an average silage. We recommend that you have your forages analysed monthly throughout the winter, as the analysis will change as you move through the clamp.

Once you have the analysis you can consider how the silage will perform in the rumen, and this is where many diets are falling behind at the moment. On paper the diet is right, but the cows aren’t milking as per the ration plan. This would suggest things aren’t right in the rumen.

Fibre

Grass silage fibre levels are very variable this season. Some early cuts contained high lignin due to over- wintered grass. We have seen a large number of forage analyses where NDF is low and ADF is high which means the rumen will be short of hemicellulose, essential for the production of glucogenic energy.

High ADF means fibre digestibility is an issue and you will see increased long particles in the dung. If this is the case, then you need to increase the supply of glucogenic energy to the cow. But do so carefully. While starch and sugars are good sources of glucogenic energy, they are rapidly fermented carbohydrates bringing the risk of reduced rumen pH which will also compromise fibre digestion.

A safe and very effective alternative is to feed UFAC Glycerene which is a proven way to boost glucogenic energy. By being rumen-inert it is an excellent source of energy for glucose production. Also, Glycerne is highly palatable, which means it helps boost intakes.

It also improves total feed efficiency by improving the utilisation of fat in the diet. Finally, it has a preservative effect and helps reduce heating to maintain feed quality in the trough.

Energy density

With diets containing higher proportions of the total dry matter from forages, a big issue could be supplying enough total energy for fresh-calved and high yield cows. Rumen-inert fatty acids like Dynalac deliver a balanced blend of fatty acids to improve energy supply and overall efficiency.

In particular, Oliec acid (C18:1), one of the fats in Dynalac, has a positive effect on total fat digestibility and the maintenance of body condition. Dynalac also includes EPA and DHA from marine sources which help get cows cycling again to get them in calf quicker.

The keys to getting the most from forage this winter are:

Understanding the quality of forage through regular analysis
Keeping the rumen efficient
Monitoring performance and to revise the diet as required.