Offering weaned lambs quality grass with a high content of leaf is central to achieving this.
The secret to achieving high levels of liveweight gain (or milk production) in any animal is to offer them highly digestible grass with a high leaf to stem ratio.
The recommended grass height for lambs post weaning is 8cm to 9cm. This could be reduced slightly if grazing high quality silage aftergrass.
If grazing permanent pasture (not silage aftergrass), it is recommended not to force lambs to graze below 5.5cm.
Doing so will only serve to reduce grass digestibility, by forcing lambs to graze an increasing proportion of stem, and ultimately impact on lamb performance.
The recommended approach is to move lambs to fresh pasture once they graze to this level and introduce weaned ewes to graze the sward down lower to 3.5cm to 4.5cm. Grazing swards with a content of clover tight will also promote clover establishment and regrowth.
Tight grazing
Grazing out paddocks tight will significantly improve the quliaty of the regrowth. Michael advises farmers to be careful that they do not leave ewes grazing bare grassland for too long as this will result in fresh leaf regrowth being regrazed continuously which
in turn will slow down regrowth of the sward. Topping can also be used to maintain grass quality where it is not possible to graze out paddocks.
The most straightforward grazing plan is to graze lambs and ewes in a leader/ follower system. Where a rotational grazing programme is in place, it may be an option for some farmers to split ewes into two groups.
Ewes in poor body condition or earmarked for culling can graze paddocks down from 5.5cm/6cm to 4.5cm while ewes in excessive body condition can be held longer in paddocks (or grazed in paddocks with more stem) to graze down to 3.5cm. If splitting ewes into two groups, it is also important to monitor body condition score regularly.
Applying fertiliser
Grass quality is harder to maintain in June and July with grass heading out at an earlier stage. This is especially common where growth has slowed down considerably or in periods of very dry weather.
Applying fertilizer will help to maintain grass growth rate and quality. Where grass supplies are tight and fodder reserves are still in deficit apply 25 to 30 units of nitrogen after each grazing.
Surplus grass can be saved as baled silage or hay by temporarily taking paddocks out of the grazing rotation. This will also help improve grass quality.
Here, the focus should be to cut grass at a lower height to generate faster regrowth and get the area back ready for grazing faster. Where silage reserves have recovered or you are lowly stocked applying a lower rate of 10 to 15 units of nitrogen will still be beneficial in helping to maintain grass quality.
Read part two of this series here