Cover crops for additional forage

The strategic use of cover crops can help plug gaps in forage supply. Learn about the types of cover crops that are suitable for feeding to livestock.

When planning cover crops for forage, take a whole-farm approach and consider:

  • The total feed requirements for the livestock on your farm
  • How feed requirements are met under the current system
  • How much feed is potentially needed from cover crops
  • Which cover crops suit your system

Cover crops for forage

  • Brassicas, including kale, grazing turnips, stubble turnips and rape/kale hybrids, are generally suitable for feeding to all classes of beef cattle and sheep
  • Under appropriate field conditions, non-lactating, spring-calving suckler cows can be outwintered on kale and stubble turnip systems with no concerns in relation to liveweight or condition loss
  • To avoid the risk of calving in an unsuitable environment, cows should not be grazed on brassicas in late pregnancy
  • In late pregnancy, ewes fed on root crops will generally need additional protein to ensure their nutritional requirements are met
  • Swedes are only recommended for cattle with fully mature teeth and are not suitable for ‘broken-mouthed’ sheep
  • Fodder beet, although technically not a brassica, can also be grazed in situ or lifted and fed to livestock
  • Forage gaps could also be filled by feeding silage or hay, but this will increase feed costs
  • Grazing buckwheat can have a toxic effect (photosensitisation) and should be avoided not be grazed

White clover has higher digestibility, protein and mineral content than grass-only swards. Unlike grass, white clover retains its digestibility throughout the season as there is a continual renewal of leaves and little stem development.

Clover will increase the crude protein content of first-cut silage by 1% for every 10% increase in the amount of clover in the sward.

Effective grazing management

Livestock should be introduced to the cover crop slowly, allowing them to get used to it.

Ideally, the cover crop should be strip grazed. If grazed areas are back-fenced, compaction can be reduced, which will benefit the establishment of any subsequent grass leys.

Given the low fibre content of a brassica crop, livestock must have access to a source of roughage, such as haylage or straw. Haylage bales may be left in place after sowing the cover crop, again to reduce compaction that may be caused while transporting bales to the area during autumn and winter months.

The correct amount of feed should be allocated depending on mob grazing requirements. This will ensure efficient use, which is important in any grazing system.

Livestock should have constant access to water, ideally through a portable trough system, for ease of use and to reduce soil compaction.

Relationships between livestock and soil health depend on the typical stocking density of the system and the duration of any intensive grazing period compared with the recovery time.

At very low stocking densities, such as in sparsely grazed upland grasslands, any increase will result in a rise in the activity and number of soilborne organisms as there will be more food sources.

Grass exceeding 25 cm is too long for grazing cattle and won’t be used effectively. Cutting some areas for silage can help manage any excess growth and control grass height and quality.

Food safety standards do not allow cover crops to be grazed immediately prior to growing leafy salads, so green manures should be flail-mown before being cultivated.

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