FAQs on grazing brassicas

Friday 25.09.2020 , News

We have composed a list of FAQs on grazing brassicas so as to support you in getting the most from your crop.

Grazing of brassica crops such as Kale and Redstart typically begins from mid to late October and is likely to continue through to next February.

The mild weather we are currently experiencing is likely to put less pressure on farmers in terms of forage shortages, as the grazing season is expected to continue through in line with typical autumn grazing targets.

Timeframes and results from grazing brassicas are largely dependent on crop yield, crop utilisation and weather conditions. However, when it comes to grazing management practises, there are a number of key guidelines that should be followed.

When is the best time to start grazing brassicas?

Mid to late October is the best time to start introducing stock to brassicas, which should be done gradually over a 7-10 day period.

How can I measure the grazing length to be expected from the crop?

To measure the DM yield of your brassica crop you will need the following:

  • 1m2 square frame
  • A large bag (old seed or fertiliser bag)
  • Garden shears
  • Scales

Take a number of samples across the field and pick representative sampling points.

  1. Place the frame in a representative area of the crop
  2. Using the shears cut each plant within the frame (about 10 cm from the ground)
  3. Place the harvested crop in the bag
  4. Using the scales record the weight of the crop per m2

DM yield = (12-14% is a typical average DM)

A more common approach is to consider how long you need to feed the crop for and the area of the field; remembering that the crop should be grazed on the long side. E.g. In a field of 240 metres X 100 metres where the requirement is for the crop to last 120 days; 240/120 = 2 meters. Therefore 2 metres is your available daily allocation. If this is insufficient for the livestock in question, any additional requirement should be supplemented accordingly.

How do I introduce livestock to the crop for the first time?

As already outlined, building up gradually to unrestricted access over a 7-10 day period is recommended. This will often take the following form;

  • Day 1, 2-3hrs,
  • Day 2, 3-4 hrs
  • Day 3, 4-5 hrs
  • Etc.

Build up gradually to unrestricted access to the crop whilst also ensuring access to a lie back area. This is especially important and useful in the early days, as it means stock do not need to be moved to alternative ground.

What mineral supplementation is required?

Brassicas are low in certain minerals especially selenium, iodine, copper and cobalt. Animals should be given a bolus before out-wintering or ever before being introduced to the crop to ensure adequate minerals are supplied.

How much of the diet can brassicas make up?

Brassicas should form no more than 70% of the diet, with the remaining 30% coming from a fibre source such as silage, hay or straw.

Do livestock require meal?

No, brassicas are a high energy high protein feed in themselves and therefore apart from above mentioned bolus and a fibre source such as silage, hay or straw, along with access to fresh water, livestock should have no further requirements.

For a full guide on utilisation of home grown forage, please use the link below: