LIC | Thump the clumps: tips for top pasture quality


Thump the clumps: tips for top pasture quality

We all know how important pasture quality is for profitability.  It’s critical for achieving high milk solids production, cow condition score targets, and good in-calf results.  And what an absolute pain it has been trying to manage quality when the growth rates have been so stop-start this season.  

Significant research has been conducted over many years to back up the need for high quality pasture at every grazing.  In the last few years the Lincoln University Dairy Farm has attained impressive performance by focusing on producing high ME feed at every grazing.

So how do we emulate these results on our own farms?  Firstly, wherever and whenever possible – get the cows to graze down to a post grazing residual of 1,500 to 1,600 kgDM/ha (the famous 7-8 clicks).  

Most importantly, target grazing at the third leaf stage of pasture growth by being on the correct grazing rotation.  

Unfortunately, this is the real world, and many farms don’t have perfect paddocks; or a high enough stocking rate to apply enough grazing pressure everyday throughout the critical times of the season.  Many farms are also without pivot irrigation or have minimal new pastures; and some farmers do lack the time or management skills to achieve the desired post grazing residuals at every single grazing.  Mistakes do happen.

With the cold winter for many this season, the onset of Sudden Stem Syndrome will come surprisingly early in a lot of regions.  Ryegrass stem elongation (with the associated hardened stalky clumps) is appearing now – well in advance of typical seed head emergence.  Average pasture covers are going from rags to riches on my farms and right around the country from all accounts.  This is starting to cause some serious grazing management issues.  

If too much grass has been left behind, another common option earlier in the season has been that of using any available dry cows or the yearling heifers to clean up.  Alas – these “follow-up” grazers often don’t take the clumps down.  They simply take the grass down between the clumps – further exacerbating the quality issue.  

We dearly need those hardened clumps back in the grazing round as they typically grow twice as fast as the rest of the sward.  They will produce a significant amount of available feed in the next round if they can be made palatable again.  

Paddocks are being dropped out for supplements and summer/winter cropping programmes, and of course the milking cows are being put back into paddocks wherever practical to clean up.  When putting the milking cows back into paddocks to try and clean up high grazing residuals, the first thing to ask is – “is it achievable”?  

Sometimes the pasture quality in that residual may be too far gone (stalky and ungrazeable), and you may in fact achieve very little apart from cows bellowing at the gate, and a shock in the vat at the next milking.  Also consider the cost of time shifting the mob twice, the likelihood that the next designated paddock will now also have a quality problem due to a grazing delay, and the possible issues you may have with lost milk production, increased lameness, reduced cow condition score or reproduction losses due to the likelihood of underfeeding or low quality feed during that clean-up of that paddock.

For many, the problem of these increasing post grazing pasture residuals will need to be dealt with by burning diesel.  So – if we are going to burn diesel, what’s the best way to do this?   

Be strategic with your mowing:

  • Always let the cows graze it first when you have it right.  If the cows leave clumps that will have a detrimental effect on cow performance – top it.
  • Top any clumps or high residuals left after grazing.  If you can’t mow the paddock, use the cows to clean it up; but expect lower production.  Aim for 1,500 to 1,600 residuals with the mower.
  • Mow excess feed in front.  That is, feeds 200 kgDM/ha + more than cow requirements, but only mow in front if you have quality feed down to the 1,500 to 1,600 residual.  This can be a useful tool if you don’t have a genuine surplus (just a couple of paddocks), or if the silage contractor is delayed.  
  • Note that if there was poor quality, a high residual or weeds on the last round, better to let the cows pick the eyes out of it; and top behind.  You can then mow in front on the next round if there is excess feed; or simply let the cows graze it.
  • It is important to remember that clumps left going into summer don’t grow either.  They are usually unpalatable and are not eaten by the cows – so top any rubbish pasture going into the dry.  It is good practice to get these clumps sorted down to 1,500 – 1,600 whenever practical.

Mowing typically costs $50/ha, including fuel, labour and depreciation etc.  It’s a useful tool to aid us in our never-ending quest to have the highest possible pasture quality available at each grazing.  

There will be many times in a season when it may well be more profitable to use the mower than the cow to clean up, particularly if the residual is hardened and not suitable for milking feed.  

Use it as a tool as required – and thump the clumps to help optimise profitable milk in the vat this season.  

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