Grass: Use forage crops to fill the gap

Supplementary feeding at grass fulfils two main roles. It can help overcome seasonal grazing shortages, or it can compensate for falling quality in grass diets to sustain higher levels of daily liveweight gain in growing stock. These two roles demand different supplementation strategies if grazing intake is to be maintained. Buffer forages are preferable when grazing is short, while concentrate feeds are the supplement of choice to optimise the nutrient density of the diet when grazing is losing quality.

Energy content within the sward is not an issue at this time of year. Last week’s metabolisable energy (ME) reading from the Forage for Knowledge monitor dairy farms averaged 11.8 megajoules of ME, so there is no need to buffer feed with expensive high-energy rations. However, it is forecasted that some producers will be experiencing a deficit in available grazing in the coming months – so may turn to forage crops, like brassicas, to fill the gap.

Top tips for feeding:


  • Identify animals that will not eat brassicas and manage separately on a different system
  • Do not feed brassicas to cows close to calving
  • Only healthy animals in good body condition should be considered
  • Foot trimming before the feeding period will minimise lameness
  • Beef cattle must be fully functioning ruminant animals before they can be reared on brassicas; preferably above 200kg liveweight.


  • Check feet before the feeding period, but foot trim only when necessary. Remove any lame sheep quickly from the crop for regular treatment, one to two times a week
  • Do not graze older ewes or any breeding stock on roots as it may damage their teeth
  • Clip the bellies of lambs and crutch before putting on brassicas to reduce fleece contamination. One comb width either side of the midline should be sufficient and will reduce the risk of skin damage
  • Present clean lambs for slaughter. They may need to be moved off the crop for the last few weeks before marketing.

For more information download our BRP manual Using brassicas for Better Returns