With the expansion of the national dairy herd in recent years, many farms have become short on housing, with many farmers now looking for options to alleviate this issue.

Having your stronger, or better-grown yearling heifers grazing a fodder crop, could solve these issues.

Could the use of a fodder crop be an option for your farm? These crops are beneficial for animal performance and reduce the stress placed on silage supplies.

Why sow a fodder crop?

Fodder crops offer farmers a cost effective winter feed, to increase liveweight gains, while also offering a solution to a lack of availability of winter housing – these animals will require less silage than housed animals.

Fodder crops can also be incorporated into your reseeding programme, with grazed fodder crops offering an ideal seed bed for an early spring reseed.

How to sow

Fodder crops require a soil pH of 6.3-6.5, phosphorus (P) and potassium (K) indexes of three, and two for nitrogen (N).

The most common method for sowing these crops is to spray off the field and then either min-till or plough.

The sowing rate will depend on the method used for sowing and crop type; it is recommended that two bags of lime/ac is applied if a min-till method is used.

Generally, the N application is split in two: 50% is spread at sowing, and the remaining 50% is spread four weeks after crop emergence.

Kale

The ideal time to plant a kale crop is now; it takes approximately 150 days for a kale crop to mature. It is advised to have kale crops planted by July 1, to ensure you achieve a high-yielding crop.

Expected return from a kale crop:

  • Yield (t DM/ha) – 10-12;
  • Dry matter (DM%) – 14-16;
  • Crude protein (CP%) – 16-18;
  • Metabolisable energy (MJ/kg DM) – 12.5-13.5;
  • UFL value (kg DM) – 1.05.

Rape

A popular variety of rape/kale hybrid sown in Ireland is Redstart. It is known for its rapid and vigorous growth habit and can be sown later than kale – around mid-June to mid-August.

Expected return from a rape crop:

  • Yield (t DM/ha) – 6-8;
  • Dry matter (DM%) – 12-14;
  • Crude protein (CP%) – 18-20
  • Metabolisable energy (MJ/kg DM) – 10-11;
  • UFL value (kg DM) – 1.1.

Precautions

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.

Kale should not be provided as 100% of the diet, only up to a maximum of 30%.

The most common way of providing a long-fibre source would be by leaving round bales in the field around sowing time.

It is also of paramount importance that you ensure these animals are bloused or drenched to ensure there are no mineral deficiencies.

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.

Make sure there are no runoffs and that poaching is minimised, and adhere to all Good Agricultural and Environmental Condition (GAEC) regulations.