Farm Ireland

Sunday 21 January 2018

If your farm is flush with grass, good quality bales will add to winter silage

Pictured at the recent Tipperary Co-op AGM in Dundrum were: John Hunter, assistant general manager; Ted O'Connor, general manager; Matthew Quinlan, chairman; and Michael Dunlea, financial controller
Pictured at the recent Tipperary Co-op AGM in Dundrum were: John Hunter, assistant general manager; Ted O'Connor, general manager; Matthew Quinlan, chairman; and Michael Dunlea, financial controller

John Donworth

Another good week last week for making silage. We need many more of them but at least we got two of them and we must thank the Lord for small mercies.

Fields are in good shape after cutting, no damage done and crops were cut dry. Preservation should be okay.

However, many of the grass samples brought into the Teagasc office last week had sugar readings of two. At this reading, preservation would be an issue. These crops certainly needed a 24-hour wilt to concentrate the sugar levels.

Nitrogen readings were very low, just like the crops cut in the very fine week. Nitrogen levels have not been an issue at all in silage crops this year and this is a puzzle in itself. Will this fact impact on the crude protein content in the subsequent silage crop? Only time will tell.

A number of you will hope to take second cuts from fields cut last week. I presume you have such fields fertilised by now and that Saturday's rain washed in the fertiliser. Such fields should have received 80 units of nitrogen, 11 units of phosphate and 84 units of potash.

Crops fertilised last week will be due for cutting again around August 15-18.

This is later than ideal because it will impact on the amount of grass you will grow this autumn.

We will need an exceptional autumn to get good grass covers on fields where second cuts are this late. But we will deal with that when the time arrives.

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Fields have greened up quickly after first cuts. This is an indication that crops weren't as heavy as usual, but the fact that they have greened up quickly will add to second-cut yields.

Grass moved well ahead of cows last week and a number of you who hadn't been walking the cows' grazing area suddenly found cows were in very stemmy swards and the rotation length had moved out to 24/25 days.

June is an exceptionally difficult month on grass, and is made even more difficult when it grows in spurts and suddenly there is stemmy grass everywhere.

Stemmy grass and milk yield, particularly milk proteins, don't go hand in hand.

The grass plant is now in the flowering phase and controlling the amount of stem in the sward is a constant battle.

In essence, the grass plant has only three leaves and no matter how long you leave it, it still will have only three leaves. But the longer you leave it, the taller the plant gets.

If you don't do anything to control it, it will eventually push out a seed head at about 25 to 30 days. At that stage you have very much lost the battle to control it.

Seed heads can appear in a sward much earlier than 24 days. You can see them at even day 15 in the rotation, particularly if the grass plant comes under any kind of stress, such as drought or excessive rain. Grass quality, in this case, is very poor.

The trick is to graze the grass plant when it is only four-to-five inches high. At that height, the leaf-to-stem ratio is about 80pc and the dry matter digestibility 80-82. Grass of this height has a cover of 1,400-1,600kg of dry matter and it is seriously good quality material for feeding.

Get it wrong and you have more stem than leaf. With this type of material, grass dry matter intake declines. In other words, the cows eat less of it.

The first item of production to go is milk protein yield, all the way down to 3.2pc. This is very sensitive to grass quality. Next to go is milk yield. You will loose a litre of milk very quickly.

You will do even more damage if you ask the cows to clean out 24/25 day old grass. Don't ask them to clean out the dung pads, because if you do, you will drop half a gallon of milk.

A number of you are pre-cutting paddocks at the moment as an emergency measure to get grass quality back into line. It works well. The alternative is to top the paddock after the cows and at least one round of topping will be required to get grass quality under control.

Rotation lengths of 18 to 22 days are ideal at present. Very good growth rates are needed for 18-day rounds but you are better to be tight on cover at the moment rather than flush with grass. If you are flush with grass, good quality round bales will add to the winter silage stocks.

John Donworth is a dairy specialist and regional manager in Kerry and Limerick.

Irish Independent