Although the majority of Irish cattle are housed over winter, there are farms on drier land that can winter livestock on forage brassicas.
Crops such as kale and forage rape offer many benefits from cutting down on slurry storage to having cows in fit condition when calving starts in spring.
However, there are a few downsides to keep in mind, some of which are outlined as follows.
Cattle on kale or forage rape will continue to be exposed to parasites such as liver fluke, so keep a close eye to cattle condition for signs of a burden.
A second fluke drench may well be needed early in the new year.
Taking a few faecal samples mid-winter will give a good indication if fluke need treating or not.
2. Mineral supplementation
Crops such as kale are low in minerals, so it is important that cattle are properly supplemented with trace elements. There are various forms of supplementation, each with their own merits.
3. Avoid grazing after heavy frost
If there is a heavy morning frost, do not move the strip wire to give cattle grazing access to fresh forage crops. Frost increases nitrate levels in the plant, which can potentially poison animals.
Wait until the frost has thawed properly before moving the wire. Offer cattle an extra bale of silage until such time as the wire fence can be moved, helping to keep animals settled.
Forage brassicas are also low in fibre, so cattle must always have access to silage, haylage or straw to avoid rumen problems.
Forage crops should be limited to 50% of dry matter intake, with the remaining 50% coming from the silage or straw bales provided.
Ideally, bales will have been placed in the field in autumn. This means there is no need for machinery to enter the field when cattle are grazing, avoiding heavy ruts and soil damage.
5. Do not graze when the crop flowers
Once forage crops start to flower in early spring, stop grazing and remove cattle from the field. Flowering plants are toxic and cattle are more prone to problems such as redwater, goitres and a sudden loss of appetite. Therefore, be vigilant as winter transitions into early spring.