Silage Advisory Centre

Those producing these later first cut silages all know the value of that first spring growth as a grazed crop be it for sheep, beef or dairy. Winter forage is therefore conserved once grass growth gets ahead of grazing requirements. 

STAGGERED FIELD CLOSURE

Once grass growth gets ahead of stock, close fields for subsequent silage cuts one by one.  This approach enables maximum grazed grass utilization. By staggering the closing of fields it is likely that there will be a need to stagger the harvesting. Whilst many may see this as an added head-ache to manage, it does spread the risks of bad weather causing problems at harvest.  

USING BALED SILAGE

By using baled silage as the preferred silage production method you gain the flexibility of harvesting smaller areas and adapting your silage quality to the stock requirements on your farm. The most extreme examples, being late pregnant ewes and dry suckler cows; the former wanting the highest quality possible and the latter requiring stemmy and mature gut fill silage. This approach provides all the solutions within a given farming enterprise, just remember to store and mark the bales so you can access each quality as and when you feed it next winter.

GOOD PRACTICES

By following good silage making practices this later cut silage can be just as good as those earlier cuts with the important factors highlighted below.

Fertilizer application

Immediately after the grazing stock have been moved off and before you shut the gate apply fertilizer.  Ideally, the exact quantity and formulation should be based on soil analysis and forage requirements but remember leave at least 1 day between fertilizer application and harvesting the grass for every 2 units/acre of nitrogen applied.

Harvesting

If you require an ME of 11.5 silage cut at around 6 weeks of re-growth.  However, if quality is not as important as quantity then the period can be extended to 8 weeks of re-growth for an ME of 10.5. 

One problem with later cut silage is the potential for dry spells of weather to increase the chances of grass going to head. So it is important to monitor the crop regularly 5 to 6 weeks after shutting the field to assess stem elongation and seed head formation.

Once it is time to harvest it is important to cut the grass when it is dry, so once any dew has risen, and preferably in the sun in the afternoon/early evening. Cut at a height between 5 and 10 cm. If ground conditions are good then the lower cutting height if they are not then consider a higher cutting height. Too low and you not only increase the risks of soil contamination but you also increase the time the crop takes to recover and re-grow so reducing annual forage yield.

Wilting

Spread the crop over as wide an area as possible immediately after cutting to improve the speed of wilting.  Have a target dry matter content for clamps this should ideally fall somewhere between 28-32%, while for bales the target can be much wider. 

Wilt until you reach your target dry matter or for grasses aim for a maximum of 30 hours and legumes for 2 days. Excessive wilting increase field dry matter losses and also reduces the nutrient content of the forage.

Baling

Ideally use a chopper bale to improve the density of the bale and so reducing the oxygen content in the bale and speed up fermentation, this also reduces your wrapping and carting costs.

Once baled preferably move to the stacking site prior to wrapping with 6 layers of good quality wrap and store on a well maintained site. Finally net the bales to ensure no bird damage and control vermin.

Dr Dave Davies is Director of Silage Solutions and independent scientist for the Silage Advisory Centre (www.silageadvice.com)