Farm Ireland

Tuesday 20 March 2018

Dairy: Big variation in grass covers but grazing rules remain the same

Grazing conditions have been excellent recently
Grazing conditions have been excellent recently

Mary Kinston

Having moved into the last quarter of 2015, it's now time to take stock and plan for 2016 season. On the grazing front, my fear of a wet autumn never became a reality.

Grazing conditions have been excellent in recent weeks, and therefore pasture residuals and cleanout should be equally good. However, average grass covers among my clients are extremely variable.

Some are wading their way through very heavy covers, others haven't built up grass as hoped or expected. Whatever predicament you find yourself in, at this stage the rules remain the same.

You should be closing up grazed ground since the beginning of October in preparation for spring 2016. Using a 45 day rotation, 1/45th of the milking platform should be grazed per day.

However, where covers are heavy and getting heavier, the area grazed is reducing on a daily basis, which may require a farmer to graze lighter covers first or increase the pasture demand. There is also an option to graze the top off with the cows and allow dry stock to clean up to achieve a decent clean out.

In contrast, where a farmer is short of pasture, the trick is to allocate no more than 1/45th of the farm per day and fill the deficit with a supplement.

But farmers must resist any temptation to re-graze paddocks unless covers are greater than 1,200kgDM/ha from this point on. Even with the opportunity to bolster this year's milk revenue by milking on, the most important thing is to protect next year's opening grass cover. Grazing it off will only rob Peter (2016) to pay Paul (2015).

At this stage many farmers have also scanned their cows, with empty rates now known. Again results have been extremely variable from excellent (less than 8pc) to poor (greater than 12pc).

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When calculating the empty rate it is essential to know of the number of weeks mating. Achieving a low empty rate is quite easy when mating continues for greater than 12 weeks. Likewise, anyone who mates for less than 10 weeks is increasing the risks of a higher empty rate.

But 2015 should have resulted in a good breeding season with a good spring and most cows well fleshed at the start after a prolonged dry period.

So where the breeding results are disappointing now is the time to figure out what's going wrong. If a herd wasn't calving compactly to start with then it's always going to be an uphill challenge to achieve a good result within 12 weeks. In this game, success breeds success.

However, as with any biological system there are numerous factors affecting breeding. You may be required to break the results into segments to identify problem areas. Either way scanning results give a farmer a clear picture of the potential size of the milking herd for 2016, even with a slip or loss here and there.

This defines the potential for next year's herd expansion. If the herd is remaining static in number, it provides options for selective culling with decisions based either on SCC, yield, age or even the option to sell surplus heifers to bolster the 2015/16 cashflow.

Drying off cows from November onwards based on predictive calving date, lactation number and condition score will also be a prudent step in autumn management, and maximising their performance next year.

Liveweight measuring

With many factors affecting herd fertility, I truly believe that a herd's success is built on a foundation of doing things right for two years.

This year's weanling heifers will hugely impact 2017 mating results so consider measuring liveweight in the next few weeks to allow you to create winter management groups.

This will be an important step in getting them to hit their spring liveweight target of 60pc of mature bodyweight at the start of mating.

Dosing prior to housing will also be a key step. It's also worth noting a farmer's tip to cut a branch of a male (without berries) holly and hang it up in the winter accommodation for any heifer presenting ringworm issues. How this works I have no idea but many swear that it does so it's certainly worth a try.

Mary Kinston is a discussion group facilitator and consultant, farming with her husband in Co Kerry

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