Most dairy farmers saw the back wall of the silage pit for the first time in a long time last winter. With below normal first cut silage yields, farmers are now looking to maximising forage yields and research other options.

Spread nitrogen now to bulk up second cut silage later

The big plus with second cut silage is that it is within your own control to some extent. To maximise yields, all the researchers suggest spreading 100kg of nitrogen/ha (80 units/acre) now.

If we allow for 80 units/acre of nitrogen as CAN at €180/tonne, harvesting at €80/acre and 15% losses, in total, then we come up with a total cost of €303/hectare for second cut silage or 10.2c/kg dry matter if we assume we can get six tonnes/acre (see Table 1).

If you have to spread cut sward, then you are looking at 15.2c/kg dry matter for a yield of five tonnes/acre. The researchers say the best you can hope for is five to six tonnes/acre for second cut silage and, in some instances, this will be back to four tonnes/acre.

So, depending on silage yield, the cost of second cut silage will work out at between 10c/kg and 15c/kg dry matter as a forage source. If you have to rent ground, even at €50 or €60/acre, it becomes a very expensive feed (almost 20c/kg DM) and other options should be considered. Again, if you have poor grass species in your fields, you won’t get the yield.

The upside is you will have a relatively stable feed source that can be left in the pit if you don’t use it.

It’s easy to feed out compared with other options, such as caustic wheat and fodder beet. You don’t need specialised machinery for feed out.

So how do you maximise the amount of second cut silage? There are two options that most farmers will aim for now.

Some who have only finished cutting first cut silage last week will close up some of this same ground again for second cut.

Fill it up with 80 units/acre of straight nitrogen, plus slurry and close the gate. Some with low soil P and K levels will have to spread a compound with some phosphorus and potassium, e.g. cut sward which will increase price slightly (see Table 1). Either way, you maximise silage yields from a set area.

More will switch silage ground and close up other paddocks for second cut silage. They will graze the after grass with cows or young stock.

In this instance, yield can be higher and if it is bulk you want, then it is a better option.

In both cases, you should try and maximise the amount of nitrogen to bulk up second cut. While maximising nitrogen on the silage area at the same time, farmers will keep spreading 35 units of nitrogen per acre on the grazing ground. This will deliver surplus silage on the grazing block and they will take out this surplus as bales.

If you have very stringy, poor quality paddocks that have been badly damaged and are not producing quality grass, then you have little choice but to top off these paddocks, spread 35 units of nitrogen/acre and try and get them back growing again.

Now, if you just have stringy dung pats and good grass growing in between, don’t bring the topper out. Spread the nitrogen and let it bulk up as much as you can and then take it for bales. Topping off grass and letting it rot down is a waste of good feed.

Winter options - in brief

• Wholecrop silage

Some farmers will look at this option if they are farming in an area where there is a lot of cereal growing. They buy the crop of barley or wheat and ensile the crop at the milky stage of ripening.

The upside is if you get a good quality crop, you can have a very good quality feed. You might buy value if the price of cereals increases significantly, depending on weather and price movements. The cereal farmer will want the same price he can get if he lets the crop ripen. This means you should get someone, who knows the crop and estimating yields, walk the crop and determine yield.

The downside is once you ensile the crop, you must use it over the winter months. You must ensile it correctly in a small narrow pit, with grass silage on top to form a good seal over the wholecrop. The cost in cent/kg DM will work out between 25c/kg and 30c/kg and you need to harvest at the right stage and do ensiling properly.

• wheat for caustic acid treatment

Another farmer I talked to last week was going to buy wheat off the combine. His plan was to put it in the feeder wagon mix in caustic acid and tip it up in a long shed. He will buy 35 tonnes to 40 tonnes of wheat and spend a day or two mixing in the acid.

He has had great success with this in the past. Again, he will use it from mid-November and December, before he opens up the silage pit. If you can buy wheat for €130/tonne off the combine, the cost per kg dry matter comes in at 20c/kg to 25c/kg DM.

• Feed now to allow more surplus grass?

This is an expensive option and one that can back fire very easily.

You feed 2kg or 3kg of meal per cow now and, really, all you end up doing is substituting grass in the diet at a time when grass is growing very well.

You end up reducing the quality of grass available to the cows and then topping to bring quality back in the sward. The other downside is that you reduce the quality of feed and don’t make a gain as waste is topped off and rots.

• Not topping - bulk up, cut and bale?

Depending on growth rates and weather, taking out surplus as round bales will be an option many will focus on during July and August.

If the paddock is growing well, instead of topping, some farmers will spread 35 to 40 units of nitrogen and let the paddock bulk up. This is cut for bales at 35 to 40 days of growth. You get no lag after cutting because you don’t have big yields.

Some paddocks that are very badly damaged and grazed very badly will have to be topped to get them back growing.

They are only producing stem and the only way to get them back growing productively is to top them off and get nitrogen out on them to get the grass plant back tillering and growing.

• Buying fodder or sugar beet

Purchasing fodder or sugar beet in late September or October for €40/tonne delivered to the yard.

Tip it up on the silage slab, wash it, chop it and have some sort of a feeder wagon for feeding out.

Some farmers will say sugar beet is a much better quality feed than fodder beet. They find fodder beet can be much lower in dry matter. The downside is there is a lot of work involved in washing and chopping, etc. You can draw a lot of vermin around the yard. You need specialised machinery.

Cost in cents per kg dry matter will work out around 20c/kg to 25 c/kg dry matter if you can buy fresh beet for around €40/tonne fresh delivered.

Of course, you can’t feed this on its own so you will need to balance this with other forage. Be careful you don’t feed too much as you could end up causing a lot of problems with over fat cows and calving problems.