Although not widely used on Irish farms, the use of a fodder crop on farms has increased as a way of reducing the pressure placed on housing.
Kale, rape and stubble turnips are some of the more commonly-grown fodder crops for grazing of ruminants.
Kale and rape are high-protein, high-energy crops, so a long-fibre source needs to be available. This can be provided by feeding silage, hay or straw.
A commonly used method to ensure this forage is available is the placing of silage bales in the crop shortly after planting.
Precautions
Kale and rape crops are low in some elements such as iodine, copper, selenium and cobalt.
Only animals that are in good condition and have no underlying health issues should be used to graze fodder crops, as weather can be harsh and only the fittest animals should be out-wintered.
Always ensure there is fresh water available and a sheltered, dry lie-back area for the stock.
Grazing
To obtain the best utilisation of the crop and limit intakes, strip grazing of fodder crops is advised.
To determine how much crop is available you need to measure it, this can be done by cut and weight method.
From this you will be able to determine how big the breaks need to be. Like grass measuring, it is a 1m2 measurement.
Sample weight (2kg) X number of quadrants/ha (40,000) X dry matter (DM) of 12% (0.12) = DM/ha (9.6t/ha).
Ideally you should have a number of breaks set up ahead of the cattle so they can be easily moved onto a new break.
Forage should be available to the stock at all times, with fresh bales being given to the stock regularly.
When the stock are grazing the crop you should be vigilant for following:
- Trace element and mineral deficiencies;
- Nitrate poisoning;
- Bloat;
- Redwater;
- Photosensitisation;
- Lameness.