4 steps to getting the most from forage crops on your farm

Many beef, sheep and dairy farmers are beginning to introduce forage crops into their animal’s winter diets.

Good management of these crops, whether they be kale, rape or hybrids of the two, is key for achieving the best results over the winter months.

At a recent Germinal Ireland farm walk in Co. Tipperary, Teagasc’s Dr Emer Kennedy highlighted a number of areas farmers need to bear in mind when it comes to grazing forage crops this winter.

1. Measure the crop

The Teagasc Research Officer said that one of the first steps farmers should take before grazing forage crops is to measure how much of the crop is available.

This can be achieved by taking a quadrant cut from the paddock and weighing the resulting sample.

From the results, farmers will be able to judge the daily forage crop allowance whilst also allowing them to budget how many days grazing the crop will provide.

Items needed:
  • Quadrant (0.5mx0.5m)
  • Shears
  • Weighing scales
  • Plastic bag

Calculating the Dry Matter yield of a Kale crop:

Sample weight (2kg) x Number of quadrants/hectare (40,000) x Dry Matter 12% (0.12) = Dry Matter per hectare (9.6t/ha).

Teagasc's Dr Emer Kennedy speaking at the farm walk.
Teagasc’s Dr Emer Kennedy speaking at the farm walk.

2. Introduce the crop slowly

Kennedy also advised farmers to introduce their stock, particularly cattle, to forage crops slowly, and generally speaking a 10-to-14 day acclimatisation period is recommended.

“Forage crops have a different taste to grass so they need to be introduced slowly,” she said.

From trial and error, she said, offering cows hay or poorer quality silage will encourage them to begin grazing the forage crop.

This hay or silage will also allow cattle to be be provided with the necessary fibre allowance to prevent digestive upsets.

The bulls are offered 2.5 bales of silage a week

Some 70% of the diet can be made up of the forage crop, while the remaining 30% should come from a fibre source such as silage or straw, she said.

Problems with introducing forage crops to quickly:
  • Stomach upsets
  • Scour
  • Bloat

3. Use iodine boluses

Farmers should also bolus their cattle prior to grazing forage crops, she said, as their Iodine levels may become imbalanced from grazing these crops.

Cattle should also be offered water at all times, despite the low Dry Matter levels of forage crops, under animal welfare grounds.


4. Risks associated with flowering crops

The Teagasc representative also said that farmers should avoid allowing their cattle to cattle to graze mature and flowering forage crops.

Grazing flowing forage crops, she said, can result in Redwater-like symptoms as cattle can develop Hemolytic anemia.

These animals will appear to be very weak and present with severe anemia.

Along with Hemolytic anemia, Kennedy also said there are risks associated with grazing in-calf heifers on these crops.

“The high Calcium-Phosphorous ratio seen in forage crops can result in milk fever,” she said.