Pre-mowing paddocks has become common practice on many Irish dairy farms.
It is used on some farms where paddocks have a pre-grazing yield that is too high for cows to graze.
It is commonly used on dairy farms in New Zealand, but it would still be considered a somewhat new practice on Irish farms.
However, the question begs: Is it worthwhile?
Pre-mowing
Pre-mowing is often used on paddocks where grass quality may be poor, or swards that have a large amount of stemmy grass.
Although this does improve the grass quality in the sward in future rotations, it is an expensive practice – especially with current input costs.
Considering the cost of diesel, it is also an expensive way to manage grass on farms.
Furthermore, cows are picky eaters, so by pre-mowing a paddock you are also preventing them from picking the best grass to eat.
This will result in a reduction in production from cows if they are forced to eat a large amount of stemmy grass.
Grass
In other cases where grass quality is not an issue, but covers may be too strong, pre-mowing is also often used.
Although pre-mowing can improve milk production from cows, once it is done on a paddock containing a large amount of high-quality grass it is expensive.
It will also likely require continual pre-mowing as covers will continue to be too strong.
The best option is to avoid pre-mowing and to skip paddocks with covers that are too heavy.
Ideally, grazing covers should be 1,300kg dry matter (DM)/ha to 1,400kg DM/ha; anything heavier than this will result in wasted grass, while covers below this will results in cows moving through a large area too quickly.
Worthwhile?
Stemmy grass is an issue at this time of year, but managing it by pre-mowing paddocks is expensive.
It also forces cows to eat this lower-quality grass as it will be mixed in with the higher-quality leafy grass.
The best option to manage these paddocks is to skip over them and bale them.
This also works in the paddocks with covers that are too high.
By baling this grass, production does not suffer, and, extra feed is added to the winter fodder budget.