Forage Rape

Ideal for extending the grazing season into autumn and winter.

Forage rape is ideal for extending the grazing season into autumn and winter. It is a winter- hardy brassica with excellent yields and quality.

  • Fast growing winter crop
  • High protein content
  • Suitable for dairy, beef and sheep systems o Flexible sowing dates

Forage Rape Varieties


  • Very quick to establish, ready to graze within 12 weeks of sowing
  • High yield potential
  • Excellent disease resistance


  • Flexible variety for spring or autumn sowing
  • Ideal for fattening lambs
  • Strong resistance to powdery mildew


  • Exciting new hybrid from New Zealand
  • Extremely high yielding
  • Excellent leaf:stem ratio means top quality and high utilisation

DLF is excited to bring Mainstar to Ireland in 2024. This variety has impressed in our on-farm grazing trials in 2023 producing the highest yields and best utilisation when grazed. Ask your merchant for Mainstar this summer.

How Much Forage Rape Do I Need?

For accurate feed planning it is essential to measure the DM yield of the crop. This can easily be done by following the steps below.

To measure your crop you will need:

● 1m² frame

● Seed bag

● Pair of garden shears

● Scales


1. Place frame in the forage crop.

2. Use shears to cut each plant inside the frame (about 10cm from the ground). Put the harvested crop in the bag.

3. Hook bag onto scales and record the crop weight per square metre (kg/m²).

4. To calculate DM yield/ha multiply the fresh weight per m² by 10,000, then multiply by the expected crop DM percentage.

Example calculation:

Forage rape from 1m² = 5kg fresh weight x 10,000 = 50,000kg fresh weight/ha

Typical rape dry matter = 13% so the formula is 50,000 x 0.13 = 6,500kg (6.5t) DM/ha

A number of samples should be taken from each field, picking representative sampling points for an accurate result.

Once you have estimated the yield of the crop you can calculate the allocation required using the tables below.


How to calculate your Forage Rape requirement.



Example based on a 270 kg weanling requiring 8 kg DM/day

Livestock & Forage requirement


Livestock total intake. (Estimate total daily intake on the basis of a dry matter requirement of 3% of liveweight)

8kg DM/day



Amount of brassica in the diet (How much of the diet will be grazed brassicas?)




Brassica daily requirement (row 1 multiplied by row 2, divided by 100)

5.6 kg DM



Number of livestock




Daily requirement from brassica (row 3 multiplied by row 4)

140 kg DM



Estimated crop DM yield/m²

0.56kg DM/m²



Total daily grazing area required (row 5 divided by row 6)

250m² of brassica



Length of feed face




Fence to be moved (row 7 divided by row 8)






Typical allocation level for different classes of stock.

Class of Stock

Allocation (% of bodyweight)

Dry cows/ewes


Mid-pregnancy cows/ewes

Mature bulls/rams


Late pregnancy cows/ewes


Late lactation cows


Finishing cattle


Early to mid-lactation cows

Mid to late-lactation ewes

Replacement stock


Growing cattle


Eary lactation ewes*

Flushing cows/ewes

Finishing lambs

 *Allocation may exceed 3 per cent in early lactation.